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1.
Anal Methods ; 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34635885

RESUMO

More than 200 million people in the world are exposed to areas where the arsenic concentration exceeds the limit allowed for living species, which urges researchers to develop low-cost methods for the selective and fast detection of arsenic ions in environmental samples. Herein, we report a novel tetraphenylimidazole-based probe (TBAB) functionalized with a Schiff base for sensing and detecting arsenic ions in aqueous media. Upon the addition of arsenic ions, an obvious fluorescence change from faint yellow to green was observed visible to the naked eye. The probe can detect arsenic selectively in the presence of interfering substances, with a lower detection limit than 0.7 ppb, a value which is far lower than the limit set by the WHO. A detailed mechanism revealed that the chelation of TBAB with arsenic activated the AIE characteristic, leading to the enhanced fluorescence, which was verified by Job's plot experiment and HRMS. Its practicality was further validated by the analysis of real water samples, demonstrating its potential application for on-site detection and biological application.

3.
Food Funct ; 2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34617945

RESUMO

In this study, the Nelumbo nucifera leaf polysaccharide (NNLP) was isolated by hot water extraction and ethanol precipitation. DEAE anion exchange chromatography and gel filtration were further performed to obtained the purified fraction NNLP-I-I, the molecular weight of which was 16.4 kDa. The monosaccharide composition analysis and linkage units determination showed that the fraction NNLP-I-I was a pectic polysaccharide. In addition, the NMR spectra analysis revealed that NNLP-I-I mainly consisted of a homogalacturonan backbone and rhamnogalacturonan I, containing a long HG region and short RG-I region, with AG-II and 1-3 linked rhamnose as side chains. The biological studies demonstrated that NNLP-I-I displayed antioxidant properties through mediating the Nrf2-regulated intestinal cellular antioxidant defense, which could protect cultured intestinal cells from oxidative stress and improve the intestinal function of aged mice.

4.
Food Funct ; 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34647565

RESUMO

The thymus and spleen are the main reservoir for T lymphocytes, which can regulate the innate immune response and provide protection against pathogens and tissue damage. Oxidative stress, excessive inflammation, abnormal autophagy and endoplasmic reticulum (ER) stress can all lead to dysfunction of the thymus and spleen. This study was conducted to investigate the effect of maternal 2-hydroxy-4-methylselenobutanoic acid (HMSeBA, an organic Se source) supplementation during pregnancy on the selenoprotein expression, inflammation, ER stress and autophagy of their young offspring's thymus and spleen. Thirty sows were randomly assigned to receive one of the following two diets during gestation: control diet (control, basal diet, n = 15) or HMSeBA supplemented diet (HMSeBA, basal diet +0.3 mg Se kg-1 as HMSeBA, n = 15). Tissues of thymus and spleen were collected from the offspring at birth and weaning after the lipopolysaccharide challenge. Results showed that maternal HMSeBA supplementation significantly up-regulated the gene expression of selenoproteins in the thymus and spleen of newborn piglets compared with the basal diet (p < 0.05), as well as the protein abundance of GPX1 and GPX4 (p < 0.05). In addition, maternal HMSeBA supplementation effectively decreased the expression of inflammation and autophagy related proteins in the thymus and spleen of newborn piglets as compared with the control group (p < 0.05). In weaning piglets, maternal HMSeBA significantly increased the antioxidative capacity of thymus and spleen (p < 0.05), and reversed LPS induced MDA content as compared with the control group (p < 0.05). Furthermore, maternal HMSeBA supplementation during gestation reversed the activation of the MAPK/NF-κB pathway, ER stress and autophagy induced by the LPS challenge in the thymus and spleen of weaning piglets (p < 0.05). In conclusion, maternal HMSeBA supplementation during gestation could decrease the level of inflammation, autophagy and ER stress in the thymus and spleen of young offspring by improving the antioxidative capacity and selenoprotein expression in these tissues. Therefore, maternal HMSeBA supplementation during gestation might be beneficial for the immune function of their offspring by alleviating inflammation, autophagy and ER stress levels in the thymus and spleen. This study showed more evidence for the function of Se on mater-offspring integrated nutrition.

5.
Artigo em Inglês | MEDLINE | ID: mdl-34534084

RESUMO

Raw polarimetric images are captured by a focal plane polarimeter which is covered by a micro-polarizer array (MPA). The design of the MPA plays a crucial role in polarimetric imaging. MPAs are predominantly designed according to expert engineering experience and rules of thumb. Typically, only one optimization criterion, maximizing bandwidth, is used to design the MPA. To select a design, an exhaustive search is usually performed on a very limited set of available polarizing patterns, which must be constrained in order to make the search tractable. In contrast, this paper proposes a fully automated and optimal MPA design method (AO-MPA) which generates significantly improved MPAs. Instead of the single criterion of bandwidth, we propose six design principles, and show how they can be utilized to mutually optimize the MPA design by formulating a tri-objective optimization problem with multiple constraints. A much larger set of possible MPA patterns is rapidly and automatically searched by applying advanced multi-objective optimization techniques. We have tested AO-MPA using two groups of experiments, in which AO-MPA is compared against several other leading MPA design methods, and the patterns generated by AO-MPA are compared against state-of-the-art patterns from the literature. The results, obtained using a public benchmark dataset, show that the AO-MPA method is very computationally efficient, and can find all optimal MPA patterns for all array sizes. Moreover, for each size, AO-MPA obtains all optimal layouts simultaneously. AO-MPA generates designs which require fewer polarization orientations, while also yielding better performance in estimating intensity measurements, Stokes vector and the degree of linear polarization. This results in MPAs which are easier to manufacture while also being more robust to noise.

6.
Animal ; 15(10): 100355, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34537443

RESUMO

Farrowing duration is a crucial factor affecting survival of piglets and health of sows, and is highly correlated with the incidence of stillbirth. The present study assessed the metabolic characteristics of sows with short farrowing duration (SFD) or long farrowing duration (LFD). A total of 20 Yorkshire sows were screened from 60 sows and were retrospectively allocated into SFD (211 min on average, n = 10) or LFD (388 min on average, n = 10) group. Parameters associated with energy metabolism and redox status were characterised. Results showed that sows at farrowing had decreased plasma concentrations of glucose, triglyceride, acetate, butyrate and total short-chain fatty acids (P < 0.05), but increased concentrations of lactic acid and propionate (P < 0.05), when compared with sows on day 107 of gestation. The SFD sows had shorter time from last meal until the onset of farrowing (P < 0.05) and tended to have less stillbirths (P = 0.08) and lower stillbirth rate (P = 0.07). For the blood metabolites, SFD sows at farrowing had higher concentration of plasma glucose (P < 0.05), but lower concentration of lactic acid (P < 0.05) than LFD sows. Besides, SFD sows tended to have higher plasma malondialdehyde concentration (P = 0.06) than LFD sows. Correlation analysis showed that farrowing duration was negatively correlated with plasma glucose concentration at onset of farrowing. In conclusion, our study strongly suggests that glucose is a key metabolite for energy metabolism of the uterus during farrowing. The farrowing process could be closely related to uterine energy expenditure, and sows with shorter farrowing duration could be resulting from the shorter time from last meal until the onset of farrowing, associated with a greater proportion of energy from glucose.

7.
Andrologia ; : e14260, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34585431

RESUMO

The present work aims to evaluate the clinical efficacy and safety of low-intensity extracorporeal shock wave therapy (Li-ESWT) on patients with prostatitis-like symptoms (PLS). Patients with PLS were recruited and received four-week Li-ESWT (once per week), which was conducted at a frequency of 3 Hz with a preferred energy flow density of 0.25 mJ/mm2 . The scores of the National Institute of Health Chronic Prostatitis Symptoms Index (NIH-CPSI), International Prostate Symptom Score (IPSS), International Index of Erectile Function (IIEF-5), and Visual Analogue Scale (VAS) were recorded to assess the remission of disease in the 0, 1st, 2nd, 3rd, 4th, 5th, 8th and 16th weeks. A decrease of the NIH-CPSI score ≥6 was regarded as the effectiveness standard of Li-ESWT. Among 91 enrolled patients, the scores of all validated questionnaires presented significant improvements in the 4th week (p < .05) compared with that in baseline, except for IIEF-5. The treatment effective rates in the 1st, 2nd, 3rd, 4th, 5th, 8th and 16th weeks were 28.57%, 38.46%, 47.25%, 51.65%, 57.30%, 68.18% and 69.44%, respectively. No pronounced undesirable side effect has occurred. Li-ESWT is effective and safe in treating PLS. The efficacy can be maintained within three months.

8.
Poult Sci ; 100(11): 101429, 2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34555757

RESUMO

The objective of this experiment was to investigate the influence of dietary tributyrin on reproduction performance and ovary function of broiler breeders with different egg laying rate. Two hundred fifty-six AA broiler breeders (48-wk-old) were allocated to 4 treatment in a 2 × 2 factorial arrangement with the main effects of tributyrin supplementation (0 and 1,000 mg/kg tributyrin [TRI]) and 2 egg laying rate levels (average [AR, 81.01 ± 0.79%] and low [LR, 70.98 ± 0.95%]). The results shown that the LR breeders presented higher egg weight, but lower egg laying rate, qualified egg rate and feed efficiency than the AR breeders (P(laying) < 0.05). Also, the superoxidase dismutase (SOD) activity in magnum was lower while malondialdehyde (MDA) was higher in ovary and magnum of LR breeders than that in the AR breeders (P(laying) < 0.05). Dietary supplementation with tributyrin significantly enhanced egg weight (P(TRI) < 0.05), increased albumen height as well as Haugh unit (HU) in AR breeders (P(interaction) < 0.05), and also had higher total antioxidant capacity (T-AOC) and lower MDA in ovary (P(TRI) < 0.05). The cell apoptosis rate and proapoptosis related gene expression (caspase 8, 9 and Bax) in the ovary of LR breeders was higher, while anti-apoptosis related gene (Bcl-2) expression were lower in LR breeders when compared with the AR breeders (P(laying) < 0.05). Dietary supplementation with tributyrin decreased the cell apoptosis rate and downregulated caspase 9 expression in LR breeders (P(Interaction) < 0.05), up-regulated the Bcl-2 expression in both 2 breeders (P(TRI) < 0.05). These findings suggest that the breeders with lower egg laying rate also characterized by deteriorate ovary function indicated by lower antioxidant capacity and higher cell apoptosis rate. Dietary supplementation with tributyrin increased egg albumen quality, decreased ovarian proapoptosis related gene expression to improve reproductive tract function; and the positive effect on egg albumen quality is more pronounced in average reproductive breeders.

9.
Int Immunopharmacol ; 100: 108138, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34509934

RESUMO

OBJECTIVE: Long noncoding RNAs (lncRNAs) regulate the occurrence and development of osteoarthritis (OA), whereas the biological roles and mechanisms of the lncRNA THUMPD3-AS1 (THUMPD3 antisense RNA 1) in OA remain still unclear. This study described the role and molecular mechanism of lncRNA THUMPD3-AS1 in regulating OA biology. METHOD: The knee normal and OA cartilage tissues from ten participants were sequenced to reveal the differentially expressed lncRNAs. The interleukin (IL)-1ß-stimulated C28/I2 cell served as OA cells. Flow cytometry assays, Western blot, enzyme-linked immunosorbent assays were used for our experiments. RESULTS: The results revealed that lncRNA THUMPD3-AS1 was downregulated in OA cartilage tissues and IL-1ß-stimulated chondrocyte cell line. Overexpression of lncRNA THUMPD3-AS1 alleviated cell apoptosis and facilitated inflammatory responses, whereas knockdown had opposite effects. LncRNA THUMPD3-AS1 markedly increased the cyclin E2, cyclin-dependent kinase 4, B-cell lymphoma 2, tumor necrosis factor-α, nitric oxide, and IL-6 levels, and decreased the caspase-3 level. Furthermore, the target proteins of phosphorylation were identified as nuclear factor-κB p65 and mitogen-activated protein kinase p38, which could be indirectly suppressed by lncRNA THUMPD3-AS1 knockdown. CONCLUSION: Our findings highlight the different effects of lncRNA THUMPD3-AS1 on cell apoptosis and inflammatory response, which extend the multiple functions of lncRNA epigenetics in OA biology.

10.
Redox Biol ; 46: 102131, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34530349

RESUMO

Ferroptosis plays a role in several diseases such as iron overload-induced liver diseases. Manipulation of ferroptosis has been explored as a potential therapeutic strategy to treat related diseases. Numerous antioxidants have been identified to control ferroptosis but the cell-autonomous mechanisms responsible for regulating ferroptosis remain elusive. In the present study, we found that iron overload promoted ferroptosis in hepatocytes by excessively inducing HO-1 expression, which contributed to the progression of liver injury and fibrosis, accompanied by the upregulation of the FGF21 protein level in vitro and in vivo. Interestingly, both recombinant FGF21 and Fgf21 overexpression significantly protected against iron overload-induced hepatocytes mitochondria damage, liver injury and fibrosis by inhibiting ferroptosis. In contrast, the loss of FGF21 aggravated iron overload-induced ferroptosis. Notably, FGF21-induced HO-1 inhibition (via the promotion of HO-1 ubiquitination and degradation) and NRF2 activation provide a mechanistic explanation for this phenomenon. Taken together, we identified FGF21 as a novel ferroptosis suppressor. Thus, FGF21 activation may provide an effective strategy for the potential treatment of iron overload-induced ferroptosis-related diseases, such as hereditary haemochromatosis (HH).

11.
Asia Pac J Clin Nutr ; 30(3): 374-382, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34587697

RESUMO

BACKGROUND AND OBJECTIVES: Surgical patients with depleted skeletal muscle mass tend to have a worse outcome. Whether perioperative change of urea to creatinine ratio (CUCR) can reflect muscle wasting and predict postoperative complications have not been investigated. This study aimed to evaluate the relationship of perioperative CUCR with postoperative complications and skeletal muscle wasting in pancreatic cancer patients undergoing pancreatoduodenectomy (PD). METHODS AND STUDY DESIGN: Pancreatic cancer patients undergoing PD were included retrospectively. The association between postoperative complications and perioperative CUCR as well as other nutritional biomarkers was analyzed. In a subset of patients with serial CT scans, the correlation of the CUCR and the changes of CT-derived skeletal muscle area (SMA) were tested. Furthermore, the capacity of complication prediction of CUCR and CT-derived parameter were compared in these patients. RESULTS: A total of 321 surgical patients were included. Univariable and multivariable logistic regression demonstrated CUCR was a strong predictor for complications in these patients, independent of age, BMI and comorbidity. Patients with CUCR above the median have higher complication rate (p=0.007) and longer postoperative days to discharge (p=0.017). In a subset patients with both pre- and postoperative digital abdominal CT scans, spearman correlation analysis shown both L3 muscle area and L4-psoas area were significantly correlated with CUCR (R2=0.64, p<0.05; R2=0.62, p<0.05, respectively). CONCLUSIONS: Perioperative CUCR is an independent predictor for postoperative complications in pancreatic cancer patients undergoing PD. Elevated CUCR is a reflection of skeletal muscle wasting in postoperative surgical patients.

12.
Oxid Med Cell Longev ; 2021: 5550196, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34336098

RESUMO

The mechanistic target of rapamycin complex 1 (mTORC1) signaling plays pivotal roles in cell growth and diseases. However, it remains mechanistically unclear about how to maintain mTORC1 activity during mammary glands development. Here we showed that mammary glands suffered from aggravated oxidative stress as pregnancy advanced and was accompanied by an increase in H2O2 levels, while the consumption for methionine and S-adenosylmethionine (SAM) rather than S-adenosylhomocysteine (SAH) were promoted in vivo. Likewise, H2O2 promoted SAM synthesis and reduced SAM utilization for methylation depending on H2O2 levels and treatment time in vitro. H2O2 inhibited phosphorylation of S6 kinase Thr 389 (p-S6K1 (T389)), 4E-BP1 Thr 37/46 and ULK1 Ser 757, the downstream of mTORC1, in mammary epithelial cells. However, methionine and SAM were shown to activate mTORC1 under H2O2-exposed condition. Moreover, this effect was not disabled by SGI-1027 which inhibits SAM transmethylation. In conclusion, methionine appeared to protect mammary cells against oxidative stress through producing SAM to maintain mTORC1 signaling activity.

13.
ACS Chem Neurosci ; 12(19): 3558-3566, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34423641

RESUMO

Recent reports indicate dominant roles of TRAAK and TREK-1 channels, i.e., mechanosensitive two-pore-domain potassium channels (K2P) at the nodes of Ranvier for action potential repolarization in mammalian peripheral nerves. Functional changes in mammalian peripheral nerve conduction by mechanical stretch studied by recording compound action potentials lack the necessary resolution to detect subtle neuromodulatory effects on conduction velocity. In this study, we developed a novel in vitro approach that enables single-fiber recordings from individual mouse sciatic nerve axons while delivering computer-controlled stepped stretch to the sciatic nerve trunk. Axial stretch instantaneously increased the conduction delay in both myelinated A-fibers and unmyelinated C-fibers. Increases in conduction delay linearly correlated with increases in axial stretch ratio for both A- and C-fibers. The slope of the increase in conduction delay versus stretch ratio was steeper in C-fibers than in A-fibers. Moderate axial stretch (14-19% of in vitro length) reversibly blocked 37.5% of unmyelinated C-fibers but none of the eight myelinated A-fibers tested. Application of arachidonic acid, an agonist to TRAAK and TREK-1 to sciatic nerve trunk, blocks axonal transmission in both A- and C-fibers with delayed onset and prolonged block. Also, the application of an antagonist ruthenium red showed a tendency of suppressing the stretch-evoked increase in conduction delay. These results could draw focused research on pharmacological and mechanical activation of K2P channels as a novel neuromodulatory strategy to achieve peripheral nerve block.

14.
Talanta ; 234: 122640, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34364449

RESUMO

Separating Yersinia pseudotuberculosis and Yersinia pestis is an important issue in plague diagnosis but can be extremely difficult because of the high similarity between the two species. MALDI-TOF MS has grown as a diagnostic tool with great potential in bacterial identification. Its application in this field is largely enhanced by multivariate analysis, especially in extracting subtle spectral differences. In this study, we built a complete MALDI-TOF MS data pipeline and found a Y. pestis-specific biomarker at 3063 Da closely related to Y. pestis plasminogen activation factor. Based on this, we achieved almost perfect separation between Y. pseudotuberculosis and Y. pestis (AUC = 0.999) using a supervised linear discriminant analysis (LDA) model. This is significantly better than the conventionally applied unsupervised spectral similarity comparison methods, such as hierarchical clustering analysis (HCA), which gave a separation accuracy of 75.0%. This new computing method paves the way for automatic differentiation between the two highly similar bacterial species with high separation accuracy.


Assuntos
Yersinia pestis , Yersinia pseudotuberculosis , Análise por Conglomerados , Análise Multivariada , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
15.
Talanta ; 233: 122472, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215106

RESUMO

Direct identification of bacteria in blood cultures using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is interfered with by a variety of non-bacterial proteins derived from blood cells and culture media. Thus, appropriate pre-treatments are needed for successful identification. Here, the bacteria in blood culture bottles were enriched using co-magnetic beads and processed for MALDI-TOF MS profiling. In this strategy, the Fc-containing mannose-binding lectin-coated Fe3O4 (Fc-MBL@Fe3O4) is incorporated with human IgG-coated Fe3O4 (IgG@Fe3O4) to form co-magnetic beads, which can recognize both Gram-positive and Gram-negative bacteria. Compared to single magnetic beads Fc-MBL@Fe3O4 or IgG@Fe3O4, co-magnetic beads resulted in better bacterial capture efficiency and, therefore, could decrease the false-negative results. Our proposed strategy is much more suitable for enrichment of clinically unknown bacteria from blood culture bottles for MALDI-TOF MS database identification.


Assuntos
Antibacterianos , Hemocultura , Bactérias , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Humanos , Fenômenos Magnéticos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
16.
Gastroenterol Nurs ; 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34269707

RESUMO

The Brussels Infant and Toddler Stool Scale was developed to improve the reliability of constipation diagnosis in non-toilet-trained children. The aim of this study was to evaluate the validity of simplified Chinese versions of the Brussels Infant and Toddler Stool Scale when used by parents, community doctors, pediatricians, and nurses. Photographs of the Scale were categorized into four categories (hard stools, formed stools, loose stools, and watery stools) and subjects assigned each photograph to a category. The study included two stages. In the first stage (n = 237 observers), percent correct allocations of the seven photographs ranged from 68.4% to 93.2%. We observed poorer recognition of the three hard stool items (77.4%, 85.8%, and 74.0%) than had been reported in the original Brussels Infant and Toddler Stool Scale validity study (95.9%, 93.4%, and 96.2%). Because hard stool items were commonly miscategorized as formed stools (21.6%, 9.5%, and 26.0%), we modified the descriptors "hard stools" and "formed stools" into "dry/hard stools" and "formed loose stools," respectively, and examined the performance of the modified Chinese Brussels Infant and Toddler Stool Scale in stage 2 of our study. The proportions of correct allocations of the three "hard stool" items in the modified Chinese Brussels Infant and Toddler Stool Scale increased to 94.7%, 90.4%, and 84.6%, values that were statistically similar to those reported previously in the original Brussels Infant and Toddler Stool Scale publisher. Renaming these categories to remove ambiguity in Chinese improved the identifiability of these items. The resultant Chinese Brussels Infant and Toddler Stool Scale was found to be valid for use with Chinese observers.

17.
Pain ; 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34232925

RESUMO

ABSTRACT: Clinical evidence indicates dorsal root ganglion (DRG) stimulation effectively reduces pain without the need to evoke paresthesia. This paresthesia-free anesthesia by DRG stimulation can be promising to treat pain from the viscera, where paresthesia usually cannot be produced. Here, we explored the mechanisms and parameters for DRG stimulation using an ex vivo preparation with mouse distal colon and rectum (colorectum), pelvic nerve, L6 DRG, and dorsal root in continuity. We conducted single-fiber recordings from split dorsal root and assessed the effect of DRG stimulation on afferent neural transmission. We determined the optimal stimulus pulse width by measuring the chronaxies of DRG stimulation to be below 216 µsec, indicating spike initiation likely at attached axons rather than somata. Sub-kilohertz DRG stimulation significantly attenuates colorectal afferent transmission (10, 50, 100, 500 and 1000 Hz), of which 50 and 100 Hz show superior blocking effects. Synchronized spinal nerve and DRG stimulation reveals a progressive increase in conduction delay by DRG stimulation, suggesting activity-dependent slowing in blocked fibers. Afferents blocked by DRG stimulation show a greater increase in conduction delay than unblocked counterparts. Mid-range frequencies (50-500 Hz) are more efficient at blocking transmission than lower or higher frequencies. In addition, DRG stimulation at 50 and 100 Hz significantly attenuates in vivo visceromotor responses to noxious colorectal balloon distension. This reversible conduction block in C- and Aδ-type afferents by sub-kilohertz DRG stimulation likely underlies the paresthesia-free anesthesia by DRG stimulation, thereby offering a promising new approach for managing chronic visceral pain.

18.
J Math Biol ; 83(2): 19, 2021 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-34324062

RESUMO

The method of administration of an effective drug treatment to eradicate viruses within a host is an important issue in studying viral dynamics. Overuse of a drug can lead to deleterious side effects, and overestimating the efficacy of a drug can result in failure to treat infection. In this study, we proposed a reaction-diffusion within-host virus model which incorporated information regarding spatial heterogeneity, drug treatment, and the intracellular delay to produce productively infected cells and viruses. We also calculated the basic reproduction number [Formula: see text] under the assumptions of spatial heterogeneity. We have shown that the infection-free periodic solution is globally asymptotically stable when [Formula: see text], whereas when [Formula: see text] there is an infected periodic solution and the infection is uniformly persistent. By conducting numerical simulations, we also revealed the effects of various parameters on the value of [Formula: see text]. First, we showed that the dependence of [Formula: see text] on the intracellular delay could be monotone or non-monotone, depending on the death rate of infected cells in the immature stage. Second, we found that the mobility of infected cells or virions could facilitate the virus clearance. Third, we found that the spatial fragmentation of the virus environment enhanced viral infection. Finally, we showed that the combination of spatial heterogeneity and different sets of diffusion rates resulted in complicated viral dynamic outcomes.


Assuntos
Preparações Farmacêuticas , Vírus , Número Básico de Reprodução , Simulação por Computador , Conceitos Matemáticos , Modelos Biológicos
19.
Artigo em Inglês | MEDLINE | ID: mdl-34212433

RESUMO

The present work aimed to explore the influence and underlying mechanisms involving arginine in testicular development in boars. To this end, thirty 30-day-old male Duroc piglets (7.00 ± 0.30 kg) were randomly sorted into two groups, maintained on either a basal diet (CON, n = 15) or a diet supplemented with 0.8% arginine (ARG, n = 15). Blood and testicular samples were collected during the experimental period to analyse amino acid composition and arginine metabolite levels. The results showed that dietary supplementation with arginine increased number of spermatogonia and height of the seminiferous epithelium (p < 0.05). Sperm density, total number and effective number of sperm of the boars in the ARG group increased significantly compared with those in the CON group (p < 0.05). Although arginine supplementation did not affect plasma amino acid levels, testicular arginine levels in 150-day-old boars exhibited a significant increase (p < 0.05). The level of serum nitric oxide (NO) and activity of nitric oxide synthase (NOS) also increased in 150-day-old boars in the ARG group (p < 0.05). Interestingly, dietary supplementation with arginine increased testicular levels of putrescine in 150-day-old boars (p < 0.05). These results indicated that arginine supplementation increased serum NO levels and testicular arginine and putrescine abundance, thereby improving testicular development and semen quality in boars.

20.
ACS Nano ; 15(6): 9732-9745, 2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34086438

RESUMO

Poly(methyl methacrylate) (PMMA) bone cement has been widely used in orthopedic surgeries including total hip/knee replacement, vertebral compression fracture treatment, and bone defect filling. However, aseptic loosening of the interface between PMMA bone cement and bone often leads to failure. Hence, the development of modified PMMA that facilitates the growth of bone into the modified PMMA bone cement is key to reducing the incidence of aseptic loosening. In this study, MgAl-layered double hydroxide (LDH) microsheets modified PMMA (PMMA&LDH) bone cement with superior osseointegration performance has been synthesized. The maximum polymerization reaction temperature of PMMA&LDH decreased by 7.0 and 11.8 °C, respectively, compared with that of PMMA and PMMA&COL-I (mineralized collagen I modified PMMA). The mechanical performance of PMMA&LDH decreased slightly in comparison with PMMA, which is beneficial to alleviate stress-shielding osteolysis, and indirectly promote osseointegration. The superior osteogenic ability of PMMA&LDH has been demonstrated in vivo, which boosts bone growth by 2.17- and 18.34-fold increments compared to the PMMA&COL-I and PMMA groups at 2 months, postoperatively. Moreover, transcriptome sequencing revealed four key osteogenic pathways: p38 MAPK, ERK/MAPK, FGF, and TGF-ß, which were further confirmed by IPA, qPCR, and Western blot assays. Hence, LDH-modified PMMA bone cement is a promising biomaterial to enhance bone growth with potential applications in relevant orthopedic surgeries.


Assuntos
Fraturas por Compressão , Fraturas da Coluna Vertebral , Cimentos Ósseos/farmacologia , Humanos , Hidróxidos , Osseointegração , Polimetil Metacrilato , Transdução de Sinais
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