Adherence to the Mediterranean diet is linked to reduced psychopathology in female celiac disease patients.

Celiac disease (CD) is a chronic enteropathy, affecting approximately 1% of the population worldwide with a higher prevalence in women. Recent studies demonstrate that CD is associated with an increased prevalence of psychopathology. The present study was undertaken to investigate the relationship between adherence to the Mediterranean Diet (MD) and psychopathological symptoms among CD patients, since the MD is a physical and mental health protective dietary regimen, which can easily be rendered gluten-free. A total of 134 CD patients (28 males and 106 females) were included in the study. Psychopathology was evaluated with the Symptom Checklist-90-Revised (SCL-90-R), and MD adherence was calculated using the Mediterranean Dietary Serving Score (MDSS). As regards psychopathological symptoms, female patients presented with statistically significant higher depression and anxiety than males. The majority of patients (64.9%) had low adherence to the MD (MDSS <14) with a mean score of 9.44 ± 3.26 and 9.14 ± 3.07 for men and women, respectively, out of a total of 24 points. High MD adherence was observed in 35.7% of the male and 34.9% of the female patients, with a mean score of 16.40 ± 2.63 and 16.35 ± 2.12, respectively. Interestingly, MD adherence was inversely associated with the intensity of several psychopathological symptoms in female patients, which represented the majority of the sample. The results of the study underline the need to encourage CD patients to adapt to a Mediterranean-style GFD.

The Association Between Handgrip Strength and Predialysis Serum Sodium Level in Patients With Chronic Kidney Disease Stage 5D.

Purpose: Handgrip strength (HGS) is a useful tool for the systematic assessment of muscle function related to nutritional status. Reduced HGS has been associated with adverse clinical outcomes in chronic kidney disease (CKD) stage 5D patients. In the same patients, predialysis low serum sodium (sNa) has been associated with malnutrition and mortality. Here, we investigated the role of predialysis sNa on muscle function in CKD-5D patients. Methods: We evaluated 45 patients on hemodialysis (HD) and 28 patients on peritoneal dialysis (PD) with HGS measurement, bioimpedance analysis, anthropometric measures, and malnutrition inflammation score (MIS). According to established diagnostic criteria, reduced HGS was defined as strength below 30 and 20 Kg in men and women, respectively. Predialysis sNa values were defined as the mean of all predialysis measurements during the preceding 6 months. Data analysis was performed separately for each of the HD and PD groups. Results: The proportions of reduced HGS did not differ between the HD (66%) and PD (54%) groups, respectively. Patients in the HD group as compared to those in the PD group had higher serum albumin and potassium and mid-arm muscle circumference and lower residual renal function (RRF) and residual urine volume. Multivariate logistic analysis, after controlling for muscle mass, nutritional biomarkers, MIS, fluid overload and RRF, showed that for every 1 mmol/l increase of sNa the odds of reduced HGS was decreased by 60% (OR = 0.40, 95% CI: 0.16-0.99) and 42% (OR = 0.58, 95% CI: 0.36-0.93) in HD and PD patients, respectively. However, stratified analysis indicated that lower sNa levels predicted reduced HGS in individuals with a background of malnutrition, inflammation, overhydration and less preserved RRF, representing unfavorable conditions strongly related to muscle wasting in the dialysis setting. Conclusions: Predialysis sNa is a strong and independent determinant of HGS, a reliable nutritional marker in CKD-5D stage patients. However, according to our findings, lower sNa levels appear to be a marker of underlying unfavorable conditions that are heavily associated with reduced HGS, rather than a causal determinant of reduced HGS. Whether optimizing sNa levels improves patient muscle performance requires further investigations.

Nutritional status in hemodialysis patients is inversely related to depression and introversion.

Although hemodialysis (HD) is a life-sustaining treatment for the majority of patients with end-stage renal disease, it may adversely affect their psychological status. Depression is highly prevalent among these patients, and it is associated with malnutrition, morbidity and mortality. Recent studies have demonstrated that depression is positively associated with neuroticism and introversion in HD patients. The aim of the present study was to explore the relationship between depression, personality traits (extraversion-introversion, neuroticism, psychoticism) and nutritional status among HD patients. Fifty-two HD patients were assessed via questionnaires for depression (CES-D) and personality traits (EYSENCK, EPQ). Nutritional assessment was conducted through bioelectrical impedance analysis (BIA) and anthropometry measurements (height, post-dialysis weight). The study revealed novel significant correlations. Both post-dialysis weight and phase angle were negatively related to introversion (r = -0.314, p < 0.05 and r = -0.542, p < 0.01, respectively) and depression (r = -0.456, p < 0.01 and r = -0.467, p < 0.01, respectively). This study demonstrates that both depression and introversion are inversely related to adequate nourishment in HD patients and suggests that personality plays an important role in the nutritional status of these patients.

Adiponectin and end-stage renal disease.

Adiponectin (ADPN) is an adipokine with significant anti-inflammatory, insulin-sensitizing and anti-atherogenic properties, which is generally associated with a beneficial cardiometabolic profile. Paradoxically, end-stage renal disease (ESRD) is characterized by markedly increased plasma ADPN levels and increased cardiovascular risk. In spite of the cardioprotective properties attributed to adiponectin, cardiovascular complications remain the main cause of mortality in the ESRD population. Furthermore, these patients have enhanced chronic inflammation, increased insulin resistance and persistent protein-energy wasting. Studies of the impact of ADPN on clinical outcomes among ESRD patients have so far yielded contradictory results. This review article summarizes the current knowledge on ADPN functions and explores the role of ADPN in ESRD patients, with specific focus on inflammation, insulin resistance, cardiovascular disease and wasting.

Purification, crystallization and preliminary X-ray analysis of the peptidoglycan N-acetylglucosamine deacetylase BC1960 from Bacillus cereus in the presence of its substrate (GlcNAc)6.

The peptidoglycan N-acetylglucosamine (GlcNAc) deacetylase BC1960 from Bacillus cereus (EC 3.5.1.33), an enzyme consisting of 275 amino acids, was crystallized in the presence of its substrate (GlcNAc)(6). The crystals belonged to the tetragonal space group P4(1)2(1)2, with unit-cell parameters a = b = 92.7, c = 242.9 A and four molecules in the asymmetric unit. A complete data set was collected at 100 K to a resolution of 2.38 A using synchrotron radiation.

Crystal structure of the BcZBP, a zinc-binding protein from Bacillus cereus.

Bacillus cereus is an opportunistic pathogenic bacterium closely related to Bacillus anthracis, the causative agent of anthrax in mammals. A significant portion of the B. cereus chromosomal genes are common to B. anthracis, including genes which in B. anthracis code for putative virulence and surface proteins. B. cereus thus provides a convenient model organism for studying proteins potentially associated with the pathogenicity of the highly infectious B. anthracis. The zinc-binding protein of B. cereus, BcZBP, is encoded from the bc1534 gene which has three homologues to B. anthracis. The protein exhibits deacetylase activity with the N-acetyl moiety of the N-acetylglucosamine and the diacetylchitobiose and triacetylchitotriose. However, neither the specific substrate of the BcZBP nor the biochemical pathway have been conclusively identified. Here, we present the crystal structure of BcZBP at 1.8 A resolution. The N-terminal part of the 234 amino acid protein adopts a Rossmann fold whereas the C-terminal part consists of two beta-strands and two alpha-helices. In the crystal, the protein forms a compact hexamer, in agreement with solution data. A zinc binding site and a potential active site have been identified in each monomer. These sites have extensive similarities to those found in two known zinc-dependent hydrolases with deacetylase activity, MshB and LpxC, despite a low degree of amino acid sequence identity. The functional implications and a possible catalytic mechanism are discussed.

A critical role for peptidoglycan N-deacetylation in Listeria evasion from the host innate immune system.

Listeria monocytogenes is a human intracellular pathogen that is able to survive in the gastrointestinal environment and replicate in macrophages, thus bypassing the early innate immune defenses. Peptidoglycan (PG) is an essential component of the bacterial cell wall readily exposed to the host and, thus, an important target for the innate immune system. Characterization of the PG from L. monocytogenes demonstrated deacetylation of N-acetylglucosamine residues. We identified a PG N-deacetylase gene, pgdA, in L. monocytogenes genome sequence. Inactivation of pgdA revealed the key role of this PG modification in bacterial virulence because the mutant was extremely sensitive to the bacteriolytic activity of lysozyme, and growth was severely impaired after oral and i.v. inoculations. Within macrophage vacuoles, the mutant was rapidly destroyed and induced a massive IFN-beta response in a TLR2 and Nod1-dependent manner. Together, these results reveal that PG N-deacetylation is a highly efficient mechanism used by Listeria to evade innate host defenses. The presence of deacetylase genes in other pathogenic bacteria indicates that PG N-deacetylation could be a general mechanism used by bacteria to evade the host innate immune system.

Purification, crystallization and preliminary characterization of a putative LmbE-like deacetylase from Bacillus cereus.

The Bacillus cereus BC1534 protein, a putative deacetylase from the LmbE family, has been purified to homogeneity and crystallized using the hanging-drop vapour-diffusion method. Crystals of the 26 kDa protein grown from MPD and acetate buffer belong to space group R32, with unit-cell parameters a = b = 76.7, c = 410.5 A (in the hexagonal setting). A complete native data set was collected to a resolution of 2.5 A from a single cryoprotected crystal using synchrotron radiation. As BC1534 shows significant sequence homology with an LmbE-like protein of known structure from Thermus thermophilus, molecular replacement will be used for crystal structure determination.

Peptidoglycan N-acetylglucosamine deacetylases from Bacillus cereus, highly conserved proteins in Bacillus anthracis.

The genomes of Bacillus cereus and its closest relative Bacillus anthracis contain 10 polysaccharide deacetylase homologues. Six of these homologues have been proposed to be peptidoglycan N-acetylglucosamine deacetylases. Two of these genes, namely bc1960 and bc3618, have been cloned and expressed in Escherichia coli, and the recombinant enzymes have been purified to homogeneity and further characterized. Both enzymes were effective in deacetylating cell wall peptidoglycan from the Gram(+) Bacillus cereus and Bacillus subtilis and the Gram(-) Helicobacter pylori as well as soluble chitin substrates and N-acetylchitooligomers. However, the enzymes were not active on acetylated xylan. These results provide insight into the substrate specificity of carbohydrate esterase family 4 enzymes. It was revealed that both enzymes deacetylated only the GlcNAc residue of the synthetic muropeptide N-acetyl-D-glucosamine-(beta-1,4)-N-acetylmuramyl-L-alanine-D-isoglutamine. Analysis of the constituent muropeptides of peptidoglycan from B. subtilis and H. pylori resulting from incubation of the enzymes BC1960 and BC3618 with these polymers and subsequent hydrolysis by Cellosyl and mutanolysin, respectively, similarly revealed that both enzymes deacetylate GlcNAc residues of peptidoglycan. Kinetic analysis toward GlcNAc(2-6) revealed that GlcNAc4 was the favorable substrate for both enzymes. Identification of the sequence of N-acetychitooligosaccharides (GlcNAc(2-4)) following enzymatic deacetylation by using 1H NMR revealed that both enzymes deacetylate all GlcNAc residues of the oligomers except the reducing end ones. Enzymatic deacetylation of chemically acetylated vegetative peptidoglycan from B. cereus by BC1960 and BC3618 resulted in increased resistance to lysozyme digestion. This is the first biochemical study of bacterial peptidoglycan N-acetylglucosamine deacetylases.