Mutational analysis of the yeast multidrug resistance ABC transporter Pdr5p with altered drug specificity

Multidrug resistance ABC transporter Pdr5p of Saccharomyces cerevisiae is particularly important due to its ability to export a wide range of unrelated substrates. To clarify its function, we generated Pdr5p mutants by random mutagenesis and screened for mutants with altered drug specificity in vivo by using 5 drug compounds. Nine point mutations that caused significant changes in drug specificity distributed throughout the length of Pdr5p, namely, in the extracellular, transmembrane or cytoplasmic regions of the transporter. We then investigated their effects upon drug resistance, using 36 chemically related or distinct substrates. From this study, overall geometry of the Pdr5p was suggested to contribute in acquiring the enormous range of drug specificity. Based on their ability to inhibit the growth of the mutant strains, the 36 tested drugs were classified into: drugs to which the mutants responded differently (Group 1), drugs to which all the mutants showed sensitivity (Group 2), and drugs to which all the mutants exhibited resistance (Group 3). The ability of the compounds to be partitioned to the plasma membrane seemed an important factor for recognition by Pdr5p.     

Loss of heterozygosity and mutational analyses of the ACTRII gene locus in human colorectal tumors

The activin type II receptorgene (ACTRII) is mutated in 58.1% of microsatellite-unstable (MSI-H) colorectal cancers and is a close relative of the TGFbeta-1 type II receptor, which is known to be involved in both MSI-H and non-MSI-H colorectal carcinogenesis. We therefore sought to determine whether ACTRII was involved in non-MSI-H colorectal cancers. We evaluated ACTRII inactivation by allelic deletion, loss of mRNA expression, or somatic mutation in 51 non-MSI-H colon cancers. Loss of heterozygosity (LOH) at the ACTRII locus (2q23.1) was found in 9 (17.6%) of 51 primary tumors. Loss of ACTRII mRNA expression was seen in one (14.3%) of the seven LOH-positive primary tumors from which total RNA was available. We also performed DNA sequencing analysis of tumors showing LOH. One LOH-positive primary tumor exhibited a novel germline missense sequence alteration (amino acid substitution, 117 Ile to Phe) that was not found in 23 additional normal individuals, implying that this alteration is not a frequent polymorphism. We conclude that ACTRII is probably involved in both non-MSI-H and MSI-H colorectal carcinogenesis, but more frequently in the latter subgroup.     

Acute gastrointestinal bleeding: A comparison between variceal and nonvariceal gastrointestinal bleeding

Acute upper gastrointestinal bleeding (UGIB) is a typical medical emergency, with an incidence of 84 to 160 cases per 100,000 individuals and a mortality rate of approximately 10%. This study aimed to identify all cases of UGIB hospitalized in a tertiary gastroenterology department, to identify possible predictive factors involved in rebleeding and mortality, potential associations between different elements and the severity of bleeding, and the differences between the upper digestive hemorrhage due to nonvariceal and variceal bleeding. This was an observational, retrospective study of patients with UGIB admitted to the tertiary Department of Gastroenterology between January 2013 and December 2020. A total of 1499 patients were enrolled in the study. One thousand four hundred and ninety-nine patients were hospitalized for 7 years with active upper digestive hemorrhage, 504 variceal bleeding, and 995 nonvariceal bleeding. When comparing variceal with nonvariceal bleeding, in nonvariceal bleeding, the mean age was higher, similar sex, higher mortality rate, higher rebleeding rate, and higher hemorrhagic shock rate. Endoscopy treatment was also performed more frequently in variceal bleeding than in nonvariceal bleeding. Severe anemia was found more frequently in patients with variceal bleeding. The mortality rate was 10% in the entire study group, which was not significantly different between the 2 batches. However, the rebleeding rate is higher in patients with variceal gastrointestinal bleeding.     

The association between parents' stress and parental feeding practices and feeding styles: Systematic review and meta‐analysis of observational studies

In the extended UNICEF framework of early childhood nutrition, parents'' stress is associated with parental feeding style. However, no comprehensive review has examined the association between parents'' stress and feeding styles and practices. The objective of our review was to synthesise the current literature examining the association between parents'' stress and their feeding practices and/or styles, among parents of children ≤ 5 years old. We searched; MEDLINE, EMBASE, PSYCHINFO and CINAHL from 2019 to 2021. Two investigators independently extracted relevant data and assessed the study quality and the certainty of evidence. Data were pooled using generic inverse variance with fixed effects (<5 comparisons) or random effects (≥5 comparisons) and expressed as correlation coefficients with 95% confidence intervals (CI). Between study heterogeneity was assessed using Cochran''s Q and quantified with I ². We identified 6 longitudinal and 11 cross‐sectional studies, of which 4 studies provided sufficient data to be pooled. A very small correlation between general stress and restrictive feeding practices was observed (r = 0.06 [95% CI: 0.01−0.12]; no substantial heterogeneity (I ² = 0.00%, P _Q < 0.85, very low certainty). No correlation between general stress and feeding pressure was identified (r = 0.06 [95% CI: −0.02 to 0.15]). Results showed that both general and parenting stress were associated with suboptimal breastfeeding practices and unresponsive feeding styles. Conclusion: This study demonstrated a low‐to‐moderate quality of literature for the inclusion of parents'' stress in the extended UNICEF care model of child nutrition. Future research needs to explore this relationship longitudinally and in ethnic diverse populations to inform tailored interventions that promote responsive feeding practices.     

Risk of Death in Comorbidity Subgroups of Hospitalized COVID-19 Patients Inferred by Routine Laboratory Markers of Systemic Inflammation on Admission: A Retrospective Study

Our study objective was to construct models using 20 routine laboratory parameters on admission to predict disease severity and mortality risk in a group of 254 hospitalized COVID-19 patients. Considering the influence of confounding factors in this single-center study, we also retrospectively assessed the correlations between the risk of death and the routine laboratory parameters within individual comorbidity subgroups. In multivariate regression models and by ROC curve analysis, a model of three routine laboratory parameters (AUC 0.85; 95% CI: 0.79–0.91) and a model of six laboratory factors (AUC 0.86; 95% CI: 0.81–0.91) were able to predict severity and mortality of COVID-19, respectively, compared with any other individual parameter. Hierarchical cluster analysis showed that inflammatory laboratory markers grouped together in three distinct clusters including positive correlations: WBC with NEU, NEU with neutrophil-to-lymphocyte ratio (NLR), NEU with systemic immune-inflammation index (SII), NLR with SII and platelet-to-lymphocyte ratio (PLR) with SII. When analyzing the routine laboratory parameters in the subgroups of comorbidities, the risk of death was associated with a common set of laboratory markers of systemic inflammation. Our results have shown that a panel of several routine laboratory parameters recorded on admission could be helpful for early evaluation of the risk of disease severity and mortality in COVID-19 patients. Inflammatory markers for mortality risk were similar in the subgroups of comorbidities, suggesting the limited effect of confounding factors in predicting COVID-19 mortality at admission.     

Collagen-Carboxymethylcellulose Biocomposite Wound-Dressings with Antimicrobial Activity

Microbial infections associated with skin diseases are frequently investigated since they impact on the progress of pathology and healing. The present work proposes the development of freeze-dried, glutaraldehyde cross-linked, and non-cross-linked biocomposite dressings with a porous structure, which may assist the reepithelization process through the presence of collagen and carboxymethylcellulose, along with a therapeutic antimicrobial effect, due to silver nanoparticles (AgNPs) addition. Phisyco-chemical characterization revealed the porous morphology of the obtained freeze-dried composites, the presence of high crystalline silver nanoparticles with truncated triangular and polyhedral morphologies, as well as the characteristic absorption bands of collagen, silver, and carboxymethylcellulose. In vitro tests also assessed the stability, functionality, and the degradability rate of the obtained wound-dressings. Antimicrobial assay performed on Gram-negative (Escherichia coli), Gram-positive (Staphyloccocus aureus) bacteria, and yeast (Candida albicans) models demonstrated that composite wound dressings based on collagen, carboxymethylcellulose, and AgNPs are suitable for skin lesions because they prevent the risk of infection and have prospective wound healing capacity. Moreover, the cell toxicity studies proved that the obtained materials can be used in long time treatments, with no cytotoxic effects.