46 research outputs found
Autotrophic and Heterotrophic Growth Conditions Modify Biomolecole Production in the Microalga Galdieria sulphuraria (Cyanidiophyceae, Rhodophyta)
Algae have multiple similarities with fungi, with both belonging to the Thallophyte, a polyphyletic group of non-mobile organisms grouped together on the basis of similar characteristics, but not sharing a common ancestor. The main difference between algae and fungi is noted in their metabolism. In fact, although algae have chlorophyll-bearing thalloids and are autotrophic organisms, fungi lack chlorophyll and are heterotrophic, not able to synthesize their own nutrients. However, our studies have shown that the extremophilic microalga Galderia sulphuraria (GS) can also grow very well in heterotrophic conditions like fungi. This study was carried out using several approaches such as scanning electron microscope (SEM), gas chromatography/mass spectrometry (GC/MS), and infrared spectrophotometry (ATR-FTIR). Results showed that the GS, strain ACUF 064, cultured in autotrophic (AGS) and heterotrophic (HGS) conditions, produced different biomolecules. In particular, when grown in HGS, the algae (i) was 30% larger, with an increase in carbon mass that was 20% greater than AGS; (ii) produced higher quantities of stearic acid, oleic acid, monounsaturated fatty acids (MUFAs), and ergosterol; (iii) produced lower quantities of fatty acid methyl esters (FAMEs) such as methyl palmytate, and methyl linoleate, saturated fatty acids (SFAs), and poyliunsaturated fatty acids (PUFAs). ATR-FTIR and principal component analysis (PCA) statistical analysis confirmed that the macromolecular content of HGS was significantly different from AGS. The ability to produce different macromolecules by changing the trophic conditions may represent an interesting strategy to induce microalgae to produce different biomolecules that can find applications in several fields such as food, feed, nutraceutical, or energy production
Impact of the peptide wmr-k on dual-species biofilm candida albicans/klebsiella pneumoniae and on the untargeted metabolomic profile
In recent years, the scientific community has focused on the development of new antibiotics to address the difficulties linked to biofilm-forming microorganisms and drug-resistant infections. In this respect, synthetic antimicrobial peptides (AMPs) are particularly regarded for their therapeutic potential against a broad spectrum of pathogens. In this work, the antimicrobial and antibiofilm activities of the peptide WMR-K towards single and dual species cultures of Candida albicans and Klebsiella pneumoniae were investigated. We found minimum inhibitory concentration (MIC) values for WMR-K of 10 µM for K. pneumoniae and of 200 µM for C. albicans. Furthermore, sub-MIC concentrations of peptide showed an in vitro inhibition of biofilm formation of mono and polymicrobial systems and also a good biofilm eradication even if higher concentrations of it are needed. In order to provide additional evidence for the effect of the examined peptide, a study of changes in extracellular metabolites excreted and/or uptaken from the culture medium (metabolomic footprinting) in the poly-microbial association of C. albicans and K. pneumoniae in presence and absence of WMR-K was performed. Comparing to the untreated dual species biofilm culture, the metabolomic profile of the WMR-K treated culture appears significantly altered. The differentially expressed compounds are mainly related to the primary metabolic pathways, including amino acids, trehalose, pyruvic acid, glycerol and vitamin B6
The membranotropic peptide gh625 to combat mixed candida albicans/klebsiella pneumoniae biofilm: Correlation between in vitro anti-biofilm activity and in vivo antimicrobial protection
The antibiofilm activity of a gH625 analogue was investigated to determine the in vitro inhibition and eradication of a dual-species biofilm of Candida albicans and Klebsiella pneumoniae, two leading opportunistic pathogens responsible for several resistant infections. The possibility of effectively exploiting this peptide as an alternative anti-biofilm strategy in vivo was assessed by the investigation of its efficacy on the Galleria mellonella larvae model. Results on larvae survival demonstrate a prophylactic efficacy of the peptide towards the infection of each single microorganism but mainly towards the co-infection. The expression of biofilm-related genes in vivo showed a possible synergy in virulence when these two species co-exist in the host, which was effectively prevented by the peptide. These findings provide novel insights into the treatment of medically relevant bacterial–fungal interaction
A new schedule of fotemustine in temozolomide-pretreated patients with relapsing glioblastoma
In the present study we investigated the feasibility and effectiveness of a new biweekly schedule of fotemustine (FTM) in patients with recurrent glioblastoma, after at least one previous treatment. The primary endpoint was progression-free survival at 6 months; secondary objectives were clinical response, overall survival, disease-free survival, and toxicity. Forty patients (median age 52.8 years; median Karnofsky Performance Status at progression 90) underwent second-line chemotherapy with FTM. Selected patients were previously treated with a standard radiotherapy course with concomitant temozolomide (TMZ). After tumor relapse or progression proven by magnetic resonance imaging (MRI), all patients underwent chemotherapy with FTM, given intravenously at dose of 80 mg/m2 every 2 weeks for five consecutive administrations (induction phase), and then every 3 weeks at 100 mg/m2 as maintenance. A total of 329 infusions were administered; the median number of cycles administered was 8. All patients completed the induction phase, and 29 patients received at least one maintenance infusion. Response to treatment was assessed using MacDonald criteria. One complete response [2.5%, 95% confidence interval (CI): 0–10%], 9 partial responses (22.5%, 95% CI: 15–37%), and 16 stable diseases (40%, 95% CI: 32–51%) were observed. Median time to progression was 6.7 months (95% CI: 3.9–9.1 months). Progression-free survival at 6 months was 61%. Median survival from beginning of FTM chemotherapy was 11.1 months. The schedule was generally well tolerated; the main toxicities were hematologic (grade 3 thrombocytopenia in two cases). To the best of our knowledge, this is the first report specifically dealing with the use of a biweekly induction schedule of FTM. The study demonstrates that FTM has therapeutic efficacy as single-drug second-line chemotherapy with a favorable safety profile
Multidimensional Signals and Analytic Flexibility: Estimating Degrees of Freedom in Human-Speech Analyses
Recent empirical studies have highlighted the large degree of analytic flexibility in data analysis that can lead to substantially different conclusions based on the same data set. Thus, researchers have expressed their concerns that these researcher degrees of freedom might facilitate bias and can lead to claims that do not stand the test of time. Even greater flexibility is to be expected in fields in which the primary data lend themselves to a variety of possible operationalizations. The multidimensional, temporally extended nature of speech constitutes an ideal testing ground for assessing the variability in analytic approaches, which derives not only from aspects of statistical modeling but also from decisions regarding the quantification of the measured behavior. In this study, we gave the same speech-production data set to 46 teams of researchers and asked them to answer the same research question, resulting in substantial variability in reported effect sizes and their interpretation. Using Bayesian meta-analytic tools, we further found little to no evidence that the observed variability can be explained by analysts’ prior beliefs, expertise, or the perceived quality of their analyses. In light of this idiosyncratic variability, we recommend that researchers more transparently share details of their analysis, strengthen the link between theoretical construct and quantitative system, and calibrate their (un)certainty in their conclusions
How do cardiologists select patients for dual antiplatelet therapy continuation beyond 1 year after a myocardial infarction? Insights from the EYESHOT Post-MI Study
Background: Current guidelines suggest to consider dual antiplatelet therapy (DAPT) continuation for longer than 12 months in selected patients with myocardial infarction (MI). Hypothesis: We sought to assess the criteria used by cardiologists in daily practice to select patients with a history of MI eligible for DAPT continuation beyond 1 year. Methods: We analyzed data from the EYESHOT Post-MI, a prospective, observational, nationwide study aimed to evaluate the management of patients presenting to cardiologists 1 to 3 years from the last MI event. Results: Out of the 1633 post-MI patients enrolled in the study between March and December 2017, 557 (34.1%) were on DAPT at the time of enrolment, and 450 (27.6%) were prescribed DAPT after cardiologist assessment. At multivariate analyses, a percutaneous coronary intervention (PCI) with multiple stents and the presence of peripheral artery disease (PAD) resulted as independent predictors of DAPT continuation, while atrial fibrillation was the only independent predictor of DAPT interruption for patients both at the second and the third year from MI at enrolment and the time of discharge/end of the visit. Conclusions: Risk scores recommended by current guidelines for guiding decisions on DAPT duration are underused and misused in clinical practice. A PCI with multiple stents and a history of PAD resulted as the clinical variables more frequently associated with DAPT continuation beyond 1 year from the index MI
Quantitative PCR Detection and Characterisation of Human Adenovirus, Rotavirus and Hepatitis A Virus in Discharged Effluents of Two Wastewater Treatment Facilities in the Eastern Cape, South Africa
Multidimensional signals and analytic flexibility: Estimating degrees of freedom in human speech analyses
Recent empirical studies have highlighted the large degree of analytic flexibility in data analysis which can lead to substantially different conclusions based on the same data set. Thus, researchers have expressed their concerns that these researcher degrees of freedom might facilitate bias and can lead to claims that do not stand the test of time. Even greater flexibility is to be expected in fields in which the primary data lend themselves to a variety of possible operationalizations. The multidimensional, temporally extended nature of speech constitutes an ideal testing ground for assessing the variability in analytic approaches, which derives not only from aspects of statistical modeling, but also from decisions regarding the quantification of the measured behavior. In the present study, we gave the same speech production data set to 46 teams of researchers and asked them to answer the same research question, resulting insubstantial variability in reported effect sizes and their interpretation. Using Bayesian meta-analytic tools, we further find little to no evidence that the observed variability can be explained by analysts’ prior beliefs, expertise or the perceived quality of their analyses. In light of this idiosyncratic variability, we recommend that researchers more transparently share details of their analysis, strengthen the link between theoretical construct and quantitative system and calibrate their (un)certainty in their conclusions