Experimental evaluation of the contribution of acidic pH and Fe concentration to the structure,function and tolerance to metals (Cu and Zn) exposure in fluvial biofilms

An indoor channel system was colonised with fluvial biofilms to study the chronic effects of high Fe and SO₄ ^2? concentrations and acidic pH, the water chemistry in the surrounding streams of Aljustrel mining area (Alentejo, Portugal), and their contribution to community (in)tolerance to metal toxicity by short-term experiments with Cu and Zn. Biofilms were subjected to four different treatments during 8 weeks: high Fe and SO₄ ^2? concentrations (1 mg Fe l^?1 + 700 mg SO ₄ ^2?  l^?1) and acidic pH, high Fe and SO₄ ^2? at alkaline pH; lower Fe and SO₄ ^2? at acidic pH: and lower Fe and SO₄ ^2? concentrations at alkaline pH as negative control. During chronic exposure, acidic pH affected growth negatively, based on low values of algal biomass and the autotrophic index, high values of the antioxidant enzyme activities and low diversity diatom communities, dominated by acidophilic species (Pinnularia aljustrelica) in acidic treatments, being the effects more marked with high Fe and SO₄ ^2?. Co-tolerance to metals (Cu and Zn) was also shown in biofilms from the acidic treatments, contrasting with the higher sensitivity observed in the alkaline treatments. We can conclude that the Aljustrel mining area acidic environment limits algal growth and exerts a strong selection pressure on the community composition which is in turn, more tolerant to metal exposure.     

Ilex paraguariensis (yerba mate) improves endocrine and metabolic disorders in obese rats primed by early weaning

Purpose

We showed that early weaned rats developed obesity, hyperleptinemia, leptin and insulin resistance at adulthood. Here, we studied the potential beneficial effects of Ilex paraguariensis aqueous solution upon body composition, glycemia, lipid and hormonal profiles, leptin signaling and NPY content.

Methods

To induce early weaning, lactating rats’ teats were blocked with a bandage to interrupt lactation during the last 3 days (EW group), while control offspring had free access to milk throughout lactation (C group). In postnatal day (PN) 150, EW offspring were subdivided into: EW and EW+ mate groups treated, respectively, with water or yerba mate aqueous solution (1 g/kg BW/day, gavage) during 30 days. C offspring received water for gavage. In PN180, offspring were killed.

Results

EW+ mate group presented lower body weight (?10 %), adipose mass (retroperitoneal:?40 % and epididymal:?44 %), total body fat (?43 %), subcutaneous fat (?46 %), visceral adipocyte area (?21 %), triglyceridemia (?31 %) and hypothalamic NPY content (?37 %) compared to EW group. However, hyperglycemia and lower HDL-c levels observed in EW group were not reverted with mate treatment. Although the hyperleptinemia, lower hypothalamic JAK2 and pSTAT3 content of EW group were not corrected by mate treatment, the hyperphagia and higher hypothalamic SOCS-3 content were normalized in EW+ mate group, indicating that the central leptin resistance could be restored.

Conclusion

Thus, the therapy with yerba mate solution was capable to reverse abdominal obesity, leptin resistance and hypertriglyceridemia, suggesting an important role of this bioactive component in the management of obesity in this programming model.     

Hope and spirituality among patients with chronic kidney disease undergoing hemodialysis: a correlational study

Objective

to analyze the relationship between the hope and spirituality of patients with chronic kidney disease undergoing hemodialysis.

Method

this is a cross-sectional, correlational study. The sample was composed of 127 patients of a Renal Replacement Unit. Data were collected through individual interviews guided by the following instruments: participant characterization, Herth Hope Index (HHI), and Pinto Pais-Ribeiro Spirituality Scale (PP-RSS).

Results

the average HHI score was 38.06 (±4.32) while the average PP-RSS score was 3.67 (±0.62) for "beliefs" and 3.21 (±0.53) for "hope/optimism". Spearman''s coefficient indicated there was a moderate positive correlation between the HHI and PP-RSS dimensions of "beliefs" (r=0.430; p<0.001) and "hope/optimism" (r=0.376; p<0.001).

Conclusion

Since a relationship between the sense of hope and spirituality of patients with chronic kidney disease was found, these constructs should be taken into account at the time health professionals deliver care to help patients coping with the disease and treatment.     

Discovery of New Sites for Drug Binding to the Hypertension‐Related Renin–Angiotensinogen Complex

Renin (REN) is a key drug target to stop the hypertension cascade, but thus far only one direct inhibitor has been made commercially available. In this study, we assess an innovative REN inhibition strategy, by targeting the interface of the renin:angiotensinogen (REN:ANG) complex. We characterized the energetic role of interfacial residues of REN:ANG and identified the ones responsible for protein:protein binding, which can serve as drug targets for disruption of the REN:ANG association. For this purpose, we applied a computational alanine scanning mutagenesis protocol, which measures the contribution of each side chain for the protein:protein binding free energy with an accuracy of ≈ 1 kcal/mol. As a result, in REN and ANG, six and eight residues were found to be critical for binding, respectively. The leading force behind REN:ANG complexation was found to be the hydrophobic effect. The binding free energy per residue was found to be proportional to the buried area. Residues responsible for binding were occluded from water at the complex, which promotes an efficient pairing between the two proteins. Two druggable pockets involving critical residues for binding were found on the surface of REN, where small drug‐like molecules can bind and disrupt the ANG:REN association that may provide an efficient way to achieve REN inhibition and control hypertension.     

Conventional type 1 dendritic cells induce TH1, TH1-like follicular helper T cells and regulatory T cells after antigen boost via DEC205 receptor

Conventional dendritic cells (cDCs) are specialized in antigen presentation. In the mouse spleen, cDCs are classified in cDC1s and cDC2s, and express DEC205 and DCIR2 endocytic receptors, respectively. Monoclonal antibodies (mAbs) αDEC205 (αDEC) and αDCIR2 have been fused to different antigens to deliver them to cDC1s or cDC2s. We immunized mice with αDEC and αDCIR2 fused to an antigen using Poly(I:C) as adjuvant. The initial immune response was analyzed from days 3 to 6 after the immunization. We also studied the influence of a booster dose. Our results showed that antigen targeting to cDC1s promoted a pro-inflammatory T_H1 cell response. Antigen targeting to cDC2s induced T_FH cells, GCs, and plasma cell differentiation. After boost, antigen targeting to cDC1s improved the T_H1 cell response and induced T_H1-like T_FH cells that led to an increase in specific antibody titers and IgG class switch. Additionally, a population of regulatory T cells was also observed. Antigen targeting to cDC2s did not improve the specific antibody response after boost. Our results add new information on the immune response induced after the administration of a booster dose with αDEC and αDCIR2 fusion mAbs. These results may be useful for vaccine design using recombinant mAbs.     

Platelet‐Rich Plasma,Low‐Level Laser Therapy,or Their Combination Promotes Periodontal Regeneration in Fenestration Defects: A Preliminary In Vivo Study

Background: This study histomorphometrically analyzes the influence of platelet‐rich plasma (PRP), low‐level laser therapy (LLLT), or their combination on the healing of periodontal fenestration defects (PFDs) in rats. Methods: PFDs were surgically created in the mandibles of 80 rats. The animals were randomly divided into four groups: 1) C (control) and 2) PRP, defects were filled with blood clot or PRP, respectively; 3) LLLT and 4) PRP/LLLT, defects received laser irradiation, were filled with blood clot or PRP, respectively, and then irradiated again. Animals were euthanized at either 10 or 30 days post‐surgery. Percentage of new bone (NB), density of newly formed bone (DNB), new cementum (NC), and extension of remaining defect (ERD) were histomorphometrically evaluated. Data were statistically analyzed (analysis of variance; Tukey test, P <0.05). Results: At 10 days, group PRP presented ERD significantly lower than group C. At 30 days, group PRP presented NB and DNB significantly greater than group C. Groups LLLT, PRP, and PRP/LLLT showed significant NC formation at 30 days, with collagen fibers inserted obliquely or perpendicularly to the root surface. NC formation was not observed in any group C specimen. Conclusions: LLLT, PRP, or their combination all promoted NC formation with a functional periodontal ligament. The combination PRP/LLLT did not show additional positive effects compared to the use of either therapy alone.     

Malaria: looking for selection signatures in the human PKLR gene region

The genetic component of susceptibility to malaria is both complex and multigenic and the better‐known protective polymorphisms are those involving erythrocyte‐specific structural proteins and enzymes. In vivo and in vitro data have suggested that pyruvate kinase deficiency, which causes a nonspherocytic haemolytic anaemia, could be protective against malaria severity in humans, but this hypothesis remains to be tested. In the present study, we conducted a combined analysis of Short Tandem Repeats (STRs) and Single Nucleotide Polymorphisms (SNPs) in the pyruvate kinase‐encoding gene (PKLR) and adjacent regions (chromosome 1q21) to look for malaria selective signatures in two sub‐Saharan African populations from Angola and Mozambique, in several groups with different malaria infection outcome. A European population from Portugal, including a control and a pyruvate kinase‐deficient group, was used for comparison. Data from STR and SNP loci spread along the PKLR gene region showed a considerably higher differentiation between African and Portuguese populations than that usually found for neutral markers. In addition, a wider region showing strong linkage disequilibrium was found in an uncomplicated malaria group, and a haplotype was found to be associated with this clinical group. Altogether, this data suggests that malaria selective pressure is acting in this genomic region.     

Cerebellar transcranial direct current stimulation in children with ataxic cerebral palsy: A sham-controlled,crossover, pilot study

Objective: The aim of the present study was to analyze the use of anodal tDCS of the cerebellar region combined with treadmill training to improve balance and functional performance in children with ataxic cerebral palsy. Design: Single-blind, sham-controlled, crossover, pilot study. Setting: Rehabilitation center and research motion analysis laboratory. Participants: Children (N = 6) with ataxic cerebral palsy and balance deficit. Main Outcome Measures: Static balance (oscillations of the center of pressure), functional balance (Pediatric Balance Scale) and functional performance (Pediatric Evaluation of Disability Inventory) were evaluated. Results: Significant reductions occurred in oscillations of the center of pressure with eyes closed after active anodal tDCS only. The effects of treadmill training on functional balance and functional performance in mobility were maintained in the active tDCS group only. Conclusion: These preliminary data support the notion that anodal tDCS of the cerebellar region combined with treadmill training improves balance in children with ataxic cerebral palsy.