In vitro influence of zinc and magnesium on the deformability of red blood cells artificially hardened by heating

Trace elements have been shown to improve red blood cell (RBC) deformability: zinc in sickle cell disease and magnesium in an in vitro model of chemically rigidified erythrocytes. In this study, we investigated the effect and the influence of incubation time of zinc or magnesium on an in vitro model of rigidified RBCs by heating. Erythrocyte rigidity was determined by viscosimetry at high shear rate by a falling ball viscosimeter MT 90. In the first part of the study, six normal volunteers participated. Viscosimetry was performed on native blood before and after heating the sample for 10 min at 50°C. Therefore, increasing concentrations of zinc gluconate (final concentration: 0.5–4 g/L) or isotonic NaCl as control medium were added to the sample. Heating induced a twofold increase in all indices of RBC rigidity (p<0.05). At all these concentrations of zinc, a highly significant, dose-related fluidifying effect was observed (40–70%): this effect was immediately obtained and did not change over 60 min. Even at the highest concentration, recovery was not complete. In the second part of the study, we studied magnesium’s effects on blood. In a first protocol, whole blood was rigidified by heating at 56°C for 10 min, and the correcting effect of 5 min of incubation at 37°C of RBCs in 150 mmol/L NaCl, MgSO₄, magnesium acetate, and magnesium gluconate was investigated. In a second protocol, the same incubation with NaCl and magnesium salts was made on blood that had not been previously heated. In a third protocol, the correcting effect of magnesium gluconate on heated red blood cells was tested at four concentrations (75, 150, 225, and 300 mmol/L) over 1 h, for evaluating the effects of both concentration and time. Erythrocyte rigidity by heating is corrected by the three salts employed in protocol 1 (compared to sodium). In protocol 2, the deformability of normal (nonheated) red cells is not modified by magnesium. In protocol 3, no marked modification over 1 h is observed. The correcting effect is not complete for 75 mmol/L Mg, but remains the same at the three other concentrations. This study shows that zinc and magnesium at supraphysiological concentration are able to reverse RBC’s rigidification induced by heating, but that magnesium does not modify the flexibility of normal RBCs. This article suggests that zinc and magnesium may be studied in vivo as potential pharmacologic tools for improving hemorheologic disturbances.     

Point Mutations in FimH Adhesin of Crohn's Disease-Associated Adherent-Invasive Escherichia coli Enhance Intestinal Inflammatory Response

Adherent-invasive Escherichia coli (AIEC) are abnormally predominant on Crohn''s disease (CD) ileal mucosa. AIEC reference strain LF82 adheres to ileal enterocytes via the common type 1 pili adhesin FimH and recognizes CEACAM6 receptors abnormally expressed on CD ileal epithelial cells. The fimH genes of 45 AIEC and 47 non-AIEC strains were sequenced. The phylogenetic tree based on fimH DNA sequences indicated that AIEC strains predominantly express FimH with amino acid mutations of a recent evolutionary origin - a typical signature of pathoadaptive changes of bacterial pathogens. Point mutations in FimH, some of a unique AIEC-associated nature, confer AIEC bacteria a significantly higher ability to adhere to CEACAM-expressing T84 intestinal epithelial cells. Moreover, in the LF82 strain, the replacement of fimH _LF82 (expressing FimH with an AIEC-associated mutation) with fimH _K12 (expressing FimH of commensal E. coli K12) decreased the ability of bacteria to persist and to induce severe colitis and gut inflammation in infected CEABAC10 transgenic mice expressing human CEACAM receptors. Our results highlight a mechanism of AIEC virulence evolution that involves selection of amino acid mutations in the common bacterial traits, such as FimH protein, and leads to the development of chronic inflammatory bowel disease (IBD) in a genetically susceptible host. The analysis of fimH SNPs may be a useful method to predict the potential virulence of E. coli isolated from IBD patients for diagnostic or epidemiological studies and to identify new strategies for therapeutic intervention to block the interaction between AIEC and gut mucosa in the early stages of IBD.     

On the origins and spread of Olea europaea L. (olive) domestication: evidence for shape variation of olive stones at Ugarit,Late Bronze Age,Syria—a window on the Mediterranean Basin and on the westward diffusion of olive varieties

Charred archaeological stones of Olea europaea L. (olive) from Late Bronze Age Ugarit, Syria, were analyzed with geometric morphometry and compared with a morphological differentiation model established on the basis of analyses of modern spontaneous (uncultivated) olive populations and cultivated varieties of various origins within the Mediterranean Basin. The results allow a reinterpretation of the east–west morphological diversity previously observed in wild olives. The archaeobotanical data were compared in detail to the partly geographically structured modern morphological diversity of the cultivated olive. Ancient morphotypes could be distinguished, among which one is dominant in the assemblage. Their diffusion from east to west is shown, and their time of arrival in the northwestern Mediterranean can be evaluated by comparison to archaeological material from that area. Combining morphometric and genetic data, modern reference and archaeological material also guides us in understanding the mechanisms that prevailed in the long-term agrobiodiversity of the olive.     

Nutritional Advice in Older Patients at Risk of Malnutrition during Treatment for Chemotherapy: A Two-Year Randomized Controlled Trial

Objective

We tested the effect of dietary advice dedicated to increase intake in older patients at risk for malnutrition during chemotherapy, versus usual care, on one-year mortality.

Method

We conducted a multicentre, open-label interventional, stratified (centre), parallel randomised controlled trial, with a 1∶1 ratio, with two-year follow-up. Patients were aged 70 years or older treated with chemotherapy for solid tumour and at risk of malnutrition (MNA, Mini Nutritional Assessment 17–23.5). Intervention consisted of diet counselling with the aim of achieving an energy intake of 30 kCal/kg body weight/d and 1.2 g protein/kg/d, by face-to-face discussion targeting the main nutritional symptoms, compared to usual care. Interviews were performed 6 times during the chemotherapy sessions for 3 to 6 months. The primary endpoint was 1-year mortality and secondary endpoints were 2-year mortality, toxicities and chemotherapy outcomes.

Results

Between April 2007 and March 2010 we randomised 341 patients and 336 were analysed: mean (standard deviation) age of 78.0 y (4·9), 51.2% male, mean MNA 20.2 (2.1). Distribution of cancer types was similar in the two groups; the most frequent were colon (22.4%), lymphoma (14.9%), lung (10.4%), and pancreas (17.0%). Both groups increased their dietary intake, but to a larger extent with intervention (p<0.01). At the second visit, the energy target was achieved in 57 (40.4%) patients and the protein target in 66 (46.8%) with the intervention compared respectively to 13 (13.5%) and 20 (20.8%) in the controls. Death occurred during the first year in 143 patients (42.56%), without difference according to the intervention (p = 0.79). No difference in nutritional status changes was found. Response to chemotherapy was also similar between the groups.

Conclusion

Early dietary counselling was efficient in increasing intake but had no beneficial effect on mortality or secondary outcomes. Cancer cachexia antianabolism may explain this lack of effect.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00459589","term_id":"NCT00459589"}}NCT00459589     

Potential of combining morphometry and ancient DNA information to investigate grapevine domestication

The goal of this work was to explore the possibility (1) of carrying out both morphogeometric and archaeological DNA analyses on the same grape pips and (2) of comparing different molecular markers to reveal DNA variation, namely Simple Sequence Repeats (SSRs) and Single Nucleotide Polymorphisms (SNPs). We focused on waterlogged seeds originating from three Roman and one medieval archaeological sites in France. Our first results indicate that taking photographs of pips is not detrimental to the preservation of DNA, provided a specific protocol is respected. Regarding the genetic markers, obtaining reliable information in sufficient quantity proved very difficult using SSRs. SNPs have a much more interesting potential, providing greater success rates and reliability. Here in four archaeological pips we studied 842 SNPs, derived from known polymorphisms in several genes, including one gene related to sex. Phylogenies built using these genetic markers indicate that three pips from the Roman site of Gasquinoy are close to modern wild grapevines and/or the female group, while the only medieval pip from Colletière is hermaphrodite and close to the modern cultivated group. Morphogeometrical results are in agreement with these findings. We conclude that the combined use of SNP markers and morphogeometry is promising for deciphering the intricate history of grapevine domestication.     

Epithelial inflammation response induced by Shigella flexneri depends on mucin gene expression

The protective effects of different mucin gene profiles on gut protection were assessed by the evaluation of TNFalpha production by intestinal epithelial cells infected by Shigella flexneri. Three HT-29 cell lines were used: HT29-G(-) (enterocyte-like cells, secreting no mucins), HT29-FU (highly expressing MUC2 and MUC4) and HT29-MTX (highly expressing MUC3 and MUC5AC). These cells were infected either by an invasive (M90T) or the control isogenic (BS176) strains of S. flexneri, and TNFalpha mRNA production was quantified by competitive PCR. In the HT29-G(-) cells, M90T induced an increased production of TNFalpha mRNA compared to BS176, giving a TNFalpha ratio of 5.6 +/- 3.3. In contrast, similar levels of TNFalpha mRNA were detected in HT29-FU and HT29-MTX cells stimulated with either M90T or BS176, giving ratios of 1.4 +/- 1.3 and 1.0 +/- 0.1, respectively. The results suggest that mucin genes have abilities to protect epithelial cells against S. flexneri. Furthermore, the difference in the TNFalpha ratio between the HT29-FU and HT29-MTX cells suggests distinct protective effects for these two mucin-secreting epithelial cells.     

Structure of the cathelicidin motif of protegrin-3 precursor: structural insights into the activation mechanism of an antimicrobial protein

Cathelicidins are a family of antimicrobial proteins isolated from leucocytes and epithelia cells that contribute to the innate host defense mechanisms in mammalians. Located in the C-terminal part of the holoprotein, the cathelicidin-derived antimicrobial peptide is liberated by a specific protease cleavage. Here, we report the X-ray structure of the cathelicidin motif of protegrin-3 solved by MAD phasing using the selenocysteine-labeled protein. Its overall structure represents a fold homologous to the cystatin family and adopts two native states, a monomer, and a domain-swapped dimer. This crystal structure is the first example of a structural characterization of the highly conserved cathelicidin motif and thus provides insights into the possible mechanism of activation of the antimicrobial protegrin peptide.     

Maintenance of cytomegalovirus-specific CD4pos T-cell response in rheumatoid arthritis patients receiving anti-tumor necrosis factor treatments

Introduction  

Anti-tumor necrosis factor (TNF)-α biotherapies have considerably changed the treatment of rheumatoid arthritis (RA). However, serious infections are a major concern in patients with rheumatic diseases treated with anti-TNF-α. Little is known about viral, especially latent, infections in anti-TNF-α treatments. Infections by cytomegalovirus (CMV), a β-herpes virus, are frequent and induce a strong CD4^pos T-cell immunity, which participates in the control of infection. We thus have chosen to analyze the CD4^pos T-cell response to CMV antigens as a model of antiviral response in RA patients treated with anti-TNF-α. CD28 expression was evaluated.