• Title/Summary/Keyword: microscopic mechanism

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The Neuroprotective Effects of Uncariae Ramulus et Uncus on focal cerebral ischemia in rats brains (백서(白鼠)의 국부(局部) 뇌경색(腦硬塞)에 대한 조구등(釣鉤藤)의 신경보호(神經保護) 효과(效果))

  • Kwon Hyung-Su;Oh Yong-Seong;Lee So-Yeon;Park Chi-Sang;Park Chang-Gook;Jang Woo-Seok
    • The Journal of Internal Korean Medicine
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    • v.24 no.2
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    • pp.181-189
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    • 2003
  • The goal of this study is to investigate whether Uncariae Ramulus et Uncus can protect nerve cells against ischemic neuronal damage is caused by middle cerebral artery occlusion (MCAO) in rats' brains and to investigate whether the neuroprotective effect of Uncariae Ramulus et Uncus is concerned with IEGs(immediate early genes) expression. Uncariae Ramulus et Uncus(l00mg/kg) was administered immediately after 2 hours of MCAO and maintained for 7 days. On 7th days after 2 hours of MCAO, the brains of rats were sliced through the hippocampus. c-Fos immunohistochemistry stain and Cresyl violet stain were done for microscopic examination. Each number of viable neurons and c-Fos immunoreactive cells in CA1 was counted. The density of neurons and c-Fos immunoreactive cells were significantly decreased in MCAO-operated ischemic rats compared to that sham-operated rats. Administration of Uncariae Ramulus et Uncus group significantly elevated MCAO-induced decrease in density of neurons, and elevated MCAO-induced decrease in c-Fos immunoreactive cells. These results suggest that the neuroprotective effect of Uncariae Ramulus et Uncus against focal cerebral ischemia. Also, we hypothesized that neuroprotective mechanism of Uncariae Ramulus et Uncus is related to IEGs expression.

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Antibody-dependent rat macrophage-mediated damage Into the excysted metacercariae of Paragonimus westeymani in vitro (폐흡충(Paragonimus westermani) 감염시의 세포 면역학적 장어 기전)

  • 정평림;장재경;소진천
    • Parasites, Hosts and Diseases
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    • v.29 no.1
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    • pp.43-54
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    • 1991
  • An in vitro immune effector mechanism against the target encysted metacercariae of Paragonimus westermani was demonstrated in the rat system. Peritoneal exudate cells, mainly macrophages from normal rats, showed adherence to and killing of encysted metacercariae of p. westermani in the presence of complement-independent serum from rats infected with Paragonimus metacercariae. These reactions were specific for the excysted metacercariae, as tissue-migrating juvenile worms were not affected. Damage of encysted metacercariae of p. westermani due to antibody and macrophages was assessed by morphological observation, by cell adherence reaction and by the use of vital dyes. frypan blue dye exclusion proved to be a reliable indicator of judging metacercarial viability. Electron microscopic studies demonstrated that macrophages reacted with fusty material on the tegumental surface and fine structures in the syncytium of the parasites. The tubular tunnels formed between the basement membrane and muscle layers of the damaged parasites were also noticeable. The relevance of these findings to cellular immunity in the early paragonimiasis was discussed.

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Numerical simulation of electrokinetic dissipation caused by elastic waves in reservoir rocks

  • Zhang, Xiaoqian;Wang, Qifei;Li, Chengwu;Sun, Xiaoqi;Yan, Zheng;Nie, Yao
    • Geomechanics and Engineering
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    • v.19 no.1
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    • pp.11-20
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    • 2019
  • The use of electrokinetic dissipation method to study the fluid flow law in micro-pores is of great significance to reservoir rock microfluidics. In this paper, the micro-capillary theory was combined with the coupling model of the seepage field and the current field under the excitation of the harmonic signal, and the coupling theory of the electrokinetic effect under the first-order approximation condition was derived. The dissipation equation of electrokinetic dissipation and viscous resistance dissipation and its solution were established by using Green's function method. The physical and mathematical models for the electrokinetic dissipation of reservoir rocks were constructed. The microscopic mechanism of the electrokinetic dissipation of reservoir rock were theoretically clarified. The influencing factors of the electrokinetic dissipation frequency of the reservoir rock were analyzed quantitatively. The results show that the electrokinetic effect transforms the fluid flow profile in the pores of the reservoir from parabolic to wavy; under low-frequency conditions, the apparent viscosity coefficient is greater that one and is basically unchanged. The apparent viscosity coefficient gradually approaches 1 as the frequency increases further. The viscous resistance dissipation is two orders of magnitude higher than the electrokinetic effect dissipation. When the concentration of the electrolyte exceeds 0.1mol/L, the electrokinetic dissipation can be neglected, while for the electrolyte solution (<$10^{-2}M$) in low concentration, the electrokinetic dissipation is very significant and cannot be ignored.

Ginsenoside Rg3 reduces the adhesion, invasion, and intracellular survival of Salmonella enterica serovar Typhimurium

  • Mechesso, Abraham F.;Quah, Yixian;Park, Seung-Chun
    • Journal of Ginseng Research
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    • v.45 no.1
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    • pp.75-85
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    • 2021
  • Background: Invasive infections due to foodborne pathogens, including Salmonella enterica serovar Typhimurium, are prevalent and life-threatening. This study aimed to evaluate the effects of ginsenoside Rg3 (Rg3) on the adhesion, invasion, and intracellular survival of S. Typhimurium. Methods: The impacts of Rg3 on bacterial growth and host cell viability were determined using the time kill and the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays, respectively. Gentamicin assay and confocal microscopic examination were undertaken to determine the effects of Rg3 on the adhesive and invasive abilities of S. Typhimurium to Caco-2 and RAW 264.7 cells. Quantitative reverse transcription polymerase chain reaction was performed to assess the expression of genes correlated with the adhesion, invasion, and virulence of S. Typhimurium. Results: Subinhibitory concentrations of Rg3 significantly reduced (p < 0.05) the adhesion, invasion, and intracellular survival of S. Typhimurium. Rg3 considerably reduced (p < 0.05) the bacterial motility as well as the release of nitrite from infected macrophages in a concentration-dependent manner. The expression of genes related to the adhesion, invasion, quorum sensing, and virulence of S. Typhimurium including cheY, hilA, OmpD, PrgK, rsgE, SdiA, and SipB was significantly reduced after Rg3 treatment. Besides, the compound downregulated rac-1 and Cdc-42 that are essential for actin remodeling and membrane ruffling, thereby facilitating Salmonella entry into host cells. This report is the first to describe the effects of Rg3 on "trigger" entry mechanism and intracellular survival S. Typhimurium. Conclusion: Rg3 could be considered as a supplement agent to prevent S. Typhimurium infection.

Application of 630-nm and 850-nm Light-emitting Diodes and Microcurrent to Accelerate Collagen and Elastin Deposition in Porcine Skin

  • Kwon, Tae-Rin;Moon, Dong Wook;Kim, Jungwook;Kim, Hyoung Jun;Lee, Seong Jae;Han, Yunhee;Dan, Hee Won;Chi, Sang Hoon;Seong, Hwan Mo;Kim, Hee Jung;Lim, Guei-Sam;Lee, Jungkwan
    • Medical Lasers
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    • v.10 no.2
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    • pp.96-105
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    • 2021
  • Background and Objectives Skin aging is reportedly associated with regulation in collagen and elastin synthesis. This study investigated the potential of combining light-emitting diode (LED) treatments using a 630-nm and 850-nm LED with simultaneous microcurrent application. Materials and Methods The dorsal skin of female pigs was treated with a home-use device. We examined the treatment effects using photography, thermocamera, microscopic pathology, and histological examination to determine the mechanism of action, efficacy, and safety of the procedure. A histological observation was performed using hematoxylin and eosin, Masson's trichrome, Victoria blue, and immunohistochemical staining. We also used the Sircol soluble collagen and elastin assay kit to measure the amounts of collagen and elastin in the porcine back skin tissue after 2 and 6 weeks. Results Evaluation by visual inspection and devices showed no skin damage or heat-induced injury at the treatment site. Histological staining revealed that accurate treatment of the targeted dermis layer effectively enhanced collagen and elastin deposition. Collagen type I, a protein defined by immunohistochemical staining, was overexpressed in the early stages of weeks 2 and 6. Combined therapy findings showed the superior capability of the 630-nm and 850-nm LED procedures to induce collagen; in contrast, elastin induction was more pronounced after microcurrent treatments. Conclusion The home-use LED device, comprising a combination of 630-nm and 850-nm LEDs and microcurrent, is safe and can be used as an adjunctive treatment for self-administered facial rejuvenation.

Nitrate enhances the secondary growth of storage roots in Panax ginseng

  • Kyoung Rok Geem ;Jaewook Kim ;Wonsil Bae ;Moo-Geun Jee ;Jin Yu ;Inbae Jang;Dong-Yun Lee ;Chang Pyo Hong ;Donghwan Shim;Hojin Ryu
    • Journal of Ginseng Research
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    • v.47 no.3
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    • pp.469-478
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    • 2023
  • Background: Nitrogen (N) is an essential macronutrient for plant growth and development. To support agricultural production and enhance crop yield, two major N sources, nitrate and ammonium, are applied as fertilizers to the soil. Although many studies have been conducted on N uptake and signal transduction, the molecular genetic mechanisms of N-mediated physiological roles, such as the secondary growth of storage roots, remain largely unknown. Methods: One-year-old P. ginseng seedlings treated with KNO3 were analyzed for the secondary growth of storage roots. The histological paraffin sections were subjected to bright and polarized light microscopic analysis. Genome-wide RNA-seq and network analysis were carried out to dissect the molecular mechanism of nitrate-mediated promotion of ginseng storage root thickening. Results: Here, we report the positive effects of nitrate on storage root secondary growth in Panax ginseng. Exogenous nitrate supply to ginseng seedlings significantly increased the root secondary growth. Histological analysis indicated that the enhancement of root secondary growth could be attributed to the increase in cambium stem cell activity and the subsequent differentiation of cambium-derived storage parenchymal cells. RNA-seq and gene set enrichment analysis (GSEA) revealed that the formation of a transcriptional network comprising auxin, brassinosteroid (BR)-, ethylene-, and jasmonic acid (JA)-related genes mainly contributed to the secondary growth of ginseng storage roots. In addition, increased proliferation of cambium stem cells by a N-rich source inhibited the accumulation of starch granules in storage parenchymal cells. Conclusion: Thus, through the integration of bioinformatic and histological tissue analyses, we demonstrate that nitrate assimilation and signaling pathways are integrated into key biological processes that promote the secondary growth of P. ginseng storage roots.

Mechanical properties and assessment of a hybrid ultra-high-performance engineered cementitious composite using calcium carbonate whiskers and polyethylene fibers

  • Wu, Li-Shan;Yu, Zhi-Hui;Zhang, Cong;Bangi, Toshiyuki
    • Computers and Concrete
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    • v.30 no.5
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    • pp.339-355
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    • 2022
  • The high cost of ultra-high-performance engineered cementitious composite (UHP-ECC) is currently a crucial issue, especially in terms of the polyethylene (PE) fibers use. In this paper, cheap calcium carbonate whiskers (CW) were evaluated on the feasibility of hybrid with PE fibers. Diverse combinations of PE fibers and CW were employed to investigate the multi-scale enhancement on the UHP-ECC performance. A probabilistic-based UHP-ECC tensile strain reliability analysis approach was utilized, which was in general agreement with the experimental results. Furthermore, a multi-dimensional integrated representation was conducted for the comprehensive assessment of UHP-ECC. Results illustrated that CW improved the compressive strength and energy dissipation capacity of UHP-ECC owing to the microscopic strengthening mechanism. CW and PE fiber further promoted the saturated cracking of composite by multi-scale crack arresting effect. In particular, PE1.75-CW0.5 specimen possessed the best overall performance. The ultimate cracking width of PE1.75-CW0.5 group had 98 ㎛, which was 46.18% lower compared to PE2-CW0 group, the 28d compressive strength were slightly improved, the tensile strain capacity was comparable to that of PE2-CW0 group. The results above demonstrated that combinations of PE fiber and CW could significantly enhance the comprehensive performance of UHP-ECC, which was beneficial for large-scale engineering applications.

Electrochemical Behaviors of Polycrystalline Silver Electrodes in 8M KOH Solutions Containing Bi2O3 (Bi2O3를 첨가한 8M KOH용액에서 다결정 Ag전극의 전기화학적 거동)

  • Hur, Tae-Uk;Kong, Yeong-Kyung;Chung, Won-Sub
    • Journal of the Korean Electrochemical Society
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    • v.8 no.1
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    • pp.17-23
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    • 2005
  • The electrochemical behaviors of polycrystalline silver electrodes in 8M KOH solutions containing $Bi_2O_3$ were studied under various conditions by cyclic voltammetry, potentiostatic and galvanostatic techniques as well as the morphology of the silver oxide structures by SEM. It was found that three new compounds comprising silver, bismuth, and oxygen as well as $Bi_2O_3$, $Ag_2O$ and AgO were formed during the electrochemical oxidation of silver. In addition, the potentiostatic current transients were characterized by the appearances of the first current peaks corresponding to the formation of silver oxides, and the second current peaks corresponding to the Ag-Bi-O compounds, indicating the presence of the nucleation and 3D growth mechanism, in the potential regions of $Ag_2O$ and AgO, respectively. Microscopic examinations showed that two types of silver (I) oxide morphologies are formed in the potential region of $Ag_2O$.

Cell clusters in intervertebral disc degeneration: an attempted repair mechanism aborted via apoptosis

  • Polly Lama;Jerina Tiwari;Pulkit Mutreja;Sukirti Chauhan;Ian J Harding;Trish Dolan;Michael A Adams;Christine Le Maitre
    • Anatomy and Cell Biology
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    • v.56 no.3
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    • pp.382-393
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    • 2023
  • Cell clusters are a histological hallmark feature of intervertebral disc degeneration. Clusters arise from cell proliferation, are associated with replicative senescence, and remain metabolically, but their precise role in various stages of disc degeneration remain obscure. The aim of this study was therefore to investigate small, medium, and large size cell-clusters. For this purpose, human disc samples were collected from 55 subjects, aged 37-72 years, 21 patients had disc herniation, 10 had degenerated non-herniated discs, and 9 had degenerative scoliosis with spinal curvature <45°. 15 non-degenerated control discs were from cadavers. Clusters and matrix changes were investigated with histology, immunohistochemistry, and Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Data obtained were analyzed with spearman rank correlation and ANOVA. Results revealed, small and medium-sized clusters were positive for cell proliferation markers Ki-67 and proliferating cell nuclear antigen (PCNA) in control and slightly degenerated human discs, while large cell clusters were typically more abundant in severely degenerated and herniated discs. Large clusters associated with matrix fissures, proteoglycan loss, matrix metalloproteinase-1 (MMP-1), and Caspase-3. Spatial association findings were reconfirmed with SDS-PAGE that showed presence to these target markers based on its molecular weight. Controls, slightly degenerated discs showed smaller clusters, less proteoglycan loss, MMP-1, and Caspase-3. In conclusion, cell clusters in the early stages of degeneration could be indicative of repair, however sustained loading increases large cell clusters especially around microscopic fissures that accelerates inflammatory catabolism and alters cellular metabolism, thus attempted repair process initiated by cell clusters fails and is aborted at least in part via apoptosis.

Glucocorticoids improve sperm performance in physiological and pathological conditions: their role in sperm fight/flight response

  • Vittoria Rago;Adele Vivacqua;Saveria Aquila
    • Anatomy and Cell Biology
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    • v.57 no.1
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    • pp.119-128
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    • 2024
  • Glucocorticoids play a physiologic role in the adult male reproductive functions, modulating gonadal steroid synthesis and spermatogenesis, through the glucocorticoid receptor (GR). The expression of GR has been described in several key testicular cell types, including somatic cells and early germ cell populations. Nothing is known on GR in human spermatozoa. Herein, we explored the GR expression and its possible role in normal and testicular varicocele semen samples from volunteer donors. After semen parameter evaluation by macro- and microscopic analysis, samples were centrifuged; then spermatozoa and culture media were recovered for further investigations. By western blotting and immunofluorescence analyses we evidenced for the first time in spermatozoa the presence of GR-D3 isoform which was reduced in sperm from varicocele patients. By treating sperm with the synthetic glucocorticoid dexamethasone (DEXA), we found that survival, motility, capacitation, and acrosome reaction were increased in both healthy and varicocele samples. GR involvement in mediating DEXA effects, was confirmed by using the GR inhibitor mifepristone (M2F). Worthy, we also discovered that sperm secretes different cortisol amounts depending on its physio-pathological status, suggesting a defence mechanism to escape the immune system attach in the female genital tract thus maintaining the immune-privilege as in the testis. Collectively, our data suggests a role for glucocorticoids in determining semen quality and function, as well as in participating on sperm immune defensive mechanisms. The novelty of this study may be beneficial and needs to take into account in artificial insemination/drug discovery aimed to enhancing sperm quality.