Genomic alterations in human umbilical cord–derived mesenchymal stromal cells call for stringent quality control before any possible therapeutic approach

Background aimsThe umbilical cord (UC) is a promising source of mesenchymal stromal cells (MSCs). UC-MSCs display very similar in vitro characteristics to bone marrow–MSCs and could represent a valuable alternative for cell-based therapies. However, it is still unclear whether UC-MSCs are prone or not to the acquisition of genomic imbalances during in vitro expansion.MethodsWith the use of array-comparative genomic hybridization, we compared copy number variations of early (P2–P3) and late (>P5) passages of in vitro–expanded UC-MSCs.ResultsIn two of 11 long-term UC-MSCs cultures, we observed the appearance of clones carrying genomic imbalances, which generated genetic mosaicism at intermediate passages. Although still able to reach the senescence phase, the cells carrying the genomic imbalance acquired a proliferative advantage, as demonstrated by the increase in frequency during long-term culture.ConclusionsAltogether, our results suggest that UC-MSC–based clinical protocols should be designed with caution; their clinical use should be preceded by array-comparative genomic hybridization screening for the acquisition of genomic imbalances during in vitro expansion.     

Inhibition of Bovine Kidney Low Molecular Mass Phosphotyrosine Protein Phosphatase by Uric Acid

Uric acid inhibited 50% of the activity of bovine kidney low molecular mass phosphotyrosine protein phosphatase at concentrations of 1.0, 0.4, 1.3, and 0.2 mM, respectively for p -nitrophenyl phosphate (p -NPP), flavine mononucleotide, β -naphthyl phosphate and tyrosine phosphate (Tyr-P) as substrates. The mixed type inhibition of p -NPP hydrolysis was fully reversible, with K ic and K iu values of 0.4 and 1.1 mM, respectively; the inhibition by uric acid shifted the pH optimum from 5.0 to 6.5. When Tyr-P was the substrate, competitive inhibition was observed with a K i value of 0.05 mM. Inhibition studies by uric acid in the presence of thiol compounds, and preincubation studies in the presence of inorganic phosphate suggest that the interaction of uric acid with the enzyme occurred at the active site, but did not involve SH residues, and that the mechanism of inhibition depended on the structure of the substrates.     

Spatial and temporal mapping of the PfEMP1 export pathway in Plasmodium falciparum

The human malaria parasite, Plasmodium falciparum, modifies the red blood cells (RBCs) that it infects by exporting proteins to the host cell. One key virulence protein, P. falciparum Erythrocyte Membrane Protein‐1 (PfEMP1), is trafficked to the surface of the infected RBC, where it mediates adhesion to the vascular endothelium. We have investigated the organization and development of the exomembrane system that is used for PfEMP1 trafficking. Maurer's cleft cisternae are formed early after invasion and proteins are delivered to these (initially mobile) structures in a temporally staggered and spatially segregated manner. Membrane‐Associated Histidine‐Rich Protein‐2(MAHRP2)‐containing tether‐like structures are generated as early as 4 h post invasion and become attached to Maurer's clefts. The tether/Maurer's cleft complex docks onto the RBC membrane at ～ 20 h post invasion via a process that is not affected by cytochalasin D treatment. We have examined the trafficking of a GFP chimera of PfEMP1 expressed in transfected parasites. PfEMP1B‐GFP accumulates near the parasite surface, within membranous structures exhibiting a defined ultrastructure, before being transferred to pre‐formed mobile Maurer's clefts. Endogenous PfEMP1 and PfEMP1B‐GFP are associated with Electron‐Dense Vesicles that may be responsible for trafficking PfEMP1 from the Maurer's clefts to the RBC membrane.     

Correction to: Are the existing eu ecolabel criteria for furniture products too complex? An analysis of complexity from a material and a supply chain perspective and suggestions for ways ahead

The International Journal of Life Cycle Assessment -     

Nonparametric variable importance assessment using machine learning techniques

In a regression setting, it is often of interest to quantify the importance of various features in predicting the response. Commonly, the variable importance measure used is determined by the regression technique employed. For this reason, practitioners often only resort to one of a few regression techniques for which a variable importance measure is naturally defined. Unfortunately, these regression techniques are often suboptimal for predicting the response. Additionally, because the variable importance measures native to different regression techniques generally have a different interpretation, comparisons across techniques can be difficult. In this work, we study a variable importance measure that can be used with any regression technique, and whose interpretation is agnostic to the technique used. This measure is a property of the true data‐generating mechanism. Specifically, we discuss a generalization of the analysis of variance variable importance measure and discuss how it facilitates the use of machine learning techniques to flexibly estimate the variable importance of a single feature or group of features. The importance of each feature or group of features in the data can then be described individually, using this measure. We describe how to construct an efficient estimator of this measure as well as a valid confidence interval. Through simulations, we show that our proposal has good practical operating characteristics, and we illustrate its use with data from a study of risk factors for cardiovascular disease in South Africa.     

Large herbivores regulate the spatial recruitment of a hyperdominant Neotropical palm

Large mammalian herbivores play an important role in shaping the diversity of tropical forests by affecting the survival of seedlings and saplings beneath parent plants. The white‐lipped peccary (Tayassu pecari) accounts for the largest herbivore biomass that controls seed and seedling survival in Neotropical ecosystems. However, hunting and habitat loss has driven peccaries to local extinction for most of their original distribution, so it is likely that their absence will affect plant recruitment dynamics. We tested the effects of peccary local extinction on the density and spatial distribution of the hyperdominant palm Euterpe edulis by performing a fine‐scale characterization of its spatial recruitment in six forest sites in the Brazilian Atlantic forest. We compared the age structure and the spatial patterns of seedlings, saplings, and adults as well as the relationship between them. We found that while under the presence of peccaries there was a decrease in recruitment rates under adults, the local extinction of these large mammals led to a more clumped process of spatial recruitment. Despite such contrasting spatial patterns of recruitment dynamics, neither age structure nor the random spatial distribution of adults was affected by the presence or absence of peccaries, indicating that their early effects on these palm populations are mitigated as recruitment advances. Our findings highlight the role of large‐bodied forest‐dwelling herbivores in regulating the fine‐scale spatial recruitment of plants and advance our understanding on the effects of defaunation in tropical forests. Abstract in Portuguese is available with online material.     

Eating catch of the day: the diet of porbeagle shark Lamna nasus (Bonnaterre 1788) based on stomach content analysis,and the interaction with trawl fisheries in the south-western Atlantic (52° S–56° S)

This work examined the diet of the porbeagle shark Lamna nasus in the south-west Atlantic Ocean (SWAO, Argentina, 52° S–56° S) by analysing the stomach content information obtained by scientific observers who sampled specimens captured as by-catch on-board commercial fishing vessels from 2010 to 2020. A total of 148 fishing sites were analysed, in which the estimated catch was composed mainly of hoki Macruronus magellanicus (56.00%) and southern blue whiting Micromesistius australis (33.13%). From 413 porbeagle sharks sampled (292 females and 121 males) ranging from 71 to 241 cm total length (L_T) (mean: 179.76 ± 26.74 cm), 310 (75.06%) contained food in the stomachs. The forage fish were mainly hoki M. magellanicus (23.53%) and southern blue whiting M. australis (19.05%), followed by the Patagonian sprat Sprattus fuegensis (4.48%) and nototheniids (1.4%). Cephalopods and crustaceans accounted for 10% of the diet. The estimated trophic level was 4.35. Generalized linear models revealed that the consumption of hoki M. magellanicus and southern blue whiting M. australis increased with the L_T of the porbeagle shark. Moreover, smaller porbeagle sharks preyed upon both small and large teleost fish, whereas larger porbeagle sharks predated exclusively upon large fish. The diet of porbeagle shark involved interactions with fisheries as it fed upon the fish species that constituted the main catch in the analysed fishing sites, as well as the main catches of the austral trawl fisheries. The ecological role of porbeagle shark observed in the SWAO exposed implications for fisheries management from a multispecies perspective.     

Can HRV Biofeedback Improve Short-Term Effort Recovery? Implications for Intermittent Load Sports

Applied Psychophysiology and Biofeedback - As intensity and physical demands continue to rise in sport competition, faster and better recovery becomes essential. The aim of this study was to assess...     

Evaluation of Interactions Between Carboxymethylcellulose and Soy Protein Isolate and their Effects on the Preparation and Characterization of Composite Edible Films

Food Biophysics - Interactions between carboxymethylcellulose (CMC) and soy protein isolate (SPI) were assessed to determine their effects on the physicochemical and morphological properties of...     

Lactobacillus rhamnosus CGMCC 1.3724 (LPR) Improves Skin Wound Healing and Reduces Scar Formation in Mice

Probiotics and Antimicrobial Proteins - Skin wounds are an important clinical problem which affects millions of people worldwide. The search for new therapeutic approaches to improve wound healing...