Frontiers in bioscience (Elite edition)最新文献

Background: The main aim of the research was to study short-term changes in the concentrations of elements in two widely distributed plant species, couch grass and nettle and in the rhizosphere soil of the plants.

Methods: The sampling of plants and soil was carried out on three dates: 3, 10, and 25 May 2021. On each day of sampling, the plants and soil were collected three times: at 9:00, 14:00, and 19:00. The ICP-OES and ICP-MS analytical techniques were used for determination of elements in the plant and soil samples. The Raman spectroscopy was applied to study variations in the organic compounds.

Results: The concentrations of both macro-nutrients and trace elements in plants varied greatly over daytime on all dates of sampling. The differences between concentrations of many elements in the plants collected at different times during a day were statistically significant. There were also statistically significant differences between concentrations of some elements (Na, Mg, P, K, Fe, Ba) in the plants collected on different dates. The relative intensity of diffuse luminescence of the rhizosphere soil of couch grass and nettle was different during daytime and also differed between the soils taken from roots of the two plant species, especially in the beginning of May.

Conclusions: The experimental data indicates that the daily variations of the element concentrations in plants might be a result of multiple effects of various factors. The differences in the daily element variations in the couch grass and nettle growing in the same site and collected simultaneously might be due to the fact that these plants belong to different clades. The diurnal fluctuations (that also include regular changes in the element concentrations in plants) can be different for monocotyledons (couch grass) and dicotyledons (nettle). New experimental findings on short-term variations in the concentrations of macro-nutrients and trace elements can help to gain a new insight into accumulation of the elements in different plant species and also be useful in agricultural practice.

Orthodontic treatment has become increasingly popular due to its benefits in improving facial and smile aesthetics, self-esteem and the function of the stomatognathic apparatus. However, orthodontic appliances make it more difficult to brush teeth effectively, as they interfere with tooth brushing and facilitate the accumulation of dental plaque (biofilm), which induces a quantitative and qualitative change in the oral microbiota. It can cause several adverse effects, such as gingivitis, periodontitis, white spot lesions (WSL), caries and halitosis, induced by an increase in periodontopathogenic and cariogenic bacteria. Therefore, this article resumes the main findings on the changes in the oral microbiota induced by different orthodontic appliances (removable, fixed and clear aligners) and gives some practical strategies in order to reduce the impact and/or incidence of local dental/periodontal complications.

Beta thalassaemia major (TM), a potentially fatal haemoglobinopathy, has transformed from a fatal to a chronic disease in the last 30 years following the introduction of effective, personalised iron chelation protocols, in particular the use of oral deferiprone, which is most effective in the removal of excess iron from the heart. This transition in TM has been achieved by the accessibility to combination therapy with the other chelating drugs deferoxamine and deferasirox but also therapeutic advances in the treatment of related co-morbidities. The transition and design of effective personalised chelation protocols was facilitated by the development of new non-invasive diagnostic techniques for monitoring iron removal such as MRI T2*. Despite this progress, the transition in TM is mainly observed in developed countries, but not globally. Similarly, potential cures of TM with haemopoietic stem cell transplantation and gene therapy are available to selected TM patients but potentially carry high risk of toxicity. A global strategy is required for the transition efforts to become available for all TM patients worldwide. The same strategy could also benefit many other categories of transfusional iron loaded patients including other thalassaemias, sickle cell anaemia, myelodysplasia and leukaemia patients.

Background: Eukaryotic initiation factor (eIF) 4G plays an important role in assembling the initiation complex required for ribosome binding to mRNA and promote translation. Translation of ferritin IRE mRNAs is regulated by iron through iron responsive elements (IREs) and iron regulatory protein (IRP). The noncoding IRE stem-loop (30-nt) structure control synthesis of proteins in iron trafficking, cell cycling, and nervous system function. High cellular iron concentrations promote IRE RNA binding to ribosome and initiation factors, and allow synthesis of ferritin.

Methods: In vitro translation assay was performed in depleted wheat germ lysate with supplementation of initiation factors. Fluorescence spectroscopy was used to characterize eIF4F/IRE binding.

Results: Eukaryotic initiation factor eIF4G increases the translation of ferritin through binding to stem loop structure of iron responsive elements mRNA in the 5'-untranslated region. Our translation experiment demonstrated that exogenous addition of eIF4G selectively enhanced the translation of ferritin IRE RNA in depleted WG lysate. However, eIF4G facilitates capped IRE RNA translation significantly higher than uncapped IRE RNA translation. Addition of iron with eIF4G to depleted WG lysate significantly enhanced translation for both IRE mRNA (capped and uncapped), confirming the contribution of eIF4G and iron as a potent enhancer of ferritin IRE mRNA translation. Fluorescence data revealed that ferritin IRE strongly interacts to eIF4G (Kd = 63 nM), but not eIF4E. Further equilibrium studies showed that iron enhanced (~4-fold) the ferritin IRE binding to eIF4G. The equilibrium binding effects of iron on ferritin IRE RNA/eIFs interaction and the temperature dependence of this reaction were measured and compared. The Kd values for the IRE binding to eIF4G ranging from 18.2 nM to 63.0 nM as temperature elevated from 5 °C to 25 °C, while the presence of iron showed much stronger affinity over the same range of temperatures. Thermodynamic parameter revealed that IRE RNA binds to eIF4G with ΔH = -42.6 ± 3.3 kJ. mole-1, ΔS = -11.5 ± 0.4 J. mole-1K-1, and ΔG = -39.2 ± 2.7 kJ. mole-1, respectively. Furthermore, addition of iron significantly changed the values of thermodynamic parameters, favoring stable complex formation, thus favoring efficient protein synthesis. This study first time demonstrate the participation of eIF4G in ferritin IRE mRNA translation.

Conclusions: eIF4G specifically interacts with ferritin IRE RNA and promotes eIF4G-dependent translation.

Background: In the wild various organisms contribute to daphnids diet. This study, intendeds to evaluate the potential of the concentration of Rhodopirellula rubra as a single or supplementary food source for Daphnia magna.

Methods: Feeding assays were performed according to standard guidelines for chronic assays (21 days), and life-history parameters and several biomarkers (protein content, oxidative stress, energetic reserves and pigments) were measured. Five food regimens were conducted with 20 individual replicates (A - R. subcapitata; 0.2 - suspension of R. rubra at 0.2 arbitrary units (AU); 0.4 - suspension of R. rubra at 0.4 AU; 0.2+A - suspension of R. rubra at 0.2+alga; 0.2+A-suspension of R. rubra at 0.4 AU + alga). Additionally, the effects of three diets (A, 0.2, and 0.2+A) on the longevity of D. magna were assessed.

Results: The five diets showed a different C, N, and carotenoids composition, with an increase in the mixed diets. The results confirmed that the mixed diets improved D. magna life-history parameters. A decrease in glycogen, and the increase of haemoglobin, protein, and gluthione-S-transferase (GST) were observed. Furthermore, D. magna fed with bacterial single diets, presented worsen life history parameters and a decrease in the protein content. An induction of oxidative stress response (increased catalase and GST), and a significant decrease in lipid peroxidation and an accumulation of glycogen and carotenoids were observed. Overall, an increase in the amount of R. rubra provided to D. magna, from 0.2 AU to 0.4 AU, negatively impacted daphnid performance. No significant effects on Daphnia longevity (a 110-day assay) were observed among the three diets tested. However, a significant survival percentage and fertility (cumulative offspring is more than twice) was observed when D. magna was fed with the mixed diet.

Conclusions: Results demonstrated that different diets provided a nutritional diversified food to the daphnids that induced differences in D. magna performance. The mixed diets proved to be beneficial (with increase in offspring) on D. magna performance, independently of the bacterial concentration tested. When in single diet, bacterial concentration is not nutritionally sufficient to raise D. magna even when in increased concentration.

Background: Halogenated aromatic compounds are more resistant to microbial degradation than non-halogenated aromatic compounds. Microbial degradation of sodium benzoate in the presence of sodium 3-chlorobenzoate is of interest. The ability to degrade aromatic compounds is largely determined by the substrate specificity of the first enzyme that initiates degradation, namely, benzoate 1,2-dioxygenase for benzoate degradation, and 3-chlorobenzoate 1,2-dioxygenase for 3-chlorobenzoate degradation. In this study, the perspective of immobilized cells of Rhodococcus opacus 1CP actinobacterium for degradation of benzoate and 3-chlorobenzoate was explored.

Methods: The biosensor approach (a membrane microbial sensor based on immobilized cells of Rhodococcus opacus 1CP and the Clark-type oxygen electrode as a transducer) was applied to evaluate the actinobacterial cells' responses to benzoate and 3-chlorobenzoate in the absence of both enzymes, benzoate 1,2-dioxygenase and 3-chlorobenzoate 1,2-dioxygenase, or in the presence of one of the said enzymes.

Results: Data obtained show that 1CP actinobacterium possessed a constitutive system for the transport of benzoate and 3-chlorobenzoate into culture cells. The affinity of the transport system for benzoate was higher than that for 3-chlorobenzoate. Moreover, adaptation to one substrate did not preclude the use of the second substrate. Probably, porins facilitated the penetration of benzoate and 3-chlorobenzoate into 1CP cells. Analyzing V vs. S dependencies, negative cooperativity was found, when benzoate 1,2-dioxygenase bound substrate (3-chlorobenzoate), while positive cooperativity was determined at benzoate binding. The observed difference could be associated with the presence of at least two systems of 3-chlorobenzoate transport into actinobacterial cells and allosteric interaction of active sites of benzoate 1,2-dioxygenase in the presence of 3-chlorobenzoate.

Conclusions: The membrane microbial sensor based on immobilized Rhodococcus opacus 1CP cells could be useful as a perspective tool for comparative evaluation of enzymes of complex structure such as benzoate- and 3-chlorobenzoate 1,2-dioxygenase.

Background and aims: Considering the advantages of rotary files in instrumenting the root canals of permanent teeth and a lack of adequate data on the use of these systems in primary teeth, the present study aimed to evaluate two rotary files and compare them with hand files in the cleaning efficacy of the root canals of primary molar teeth.

Materials and methods: In the present study, three groups of teeth were prepared with Kedo-S paediatric rotary file system, RaCe (reamer with alternating cutting edges), and hand files (n = 40). The groups were evaluated under a stereomicroscope concerning the cleaning efficacy of the files after cleaning the teeth in the apical, middle, and coronal thirds. The data were analyzed with SPSS 24 (IBM Corporation, USA, 2016) using Fisher's exact test and chi-squared test; statistical significance was set at p < 0.05.

Results: There were no significant differences in the apical and middle thirds between the different study groups. However, there were significant differences in the coronal third between the hand file and Kedo-S (p = 0.016) and RaCe and Kedo-S (p = 0.001) groups.

Conclusions: The present study showed that Kedo-S files were more effective than RaCe and hand files in the coronal area than the hand and RaCe files.

Aqueous extracts of two red seaweeds Halymenia porphyriformis and Solieria robusta were used to synthesize green silver nanoparticles. These biogenic nanoparticles were tested against four strains of oral pathogenic bacteria which cause tooth decay or cavities. Staphylococcus aureus (MT416445), Streptococcus viridans (MT416448), Lactobacillus acidophilus (MT416447) and Lactobacillus brevis (MT416446) were used. Characterization of AgNPs was done by UV-Visible spectroscopy, SEM, XRD and FTIR. XRD analysis revealed the crystalline nature of the particles. The size analysis by XRD of the green AgNPs by H. porphyriformis indicated it had smaller particles, 15.23 nm, when compared to AgNPs by S. robusta (17 nm). Both green synthesized silver nanoparticles showed moderate antibacterial activity against all strains of bacteria, except L. acidophilus. Both particles showed their maximum zone of inhibition against L. acidophilus at a lower concentration of 50 and 100 μg. However, it was concluded that silver nanoparticles of H. porphyriformis are more effective than that of S. robusta due to their smaller size.

Background: Wound infection represents a frequent trouble following open saphenous vein harvesting in cardiac surgery. Platelets' growth factors are crucial for the healing process. Prophylactic platelet rich plasma (PRP) application on leg wound might reduce the incidence of saphenous vein harvest site infections in patients undergoing coronary artery bypass graft surgery (CABG).

Methods: Between January 2009 and December 2020, 987 consecutive patients underwent CABG using saphenous vein as conduit graft and were retrospectively divided into two groups. All patients had standard surgical leg wound closure and wound care, but treatment group received adjunctive topical application of PRP (no-PRP and PRP group, respectively). The primary outcome was wound infection.

Results: Saphenous vein harvest site infection rate was similar between PRP (3.5%) and No-PRP (5.2%) group, p = 0.215. The ASEPSIS score was lower for the PRP group (PRP: 3.6 ± 9.1 vs. No-PRP: 5.3 ± 11.2; p = 0.014). Performing a subgroup analysis, the diabetic patients (PRP-DM) group had a lower rate of infection than control group (No-PRP DM) (2.6% vs. 7.7%, p = 0.026). PRP-DM patients had an inferior ASEPSIS score (PRP-DM: 2.7 ± 8.3 vs. No PRP-DM: 7.5 ± 13.2, p < 0.001).

Conclusions: Topical application of autologous PRP on saphenoug vein harvest site might reduce the rate of surgical site infection, with particular benefit among diabetic patients.

Background: The high salt concentration is the major factor limiting microbial growth at salterns, along with solar radiation, temperature, and pH. These environmental factors play key roles in the acquisition of unique genetic adaptations for the survival of microorganisms in salterns, which can result in the production of interesting secondary metabolites. The main goal of the present work was to isolate and compare the culturable microbiota from two geographically distant salterns in Portugal and access their biotechnological potential.

Methods: Culturomics approaches using different culture media were applied for microbial isolation. All isolates were identified either by 16S rRNA or ITS genes sequencing, and their biotechonological potential was assessed by PCR.

Results: Overall, 154 microbial isolates were recovered that were phylogenetically assigned to 45 taxa from 9 different phyla. From these, 26 isolates may represent putative new taxa. The predominant genera obtained were Penicillium (41 isolates, 26.6%), Streptomyces (13 isolates, 8.4%) and Sinomicrobium (11 isolates, 7.1%). Moreover, the polyketide synthase I gene was present in 64 isolates, the nonribosomal peptide synthethase gene in 16 isolates, and both genes in 23 isolates.

Conclusions: This study adds up valuable knowledge on the culturable microbiota of Portuguese salterns and on its potential for production of secondary metabolites. In the long run, this study provides a widely diverse microbial collection for future works. Data public repository: All DNA sequences were deposited in the GenBank database at National Centre for Biotechnology Information (NCBI) web platform under accession numbers OK169439-OK169485, OK216020-OK216124, OK287059 and OK326927.