55 research outputs found
Bone Mesenchymal Stem Cell-Derived Extracellular Vesicles Promote Recovery Following Spinal Cord Injury via Improvement of the Integrity of the Blood-Spinal Cord Barrier
Mesenchymal stem cell (MSC) transplantation has been shown to represent a potential treatment for traumatic spinal cord injury (SCI). However, there are several obstacles that need to be overcome before MSCs can be considered for clinical application, such as failure of MSCs to reach the spinal cord lesion core and possible tumor formation. Recent studies have suggested that MSC treatment is beneficial owing to paracrine-secreted factors. Extracellular vesicles are considered to be some of the most valuable paracrine molecules. However, the therapeutic mechanism of extracellular vesicles on spinal cord injury has not been studied clearly. Therefore, our study investigated the effect of systemic administration of extracellular vesicles on the loss of motor function after SCI and examined the potential mechanisms underlying their effects. Disruption of the blood-spinal cord barrier (BSCB) is a crucial factor that can be detrimental to motor function recovery. Pericytes are an important component of the neurovascular unit, and play a pivotal role in maintaining the structural integrity of the BSCB. Our study demonstrated that administration of bone mesenchymal stem cell-derived extracellular vesicles (BMSC-EV) reduced brain cell death, enhanced neuronal survival and regeneration, and improved motor function compared with the administration of BMSC-EV free culture media (EV-free CM). Besides, the BSCB was attenuated and pericyte coverage was significantly decreased in vivo. Furthermore, we found that exosomes reduced pericyte migration via downregulation of NF-κB p65 signaling, with a consequent decrease in the permeability of the BSCB. In summary, we identified that extracellular vesicles treatment suppressed the migration of pericytes and further improved the integrity of the BSCB via NF-κB p65 signaling in pericytes. Our data suggest that extracellular vesicles may serve as a promising treatment strategy for SCI
Moderate Hyperglycemia-Preventive Effect and Mechanism of Action of <i>Periplaneta americana</i> Oligosaccharides in Streptozotocin-Induced Diabetic Mice
Periplaneta americana is a kind of medicinal and edible insect, and its oligosaccharides (PAOS) have been reported to exert anti-inflammatory effects by regulating immunity, reducing oxidative stress, and meliorating gut microbiota. We hypothesized PAOS might benefit experimental diabetes mellitus (DM), an inflammatory disease coordinated by both innate and adaptive immunity. This study aimed to evaluate the effect of PAOS on glycemia and its potential mechanisms. Mice model of diabetes was established, and then the potential effects of PAOS was tested in vivo. Here, we found that PAOS triggered a moderate hyperglycemia-preventive effect on DM mice, showing markedly alleviated symptoms of DM, reduced blood glucose, and meliorated functions of liver and pancreas β cell. Deciphering the underlying mechanism of PAOS-improving diabetes, the results revealed that PAOS downregulated the blood glucose level by activating PI3K/AKT/mTOR and Keap/Nrf2/HO-1 pathways, meanwhile inhibiting TLR4/MAPK/NF-κB, Beclin1/LC3, and NLRP3/caspase1 pathways in vivo. Furthermore, analyses of the microbial community intriguingly exhibited that PAOS promoted the communities of bacteria producing short-chain fatty acids (SCFAs), whereas attenuating lipopolysaccharides (LPS)-producing ones that favored inflammatory tolerance. Collectively, balancing the intestinal bacterial communities by PAOS, which favored anabolism but suppressed inflammatory responses, contributed substantially to the glycemia improvement of PAOS in DM mice. Accordingly, PAOS might function as complementary and alternative medicine for DM
Smart caching for web browsers
ABSTRACT In modern Web applications, style formatting and layout calculation often account for a substantial amount of local Web page processing time. In this paper 1 , we present two novel caching schemes, the smart style caching and the layout caching, for Web browsers. They cache stable style data and layout data for DOM (Document Object Model) elements, and apply directly without re-calculation when the same data is subsequently processed, possibly across different visits of a Web page. Redundant computations in both style formatting and layout calculation could be eliminated, resulting in more efficient local Web page processing. The proposed caching schemes are still applicable and effective even there are changes in the DOM structure or style rules of a Web page. The experiments on the homepages of the Top 25 Web sites show that on average, in a subsequent visit of the same Web page, the smart style caching could reduce the style formatting time by about 64%, and the combination of both caching schemes could reduce the layout calculation time by about 61%, with about 46% overall performance improvement on the local Web page processing time. For the overall performance when networking, Web servers, and local Web page processing were all included, our caching schemes could improve up to 56% when browsing these Web sites on a desktop PC and up to 60% when browsing on a netbook
Periplaneta americana Oligosaccharides Exert Anti-Inflammatory Activity through Immunoregulation and Modulation of Gut Microbiota in Acute Colitis Mice Model
The incidence and prevalence of inflammatory bowel disorders (IBD) are increasing around the world due to bacterial infection, abnormal immune response, etc. The conventional medicines for IBD treatment possess serious side effects. Periplaneta americana (P. americana), a traditional Chinese medicine, has been used to treat arthritis, fever, aches, inflammation, and other diseases. This study aimed to evaluate the anti-inflammatory effects of oligosaccharides from P. Americana (OPA) and its possible mechanisms in vivo. OPA were purified and biochemical characterization was analyzed by HPGPC, HPLC, FT-IR, and GC–MS. Acute colitis mice model was established, the acute toxicity and anti-inflammatory activity were tested in vivo. The results showed OPA with molecular mass of 1.0 kDa were composed of 83% glucose, 6% galactose, 11% xylose, and the backbone was (1→4)-Glcp. OPA had potent antioxidant activities in vitro and significantly alleviated the clinical symptoms of colitis, relieved colon damage without toxic side effects in vivo. OPA exhibited anti-inflammatory activity by regulating Th1/Th2, reducing oxidative stress, preserving intestinal barrier integrity, and inhibiting TLR4/MAPK/NF-κB pathway. Moreover, OPA protected gut by increasing microbial diversity and beneficial bacteria, and reducing pathogenic bacteria in feces. OPA might be the candidate of complementary and alternative medicines of IBD with low-cost and high safety
Cloning and Expression Pattern of rnd1 and Its Involvement in Disease Resistance in Japanese Flounder (Paralichthys olivaceus)
Edwardsiella tarda is a major causative pathogen of bacterial ascites in Japanese flounder, leading to massive economic losses, and the discovery of molecular markers linked to disease resistance is an effective strategy in resistance breeding programs. The Rho GTPase family comprises small proteins with a molecular weight of 20~30 kDa. Rho GTPase family members are involved in diverse cellular processes, such as cytoskeleton, cell adhesion, vesicle transport, and proliferation. In addition, they play pivotal roles in infection by different pathogens. Rho-related GTP-binding protein Rho6 (Rnd1), a member of the Rho-GTPase family, participates in various biological functions, including neural junction formation, axonal extension, tumorigenesis, neuronal function, and apoptosis. Some members of the Rho family, such as Rac1 and Rac2, regulate immune response in grass carp, large yellow croaker, zebrafish, and half-smooth tongue sole. However, the function of Rnd1 in fish is poorly understood. Japanese flounder (Paralichthys olivaceus) is greatly affected by E. tarda infections during the breeding process. In previous studies, whole-genome sequencing and assembly of Japanese flounder were performed, and subsequently, various disease resistance genes were screened to support the improvement of Japanese flounder germplasm resources. To study the role of Pornd1 in resistance against E. tarda infection in Japanese flounder, Pornd1 was cloned and identified using PCR. The full-length Pornd1 cDNA was 699 bp, containing an open reading frame encoding a 232-amino acid protein. The predicted molecular weight of PoRnd1 was 26 kDa. Sequence and homology analyses showed that the Rnd1 protein harbors a Rho-GTP superfamily structural domain, which is highly conserved in various species. PoRnd1 shares the highest homology with Rnd1 from Hippoglossus hippoglossus (98.28%). On phylogenetic tree, PoRnd1 was clustered with Rnd1 from other fish species. The single-nucleotide polymorphism (SNP) locus associated with E. tarda resistance is located at 4 575 720 bp on chromosome 14 of Japanese flounder. The frequency of the T allele in disease-resistant families (freqT=0.92) was significantly higher than that in susceptible families (freqT=0.20). The SNP was located at the 2nd intron of Pornd1. Real-time quantitative PCR was employed to characterize the expression profiles of Pornd1 in the tissues of healthy and E. tarda-infected fish. Pornd1 expression was the highest in the heart, followed by the liver, kidney, head kidney, and spleen, but its expression was low in the skin, blood, gills, and muscle. In E. tarda-infected fish, the expression of Pornd1 mRNA decreased after 6 h, then gradually increased, and subsequently reached the highest level after 48 h in the liver, kidney, and spleen. Pornd1 expression in the kidney and spleen in the 48 h group was significantly higher than that in the 6 and 12 h groups. Furthermore, Pornd1 expression in the liver of resistant families was significantly higher than that in susceptible families. Based on its His tag, the PoRnd1 recombinant protein was purified using an Ni column and subjected to SDS-PAGE. The target band of PoRnd1 at 32 kDa was observed in the gel after Coomassie Blue staining. The PoRnd1 recombinant protein (0.5 mg/mL) was used to study antibacterial activity through the Oxford cup assay. PoRnd1 significantly inhibited the growth of Staphylococcus aureus, Escherichia coli, E. tarda, and Vibrio harveyi. In summary, Pornd1 may be closely linked to disease resistance in Japanese flounder and can thus serve as an effective gene marker for disease resistance breeding. Our findings provide a theoretical basis for further elucidating the molecular mechanisms of immunity in Japanese flounder
Prevalência de HPV em material cérvico-uterino de mulheres de Tomé-Açú – PA
The human papillomavirus (HPV) infects basal of stratified epithelium and develop proliferative benign lesions in skin or mucous. The infection has a universal distribution however many studies have demonstrated a strong association of infections by high risk species in cases of cervical cancer. In Brazil, this type of cancer is the second most common among women, while the north and northeast region of this country have the highest incidence. Therefore, this study has as focus the determination of infection prevalence in a group of women screened to cervical cancer. During the period of July 2008 to March 2009 were collected cervical samples from 144 women received at Laboratório de Citopatologia of Hospital Amazônia from Quatro Bocas, Tomé-Açú, Pará. All women were informed about the purpose of that research and then signed the Consent Form and answered the epidemiological questionnaire. The data obtained from the questionnaire correlated with the infection through the testing qui -quadradot. The HPV prevalence was 6,94% and the majority age was between 18-28 years. Samples from 76 patients showed inflammatory aspect (52,02%) and 60 patients did not showed any change (41,09%). Among smears with cytological ASC-US in the most of cases (6/10) followed by LSIL (2/10), and ASC-H (1/10) and HSIL (1/10). The HPV infection is statistically significant correlated PCR-HPV test with the age group, and cytomorphology. Prevalence found in this study corroborants with other findings reported in the literature. The predominance of infection in women with abnormal
cytology strengthens the concept that infection is, in most of cases, asymptomatic, and the Pap smear method is lesser efficient to detect infection than techniques of molecular biolology.O Papilomavirus humano infecta as células basais do epitélio estratificado, induzindo
a lesões proliferativas benignas na pele ou mucosas. As infecções apresentam distribuição universal, no entanto muitos estudos têm demonstrado a forte associação da infecção por espécies de alto risco com casos de câncer cervical. No Brasil, esse tipo de câncer é o segundo tipo mais comum entre as mulheres, sendo que as regiões norte e nordeste do país apresentam a maior incidência. O presente estudo visou determinar a prevalência da infecção em um grupo de mulheres rastreadas para o câncer cervical. No período de julho de 2008 a março de 2009 foram coletadas amostras cervicais de 144 mulheres atendidas no Laboratório de Citopatologia do Hospital Amazônia de Quatro Bocas, Tomé – Açu, estado do Pará. Os dados obtidos foram correlacionados com a infecção através do teste do qui-quadrado. A Prevalência do HPV foi de 6,94%, a idade variou em 18 -28 anos, 76 pacientes apresentaram quadro inflamatório, ou seja, 52,05%, enquanto que 60 pacientes não apresentaram alteração, com 41,09% do total. Dentre os esfregaços com alterações citológicas, ASC-US foi encontrado na maioria dos casos, (6/10), seguido de LSIL (2/10), e ASC-H (1/10), e HSIL (1/10). A infecção pelo HPV mostrou associação estatisticamente significativa com a PCR, faixa etária e citomorfologia. A prevalência encontrada no estudo corrobora com outros achados descritos na literatura. A predominância da infecção em mulheres com citologia anormal reforça a ideia de que a infecção é, em sua maioria, assintomática e que o método de Papanicolau é menos eficiente na detecção da infecção em relação às técnicas de biologia molecular
Temperature dependent effects of elevated CO2 on shell composition and mechanical properties of Hydroides elegans: insights from a multiple stressor experiment.
The majority of marine benthic invertebrates protect themselves from predators by producing calcareous tubes or shells that have remarkable mechanical strength. An elevation of CO2 or a decrease in pH in the environment can reduce intracellular pH at the site of calcification and thus interfere with animal's ability to accrete CaCO3. In nature, decreased pH in combination with stressors associated with climate change may result in the animal producing severely damaged and mechanically weak tubes. This study investigated how the interaction of environmental drivers affects production of calcareous tubes by the serpulid tubeworm, Hydroides elegans. In a factorial manipulative experiment, we analyzed the effects of pH (8.1 and 7.8), salinity (34 and 27‰), and temperature (23°C and 29°C) on the biomineral composition, ultrastructure and mechanical properties of the tubes. At an elevated temperature of 29°C, the tube calcite/aragonite ratio and Mg/Ca ratio were both increased, the Sr/Ca ratio was decreased, and the amorphous CaCO3 content was reduced. Notably, at elevated temperature with decreased pH and reduced salinity, the constructed tubes had a more compact ultrastructure with enhanced hardness and elasticity compared to decreased pH at ambient temperature. Thus, elevated temperature rescued the decreased pH-induced tube impairments. This indicates that tubeworms are likely to thrive in early subtropical summer climate. In the context of climate change, tubeworms could be resilient to the projected near-future decreased pH or salinity as long as surface seawater temperature rise at least by 4°C
Extraction of Metallic Lead from Cathode Ray Tube (CRT) Funnel Glass by Thermal Reduction with Metallic Iron
A novel and effective
process of thermal reduction treatment with
the addition of metallic iron (Fe(0)) to recover lead from cathode
ray tube (CRT) funnel glass is introduced. The key technological breakthrough
of this process is the use of a relatively lower temperature and an
inexpensive reducing agent to extract the metallic lead. The influences
of temperature, the reducing agent content, and the holding time for
lead reduction were examined to determine the optimal extraction efficiency.
The lead extraction efficiency first increased and then decreased
with increasing temperature. The maximum lead extraction efficiency
occurred at 700 °C. The growth of crystalline lead first increased
significantly with an increase in the Fe content, reaching maximum
growth at an Fe addition of 50 wt %. The most effective treatment
time was determined to be 30 min, as the vitrification of lead back
to the glass matrix occurred under longer treatment times. The experimentally
derived results indicate that a 58 wt % lead extraction can be achieved
with the optimized operational parameters (50 wt % Fe addition, heating
at 700 °C for 30 min) in a single extraction operation
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