• Title/Summary/Keyword: Challenge stress

Search Result 181, Processing Time 0.026 seconds

Optical Stimulation and Pacing of the Embryonic Chicken Heart via Thulium Laser Irradiation

  • Chung, Hong;Chung, Euiheon
    • Current Optics and Photonics
    • /
    • v.3 no.1
    • /
    • pp.1-7
    • /
    • 2019
  • Optical stimulation provides a promising alternative to electrical stimulation to selectively modulate tissue. However, developing noninvasive techniques to directly stimulate excitable tissue without introducing genetic modifications and minimizing cellular stress remains an ongoing challenge. Infrared (IR) light has been used to achieve optical pacing for electrophysiological studies in embryonic quail and mammalian hearts. Here, we demonstrate optical stimulation and pacing of the embryonic chicken heart using a pulsed infrared thulium laser with a wavelength of 1927 nm. By recording stereomicroscope outputs and quantifying heart rates and movements through video processing, we found that heart rate increases instantly following irradiation with a large spot size and high radiant exposure. Targeting the atrium using a smaller spot size and lower radiant exposure achieved pacing, as the heart rate synchronized with the laser to 2 Hz. This study demonstrates the viability of using the 1927 nm thulium laser for cardiac stimulation and optical pacing, expanding the optical parameters and IR lasers that can be used to modulate cardiac dynamics.

Psychological Aspects of Child Maltreatment

  • Ahn, Yebin D.;Jang, Soomin;Shin, Jiyoon;Kim, Jae-Won
    • Journal of Korean Neurosurgical Society
    • /
    • v.65 no.3
    • /
    • pp.408-414
    • /
    • 2022
  • In this review, we provide information about the etiology, risk factors, and clinical presentations of maltreatment to help clinicians better understand child abuse and neglect. Child maltreatment is a major global health challenge that can result in severe consequences. Abused and neglected children are likely to develop psychiatric disorders, such as major depressive disorder, anxiety disorder, and posttraumatic stress disorder. Understanding child maltreatment is expected to prevent and reduce victimization in children, adolescents, and their families.

Fusion Peptide Improves Stability and Bioactivity of Single Chain Antibody against Rabies Virus

  • Xi, Hualong;Zhang, Kaixin;Yin, Yanchun;Gu, Tiejun;Sun, Qing;Shi, Linqing;Zhang, Renxia;Jiang, Chunlai;Kong, Wei;Wu, Yongge
    • Journal of Microbiology and Biotechnology
    • /
    • v.27 no.4
    • /
    • pp.718-724
    • /
    • 2017
  • The combination of rabies immunoglobulin (RIG) with a vaccine is currently effective against rabies infections, but improvements are needed. Genetic engineering antibody technology is an attractive approach for developing novel antibodies to replace RIG. In our previous study, a single-chain variable fragment, scFv57R, against rabies virus glycoprotein was constructed. However, its inherent weak stability and short half-life compared with the parent RIG may limit its diagnostic and therapeutic application. Therefore, an acidic tail of synuclein (ATS) derived from the C-terminal acidic tail of human alpha-synuclein protein was fused to the C-terminus of scFv57R in order to help it resist adverse stress and improve the stability and half-life. The tail showed no apparent effect on the preparation procedure and affinity of the protein, nor did it change the neutralizing potency in vitro. In the ELISA test of molecular stability, the ATS fusion form of the protein, scFv57R-ATS, showed an increase in thermal stability and longer half-life in serum than scFv57R. The protection against fatal rabies virus challenge improved after fusing the tail to the scFv, which may be attributed to the improved stability. Thus, the ATS fusion approach presented here is easily implemented and can be used as a new strategy to improve the stability and half-life of engineered antibody proteins for practical applications.

Characterization of Copper/Zinc-Superoxide Dismutase (Cu/Zn-SOD) Gene from an Endangered Freshwater Fish Species Hemibarbus mylodon (Teleostei; Cypriniformes)

  • Lee, Sang-Yoon;Kim, Keun-Yong;Bang, In-Chul;Nam, Yoon-Kwon
    • Fisheries and Aquatic Sciences
    • /
    • v.14 no.1
    • /
    • pp.43-54
    • /
    • 2011
  • Gene structure of copper/zinc-superoxide dismutase (Cu/Zn-SOD; sod1) was characterized in Hemibarbus mylodon (Teleostei; Cypriniformes), an endangered freshwater fish species in Korean peninsula. Full-length cDNA of H. mylodon SOD1 consisted of a 796-bp open reading frame sequence encoding 154 amino acids, and the deduced polypeptide sequence shared high sequence homology with other orthologs, particularly with regard to metal-coordinating ligands. Genomic structure of the H. mylodon sod1 gene (hmsod1; 1,911 bp from the ATG start codon to the stop codon) was typical quinquepartite (i.e., five exons interrupted by four introns); the lengths of the exons were similar among species belonging to various taxonomic positions. The molecular phylogeny inferred from sod1 genes in the teleost lineage was in accordance with the conventional taxonomic assumptions. 5'-flanking upstream region of hmsod1, obtained using the genome walking method, contained typical TATA and CAAT boxes. It also showed various transcription factor binding motifs that may be potentially involved in stress/immune response (e.g., sites for activating proteins or nuclear factor kappa B) or metabolism of xenobiotic compounds (e.g., xenobiotic response element; XRE). The hmsod1 transcripts were ubiquitously detected among tissues, with the liver and spleen showing the highest and lowest expression, respectively. An experimental challenge with Edwardsiella tarda revealed significant upregulation of the hmsod1 in kidney (4.3-fold) and spleen (3.1-fold), based on a real-time RT-PCR assay. Information on the molecular characteristics of this key antioxidant enzyme gene could be a useful basis for a biomarker-based assay to understand cellular stresses in this endangered fish species.

Effects of Chromium Propionate Supplementation on Growth Performance, Serum Traits and Immune Response in Weaned Pigs

  • Lien, T.-F.;Yang, K.-H.;Lin, K.-J.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.18 no.3
    • /
    • pp.403-408
    • /
    • 2005
  • This study investigated the effects of chromium propionate on growth performance, serum traits and immune response in weaned pigs. Twenty-four 4 wk-old crossbred weanling pigs (initial body weight about 9.52${\pm}$0.48 kg) were randomly allotted into one of two groups, a control group (basal diet), chromium propionate group (diet supplemented with 200 ${\mu}g$ $kg^{-1}$ (ppb) of chromium propionate). This experiment was conducted over nine weeks. Escherichia coli lipopolysaccharide (LPS) 100 ${\mu}g$ $kg^{-1}$ BW was used as the stress-inducing agent in the middle (4 wks) and final (8 wks) periods. The experimental results indicated that chromium propionate had no effect on growth performance (p>0.05). Chromium propionate supplementation reduced the percentage of LDL+VLDL (low and very low-density lipoprotein) and increased HDL (high-density lipoprotein), but did not affect other serum traits. Pigs supplemented with chromium propionate had higher antibody titers specific for sheep red blood cells (SRBC) and serum total globulin relative to the control during the final period (p<0.05). A challenge with LPS increased white blood cells in the chromium propionate group in both experimental periods (p<0.05). The chromium propionate group exhibited higher IgG and $\gamma$-globulin than the control during the middle experimental period (p<0.05). Moreover, the PHA (phytohemagglutinin) challenge result in the chromium propionate group was better than the control group (p=0.056). Greater neutrophil activity was displayed than in the control (p<0.05). This suggests that chromium propionate supplementation benefited the weaned pigs in lipoprotein and immune response.

Molecular characterization and expression of suppressor of cytokine signaling (SOCS) 1, 2 and 3 under acute hypoxia and reoxygenation in pufferfish, Takifugu fasciatus

  • Wang, Dan;Wen, Xin;Zhang, Xinyu;Hu, Yadong;Li, Xinru;Zhu, Wenxu;Wang, Tao;Yin, Shaowu
    • Genes and Genomics
    • /
    • v.40 no.11
    • /
    • pp.1225-1235
    • /
    • 2018
  • Hypoxia seriously affects the innate immune system of fish. However, the roles of suppressor of cytokine signaling (SOCS), pivotal anti-inflammatory genes, in response to hypoxia/reoxygenation remain largely unexplored. The primary objective of this study was to elucidate the function of SOCS genes under acute hypoxia and reoxygenation in pufferfish (Takifugu fasciatus). In the present study, SOCS1, 2 and 3 were identified in T. fasciatus referred to as TfSOCS1, 2 and 3. Then, qRT-PCR and western blot analysis were employed to assess their expressions at both the mRNA and protein levels. Tissue distribution demonstrated that the three SOCS genes were predominantly distributed in gill, brain and liver. Under hypoxia challenge ($1.63{\pm}0.2mg/L$ DO for 2, 4, 6 and 8 h), the expressions of TfSOCS1 and 3 in brain and liver at the mRNA and protein levels were significantly decreased, while their expressions showed an opposite trend in gill. Different from the expressions of TfSOCS1 and 3, the expression of TfSOCS2 was inhibited in gill, along with its increased expression in brain and liver. After normoxic recovery ($7.0{\pm}0.3mg/L$ of DO for 4 and 12 h), most of TfSOCS genes were significantly altered at R4 (reoxygenation for 4 h) and returned to the normal level at R12 (reoxygenation for 12 h). SOCS genes played vital roles in response to hypoxia/reoxygenation challenge. Our findings greatly strengthened the relation between innate immune and hypoxia stress in T. fasciatus.

Various vertical motions and mechanisms in intraplate settings (판 내부 융기 운동의 다양한 스케일과 매커니즘)

  • SHIN, Jaeryul
    • Journal of The Geomorphological Association of Korea
    • /
    • v.19 no.3
    • /
    • pp.153-163
    • /
    • 2012
  • The Earth's surface deforms vertically in response to a variety of sources relating to lithospheric and sub-lithospheric processes, and distinguishing the continental mechanisms for vertical motions of the lithosphere remains a fundamental challenge in geosciences. A key prerequisite to the challenge is documentation of the temporal and spatial pattern of vertical motions in different tectonic settings. This study is aimed at elucidating the geodynamic factors that can contribute to vertical motions of the Earth's surface in intraplate continental settings including the Neogene uplift in the Korean peninsula based on numerous recent achievements in relevant fields. Ultimately, deciphering the interplay between the Earth's surface and the Earth's interior processes leads us to the notion of "the importance of geomorphic landscape" as a prism to view the dynamics of the Earth's inside.

The Correlation between NaCl Adaptation and Heat Sensitivity of Listeria monocytogenes, a Foodborne Pathogen through Fresh and Processed Meat

  • Lee, Jeeyeon;Ha, Jimyeong;Kim, Sejeong;Lee, Soomin;Lee, Heeyoung;Yoon, Yohan;Choi, Kyoung-Hee
    • Food Science of Animal Resources
    • /
    • v.36 no.4
    • /
    • pp.469-475
    • /
    • 2016
  • This study examined the relationship between NaCl sensitivity and stress response of Listeria monocytogenes. Nine strains of L. monocytogenes (NCCP10805, NCCP10806, NCCP10807, NCCP10808, NCCP10809, NCCP10810, NCCP10811, NCCP10920 and NCCP 10943) were exposed to 0%, 1%, 2% and 4% NaCl, and then incubated at 60℃ for 60 min to select strains that were heat-sensitized (HS) and non-sensitized (NS) by NaCl exposure. After heat challenge, L. monocytogenes strains were categorized as HS (NCCP 10805, NCCP10806, NCCP10807, NCCP10810, NCCP10811 and NCCP10920) or NS (NCCP10808, NCCP10809 and NCCP10943). Total mRNA was extracted from a HS strain (NCCP10811) and two NS strains (NCCP10808 and NCCP10809), and then cDNA was prepared to analyze the expression of genes (inlA, inlB, opuC, betL, gbuB, osmC and ctc) that may be altered in response to NaCl stress, by qRT-PCR. The expression levels of two invasion-related genes (inlA and inlB) and two stress response genes (opuC and ctc) were increased (p<0.05) in NS strains after NaCl exposure in an NaCl concentration-dependent manner. However, only betL expression was increased (p<0.05) in the HS strains. These results indicate that the effect of NaCl on heat sensitization of L. monocytogenes is strain dependent and that opuC and ctc may prevent NS L. monocytogenes strains from being heat sensitized by NaCl. Moreover, NaCl also increases the expression of invasion-related genes (inlA and inlB).

Finite Element Modeling of Perturbation Fields due to Colonies of Stress Corrosion Cracks(SCCs) in a Gas Transmission Pipeline (가스공급배관에서 응력부식균열 군에 의해 교란된 자속의 유한요소 모델링)

  • Yang, Sun-Ho
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.21 no.5
    • /
    • pp.493-500
    • /
    • 2001
  • The detection of axial cracks using conventional MFL pig is a significant challenge in the gas pipeline inspection. In this study, a technique using interaction of circumferentially induced torrents with axial stress corrosion crack is presented. The feasibility of this technique is investigated using finite element modeling. Finite element analysis of such interaction is a difficult problem in terms of both computation time and memory requirements. The challenges arise due to the nonlinearity of material properties, the small sire of tight cracks relative to that of the magnetizer, and also time stepping involved in modeling velocity effects. This paper presents an approach based on perturbation methods. The overall analysis procedure is divided into 4 simple steps that can be performed sequentially. Modeling results show that this technique can effectively detect colonies of SCC as well as single SCC.

  • PDF

Involvement of the OsMKK4-OsMPK1 Cascade and its Downstream Transcription Factor OsWRKY53 in the Wounding Response in Rice

  • Yoo, Seung Jin;Kim, Su-Hyun;Kim, Min-Jeong;Ryu, Choong-Min;Kim, Young Cheol;Cho, Baik Ho;Yang, Kwang-Yeol
    • The Plant Pathology Journal
    • /
    • v.30 no.2
    • /
    • pp.168-177
    • /
    • 2014
  • Plant has possessed diverse stress signals from outside and maintained its fitness. Out of such plant responses, it is well known that mitogen-activated protein kinase (MAPK) cascade plays important role in wounding and pathogen attack in most dicot plants. However, little is understood about its role in wounding response for the economically important monocot rice plant. In this study, therefore, the involvement of MAPK was investigated to understand the wounding signaling pathway in rice. The OsMPK1 was rapidly activated by wounding within 10 min, and OsMPK1 was also activated by challenge of rice blast fungus. Further analysis revealed that OsMKK4, the upstream kinase of OsMPK1, phosphorylated OsMPK1 by wounding in vivo. Furthermore, OsMPK1 directly interacted with a rice defense-related transcription factor OsWRKY53. To understand a functional link between MAPK and its target transcription factor, we showed that OsMPK1 activated by the constitutively active mutant $OsMKK4^{DD}$ phosphorylated OsWRKY53 in vitro. Taken together, components involving in the wounding signaling pathway, OsMKK4-OsMPK1-OsWRKY53, can be important players in regulating crosstalk between abiotic stress and biotic stress.