• Title/Summary/Keyword: failure mechanisms

Search Result 672, Processing Time 0.035 seconds

Apoptosis in the Bovine Blastocyst following Nnclear Transfer and In Vitro Fertilization (핵치환과 체외수정에 유래된 소의 배반포에서의 Apoptosis)

  • Kim, . E.H;D.W. Han;K.S. Chung;Lee, H.T.
    • Korean Journal of Animal Reproduction
    • /
    • v.26 no.2
    • /
    • pp.173-182
    • /
    • 2002
  • The mechanisms underlying of the visual assessment and resulting in optimum embryonic development following in vitro maturation, fertilization, and culture are unclear, It was known that in vitro produced embryos show more frequent occurrence of fragmentation, which resulted in poor developmental potential and decreased implantation rate. The objective of this study was to investigate the apoptotic rates in bovine blastocyst derived from in vitro fertilization (IVF) and nuclear transfer (NT). In addition, the expression levels of Bcl-2 and Bax gene were investigated in the blastocyst to confirm their potential roles in the regulation of apoptosis during preimplantation embryonic development. Analysis of apoptosis was carried out by using terminal deoxynucleotidyl transferase mediate dUTP nick end labeling (TUNEL) method. The levels of Bcl-2 and Bax gene in the blastocyst derived from IVF and NT were determined by RT-PCR. The proportion of TUNEL positive signal in blastocyst derived from NT was significantly higher than that in blastocyst derived from IVF (p<0.001). Bcl-2 expression level of blastocyst derived from IVF was higher than that of blstocyst derived from NT. However, high expression level of Bax was observed in the blastocyst derived from NT. These results indicates that apoptosis is more responsible for fiagmentation in bovine blastocyst derived from NT than IVF. These results suggested that the increase of developmental failure followed by NT could be caused by nuclear fragmentation as apoptosis.

Inhibitory Effect of Stephanniae Tetrandrae Radix Extract on $TNF-{\alpha}$, $IL-1{\beta}$, IL-6 and Nitric Oxide Production in Lipopolysaccharide - Activated RAW 264.7 Cells (방기(防己) 추출물이 LPS로 유도된 Raw 264.7 cell에서의 $TNF-{\alpha}$, $IL-1{\beta}$, IL-6 및 Nitric Oxide Production에 미치는 영향)

  • Kim, Dae-Hee;Lee, Jong-Rok;Byun, Sung-Hui;Shin, Sang-Woo;Kwon, Young-Kyu;Kim, Sang-Chan
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.20 no.4
    • /
    • pp.902-908
    • /
    • 2006
  • Tetrandra is the root of Stephania tetrandra 5. Moore (family Menispermaceae), or of Aristolochia frangchi Wu (family Aristolochiaceae). It is a Differ-flavored and cold-property herb acting on the urinary bladder, kidney and spleen meridiands. Known biological effects of this herb are expelling wind to relieve pain and inducing diuresis to alleviate edema. This herb also has anti-inflammatory and anti-hypersensitivity actions. Recent studies have shown that Stephanniae Tetrandrae Radix has antimicrobial effects, namely, a protective effect on acute renal failure induce by gentamicin sulfate and a suppressive effect against clostridium perfringes. However, there is a lack of studies concerning the immunological activities of this herb. The present study was conducted to evaluate the immunological activities of Stephanniae Tetrandrae Radix on the regulatory mechanisms of cytokines and nitric oxide (NO) in Raw 264.7 cells. Cell viability was measured by MTT assay after the treatment of Stephanniae Tetrandrae Radix extract (STRE) and NO production was monitored by measuring the nitrite content in culture medium. COX-2 and iNOS were determined by immunoblot analysis, and levels of cytokine were analyzed by sandwich immunoassays. Results provided evidences that STRE inhibited the production of nitrite and nitrate (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$, $interleukin-1{\beta}(IL-1{\beta})$ and interleukin-6 (IL-6) in Raw 264.7 cells activated with lipopolysaccharide (LPS). These findings showed that STRE could produce some anti-inflammatory effects which might play a role in adjunctive therapy in Gram-negative bacterial infections.

Spinocerebellar ataxia 7 (SCA7) (척수소뇌성 운동실조증 제7형)

  • Seon-Yong, Jeong;Seok-Hun, Jang;Hyon-J., Kim
    • Journal of Genetic Medicine
    • /
    • v.4 no.1
    • /
    • pp.22-37
    • /
    • 2007
  • The autosomal dominant spinocerebellar ataxias (SCAs) are a group of neurodegenerative diseases, clinically and genetically heterogeneous, characterized by degeneration of spinocerebellar pathways with variable involvement of other neural systems. At present, 27 distinct genetic forms of SCAs are known: SCA1-8, SCA10-21, SCA23, SCA25-28, DRPLA (dentatorubral-pallidoluysian atrophy), and 16q-liked ADCA (autosomal dominant cerebellar ataxia). Epidemiological data about the prevalence of SCAs are restricted to a few studies of isolated geographical regions, and most do not reflect the real occurrence of the disease. In general a prevalence of about 0.3-2 cases per 100,000 people is assumed. As SCA are highly heterogeneous, the prevalence of specific subtypes varies between different ethnic and continental populations. Most recent data suggest that SCA3 is the commonest subtype worldwide; SCA1, SCA2, SCA6, SCA7, and SCA8 have a prevalence of over 2%, and the remaining SCAs are thought to be rare (prevalence <1%). In this review, we highlight and discuss the SCA7. The hallmark of SCA7 is the association of hereditary ataxia and visual loss caused by pigmentary macular degeneration. Visual failure is progressive, bilateral and symmetrical, and leads irreversibly to blindness. This association represents a distinct disease entity classified as autosomal dominant cerebellar ataxia (ADCA) type II by Harding. The disease affectsprimarily the cerebellum and the retina by the moderate to severe neuronal loss and gliosis, but also many other central nervous system structures as the disease progresses. SCA7 is caused by expansion of an unstable trinucleotide CAG repeat in the ATXN7 gene encoding a polyglutamine (polyQ) tract in the corresponding protein, ataxin-7. Normal ATXN7 alleles contain 4-35 CAG repeats, whereas pathological alleles contain from 36->450 CAG repeats. Immunoblott analysis demonstrated that ataxin-7 is widely expressed but that expression levels vary among tissues. Instability of expanded repeats is more pronounced in SCA7 than in other SCA subtypes and can cause substantial lowering of age at onset in successive generations termed ‘anticipation’ so that children may become diseased even before their parents develop symptoms. The strong anticipation in SCA7 and the rarity of contractions should have led to its extinction within a few generations. There is no specific drug therapy for this neurodegenerative disorder. Currently, therapy remains purely symptomatic. Cellular models and SCA7 transgenic mice have been generated which constitute valuable resources for studying the disease mechanism. Understanding the pathogenetic mechanisms of neurodegeneration in SCAs should lead to the identification of potential therapeutic targets and ultimately facilitate drug discovery. Here we summarize the clinical, pathological, and genetic aspects of SCA7, and review the current understanding of the pathogenesis of this disorder. Further, we also review the potential therapeutic strategies that are currently being explored in polyglutamine diseases.

  • PDF

Dynamic Behavior Characteristics of Group Piles with Relative Density in Sandy Soil (건조 모래지반의 상대밀도에 따른 무리말뚝의 동적거동특성)

  • Heungtae Kim;Hongsig Kang;Kusik Jeong;Kwangkuk Ahn
    • Journal of the Korean GEO-environmental Society
    • /
    • v.24 no.9
    • /
    • pp.33-40
    • /
    • 2023
  • The lateral load which is applied to the pile foundation supporting the superstructure during an earthquake is divided into the inertia force of the upper structure and the kinematic force of the ground. The inertia force and the kinematic force could cause failure to the pile foundation through different complex mechanisms. So it is necessary to predict and evaluate interaction of the ground-pile-structure properly for the seismic design of the foundation. The interaction is affected by the lateral behavior of the structure, the length of the pile, the boundary conditions of the head, and the relative density of the ground. Confining pressure and ground stiffness change accordingly when the relative density changes, and it results that the coefficient of subgrade reaction varies depending on each system. Horizontal bearing behavior and capacity of the pile foundation vary depending on lateral load condition and relative density of the sandy soil. Therefore, the 1g shaking table tests were conducted to confirm the effect of the relative density of the dried sandy soil to dynamic behavior of the group pile supporting the superstructure. The result shows that, as the relative density increases, maximum acceleration of the superstructure and the pile cap increases and decreases respectively, and the slope of the p-y curve of the pile decreases.

Numerical Analyses on the Behavioral Characteristics of Side of Drilled Shafts in Rocks and Suggestion of Design Charts (수치해석을 통한 암반에 근입된 현장타설말뚝의 주면부 거동특성 분석 및 설계차트 제시)

  • Lee, Hyuk-Jin;Kim, Hong-Taek
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.6C
    • /
    • pp.407-419
    • /
    • 2006
  • Situations where support is provided solely in shaft resistance of drilled shafts are where the base of the drilled hole cannot be cleaned so that it is uncertain that any end bearing support will be developed. Alternatively, where sound bed rock underlies low strength overburden material, it may be possible to achieve the required support in end bearing on the rock only, and assume that no support is developed in the overburden. However, where the drilled shaft is drilled some depth into sound rock, a combination of side wall resistance and end bearing can be assumed. Both theoretical and field studies of the performance of rock socketed drilled shafts show that the major portion of applied load is usually carried in side wall resistance. Normal stress at the rock-concrete interface is induced by two mechanisms. First, application of a compressive load on the top of the pile results in elastic dilation of the concrete, and second, shear displacement at the rough surface of the drilled hole results in mechanical dilation of the interface. If the stiffness of the material surrounding the socket with respect to normal displacement is constant, then the normal stress will increase with increasing applied load, and there will be a corresponding increase in the shear strength. In this study, the numerical analyses are carried out to investigate the behavioral characteristics of side of rock socketed drilled shafts. The cause of non-linear head load-settlement relationship and failure mechanism at side are also investigated properly and the design charts are suggested and verified for the leading to greater efficiency and reliability in the pile design.

Promising Therapeutic Effects of Embryonic Stem Cells-Origin Mesenchymal Stem Cells in Experimental Pulmonary Fibrosis Models: Immunomodulatory and Anti-Apoptotic Mechanisms

  • Hanna Lee;Ok-Yi Jeong;Hee Jin Park;Sung-Lim Lee;Eun-yeong Bok;Mingyo Kim;Young Sun Suh;Yun-Hong Cheon;Hyun-Ok Kim;Suhee Kim;Sung Hak Chun;Jung Min Park;Young Jin Lee;Sang-Il Lee
    • IMMUNE NETWORK
    • /
    • v.23 no.6
    • /
    • pp.45.1-45.22
    • /
    • 2023
  • Interstitial lung disease (ILD) involves persistent inflammation and fibrosis, leading to respiratory failure and even death. Adult tissue-derived mesenchymal stem cells (MSCs) show potential in ILD therapeutics but obtaining an adequate quantity of cells for drug application is difficult. Daewoong Pharmaceutical's MSCs (DW-MSCs) derived from embryonic stem cells sustain a high proliferative capacity following long-term culture and expansion. The aim of this study was to investigate the therapeutic potential of DW-MSCs in experimental mouse models of ILD. DW-MSCs were expanded up to 12 passages for in vivo application in bleomycin-induced pulmonary fibrosis and collagen-induced connective tissue disease-ILD mouse models. We assessed lung inflammation and fibrosis, lung tissue immune cells, fibrosis-related gene/protein expression, apoptosis and mitochondrial function of alveolar epithelial cells, and mitochondrial transfer ability. Intravenous administration of DWMSCs consistently improved lung fibrosis and reduced inflammatory and fibrotic markers expression in both models across various disease stages. The therapeutic effect of DW-MSCs was comparable to that following daily oral administration of nintedanib or pirfenidone. Mechanistically, DW-MSCs exhibited immunomodulatory effects by reducing the number of B cells during the early phase and increasing the ratio of Tregs to Th17 cells during the late phase of bleomycin-induced pulmonary fibrosis. Furthermore, DW-MSCs exhibited anti-apoptotic effects, increased cell viability, and improved mitochondrial respiration in alveolar epithelial cells by transferring their mitochondria to alveolar epithelial cells. Our findings indicate the strong potential of DW-MSCs in the treatment of ILD owing to their high efficacy and immunomodulatory and anti-apoptotic effects.

Detection of Multidrug Resistance Using Molecular Nuclear Technique (분자핵의학 기법을 이용한 다약제내성 진단)

  • Lee, Jae-Tae;Ahn, Byeong-Cheol
    • The Korean Journal of Nuclear Medicine
    • /
    • v.38 no.2
    • /
    • pp.180-189
    • /
    • 2004
  • Although the outcome of cancer patients after cytotoxic chemotherapy is related diverse mechanisms, multidrug resistance (MDR) for chemotherapeutic drugs due to cellular P-glycoprotein (Pgp) or multidrug-resistance associated protein (MRP) is most important factor in the chemotherapy failure to cancer. A large number of pharmacologic compounds, including verapamil, quinidine, tamoxifen, cyclosporin A and quinolone derivatives have been reported to overcome MDR. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are available for the detection of Pgp and MRP-mediated transporter. $^{99m}Tc$-MIBI and other $^{99m}Tc$-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies for tumor imaging, and to visualize blockade of PgP-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with $^{11}C$ have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and $N-[^{11}C]acetyl-leukotriene$ E4 provides an opportunity to study MRP function non-invasively in vivo. SPECT and PET pharmaceuticals have successfully used to evaluate pharmacologic effects of MDR modulators. Imaging of MDR and reversal of MDR with bioluminescence in a living animal is also evaluated for future clinical trial. We have described recent advances in molecular imaging of MDR and reviewed recent publications regarding feasibility of SPECT and PET imaging to study the functionality of MDR transporters in vivo.

Effects of Aminotriazole on Lung Toxicity of Paraquat Intoxicated Mice (Paraquat중독에 의한 폐독성에 미치는 Aminotriazole의 영향)

  • Lee, Seung-Il;An, Gi-Wan;Chung, Choon-Hae
    • Tuberculosis and Respiratory Diseases
    • /
    • v.41 no.3
    • /
    • pp.222-230
    • /
    • 1994
  • Background: Paraquat, a widely used herbicide, is extremely toxic, causing multiple organ failure in humans. Paraquat especially leads to irreversible progressive pulmonary fibrosis, which is related to oxygen free radicals. However, its biochemical mechanism is not clear. Natural mechanisms that prevent damage from oxygen free radicals include changes in glutathione level, G6PDH, superoxide dismutase(SOD), catalase, and glutathione peroxidase. The authors think catalase is closely related to paraquat toxicity in the lungs Method: The effects of 3-amino-1,2,4-triazole(aminotriazole), a catalase inhibitor, on mice administered with paraquat were investigated. We studied the effects of aminotriazole on the survival of mice administered with paraquat, by comparing life spans between the group to which paraquat had been administered and the group to which a combination of paraquat and aminotriazole had been administered. We measured glutathion level, glucose 6-phosphate dehydrogenase(G6PDH), superoxide dismutase(SOD), catalase, and glutathione peroxidase(GPx) in the lung tissue of 4 groups of mice: the control group, group A(aminotriazole injected), group B(paraquat administered), group C(paraquat and aminotriazole administered). Results: The mortality of mice administered with paraquat which were treated with aminotriazole was significantly increased compared with those of mice not treated with aminotriazole. Glutathione level in group B was decreased by 20%, a significant decrease compared with the control group. However, this level was not changed by the administration of aminotriazole(group C). The activity of G6PDH in all groups was not significantly changed compared with the control group. The activities of SOD, catalase, and glutathione peroxidase(GPx) in the lung tissue were significantly decreased by paraquat administration(group B); catalase showed the largest decrease. Catalase and GPX were significantly decreased by aminotriazole treatment in mice administered with paraquat but change in SOD activity was not significant(group C). Conclusion: Decrease in catalase activity by paraquat suggests that paraquat toxicity in the lungs is closely related to catalase activity. Paraquat toxicity in mice is enhanced by aminotriazole administration, and its result is related to the decrease of catalase activity rather than glutathione level in the lungs. Production of hydroxyl radicals, the most reactive oxygen metabolite, is accelerated due to increased hydrogen peroxide by catalase inhibition and the lung damage probably results from nonspecific tissue injury of hydroxyl radicals.

  • PDF

Synchronized Synergism Using Ethanol, L-lysine and $NaBH_4$ Glutaraldehyde Treated Porcine Pericardium (글루타르알데하이드 고정 돼지 심낭에서 Ethanol, L-lysine, $NaBH_4$ 병합 처치시 상승효과)

  • Kim, Kwan-Chang;Kim, Yong-Jin;Kim, Soo-Hwan;Choi, Seung-Hwa
    • Journal of Chest Surgery
    • /
    • v.42 no.6
    • /
    • pp.685-695
    • /
    • 2009
  • Background: Calcification is the most frequent cause of clinical failure of bioprosthetic tissues that are fabricated from Glutaraldehyde (GA)-fixed porcine valve or bovine pericardium. We recently used a multi-factorial approach of employing different mechanisms to investigate how to reduce the calcification of bioprosthetic tissues. The purpose of the present study was to evaluate the synchronized synergism using ethanol, L-lysine and $NaBH_4$ in glutaraldehyde treated porcine pericardium from the standpoint of calcification and tissue elasticity. Material and Method: Porcine pericardium was fixed with 0.625% GA (commercial fixation). An interim step of ethanol (80%; 1 day at room temperature) or L-lysine (0.1 M; 2 days at $37^{\circ}C$) or $NaBH_4$ (0.1 M; 2 days at room temperature) was followed by completion of the GA fixation (2 days at $4^{\circ}C$ and 7 days at room temperature). The tensile strength and thickness of the samples were measured. The treated pericardiums were implanted subcutaneously into three-week old Sprague-Dawley rats for 8 weeks. The calcium content was assessed by atomic absorption spectroscopy and the histology of the samples. Result: The amount of calcium in the pericardium pretreated with ethanol (13.6${\pm}$10.0 ug/mg, p=0.008), L-lysine (15.3${\pm}$1.0 ug/mg, p=0.002) and both (16.1${\pm}$11.1 ug/mg, p=0.012) was significantly reduced compared with the control (51.2${\pm}$8.5 ug/mg). However, $NaBH_4$ pretreatment (65.7${\pm}$61.8 ug/mg, p=0.653) and combined pretreatment that including ethanol, L-lysine and $NaBH_4$ (92.9${\pm}$58.3 ug/mg, p=0.288) were not significantly different from the controls(51.2${\pm}$8.5 ug/mg). Both the combined pretreatment using ethanol and L-lysine (7.60${\pm}$1.55, p=0.76) and the combined pretreatment that included ethanol, L-lysine and $NaBH_4$ (7.47${\pm}$1.85, p=0.33) increased the tensile strength/thickness ratio compared with that of the controls (4.75${\pm}$1.88). Conclusion: The combined pretreatment using ethanol and L-lysine seemed to decrease the calcification of porcine pericardium fixed with glutaraldehyde, as compared to single pretreatment, and it increase the tissue elasticity, but to the degree that showed synchronized synergism. $NaBH_4$ pretreatment seemed to increase the calcification of porcine pericardium, irrespective of whether single or combined pretreatment was used.

A Study of Zhuxi's Daoxuezhengzhi(道學政治) through his political frustration in the partisan struggle of 1196 Qingyuandanghuo(慶元黨禍) (1196년 경원당화(慶元黨禍)의 사상정국에서 주희의 정치적 좌절을 통해서 본 주희의 도학정치고찰)

  • Lee, Wook-Keun
    • (The)Study of the Eastern Classic
    • /
    • no.37
    • /
    • pp.473-507
    • /
    • 2009
  • The purpose of this study is to understand Zhuxi's Taoxuezhengzhi(道學政治) by reorganizing both his political opinion in each different political situation and his consistent political consciousness appeared in his whole political career. He concluded that the politics was the real problematic in Southern Sung, which made its structure distorted. This distorted structure of politics had widely rooted in whole sphere of society. In order to cure this political problematic, Zhuxi had focused on huangdi(皇帝) and chaoting(朝廷). That is why people is the basis of State and the result of politics, while huangdi and chaoting is the basis of politics and the beginnig of politics. According to Zhuxi, forming their political power group of their own will by using huangdi's power, the political elites close to only to huangdi made the function of chaoting unstable, with the result that the political decay produced. In chaoting, it resulted in the weakness of huangdi's power, the collapse of official discipline(紀綱), and the absence of public opinion(公論) and public aggreement(公議). Beyond chaoting, it resulted in the absence of political trust and the degeneration of public morals(風俗). In the Southern Sung were not altered the political orientation and culture based on the political decay, but only political orientation and characteristics of political elite only altered. This proves Zhuxi's approach that all problems in Southern Sung could resolve by the political approach. Zhuxi had suggested political issues in office. The alternatives for those political issues had basis of the theme, the one that saving people(恤民) is the purpose of politics. However his political ideas and the execution of them had been occsionally collapsed by the complex political structue, the mechanisms of political power, and the sameness and privatization of political geography in Southern Sung. Qingyuandanghuo(慶元黨禍) was the final stage of his political frustration, with the result that it led to the failure of Zhuxi's taoxuezhengzhi and interrupted the tradition of taoxue(道學) for the time being.