The role of nutraceuticals in heart failure muscle wasting as a result of inflammatory activity. The International Lipid Expert Panel (ILEP) Position Paper

Muscle wasting is one of the main causes for exercise intolerance and ventilatory inefficiency in patients with heart failure and a strong predictor of frailty and reduced survival. The prevalence of sarcopenia is at least 20% in patients with heart failure. Patients with heart failure often have subclinical systemic inflammation, which may exert sustained effects on skeletal muscle. Besides exercise, nutrition should also be carefully evaluated as an appropriate diet with selected nutraceuticals may be able to stimulate muscle anabolism and inhibit muscle catabolism. This review summarizes the epidemiological and clinical trial evidence supporting the recommendations for the use of nutraceuticals with anti-inflammatory properties in heart failure and provides an overview of the state of the evidence for nutraceutical supplementation to prevent and/or mitigate heart failure muscle wasting.

Nutraceutical approaches to non-alcoholic fatty liver disease (NAFLD): A position paper from the International Lipid Expert Panel (ILEP)

Non-Alcoholic Fatty Liver Disease (NAFLD) is a common condition affecting around 10-25% of the general adult population, 15% of children, and even > 50% of individuals who have type 2 diabetes mellitus. It is a major cause of liver-related morbidity, and cardiovascular (CV) mortality is a common cause of death. In addition to being the initial step of irreversible alterations of the liver parenchyma causing cirrhosis, about 1/6 of those who develop NASH are at risk also developing CV disease (CVD). More recently the acronym MAFLD (Metabolic Associated Fatty Liver Disease) has been preferred by many European and US specialists, providing a clearer message on the metabolic etiology of the disease. The suggestions for the management of NAFLD are like those recommended by guidelines for CVD prevention. In this context, the general approach is to prescribe physical activity and dietary changes the effect weight loss. Lifestyle change in the NAFLD patient has been supplemented in some by the use of nutraceuticals, but the evidence based for these remains uncertain. The aim of this Position Paper was to summarize the clinical evidence relating to the effect of nutraceuticals on NAFLD-related parameters. Our reading of the data is that whilst many nutraceuticals have been studied in relation to NAFLD, none have sufficient evidence to recommend their routine use; robust trials are required to appropriately address efficacy and safety.

Step-by-step diagnosis and management of the nocebo/drucebo effect in statin-associated muscle symptoms patients: a position paper from the International Lipid Expert Panel (ILEP)

Statin intolerance is a clinical syndrome whereby adverse effects (AEs) associated with statin therapy [most commonly statin-associated muscle symptoms (SAMS)] result in the discontinuation of therapy and consequently increase the risk of adverse cardiovascular outcomes. However, complete statin intolerance occurs in only a small minority of treated patients (estimated prevalence of only 3-5%). Many perceived AEs are misattributed (e.g. physical musculoskeletal injury and inflammatory myopathies), and subjective symptoms occur as a result of the fact that patients expect them to do so when taking medicines (the nocebo/drucebo effect)-what might be truth even for over 50% of all patients with muscle weakness/pain. Clear guidance is necessary to enable the optimal management of plasma in real-world clinical practice in patients who experience subjective AEs. In this Position Paper of the International Lipid Expert Panel (ILEP), we present a step-by-step patient-centred approach to the identification and management of SAMS with a particular focus on strategies to prevent and manage the nocebo/drucebo effect and to improve long-term compliance with lipid-lowering therapy.

Low Plasma 25-Hydoxyvitamin D at Diagnosis Predicts Poor Outcomes in Patients with Bladder Cancer: A Prospective Cohort Study

This study aimed to investigate whether plasma 25-hydroxyvitamin D (25-OHD) at diagnosis predicts poor outcomes in patients with urothelial bladder cancer. A total of 177 patients with non-muscle-invasive bladder cancer (NMIBC) were prospectively followed up over a period extending beyond 6 years. Data on poor outcomes (ie., recurrence, progression, and mortality) were collected. Plasma 25-OHD was measured by immunoassay. Cutoff-Finder web application was used to determine the best 25-OHD cutoff point to predict a specific poor outcome. Cox-hazard models were applied to test how plasma 25-OHD affect patients outcome while adjusting for potential confounding factors. During the follow-up period, tumor recurrence and progression occurred in 40.7% and 14.1% of patients, respectively and 11.3% of patients died. Baseline 25-OHD was lower in patients who experienced poor outcome (12.2 ± 7.44 vs. 16.7 ± 10.6 ng/mL; p < 0.001). Multi-adjusted HR (95% CI) for vitamin D deficiency (25-OHD < 12 ng/mL) was 2.09 (1.27-3.44) for recurrence, 2.63 (1.06-6.49) for progression and 2.93 (1.04-8.25) for mortality in patients with NMIBC. Low plasma 25-OHD in NMIBC patients is associated with higher risk of poor outcome. Future work is required to test whether correction of vitamin D deficiency will improve quality of life and extend survival in these patients.

Exchange Process in the Dielectric Loss of Molecular and Macromolecular Ionic Conductors in the Interfacial Layers Formed by Electrode Polarization Effects

Here we report a first analytical approach to determine the spectral dependence of the complex permittivity function of molecular and macromolecular ionic conductors in the interfacial layers formed by electrode polarization effects. We show that a previous model of electrode polarization effects that was successfully applied for describing the dielectric behavior of ionic liquids ( Serghei, A.; Tress, M.; Sangoro, J. R.; Kremer, F. Electrode polarization and charge transport at solid interfaces. Phys. Rev. B 2009 , 80 , 184301 ) can be now generalized and applied for polymer/ionic liquid blends as well as for poly(ionic liquid)s. The determined dielectric function of the interfacial layers reveals a dramatic change in the charge transport process manifested by a large decrease in conductivity. Our approach brings the first evidence for a relaxation peak detected in the dielectric loss of the interfaces, which is attributed to an exchange process between the interface and the bulk. This study gives new insights into the mechanism of charge transport at interfaces and could thus contribute to a better correlation between the dielectric properties of ion conducting materials and their electrochemical behavior at interfaces.

Study of Bonding Formation between the Filaments of PLA in FFF Process

Fused filament fabrication (FFF) is an additive manufacturing (AM) process that provides physical objects commonly used for modeling, prototyping and production applications. The major drawback of this process is poor mechanical property due to the porous structure of final parts. This process requires careful management of coalescence phenomenon. In this paper, the major influencing factors during the FFF processing of poly(lactic acid) (PLA) were investigated experimentally and with a numerical model. It has been shown that the polymer temperature has a significant effect on the rheological behavior of PLA, especially on the adhesion of the filaments. An experimental set-up has been placed in the machine to have the cyclic temperature of the filament. A variation of the polymer temperature influences process parameters such as feed rate, temperature of the nozzle and temperature of the platform. The results showed that the amount of polymeric coalescence (neck growth) rises when increasing the feed rate, the nozzle temperature, and the platform temperature. A model to predict the neck growth is proposed. It predicts a lower amount of neck growth value than obtained experimentally. This difference has been explained as the effect of other phenomena, such as polymer relaxation time, pressure of the nozzle and especially cyclic temperature which is not taken into account in the model.

Association of systemic beta-defensin-1 and -20G/A DEFB1 gene polymorphism with Behçet's disease

BACKGROUND

Behçet's disease (BD) is a multisystem inflammatory disease of unknown etiology. Beta-defensins are antimicrobial peptides involved in epithelial host defense. To explore whether beta-defensins might be involved in BD pathogenesis, we examined plasma human beta-defensin-1 (hBD-1) and DEFB1 -20G/A polymorphism in BD patients.

METHODS

This case-control study included 106 BD patients fulfilling the criteria of the International Study Group for BD and 156 controls. The -20G/A genotypes were determined by PCR-RFLP analysis in all participants, and plasma hBD-1 was assessed by ELISA in 77 BD patients and 44 controls, only. Stepwise multiple regression models were applied to determine independent predictors for plasma hBD-1 in BD patients.

RESULTS

Distribution of -20G/A genotypes was different between BD patients and controls. Compared to GG genotype, "GA" genotype [OR (95% CI), 3.12 (1.56-6.16); p = .001] and "AA" genotype [2.57 (1.10-5.96); p = .027)] were associated with increased risk for BD. Plasma hBD-1 concentrations were significantly higher in BD patients than controls (9.81 ± 3.52 ng/mL vs. 5.30 ± 3.02 ng/mL; p < .001), and in BD patients with neurological involvement than those without (11.1 ± 4.12 ng/mL vs. 9.19 ± 3.10 ng/mL; p = .040). No variation was noted according to other clinical features, treatment received or -20G/A genotypes. In multivariate analysis, neurological involvement was the only predictor for plasma hBD-1 (β, 0.274; p = .029).

CONCLUSIONS

Findings suggest that hBD-1 and its encoding gene DEFB1 could modulate the risk for BD, especially for BD neurological involvement. Further work is needed for a better understanding of role of hBD-1 and its genetic variants in the pathogenesis of BD.

Association of MTHFR C677T, MTHFR A1298C, and MTRR A66G Polymorphisms with Neural Tube Defects in Tunisian Parents

OBJECTIVE

This study aims to investigate the association of 5,10-methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and methionine synthase reductase (MTRR A66G) gene polymorphisms with neural tube defects (NTDs) in a Tunisian population.

METHODS

Genotyping was performed by polymerase chain reaction with restriction fragment length polymorphisms (PCR-RFLPs) using the restriction enzymes. Allele and genotype frequencies were compared between mothers and fathers of fetuses with NTDs with matched controls based on an association analysis using SPSS software.

RESULTS

MTHFR (C677T, A1298C) and MTRR A66G polymorphisms were found to be protector factors for NTD fetuses in the mother group. In addition, a combination of the three wild-type alleles C677/A1298/A66 has increased four-fold the incidence of NTDs (p = 0.004, OR = 3.96, 95% CI: 1.53-10.23). In the father group, MTHFR C677T was a risk factor for NTDs. However, no association was found between MTHFR A1298C, MTRR A66G, and the occurrence of this anomaly. The analysis of MTHFR C677T and MTRR A66G polymorphisms has demonstrated a significant difference in vitamin B12 levels between recessive and dominant genotypes in case mothers (p < 0.05).

CONCLUSION

Additional studies are required to better understand the roles of parental gene polymorphisms related to folate-homocysteine metabolism in the pathogenesis of NTD.

Associations of rs1883832 and rs4810485 polymorphisms of CD40 gene with myocardial infarction in the Tunisian population

Context: Cluster of differentiation 40 (CD40), and its ligand CD40L, are major co-stimulatory molecules whose interactions are important in both cellular and humoral immunity, and has been suggested to play a role in the pathogenesis of acute coronary syndrome. Objective: The aim of this study was to examine the association of CD40 polymorphisms (-1 C>T (rs1883832) and 945G>T (rs4810485)) and myocardial infarction (MI), and to test the association of CD40 gene haplotypes with MI in Tunisians. Materials and methods: Three hundred and fifty MI patients and 301 apparently healthy controls were included in the study. The polymorphisms of CD40 were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: There were significant differences in the genotype and allele frequencies of CD40 gene -1 C>T (rs1883832) polymorphism between cases and controls. Stratifying according to gender, the association between the TT genotype and MI was statistically significant in males, only. Haplotype analysis revealed that the C-T and T-G haplotypes were associated with an increased risk of MI (p = 0.012 and p < 0.001, respectively). Conclusions: Our work showed a significant association between the -1 C>T (rs1883832) polymorphism of the CD40 gene and MI in the Tunisians.

Interaction Effects of Plasma Vitamins A, E, D, B9, and B12 and Tobacco Exposure in Urothelial Bladder Cancer: A Multifactor Dimensionality Reduction Analysis

The study aimed to examine circulating vitamins A, E, D, and B12 and folate in patients with urothelial bladder cancer (UBC) and detect potential interaction effects of these micronutrients on UBC risk. A case-control study was conducted on 262 UBC patients and 254 matched controls. Vitamins A and E were assessed by ultra performance liquid chromatography, and vitamins D and B12 and folate were assessed by immunological methods. Binary logistic regression models were used to test associations of plasma vitamins tertiles with UBC risk. A multifactor dimensionality reduction method (MDR) was applied to assess interactive effects of the vitamins and tobacco on UBC risk. Higher levels in vitamins A, E, and D were associated with lower occurrence of UBC. No significant association was observed in plasma folate or vitamin B12 with UBC. There were redundancy interactions of plasma vitamin D with tobacco and with plasma vitamin A on UBC risk. Even though the study could not ascertain causality, the findings suggest that vitamins A, E, and D might be protective against UBC. Vitamins A and D interact antagonistically with each other's and with tobacco to modulate UBC risk. These interactions should be taken in consideration for the prevention of UBC.

Decreased Oleic Acid and Marine n - 3 Polyunsaturated Fatty Acids in Tunisian Patients with Urothelial Bladder Cancer

Fatty acids (FAs) are thought to impact carcinogenesis by affecting cell signaling. A case-control study including 250 patients with urothelial bladder cancer (UBC) and 250 controls was conducted. Plasma FAs composition was assessed using capillary gas chromatography. Associations of individual and classes of FAs with UBC were controlled for the main risk factors for UBC. Plasma FAs profile was different in patients compared to controls. Higher levels (third tertile vs. first tertile) in palmitic acid (PA) [multi-adjusted OR (95% CI), 1.83 (1.14-2.92)], and n - 6:n - 3 FA ratio [4.13 (2.38-7.16)] were associated with increased risk for UBC [multi-adjusted OR (95% CI), 1.83 (1.14-2.92)]. In contrast, higher levels (third tertile vs. first tertile) in oleic [0.54 (0.34-0.86)], dihomo-γ-linolenic (DGLA) [0.47 (0.29-0.74)], eicosapentaenoic (EPA) [0.32 (0.19-0.52)], and docosahexaenoic (DHA) acids [0.33 (0.20-0.53)] were associated with lower risk for UBC. Although the study design does not allow proving causality, the findings suggest a possible protective role of oleic acid and marine n - 3 polyunsaturated FAs (PUFAs) against bladder carcinogenesis.

The rs9939609 polymorphism in the fat mass and obesity associated (FTO) gene is associated with obesity in Tunisian population

CONTEXT

Variations in the fat mass and obesity-associated gene (FTO) has been associated with obesity in many populations, but the results are conflicting.

OBJECTIVE

The aim of this study was to evaluate the effect of the rs9939609 polymorphism in the FTO gene on obesity risk and plasma leptin, adiponectin, insulin and lipid concentrations in Tunisians.

MATERIALS AND METHODS

Four hundred and ninety-four subjects with obesity and 334 non-obese participated in this study. The rs9939609 (T/A) genotype was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

Significant differences in genotype frequencies were observed between cases and controls. In the separate analysis by gender, the association between the AA genotype and obesity was statistically significant in women but not in men. After stratification by obesity class this association remains only with obesity class III.

DISCUSSION

Our study is in agreement with studies on Caucasian, Portuguese and Cebu Filipino populations where a gender-specific association was found between rs9939609 polymorphism and obesity. It is also in agreement with studies on Mexican, Spanish and European populations, where an association was found with obesity class III.

CONCLUSION

The rs9939609 polymorphism of FTO gene is associated with obesity, especially obesity class III in women.

Haplotype-based association of Vascular Endothelial Growth Factor gene polymorphisms with urothelial bladder cancer risk in Tunisian population

BACKGROUND/AIM

Accumulated data suggested that Vascular Endothelial Growth Factor is a major mediator in vasculogenesis, angiogenesis and recently in tumorigenesis. Therefore, we aimed to investigate for the first time the association between VEGF gene variants (-2549I/D (rs35569394), -2578C/A (rs699947), and +936C/T (rs3025039)) with urothelial bladder cancer (UBC) in Tunisian population.

METHODS

A total of 218 UBC patients and 204 controls were recruited and genotyped by Polymerase Chain Reaction technique. Odds ratios (OR) and 95% confidence intervals (CIs) were used to access the association between the VEGFA gene polymorphisms and UBC.

RESULTS

We found a significant decreased risk association of -2578 C/A polymorphism with UBC (OR (95% CI), 0.62 (0.41-0.94), P = .026) for CA genotype and (OR (95% CI), 0.40 (0.21-0.76), P = .005) for double homozygous mutant genotype. No associations were found in case of both polymorphic sites of VEGF, vis. -2549I/D and +936C/T, respectively. Haplotype analysis revealed a strong linkage disequilibrium between -2578C/A and -2549I/D and CIC combination is the significant haplotype associated with increased risk of UBC (OR (95% CI), 3.63 (1.47-8.97), P = .005). Regarding tumor grade/stage and family history of cancer, no associations were found for -2578C/A polymorphism.

CONCLUSION

CIC haplotype of VEGF gene may be important risk factor for UBC development in Tunisia.

Disseminated histoplasmosis diagnosed in the bone marrow of an HIV-infected patient: First case imported in Tunisia

Histoplasmosis is a fungal infection caused by a dimorphic fungus, Histoplasma capsulatum. We report a first case of disseminated histoplasmosis in a 34-year-old woman, infected with human immunodeficiency virus (HIV), originating from Ivory Coast and living in Tunisia for 4 years. She was complaining from fever, chronic diarrhoea and pancytopenia. The Histoplasma capsulatum var. capsulatum was identified by direct microscopic examination of the bone marrow. She was treated by Amphotericin B, relayed by itraconazole. Even though a regression of symptoms and normalization of blood cell count (BCC), the patient died in a respiratory distress related to CMV hypoxemic pneumonia.

[Tinea capitis: Main mycosis child. Epidemiological study on 10years]

Despite the changes in their epidemiology, and the improving level of hygiene of the population, tinea capitis is still considered a public health problem in our country, and is the most common type of dermatophytosis in our country. The aim of our study was to evaluate the epidemiological, clinical and mycological features of tinea capitis in children encountered in the Tunis region. A retrospective study concerned 1600 children aged 6 months to 15 years suspected to have tinea capitis was conducted in Parasitology-Mycology laboratory, Rabta hospital, over a 10-years period (2005-2014). Dermatophyte infections were confirmed using scalp scrapings examinated with direct microscopy using potash at 30% and/or culture on Sabouraud medium agar. Tinea capitis diagnosis was confirmed in 947 cases (59.18%). The sex ratio was 2.61 and the average age of 6.28 years with predominance in the age group of 4 to 8 years (52.27%). The most common clinical presentation was ringworm (87.65%). Ringworm large plaque was predominant (65.9%). Direct examination was positive in 884 cases (93.35%). Microsporic tinea was the most frequent (63.25%) followed by trichophytic tinea (29.78%). Positive cultures of dermatophytes were obtained in 912 cases (96.30%). The following dermatophyte species were isolated: Microsporum canis (67%), Trichophyton violaceum (31.68%), Trichophyton mentagrophytes (0.66%), Microsporum audouinii (0.22%), Trichophyton schoenleinii (0.22%) and Microsporum gypseum (0.22%). M. canis is currently the most frequently incriminated species in tinea capitis in Tunisia. This change is related to a change in behavior of our population, in fact the cat; main reservoir of M. canis cohabiting increasingly with Tunisian families.

Vulvovaginal candidiasis: Etiology, symptomatology and risk factors

OBJECTIVE

To determine epidemiological, clinical and mycological characteristics of vulvovaginal candidiasis (VVC) in Tunisian population and to evaluate predisposing factors.

PATIENTS AND METHODS

In this retrospective study, 2160 vaginal swabs were performed over 2 years (January 2014-December 2015). It was carried out at the laboratory of Parasitology and Mycology, Rabta Hospital in Tunisia. After swab collecting, direct examination and culture on Sabouraud Chloramphenicol and Sabouraud Chloramphenicol Actidione media were implemented to research yeasts. Then identifying of yeast species was through chlamydosporulation test and auxanogram. For each patient, a questionnaire was filled noting age, medical and surgical history, symptoms and risk factors. Statistical analysis of data was performed on SPSS 16 using Khi² test, P<0.05 was considered significant.

RESULTS

Direct examination was positive showed spore and/or pseudohypha in 24.72%. Candida albicans was isolated most frequently (76.61%) followed by Candida glabrata (17.18%). The maximum frequency of Candida-positive cultures was in 25-34 years old age group. Leucorrhea was the most common symptom (72.25%) followed by vulvar prurits (63.23%), dyspareunia (32.25%) and urinary burning (24.92%). Only pregnancy was correlated positively with VVC.

CONCLUSION

It appears from our study that VVC is relatively common in Tunisia. His diagnosis results from confrontation of anamnestic, clinical and mycological data. The knowledge of risk factors and their correction would be necessary to prevent the occurrence of VVC, especially in its recurrent form.

Alpha Adducin G460T Variant is a Risk Factor for Hypertension in Tunisian Population

BACKGROUND

Adducin is a membrane cytoskeletal protein, consisting of three subunits: α, β, and γ subunits encoded by three different genes (ADD1, ADD2, ADD3). A specific mutation G460T of the α-adducin gene (ADD1) is associated with high renal tubular sodium reabsorption. This mutation is associated with salt sensitivity and may influence the risk of hypertension. In this study, we investigated the relationship between the G460T polymorphism of the ADD1 and essential hypertension (EH) in the Tunisian population.

METHODS

The case-controlled study included 280 patients with hypertension and 257 healthy controls. The G460T polymorphism of ADD1 was determined by polymerase chain reaction-restriction fragment length polymorphism analysis method.

RESULTS

In the whole population, the genotypic frequencies of the a-adducin G460T polymorphism in hypertensive and control groups (GG, GT, TT) were 78.6%, 17.5%, 3.9% and 87.5%, 11.29%, 1.16%, respectively (χ2 = 9.13, p < 0.01). The genotype was associated with hypertension, OR = 1.79, 95% CI (1.04 - 3.41), p < 0.03 for GT heterozygous and OR = 1.93, 95% CI (1.39 - 2.22), p < 0.03 for TT homozygous. Moreover, when we stratified the population according to gender, the genotypic frequencies were significantly associated with G460T polymorphism in men (p < 0.01) and in women (p < 0.05). Furthermore, no relationship was found between clinical characteristics and ADD1 G460T genotypes.

CONCLUSIONS

The present study shows that the a-adducin G460T polymorphism is associated with EH. Our results suggest that this variant can be considered a genetic risk factor for hypertension in the Tunisian population.

Lack of association between FokI polymorphism in vitamin D receptor gene (VDR) & type 2 diabetes mellitus in the Tunisian population

BACKGROUND & OBJECTIVES

The impact of several environmental and genetic factors on diabetes is well documented. Though the association between the vitamin D receptor (VDR) gene polymorphisms and type 2 diabetes mellitus (T2DM) has been analyzed in different ethnic groups, the results have been inconsistent. The aim of this study was to evaluate the possible association between VDR FokI polymorphism and genetic susceptibility to T2DM in Tunisian population.

METHODS

A total of 439 unrelated patients with T2DM and 302 healthy controls were included in the study. Genomic DNA was extracted from blood and genotyped for the single nucleotide polymorphism (SNP) of FokI (T/C: (rs2228570) by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis.

RESULTS

The genotype distribution and the relative allelic frequencies for the FokI polymorphism were not significantly different between T2DM and controls: in T2DM patients the frequencies of the CC, CT, and TT genotypes were 52.6, 41.0, and 6.1 per cent, respectively, and in controls the genotype frequencies were 55.6, 38.7, and 5.6 per cent, respectively. In our study, the TT genotype of the FokI polymorphism was not associated with T2DM (OR =1.19, 95% CI 0.63 - 2.25, P=0.577).

INTERPRETATION & CONCLUSIONS

Our study showed no significant association of the FokI polymorphism in the vitamin D receptor gene with type 2 diabetes mellitus in Tunisian population.

Association Between the G20210A Polymorphism of Prothrombin Gene and Myocardial Infarction in Tunisian Population

The prothrombin is the precursor of the serine protease thrombin, a key enzyme in homeostasis. Prothrombin G20210A polymorphism (rs1799963) was described as a moderate risk factor for venous thrombosis because this mutation is associated with prothrombin elevated levels which may lead to an imbalance between the procoagulant, anticoagulant, and fibrinolytic system. 20210A carriers have an increased risk of thrombosis. In this study, we proposed to determine the prevalence of 20210A prothrombin variant among Tunisian population, and to evaluate the potential relevance of this variant with myocardial infarction. This study included 1290 unrelated Tunisians (1007 male and 283 female) divided in two groups: Four hundred and eighty-seven MI patients (mean age: 52.64 ± 8.98 years) and 803 apparently healthy controls (mean age: 51 ± 8.99). The prothrombin G20210A polymorphism was carried out by polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP) analysis. The distribution of genotypes was in accordance with Hardy-Weinberg equilibrium (p > 0.05). A significant difference in genotype distribution and allele frequency was observed between patients and controls. Male patients with MI had a frequency of 97 % for GG genotype and 3 % for GA+AA genotypes. The control group had a frequency of 99 % for the GG genotype and 1 % for the GA+AA genotypes which is significantly lower than the frequency found in patients (p = 0.01). The same genotype frequencies were found in women (p = 0.032). The MI patient group showed a significantly higher frequency of 20210A allele compared to controls 0.02 versus 0.01 [OR = 3.60 (95 % CI = 1.29-10.53), p = 0.005] in men and 0.015 versus 0.068 [OR = 4.68 (95 % CI = 1.60-14.26), p = 0.001] in women. Our work showed a significant but not independent association between the G20210A polymorphism of the prothrombin gene and MI in the Tunisian population.

Bladder Cancer is Associated with Low Plasma 25-hydroxyvitamin D Concentrations in Tunisian Population

Little evidence suggests an impact of vitamin D on bladder cancer risk in Caucasians. This study aimed to investigate association of plasma 25-hydroxyvitamin D (25-OHD) with urothelial bladder cancer (UBC) risk in Tunisians. A case-control study included 250 patients with UBC and 250 healthy controls. Plasma 25-OHD was assessed by a competitive chemiluminescence immunoassay. Vitamin D deficiency and insufficiency were defined as 25-OHD <30 nmol/L and 30 to 49.99 nmol/L, respectively. Logistic regression models adjusting for gender, age, smoking status, duration of smoking, occupational exposure, and season were applied. Vitamin D deficiency (50.4% vs. 34.8%; P < 0.001) and insufficiency (40.4% vs. 26.8%; P < 0.001) were more frequent in patients than controls. Multivariate analysis showed that UBC is associated with vitamin D deficiency [odd-ratio (95% confidence interval), 3.71 (1.76-7.80); P = 0.001] and vitamin D insufficiency [2.65 (1.40-5.01); P = 0.003]. Other predictors of UBC were female gender, tobacco use, smoking duration, and occupational exposure. Plasma 25-OHD concentrations are low in Tunisian patients with UBC. These findings support experimental and epidemiological evidence of protective role of vitamin D against UBC but could not ascertain causal relationship. Further prospective studies and clinical trials are warranted to check causality.

Structure and reorientational dynamics of 1-F-adamantane

Bimodal reorientational relaxations along the twofold (α) and threefold (α′) axes of the disordered Phase II (P4̄2₁c) of 1-F-adamantane.

Association of FokI polymorphism of vitamin D receptor with urothelial bladder cancer in Tunisians: role of tobacco smoking and plasma vitamin D concentration

The aim of the study was to test whether the VDR FokI polymorphism is associated with the risk of urothelial bladder cancer (UBC) in Tunisians. The study included 200 unrelated patients with UBC and 200 healthy controls. Genotyping of the VDR FokI polymorphism was determined by PCR-RFLP method. Plasma 25-hydroxyvitamin D concentrations were measured by immunoassay. Binary logistic regression model was applied to test how the association of VDR FokI polymorphism is independent of potential confounding factors. Genotype distribution (FF, 45 vs. 55 %; Ff, 52.1 vs. 47.9 %, and ff, 12 vs. 5.5 %, respectively) and allele frequencies (F, 66.5 vs. 74.8 % and f, 33.5 vs. 25.2 %, respectively) were significantly different between UBC patients and controls. The "ff" genotype [OR (95 % CI), 2.66 (1.24-5.73); p = 0.012] and "f" allele [1.49 (1.09-2.02); p = 0.010] were associated with increased risk of UBC. The association remained significant in multivariate analysis. Stratified analyses showed that VDR FokI polymorphism is only associated with UBC risk in ever-smokers, subjects exposed to chemical carcinogens and those with plasma 25-hydroxyvitamin D over 12 μg/L. The "f" allele of VDR FokI polymorphism is associated with a higher risk of UBC in Tunisians, especially in smokers as well as subjects with occupational exposition and subjects without vitamin D deficiency. These results should be replicated in other ethnic groups and the influence of other genetic factors and environments on this association should be investigated.

The Gly482Ser polymorphism of the peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is associated with type 2 diabetes in Tunisian population

BACKGROUND AND AIMS

Peroxisome proliferator-activated receptor-γ co-activator-1α (PGC-1α) is a transcriptional co-activator involved in adaptive thermogenesis, skeletal muscle metabolism, fatty acid oxidation, and gluconeogenesis. Several studies have suggested that the common PGC-1α polymorphism Gly482Ser (rs8192678) may be associated with risk of type 2 diabetes (T2D), with conflicting results. The aim of this study was to analyze whether the Gly482Ser variant is a risk factor for development of T2D in Tunisian population.

METHODS

In a case-control study 487 unrelated patients with type 2 diabetes and 402 apparently healthy controls were recruited from January 2008 to August 2010. The Gly482Ser polymorphism was determined by PCR-RFLP analysis.

RESULTS

A significant difference in genotypes distribution was observed between patients (Gly/Gly: 34.1%; Gly/Ser: 47.1%; Ser/Ser: 18.5%) and controls (Gly/Gly: 43.8%; Gly/Ser: 42.3%; Ser/Ser: 13.9%) (χ(2)=9.44, p=0.009). The T2D patient group showed a significant higher frequency of the Ser allele compared to the controls (43% vs. 34%; OR: 1.35, 95% [CI]: 1.11-1.65, p=0.002). The association between the Gly482Ser polymorphism and T2D remained significant after adjustment for other well-established cardiovascular risk factors.

CONCLUSIONS

In the current study, a significant and independent association between the Gly482Ser polymorphism (rs8192678) of the PGC-1α gene and T2D in the Tunisian population was found.

Electrode polarization vs. Maxwell-Wagner-Sillars interfacial polarization in dielectric spectra of materials: Characteristic frequencies and scaling laws

The characteristic frequencies of electrode polarization and of interfacial polarization effects in dielectric spectra of ionic liquids and of polymer bi-layers are determined and systematically analyzed, based on dielectric measurements by means of broadband dielectric spectroscopy, numerical simulations, and analytical calculations. It is shown that, to a large extent, identical scaling laws can be derived for these two dielectric phenomena taking place at external and internal interfaces. Surprisingly, a fundamentally different behavior concerning the interrelation between the characteristic frequencies is found. This brings direct evidence that different manifestations of the phenomenon of electrical polarization can be discriminated by examining the inter-relation governing their characteristic frequencies, which can be of significant importance in disseminating the nature of different contributions appearing in the dielectric spectra of complex materials. Based on our analysis, we derive a new formula, valid for both electrode polarization and interfacial polarization effects, that allows one to determine the conductivity value from the frequency position of the Maxwell-Wagner-Sillars peak. An excellent agreement between experiment and calculations is obtained. The formula can be used, furthermore, to estimate the thickness of the interfacial layers formed due to electrode polarization effects. Values in the order of several nanometers, increasing with decreasing temperature, are reported.

Effect of the sample annealing temperature and sample crystallographic orientation on the charge kinetics of MgO single crystals subjected to keV electron irradiation

This paper focuses on the effect of sample annealing temperature and crystallographic orientation on the secondary electron yield of MgO during charging by a defocused electron beam irradiation. The experimental results show that there are two regimes during the charging process that are better identified by plotting the logarithm of the secondary electron emission yield, lnσ, as function of the total trapped charge in the material QT. The impact of the annealing temperature and crystallographic orientation on the evolution of lnσ is presented here. The slope of the asymptotic regime of the curve lnσ as function of QT, expressed in cm(2) per trapped charge, is probably linked to the elementary cross section of electron-hole recombination, σhole, which controls the trapping evolution in the reach of the stationary flow regime.

Evaluation of the effective cross-sections for recombination and trapping in the case of pure spinel

In this paper, we have investigated the evolution of the secondary electron emission in the case of pure spinel during electron irradiation, achieved in a scanning electron microscope at room temperature, which is derived from the measurement of the induced and the secondary electron currents. It was observed from the experimental results, that there are two regimes during the charging process: a plateau followed by a linear variation, which are better identified by plotting the logarithm of the secondary electron emission yield lnσ as function of the total surface density of trapped charges in the material QT . For positive charging, E0 = 1.1 and 5 keV, the slope of the linear part, whose value is of about 10(-10) cm(2) charge(-1), is independent of the primary electron energy. It is interpreted as a microscopic cross section for electron-hole recombination. For negative charging of pure spinel, E0 = 15 and 30 keV, the slope is associated with an electron trapping cross section close to 10(-14) cm(2) charge(-1), which can be assigned to the microscopic cross section for electron trapping. This trapping cross section is four orders of magnitude lower than the recombination one.