In vitro and in vivo hypolipidemic properties of the aqueous extract of Spirulina platensis, cultivated in colored flasks under artificial illumination
Background Spirulina is blue-green algae that grows mainly in tropical and subtropical lakes and is commonly used due to its nutritional features including high concentrations of protein, vitamins, mineral salts, carotenoids and antioxidants. This study aimed to investigate the anti-hypercholesterolemic potential of aqueous extract of Spirulina platensis cultivated in different colored flasks under artificial illumination; in vitro and in the diet induced hypercholesterolemic Swiss albino mice. Methods Spirulina platensis was cultivated in red, blue, green and colorless Erlenmeyer flasks containing Zarrouk’s medium under aerobic conditions, with incessant illumination by artificial cool white fluorescent with light intensity of 2500 lux (35 µmol photon m−2 s−1). Chlorophyll a and total carotenoid contents were estimated using colorimetric methods, fatty acids composition was determined by GC-Mass, in vitro and in vivo anti-cholesterol assays were used in assessing the anti-hypercholesterolemia potential of obtained Spirulina cells. Results The results showed that the highest cell dry weight, chlorophyl a, and carotenoid of S. platensis were observed in colorless flasks and that the lowest values were recorded with the green colored flasks. Also, the hot water extract of S. platensis obtained from colorless flasks at a concentration of 15 mg/mL after 60 min of incubation exhibited the greatest reduction of cholesterol level. Gas chromatography-mass spectrometry analysis of S. platensis methanolic extract showed 15 bioactive compounds were identified and grouped according to their chemical structures. An experimental model of hypercholesterolemic mice had been examined for impact of S. platensis individually and combined with atorvastatin drug. All S. platensis groups resulted in a remarkable decrease in plasma total cholesterol, triglycerides and low density lipoprotein; and increase in high density lipoprotein. Conclusion The present study concluded that the hot aqueous extract of S. platensis developed in colorless flasks is recommended as a natural source for bioactive compounds, with anti-cholesterol and antioxidant potentialities.
Al-Saman et al. (2020) In vitro and in vivo hypolipidemic properties of the aqueous extract of Spirulina platensis, cultivated in colored flasks under artificial illumination. PeerJ 8:e10366 https://doi.org/10.7717/peerj.10366
Effects of plastic mulching on the accumulation and distribution of macro and micro plastics in soils of two farming systems in Northwest China
Background Inappropriate disposal of the plastic mulching debris could create macroplastics (MaPs) and microplastics (MiPs) pollution in agricultural soil. Methods To study the effects of farming systems on accumulation and distribution of agricultural plastic debris, research was carried out on two farming systems in Northwest China. Farming in Wutong Village (S1) is characterized by small plots and low-intensity machine tillage while farming in Shihezi (S2) is characterized by large plots and high-intensity machine tillage. In September 2017, we selected six fields in S1, three fields with 6–8 years of continuous plastic mulching (CM) as well as three fields with over 30 years of intermittent mulching (IM). In S2, we selected five cotton fields with 6, 7, 8, 15 and 18 years of continuous mulching. In both regions, MaPs and MiPs from soil surface to 30 cm depth (0–30 cm) were sampled. Results The results showed that in S1, MaPs mass in fields with 6–8 years CM (i.e., 97.4kg·ha−1) were significantly higher than in fields with 30 years IM (i.e., 53.7 kg·ha−1). MaPs in size category of 10–50 cm2 accounted for 46.9% in fields of CM and 44.5% in fields of IM of total collected MaPs number. In S2, MaPs mass ranged from 43.5 kg·ha−1 to 148 kg·ha−1. MaPs in size category of 2–10 cm2 account for 41.1% of total collected MaPs number while 0.25–2 cm2 accounted for 40.6%. MiPs in S1 were mainly detected in fields with over 30 years of intermittent mulching (up to 2,200 particles·kg−1 soil), whereas in S2 were detected in all fields (up to 900 particles·kg−1 soil). The results indicated farming systems could substantially affect the accumulation and distribution of agricultural plastic debris. Continuous plastic mulching could accumulate higher amount of MaPs than intermittent plastic mulching. High-intensity machine tillage could lead to higher fragmentation of MaPs and more severe MiPs pollution. These results suggest that agricultural plastic regulations are needed.
Environmental Contamination and Remediation
Meng et al. (2020) Effects of plastic mulching on the accumulation and distribution of macro and micro plastics in soils of two farming systems in Northwest China. PeerJ 8:e10375 https://doi.org/10.7717/peerj.10375
Expression and phylogeny of multidrug resistance protein 2 and 4 in African white backed vulture (Gyps africanus)
Diclofenac toxicity in old world vultures is well described in the literature by both the severity of the toxicity induced and the speed of death. While the mechanism of toxicity remains unknown at present, the necropsy signs of gout suggests primary renal involvement at the level of the uric acid excretory pathways. From information in the chicken and man, uric acid excretion is known to be a complex process that involves a combination of glomerular filtration and active tubular excretion. For the proximal convoluted tubules excretion occurs as a two-step process with the basolateral cell membrane using the organic anion transporters and the apical membrane using the multidrug resistant protein to transport uric acid from the blood into the tubular fluid. With uric acid excretion seemingly inhibited by diclofenac, it becomes important to characterize these transporter mechanism at the species level. With no information being available on the molecular characterization/expression of MRPs of Gyps africanus, for this study we used next generation sequencing, and Sanger sequencing on the renal tissue of African white backed vulture (AWB), as the first step to establish if the MRPs gene are expressed in AWB. In silico analysis was conducted using different software to ascertain the function of the latter genes. The sequencing results revealed that the MRP2 and MRP4 are expressed in AWB vultures. Phylogeny of avian MRPs genes confirms that vultures and eagles are closely related, which could be attributed to having the same ancestral genes and foraging behavior. In silico analysis confirmed the transcribed proteins would transports anionic compounds and glucose.
Nethathe et al. (2020) Expression and phylogeny of multidrug resistance protein 2 and 4 in African white backed vulture (Gyps africanus). PeerJ 8:e10422 https://doi.org/10.7717/peerj.10422
Comprehensive pathway-related genes signature for prognosis and recurrence of ovarian cancer
Background Ovarian cancer (OC) is a highly malignant disease with a poor prognosis and high recurrence rate. At present, there is no accurate strategy to predict the prognosis and recurrence of OC. The aim of this study was to identify gene-based signatures to predict OC prognosis and recurrence. Methods mRNA expression profiles and corresponding clinical information regarding OC were collected from The Cancer Genome Atlas (TCGA) database. Gene set enrichment analysis (GSEA) and LASSO analysis were performed, and Kaplan–Meier curves, time-dependent ROC curves, and nomograms were constructed using R software and GraphPad Prism7. Results We first identified several key signalling pathways that affected ovarian tumorigenesis by GSEA. We then established a nine-gene-based signature for overall survival (OS) and a five-gene-based-signature for relapse-free survival (RFS) using LASSO Cox regression analysis of the TCGA dataset and validated the prognostic value of these signatures in independent GEO datasets. We also confirmed that these signatures were independent risk factors for OS and RFS by multivariate Cox analysis. Time-dependent ROC analysis showed that the AUC values for OS and RFS were 0.640, 0.663, 0.758, and 0.891, and 0.638, 0.722, 0.813, and 0.972 at 1, 3, 5, and 10 years, respectively. The results of the nomogram analysis demonstrated that combining two signatures with the TNM staging system and tumour status yielded better predictive ability. Conclusion In conclusion, the two-gene-based signatures established in this study may serve as novel and independent prognostic indicators for OS and RFS.
Zhao et al. (2020) Comprehensive pathway-related genes signature for prognosis and recurrence of ovarian cancer. PeerJ 8:e10437 https://doi.org/10.7717/peerj.10437
Salivary microbial changes during the first 6 months of orthodontic treatment
Background Orthodontic treatment is widely used to treat malocclusion. However, the influence of treatment on the oral microbiome remains unclear. In this study, we investigated salivary microbial changes in patients undergoing orthodontic treatment. Methods In total, 19 orthodontic patients participated in this study. Saliva samples were collected at the following three timepoints: before (T0) and 3 months (T1) and 6 months (T2) after the placement of orthodontic appliances. High-throughput sequencing was performed based on the 16S rRNA gene V4 region. Results The phyla of Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria and Fusobacteria were predominant. Observed Species, Chao1 and ACE, which represent α diversity, were significantly decreased at T1 and subsequently increased at T2. In addition, the β diversity at T1 based on the Bray-Curtis distances differed from T0 and T2. The relative abundances of Prevotella, Porphyromonas and Peptostreptococcus were decreased with treatment, whereas those of Capnocytophaga and Neisseria exhibited the opposite results. In total, 385 of 410 operational taxonomic units were shared at T0, T1 and T2. The co-occurrence networks with hub nodes at T1 were the most complex. Conclusion Orthodontic treatment temporarily affected the saliva microbial community. This dynamic alteration in species did not induce deterioration in oral health. Oral hygiene instructions were necessary and should be emphasized during each visit. Further studies with longer observation periods and more participants are required.
Zhao et al. (2020) Salivary microbial changes during the first 6 months of orthodontic treatment. PeerJ 8:e10446 https://doi.org/10.7717/peerj.10446
Assessing anxiety, depression and quality of life in patients with peripheral facial palsy: a systematic review
Objective Peripheral facial palsy (PFP) is predominantly a unilateral disorder of the facial nerve, which can lead to psychological disorders that can result in decreased quality of life. The aim of this systematic review was to assess anxiety, depression and quality of life symptoms associated with PFP. Data sources We searched the Medline, PEDro, CINAHL and Google Scholar databases to conduct this systematic review while following Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards. The search was performed by two independent reviewers, and differences between the two reviewers were resolved by consensus. Study Selection The search terms used were derived from the combination of the following MeSH terms: “facial paralysis”, “bell palsy”, “anxiety”, “anxiety disorders”, “depression”, “depressive disorders”, “quality of life” and not MeSH: “facial palsy”, “hemifacial paralysis”, “facial paresis”, “Peripheral Facial Paralysis”, using the combination of different Boolean operators (AND/OR). Data Extraction On November 1st (2019). Data Synthesis In total, 18 cross-sectional articles and two case-control studies were selected. Conclusions The cross-sectional articles showed low methodological quality, while the case-control studies showed acceptable methodological quality. Limited evidence suggests that patients with PFP might have increased levels of anxiety and depressive symptoms. A qualitative analysis also showed limited evidence that quality of life might be diminished in patients with PFP. PROSPERO CRD42020159843.
Cuenca-Martínez et al. (2020) Assessing anxiety, depression and quality of life in patients with peripheral facial palsy: a systematic review. PeerJ 8:e10449 https://doi.org/10.7717/peerj.10449
Clinical significance of pretreatment prognostic nutritional index and lymphocyte-to-monocyte ratio in patients with advanced p16-negative oropharyngeal cancer—a retrospective study
Background Systemic inflammation and nutritional status both play roles in the survival of cancer patients. Therefore, it is important to understand the effects of prognostic nutritional index (PNI) and lymphocyte-to-monocyte ratio (LMR) on the survival of patients with advanced p16-negative oropharyngeal cancer. Methods A total of 142 patients diagnosed with advanced p16-negative oropharyngeal cancer between 2008 and 2015 were enrolled in this study. All patients received primary treatment with definite concurrent chemoradiotherapy (CCRT). Optimal cutoff values for PNI and LMR were determined using receiver operating characteristic curves for survival prediction. Survival rates for different level of PNI and LMR were estimated and compared using Kaplan–Meier method and log-rank test to see if there were significant effects on these end points, including 5-year overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS) rates. The effects of PNI and LMR on survival were assessed using Cox regression model adjusted for other prognostic factors. Results The results showed the optimal cutoff values for PNI and LMR were 50.5 and 4.45, respectively. A high PNI (≧50.5) was significantly improved the 5-year OS. A low LMR (<4.45) was significantly associated with a poor 5-year DFS, DSS, and OS. In multivariate analysis, both PNI and LMR were independent prognosticators for 5-year OS. Conclusions Elevated pretreatment PNI and LMR are both favorable prognosticators in advanced p16-negative oropharyngeal cancer patients undergoing CCRT.
Tsai et al. (2020) Clinical significance of pretreatment prognostic nutritional index and lymphocyte-to-monocyte ratio in patients with advanced p16-negative oropharyngeal cancer—a retrospective study. PeerJ 8:e10465 https://doi.org/10.7717/peerj.10465
Using high-resolution melting to identify Calliphoridae (blowflies) species from Brazil
Forensic entomology is the study of insects and other arthropods used in the solution of crimes. Most of entomological evidences strongly depend on accurate species identification. Therefore, new methods are being developed due to difficulties in morphological identification, including molecular methods such as High-Resolution Melting. In this study, we reported a new HRM primer set to identify forensically important Calliphoridae (blowflies) from Brazil. For such purpose, Calliphoridae species of forensic importance in Brazil were listed and confirmed by specialists. Mitochondrial COI sequences of those species were downloaded from databases and aligned, and polymorphic variations were selected for distinction between species. Based on it, HRM primers were designed. Forty-three fly samples representing six species were tested in the HRM assay. All samples had the COI gene sequenced to validate the result. Identifying and differentiating the six species proposed using a combination of two amplicons was possible. The protocol was effective even for old insect specimens, collected and preserved dried for more than ten years, unlike the DNA sequencing technique that failed for those samples. The HRM technique proved to be an alternative tool to DNA sequencing, with advantage of amplifying degraded samples and being fast and cheaper than the sequencing technique.
Oliveira et al. (2020) Using high-resolution melting to identify Calliphoridae (blowflies) species from Brazil. PeerJ 8:e9680 https://doi.org/10.7717/peerj.9680
Addition of L-cysteine to the N- or C-terminus of the all-D-enantiomer [D(KLAKLAK)2] increases antimicrobial activities against multidrug-resistant Pseudomonas aeruginosa, Acinetobacter baumannii and Escherichia coli
Background Antimicrobial peptides have a broad spectrum of antimicrobial activities and are attracting attention as promising next-generation antibiotics against multidrug-resistant (MDR) bacteria. The all-d-enantiomer [D(KLAKLAK)2] has been reported to have antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa, and to be resistant to protein degradation in bacteria because it is composed of D-enantiomer compounds. In this study, we demonstrated that modification of [D(KLAKLAK)2] by the addition of an L-cysteine residue to its N- or C- terminus markedly enhanced its antimicrobial activities against Gram-negative bacteria such as MDR Acinetobacter baumannii, E. coli, and P. aeruginosa. Methods The peptides [D(KLAKLAK)2] (DP), DP to which L-cysteine was added at the N-terminus C-DP, and DP to which L-cysteine was added at the C-terminus DP-C, were synthesized at >95% purity. The minimum inhibitory concentrations of peptides and antibiotics were determined by the broth microdilution method. The synergistic effects of the peptides and the antibiotics against MDR P. aeruginosa were evaluated using the checkerboard dilution method. In order to assess how these peptides affect the survival of human cells, cell viability was determined using a Cell Counting Kit-8. Results C-DP and DP-C enhanced the antimicrobial activities of the peptide against MDR Gram-negative bacteria, including A. baumannii, E. coli, and P. aeruginosa. The antimicrobial activity of DP-C was greater than that of C-DP, with these peptides also having antimicrobial activity against drug-susceptible P. aeruginosa and drug-resistant P. aeruginosa overexpressing the efflux pump components. C-DP and DP-C also showed antimicrobial activity against colistin-resistant E. coli harboring mcr-1, which encodes a lipid A modifying enzyme. DP-C showed synergistic antimicrobial activity against MDR P. aeruginosa when combined with colistin. The LD50 of DP-C against a human cell line HepG2 was six times higher than the MIC of DP-C against MDR P. aeruginosa. The LD50 of DP-C was not altered by incubation with low-dose colistin. Conclusion Attachment of an L-cysteine residue to the N- or C-terminus of [D(KLAKLAK)2] enhanced its antimicrobial activity against A. baumannii, E. coli, and P. aeruginosa. The combination of C-DP or DP-C and colistin had synergistic effects against MDR P. aeruginosa. In addition, DP-C and C-DP showed much stronger antimicrobial activity against MDR A. baumannii and E. coli than against P. aeruginosa.
Ohno et al. (2020) Addition of L-cysteine to the N- or C-terminus of the all-D-enantiomer [D(KLAKLAK)2] increases antimicrobial activities against multidrug-resistant Pseudomonas aeruginosa, Acinetobacter baumannii and Escherichia coli. PeerJ 8:e10176 https://doi.org/10.7717/peerj.10176
A Bayesian brain model of adaptive behavior: an application to the Wisconsin Card Sorting Task
Adaptive behavior emerges through a dynamic interaction between cognitive agents and changing environmental demands. The investigation of information processing underlying adaptive behavior relies on controlled experimental settings in which individuals are asked to accomplish demanding tasks whereby a hidden regularity or an abstract rule has to be learned dynamically. Although performance in such tasks is considered as a proxy for measuring high-level cognitive processes, the standard approach consists in summarizing observed response patterns by simple heuristic scoring measures. With this work, we propose and validate a new computational Bayesian model accounting for individual performance in the Wisconsin Card Sorting Test (WCST), a renowned clinical tool to measure set-shifting and deficient inhibitory processes on the basis of environmental feedback. We formalize the interaction between the task’s structure, the received feedback, and the agent’s behavior by building a model of the information processing mechanisms used to infer the hidden rules of the task environment. Furthermore, we embed the new model within the mathematical framework of the Bayesian Brain Theory (BBT), according to which beliefs about hidden environmental states are dynamically updated following the logic of Bayesian inference. Our computational model maps distinct cognitive processes into separable, neurobiologically plausible, information-theoretic constructs underlying observed response patterns. We assess model identification and expressiveness in accounting for meaningful human performance through extensive simulation studies. We then validate the model on real behavioral data in order to highlight the utility of the proposed model in recovering cognitive dynamics at an individual level. We highlight the potentials of our model in decomposing adaptive behavior in the WCST into several information-theoretic metrics revealing the trial-by-trial unfolding of information processing by focusing on two exemplary individuals whose behavior is examined in depth. Finally, we focus on the theoretical implications of our computational model by discussing the mapping between BBT constructs and functional neuroanatomical correlates of task performance. We further discuss the empirical benefit of recovering the assumed dynamics of information processing for both clinical and research practices, such as neurological assessment and model-based neuroscience.
D’Alessandro et al. (2020) A Bayesian brain model of adaptive behavior: an application to the Wisconsin Card Sorting Task. PeerJ 8:e10316 https://doi.org/10.7717/peerj.10316