title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=1330 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: The effect of platelet lysate in culture of PDLSCs: an in vitro comparative study link: https://peerj.com/articles/7465 last-modified: 2019-08-08 description: BackgroundCellular therapy clinical applications require large-scale production of stem cells. Therefore, abundance, ease of isolation, and proliferative potential are the most important factors in choosing the appropriate source of cells for transplantation studies. Multipotent stem cells obtained from periodontal ligament (PDL) can be used in periodontal tissue regeneration. In this study, we aimed to evaluate and compare the characteristics of periodontal ligament stem cells (PDLSCs), extracted by either enzymatic digestion or explant methods, and expanded using two different serum types: fetal bovine serum (FBS) and xeno-free platelet lysate (PL).MethodsExpanded PDLSCs were assessed for their proliferation capacity, surface markers expression, colony formation, differentiation potential and ability to self-renewal. Most importantly, PDLSCs were evaluated for their ability to produce osteoblasts in vitro.ResultsPDLSCs isolated by explant method and expanded in PL serve as a promising source of stem cells for osteoblasts regeneration. These cells showed higher proliferation capacity, they retained their stemness characteristics throughout the passages and they revealed an increase in the expression level of osteogenic markers, without showing any karyotypic abnormalities after cell expansion.ConclusionsPDLSCs produced using explant extraction method and expanded in cell culture media supplemented with PL provide an excellent source of xeno-free cells for the generation of functional osteoblasts. creator: Duaa A. Abuarqoub creator: Nazneen Aslam creator: Raghda B. Barham creator: Nidaa A. Ababneh creator: Diana A. Shahin creator: Abdallah A. Al-oweidi creator: Hanan D. Jafar creator: Mazin A. Al-Salihi creator: Abdalla S. Awidi uri: https://doi.org/10.7717/peerj.7465 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Abuarqoub et al. title: Cortisol, progesterone, 17α-hydroxyprogesterone, and TSH responses in dogs injected with low-dose lipopolysaccharide link: https://peerj.com/articles/7468 last-modified: 2019-08-08 description: BackgroundStress and diseases such as endotoxemia induce cortisol synthesis through a complex biosynthetic pathway involving intermediates (progesterone, and 17α-hydroxyprogesterone (17α-OHP)) and suppression of the hypothalamus-pituitary-thyroid axis.ObjectiveTo measure plasma concentrations of cortisol, progesterone, 17α-OHP, and thyroid stimulating hormone (TSH) in dogs experimentally injected with intravenous low-dose lipopolysaccharide (LPS). Our hypothesis was that LPS treatment would elicit a significant increase in cortisol and its precursors, and a significant decrease in TSH concentration.MethodsHormone measurements were performed on blood samples left over from a previous investigation (2011) on the effect of low-dose LPS on hematological measurands. Five sexually intact female dogs, none in estrous at the time of the study, were administered saline treatment two weeks prior to LPS treatment. LPS was administered intravenously at a dose of 0.1 µg/kg. Blood was collected before (baseline, time -24 hours) and 3-, 6- and 24-hours post-injection. Mixed model analysis for repeated measures was used, with both treatment and time as the repeated factors. Ranked transformation were applied when diagnostic analysis exhibited violation of normality and equal variance assumptions. Post hoc multiple comparisons were performed with Tukey’s adjustment. Statistical significance was defined as p < 0.05.ResultsSignificant differences relative to baseline values were detected following both treatments. Compared to baseline, dogs had significantly higher cortisol and 17α-OHP at 3-hours, and significantly lower TSH at 3- and 6-hours following LPS treatment. Dogs had significantly lower TSH at 6- and 24- following saline treatment. Though not statistically significant, the trend in progesterone concentrations was similar to cortisol and 17α-OHP, with an increase at 3-hours post-injection followed by a decrease close to baseline following both LPS and saline. Cortisol and 17α-OHP concentrations were higher after LPS treatment than after saline treatment at 3- and 6-hours post-injection, but differences were not statistically significant, and no significant differences between treatments were detected for any other hormone or timepoint.Discussion and conclusionCortisol and its adrenal precursors are released in the bloodstream following a low dose of LPS, while TSH appears to decrease. Similar changes occurred following saline treatment, suggesting that even routine handling and saline injection in conditioned dogs can elicit alterations in the internal equilibrium with subsequent modification of both hypothalamus-pituitary-adrenal and thyroid axes. Changes to adrenal and thyroid hormone concentrations must be interpreted in light of clinical information. Further studies are needed to elucidate mechanisms of adrenal steroidal hormone synthesis and secretion in response to various stressful stimuli in both neutered and intact animals. creator: Nicole L.B. Corder-Ramos creator: Bente Flatland creator: Michael M. Fry creator: Xiaocun Sun creator: Kellie Fecteau creator: Luca Giori uri: https://doi.org/10.7717/peerj.7468 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Corder-Ramos et al. title: Genome-wide identification, characterization and expression analysis of the HD-Zip gene family in the stem development of the woody plant Prunus mume link: https://peerj.com/articles/7499 last-modified: 2019-08-08 description: The homeodomain-leucine zipper (HD-Zip) gene family, a group of plant-specific transcriptional factors (TFs), participates in regulating growth, development, and environmental responses. However, the characteristics and biological functions of HD-Zip genes in Prunus mume, which blooms in late winter or early spring, have not been reported. In this study, 32 HD-Zip genes, named PmHB1–PmHB32 based on their chromosomal positions, were identified in the genome of P. mume. These genes are distributed among seven chromosomes and are phylogenetically clustered into four major groups. Gene structure and motif composition were mostly conserved in each group. The Ka/Ks ratios showed that purifying selection has played a leading role in the long-term evolution of the genes, which maintained the function of this family. MicroRNA target site prediction indicated that the genes of the HD-Zip III subfamily may be regulated by miR165/166. Expression pattern analysis showed that the 32 genes were differentially expressed across five different tissues (leaf, flower bud, stem, fruit, and root) and at different stages of stem and leaf-bud development, suggesting that 10 of the genes may play important roles in stem development. Protein–protein interaction predictions showed that the subfamily III genes may regulate vascular development and shoot apical meristem (SAM) maintenance. Promoter analysis showed that the HD-Zip III genes might be involved in responses to light, hormones, and abiotic stressors and stem development. Taken together, our results provide an overview of the HD-Zip family in P. mume and lay the foundation for the molecular breeding of woody ornamental plants. creator: Lulu Li creator: Tangchun Zheng creator: Xiaokang Zhuo creator: Suzhen Li creator: Like Qiu creator: Jia Wang creator: Tangren Cheng creator: Qixiang Zhang uri: https://doi.org/10.7717/peerj.7499 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Li et al. title: Gaining insights in the nutritional metabolism of amphibians: analyzing body nutrient profiles of the African clawed frog, Xenopus laevis link: https://peerj.com/articles/7365 last-modified: 2019-08-07 description: Whole bodies of Xenopus laevis (n = 19) were analysed for chemical composition and morphometrics. The nutrient profile (macronutrients, amino acids, fatty acids and minerals) was evaluated by sex; interactions among variables with body weights and lengths, and comparisons made with different species of marine and fresh water fish. Significant differences were found in morphometric measurements, water content, several minerals and fatty acids between sexes of X. laevis. Amino acid profiles differed in methionine, proline and cysteine, which could underlie different metabolic pathways in frogs when compared to fish. In addition, fatty acid profiles revealed more monounsaturated and n − 6 polyunsaturated fatty acids in frogs than in fish, more similar to values reported for terrestrial than aquatic vertebrates. Important interactions were also found between body measurements and fat, calcium, and phosphorus, as well as between essential and non-essential amino acids. The results indicate that frogs might have particular biochemical pathways for several nutrients, dependent on sex and linked to body weight, which ultimately could reflect specific nutrient needs. creator: Andrea Brenes-Soto creator: Ellen S. Dierenfeld creator: Guido Bosch creator: Wouter H. Hendriks creator: Geert P.J. Janssens uri: https://doi.org/10.7717/peerj.7365 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Brenes-Soto et al. title: Validity of the iLOAD® app for resistance training monitoring link: https://peerj.com/articles/7372 last-modified: 2019-08-07 description: BackgroundThis study aimed (I) to assess the inter-rater agreement for measuring the mean velocity (MV) of the barbell with the iLOAD® app, and (II) to compare the magnitude of the MV and total work of a training session between the iLOAD® app and a linear encoder (reference method).MethodSixteen young healthy individuals (four women and 12 men) were tested in two sessions separated by 48 h. The 10 repetition maximum (RM) load was determined in the first testing session in the half squat exercise. The second testing session consisted of 3 sets of 10 repetitions during the half squat exercise performed against the 10RM load. Both the iLOAD® app and a linear encoder were used to calculate the MV and total work of each training set. MV was recorded with the iLOAD® app by two independent researchers to evaluate the inter-rater agreement.ResultsTrivial differences and nearly perfect correlations were observed between raters for the MV values collected under individual sets (effect size [ES] ≤ 0.02, r ≥ 0.987), as well as for the whole training session (ES = 0.01, r = 0.997). Trivial-small differences and nearly perfect correlations were observed between the iLOAD® app and the linear encoder (Chronojump, Barcelona, Spain) for MV (EV ≤ 0.25, r ≥ 0.903) and total work (ES ≤ 0.05, r ≥ 0.973). Bland-Altman plots did not reveal heteroscedasticity of the errors between the iLOAD® app and the linear encoder for MV (r2 = 0.010) and total work (r2 < 0.001).ConclusionsiLOAD® is a valid smartphone app which can provide real-time feedback of the MV and total work completed in a set of multiple repetitions in the half squat exercise. creator: Evandro Claudino de Sá creator: André Ricarte Medeiros creator: André Santana Ferreira creator: Amador García Ramos creator: Danica Janicijevic creator: Daniel Boullosa uri: https://doi.org/10.7717/peerj.7372 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 de Sá et al. title: The clinical value of carcinoembryonic antigen for tumor metastasis assessment in lung cancer link: https://peerj.com/articles/7433 last-modified: 2019-08-07 description: BackgroundCarcinoembryonic antigen (CEA) as a diagnostic or prognostic marker has been widely studied in patients with lung cancer. However, the relationship between serum CEA and tumor metastasis in lung cancer remains controversial. This study aimed to investigate the ability of serum CEA to assess tumor metastasis in lung cancer patients.MethodsWe performed a retrospective analysis of 238 patients diagnosed with lung cancer from January to December 2016 at pneumology department of Dazhou Central Hospital (Dazhou, China). Serum CEA levels were quantified in each patient at the time of diagnosis of lung cancer. Metastasis was confirmed by computed tomography (CT), and/or positron emission tomography (PET) and/or surgery or other necessary detecting methods.ResultsOf the 213 patients eligible for final analysis, 128 were diagnosed with metastasis and 85 were diagnosed without metastasis. Compared to non-metastatic patients, the serum CEA was markedly higher in patients with metastasis (p < 0.001), and the area under the curve (AUC) was 0.724 (95% CI [0.654–0.793]). Subsequent analyses regarding the number and location of tumor metastases showed that CEA also had clinical value for multiple metastases versus single metastasis (AUC = 0.780, 95% CI [0.699–0.862]) and distant metastasis versus non-distant metastasis (AUC = 0.815, 95% CI [0.733–0.897]). In addition, we found that tumor size, histology diagnosis, age and gender had no impact on the assessment performance of CEA.ConclusionOur study suggested the serum CEA as a valuable marker for tumor metastases assessment in newly diagnosed lung cancer patients, which could have some implications in clinical application. creator: Jiasi Wang creator: Yanpeng Chu creator: Jie Li creator: Tingjie Wang creator: Liangli Sun creator: Pingfei Wang creator: Xiangdong Fang creator: Fanwei Zeng creator: Junfeng Wang creator: Fanxin Zeng uri: https://doi.org/10.7717/peerj.7433 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Wang et al. title: Patient-reported outcomes measured with and without dizziness associated with non-specific chronic neck pain: implications for primary care link: https://peerj.com/articles/7449 last-modified: 2019-08-07 description: BackgroundThe aim of this study was to compare health-related quality of life (HRQoL) and disability and fear of movement in patients with non-specific chronic neck pain (NSCNP) associated with dizziness with respect to patients with isolated NSCNP in primary care settings.MethodsA cross-sectional study was carried out in a primary care center. A total of 120 patients were divided into two groups and analyzed in this study. One group of patients reported dizziness combined with NSCNP (n = 60), and the other reported no dizziness with their NSCNP (n = 60). Patient-reported outcome measurements were HRQoL (primary outcome) and disability and kinesiophobia (secondary outcomes) assessed by the EuroQoL Five Dimensions and Five Levels (EQ-5D-5L), neck disability index (NDI) and Tampa Scale of Kinesiophobia (TSK-11), respectively.ResultsStatistically significant differences (P < 0.05) for a 95% confidence interval (CI) with a large effect size (Cohen d) were found between both groups with greater values of disability (mean difference = 6.30 points; 95% CI [3.84–8.75]; d = 0.94) and kinesiophobia (mean difference = 8.36 points; 95% CI [6.07–10.65]; d = 1.33), and an impairment of HRQoL (mean difference = 16.16 points; 95% CI [11.09–21.23]; d = 1.16), for patients with NSCNP associated with dizziness with respect to patients with isolated NSCNP.ConclusionsPatients with NSCNP in conjunction with dizziness present higher HRQoL impairment and higher disability and kinesiophobia compared to patients with isolated NSCNP. creator: Raúl Ferrer-Peña creator: Gonzalo Vicente-de-Frutos creator: Diego Flandez-Santos creator: Carlos Martín-Gómez creator: Carolina Roncero-Jorge creator: César Calvo-Lobo uri: https://doi.org/10.7717/peerj.7449 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Ferrer-Peña et al. title: Acute net stress of young adult zebrafish (Danio rerio) is not sufficient to increase anxiety-like behavior and whole-body cortisol link: https://peerj.com/articles/7469 last-modified: 2019-08-07 description: In recent years, the zebrafish (Danio rerio) has become a popular model to study the mechanisms of physiological and behavioral effects of stress, due to the similarity in neural structures and biochemical pathways between zebrafish and mammals. Previous research in this vertebrate animal model has demonstrated an increase in whole-body cortisol resulting from an acute (30-second) net handling stress, but it remains unclear whether such a stressor will concomitantly increase anxiety-like behavior. In addition, as the previous study examined the effects of this acute stressor in adult zebrafish after a brief period of isolation, it is unclear whether this stressor would be effective in eliciting cortisol increases in younger aged subjects without isolation. In the current study, young adult zebrafish (approximately 90 days post-fertilization) were briefly exposed to a net handling stressor and were subsequently subjected to either the novel tank test or the light/dark preference test. The novel tank test was used to measure exploration and habituation in response to a novel environment, and the light/dark preference test was used to measure locomotor activity and scototaxis behavior. All subjects were sacrificed 15 minutes post-stressor and were analyzed for whole-body levels of cortisol. Contrary to expectations, there was no effect of acute net handling on cortisol levels. Similarly, acute net handling did not significantly induce anxiety-like behavior during the novel tank test or the light/dark preference test. Our findings demonstrate that there are possible developmental differences in response to an acute net handling stress, as we did not observe alterations in hormonal or behavioral measures of anxiety in young adult zebrafish. Alternatively, if zebrafish are not isolated before the stressor, they may be more resilient to a brief acute stressor. These results suggest the need for a different or more intense acute stressor in order further explore neuroendocrine mechanisms and anxiety-like behavior at this developmental stage in the zebrafish animal model. creator: Amy Aponte creator: Maureen L. Petrunich-Rutherford uri: https://doi.org/10.7717/peerj.7469 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Aponte and Petrunich-Rutherford title: Muscle quality index and isometric strength in older adults with hip osteoarthritis link: https://peerj.com/articles/7471 last-modified: 2019-08-07 description: BackgroundOlder adults with hip osteoarthritis (OA) suffer a progressive loss of muscle quality and strength, affecting their daily activities and quality of life. The purpose of this study is to compare the levels of isometric strength among older adults with and without hip OA and healthy young adults, and to determine the relationship between muscle quality index (MQI) and isometric strength.MethodsFourteen subjects with hip OA (65.6 ± 3.0 years), 18 healthy older adults (66.6 ± 6.5 years) and 32 young adults (20.7 ± 2.0 years) participated in the study. MQI, isometric muscle strength of the hip, ten time sit-to-stand tests, and body composition were measured.ResultsThe MQI was lower in subjects with hip OA, with no significant differences between groups (p > 0.054). Subjects with OA produced significantly less isometric strength in hip extension (p < 0.001), flexion (p < 0.001), abduction (p < 0.05), adduction (p < 0.001), external (p < 0.05) and internal rotation (p < 0.05). Subjects with OA demonstrated longer time in the execution of the sit-to-stand test (p < 0.001) in comparison with healthy older and young adults. High correlations between MQI, sit-to-stand (r =  − 0.76, p < 0.01) and peak force during hip abduction (r = 0.78, p < 0.01) where found in subjects with OA. Moderate correlation between MQI and peak force during hip flexion (r = 0.55, p < 0.05) and external rotation (r = 0.61, p < 0.05) were found in the OA group.ConclusionsSubjects with OA have lower MQI than old and young healthy controls. In subjects with OA, there was a significant relationship between isometric strength of hip muscles and performance on the sit-to-stand test and the MQI. creator: Daniel Jerez-Mayorga creator: Luis Javier Chirosa Ríos creator: Alvaro Reyes creator: Pedro Delgado-Floody creator: Ramon Machado Payer creator: Isabel María Guisado Requena uri: https://doi.org/10.7717/peerj.7471 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Jerez-Mayorga et al. title: Development of genomic simple sequence repeat markers for Glycyrrhiza lepidota and cross-amplification of other Glycyrrhiza species link: https://peerj.com/articles/7479 last-modified: 2019-08-07 description: BackgroundLicorice (Glycyrrhiza spp. L.) is used as a natural sweetener and medicinal herb in European and Asian countries. Molecular studies have been conducted to find differences between wild and cultivated species because most wild species are highly resistant to abiotic and biotic stresses compared with their cultivated species. However, few molecular markers have been developed for studying the genetic diversity and population structure of licorice species and to identify differences between cultivars. Thus, the present study aimed to develop a set of genomic simple sequence repeat (SSR) markers for molecular studies of these species.MethodsIn the present study, we developed polymorphic SSR markers based on whole-genomesequence data of Glycyrrhiza lepidota. Then, based on the sequence information, the polymorphic SSR markers were developed. The SSR markers were applied to 23 Glycyrrhiza individual plants. We also evaluated the phylogenetic relationships and interspecies transferability among samples.ResultsThe genetic diversity analysis using these markers identified 2–23 alleles, and the major allele frequency, observed heterozygosity, genetic diversity, and polymorphism information content were 0.11–0.91, 0–0.90, 0.17–0.94, and 0.15–0.93, respectively. Interspecies transferability values were 93.5%, 91.6%, and 91.1% for G. echinata, G. glabra, and G. uralensis, respectively. Phylogenetic analysis clustered cultivated (group 1) and wild (group 2) species into three and two subgroups, respectively. The reported markers represent a valuable resource for the genetic characteri z ation of Glycyrrhiza spp. for theanalysis of its genetic variability, and as a tool for licorice transferability. This is the first intraspecific study in a collection of Glycyrrhiza spp. germplasm using SSR markers. creator: Jun Hyoung Bang creator: Chi Eun Hong creator: Sebastin Raveendar creator: Kyong Hwan Bang creator: Kyung Ho Ma creator: Soon Wook Kwon creator: Hojin Ryu creator: Ick Hyun Jo creator: Jong-Wook Chung uri: https://doi.org/10.7717/peerj.7479 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2019 Bang et al.