Nitric Oxide Bioavailability and Its Potential Relevance to the Variation in Susceptibility to the Renal and Vascular Complications in Patients With Type 2 Diabetes

OBJECTIVE—We compared the renal and systemic vascular (renovascular) response to a reduction of bioavailable nitric oxide (NO) in type 2 diabetic patients without nephropathy and of African and Caucasian heritage. RESEARCH DESIGN AND METHODS—Under euglycemic conditions, renal blood flow was determined by a constant infusion of paraminohippurate and changes in blood pressure and renal vascular resistance estimated before and after an infusion of l-Ng-monomethyl-l-arginine. RESULTS—In the African-heritage group, there was a significant fall in renal blood flow (Δ−46.0 ml/min per 1.73 m(2); P < 0.05) and rise in systolic blood pressure (Δ10.0 mmHg [95% CI 2.3–17.9]; P = 0.017), which correlated with an increase in renal vascular resistance (r(2) = 0.77; P = 0.004). CONCLUSIONS—The renal vasoconstrictive response associated with NO synthase inhibition in this study may be of relevance to the observed vulnerability to renal injury in patients of African heritage

Lipopolysaccharide-induced VEGF production and ambient oxidative stress in type 2 diabetes

Context Oxidative stress is implicated in the development of microvascular disease and is associated with an upregulation of vascular endothelial growth factor (VEGF) which is pathogenetically linked to microvascular complications of diabetes. Patients of African origin have an increased susceptibility to microvascular kidney disease compared with Caucasians, the reasons and the mechanisms that contributes to this vulnerability are unclear. Objectives Primary) Investigate whether there are ethnic differences in Lipopolysaccharide induced monocyte VEGF production in whole blood cell cultures. Secondary) whether stimulated VEGF production is related to prevailing oxidative stress assessed by plasma lipid hydroperoxides (LOOH) and α-Tocopherol. Design and Setting Cross sectional study at a secondary care centre in North London, UK, serving an inner-city community of 154,000 adults. Patients African-Caribbean and Caucasian patients with type 2 diabetes (n=52) Results Lipopolysaccharide induced production of VEGF in whole blood cultures (61.8[31.9] pg/mL to 78.4[36.0] pg/mL; p<0.001) that correlated positively with LOOH levels (r=0.3, P=0.04) and was significantly higher in African-Caribbean than Caucasian type 2 diabetes patients (404 [207.5] vs 268.8 [137.0] pg/mL X109/L monocytes; P=0.018). Plasma α-Tocopherol concentration was higher in Caucasian patients (40.3[18.3] vs 30.0[9.6] µmol/L; p=0.04) compared to African-Caribbeans. Conclusions This study suggests that the redox environment influences VEGF production in response to proinflammatory stimuli in type 2 diabetes. The differential responsiveness by ethnic origin may be of relevance in the variations in susceptibility to the long-term microvascular complications

Sex Differences in Glutathione Peroxidase Activity and Central Obesity in Patients with Type 2 Diabetes at High Risk of Cardio-Renal Disease.

Women with type 2 diabetes (T2DM) have an increased susceptibility of developing cardio-renal disease compared to men, the reasons and the mechanisms of this vulnerability are unclear. Since oxidative stress plays a key role in the development of cardio-renal disease, we investigated the relationship between sex, plasma antioxidants status (glutathione peroxidase (GPx-3 activity), vitamin E and selenium), and adiposity in patients with T2DM at high risk of cardio-renal disease. Women compared to men had higher GPx-3 activity (p = 0.02), bio-impedance (p ≤ 0.0001), and an increase in waist circumference in relation to recommended cut off-points (p = 0.0001). Waist circumference and BMI were negatively correlated with GPx-3 activity (p ≤ 0.05 and p ≤ 0.01, respectively) and selenium concentration (p ≤ 0.01 and p ≤ 0.02, respectively). In multiple regression analysis, waist circumference and sex were independent predictors of GPx-3 activity (p ≤ 0.05 and p ≤ 0.05, respectively). The data suggest that increased central fat deposits are associated with reduced plasma antioxidants which could contribute to the future risk of cardio-renal disease. The increased GPx-3 activity in women could represent a preserved response to the disproportionate increase in visceral fat. Future studies should be aimed at evaluating if the modulation of GPx-3 activity reduces cardio-renal risk in men and women with T2DM

Angiodysplasies des maxillaires de l’enfant

Les angiodysplasies des maxillaires sont des affections rares et graves. Leur mauvais pronostic est surtout lié aux complications hémorragiques redoutables, dues le plus souvent à des extractions dentaires abusives sans examens radiologiques préalables. L’angio-IRM a permis d’une manière non invasive une meilleure connaissance de ces lésions en étudiant leur angio-architecture et leur hémodynamique. Jadis, le seul traitement efficace consistait en une exérèse chirurgicale mutilante entraînant des complications esthétiques et fonctionnelles sévères avec une morbidité importante. Actuellement, la radiologie interventionnelle a révolutionné la prise en charge grâce à l’artériographie hypersélective et àla découverte de nouveaux matériaux d’obturation plus faciles à manier. L’embolisation hypersélective est devenue l’arme de première intention en raison de son caractère conservateur et de son faible taux de  complications. Le but de ce travail est de rappeler les différents aspects étiopathogéniques, cliniques et para cliniques des angiodysplasieset de définir l’attitude thérapeutique.Mots clefs : angiodysplasie, embolisation, chirurgie

4-[(E)-4-Bromo­benzyl­ideneamino]-3-[1-(4-isobutyl­phen­yl)eth­yl]-1H-1,2,4-triazole-5(4H)-thione

In the title compound, C21H23BrN4S, the 4-bromo­benzyl­idene group is disordered over two orientations with occupancies of 0.504 (5) and 0.496 (5). One of the methyl groups of the isobutyl unit is disordered over two sites with occupancies of 0.751 (19) and 0.249 (19). The benzene rings of the isobutylphenyl and bromo­phenyl (major disorder component) groups form dihedral angles of 71.63 (11) and 21.8 (3)°, respectively, with the triazole ring. In the crystal, centrosymmetrically related mol­ecules exist as centrosymmetric N—H⋯S hydrogen-bonded dimers

Visualization of grapevine root colonization by the Saharan soil isolate Saccharothrix algeriensis NRRL B-24137 using DOPE-FISH microscopy

Background and aim There is currently a gap of knowledge regarding whether some beneficial bacteria isolated from desert soils can colonize epi- and endophytically plants of temperate regions. In this study, the early steps of the colonization process of one of these bacteria, Saccharothrix algeriensis NRRL B-24137, was studied on grapevine roots to determine if this beneficial strain can colonize a non-natural host plant. An improved method of fluorescence in situ hybridization (FISH), the double labeling of oligonucleotide probes (DOPE)-FISH technique was used to visualize the colonization behavior of such bacteria as well as to determine if the method could be used to track microbes on and inside plants. Methods A probe specific to Saccharothrix spp. was firstly designed. Visualization of the colonization behavior of S. algeriensis NRRL B-24137 on and inside roots of grapevine plants was then carried out with DOPE-FISH microscopy. Results The results showed that 10 days after inoculation, the strain could colonize the root hair zone, root elongation zone, as well as root emergence sites by establishing different forms of bacterial structures as revealed by the DOPE-FISH technique. Further observations showed that the strain could be also endophytic inside the endorhiza of grapevine plants. Conclusions Taking into account the natural niches of this beneficial strain, this study exemplifies that, in spite of its isolation from desert soil, the strain can establish populations as well as subpopulations on and inside grapevine plants and that the DOPE-FISH tool can allow to detect it

Modulation of endogenous antioxidant defense and the progression of kidney disease in multi-heritage groups of patients with type 2 diabetes: PRospective EValuation of Early Nephropathy and its Treatment (PREVENT).

BACKGROUND: Diabetes is the western world's leading cause of end-stage renal disease. Glucose-dependent, oxidative stress is linked to the development of renal inflammation and sclerosis, which, in animal models of diabetes, can be prevented by anti-oxidative treatment. Patients of non-Caucasian heritage have low activity of the selenoprotein, antioxidant enzyme, glutathione peroxidase (GPx) and its co-factor vitamin E, which may be linked to their increased propensity to developing end-stage renal disease. RESEARCH DESIGN AND METHODS: We have designed a double-blind, randomized, placebo controlled study with selenium and/or vitamin E versus placebo as the interventions for patients with type 2 diabetes and chronic kidney disease (CKD) stages 1-3. A 2 × 2 factorial design will allow a balanced representation of the heritage groups exposed to each intervention. The primary biochemical outcome is change in GPx activity, and clinical outcome measure is the actual, rate of-and/or percentage change in estimated glomerular filtration rate (eGFR) from baseline. Analysis will be with a marginal model for longitudinal data using Generalized Estimating Equations corrected for measures of baseline serum antioxidant enzyme activities (GPx, superoxide dismutase and catalase), micronutrient levels (vitamins E and C), measures of inflammation (interleukin 6, c-reactive protein and monocyte chemoattractant protein-1) and markers of oxidative damage (plasma 8-isoprostaglandin F2α and urinary 8-hydroxydeoxyguanosine). EXPECTED RESULTS: The study will assess the relationship between GPx activity, oxidative stress, inflammation and eGFR. It will test the null hypothesis that antioxidant therapy does not influence the activity of GPx or other antioxidant enzymes and/or alter the rate of change in eGFR in these patient groups. CONCLUSIONS: Outcome data on the effect of antioxidants in human diabetic renal disease is limited. Previous post hoc analyses have not shown a beneficial effect of vitamin E on renal function. A recent trial of a pharmaceutical antioxidant agent, improved eGFR, but in patients with advanced diabetes-related chronic kidney disease its use was associated with an increased incidence of cardiovascular events. We will explore whether the nutritional antioxidants, vitamin E and selenium alone, or in combination in patients at high risk of renal disease progression, forestalls a reduction in eGFR. The study will describe whether endogenous antioxidant enzyme defenses can be safely modified by this intervention and how this is associated with changes in markers of oxidative stress. Trial registration ISRCTN 97358113. Registered 21st September 2009

4-[(E)-2,6-Dichloro­benzyl­ideneamino]-3-{1-[4-(2-methyl­prop­yl)phen­yl]eth­yl}-1H-1,2,4-triazole-5(4H)-thione

In the title Schiff base compound, C21H22Cl2N4S, the triazole ring makes dihedral angles of 2.15 (11) and 87.48 (11)° with the 2,6-dichloro­phenyl and methyl­propyl­phenyl rings, respectively. Weak intra­molecular C—H⋯S and C—H⋯Cl inter­actions generate S(6) and S(5) ring motifs, respectively. In the crystal structure, centrosymmetrically related mol­ecules are linked into dimers by N—H⋯S hydrogen bonds. These dimers are arranged into sheets parallel to the ab plane and are stacked along the c axis. C—H⋯π inter­actions involving the methyl­propyl­phenyl ring and π–π inter­actions involving the dichloro­phenyl ring [centroid–centroid distance = 3.5865 (3) Å] are also observed

Actinopolyspora algeriensis sp. nov., a novel halophilic actinomycete isolated from a Saharan soil

A halophilic actinomycete strain designated H19T, was isolated from a Saharan soil in the Bamendil region (Ouargla province, South Algeria) and was characterized taxonomically by using a polyphasic approach. The morphological and chemotaxonomic characteristics of the strain were consistent with those of members of the genus Actinopolyspora, and 16S rRNA gene sequence analysis confirmed that strain H19T was a novel species of the genus Actinopolyspora. DNA–DNA hybridization value between strain H19T and the nearest Actinopolyspora species, A. halophila, was clearly below the 70 % threshold. The genotypic and phenotypic data showed that the organism represents a novel species of the genus Actinopolyspora for which the name Actinopolyspora algeriensis sp. nov. is proposed, with the type strain H19T (= DSM 45476T = CCUG 62415T)