• Title/Summary/Keyword: preclinical study

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Evaluating Course of Pediatric Dentistry on Correlation Analysis between Dental Students' Achievements of Subjects and OSCE (임상술기능력평가와 교과목간의 학업성취도 분석을 통한 소아치과학의 교육과정 평가)

  • Bang, Jaebeum;Rim, Jaeyoung;Park, Jaehong
    • Journal of the korean academy of Pediatric Dentistry
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    • v.40 no.4
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    • pp.253-259
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    • 2013
  • This study aimed to evaluate the courses of pediatric dentistry based on correlation analysis between scores of objective structured clinical examination (OSCE) and related subjects for 79 fourth-year students. The score of theory were related to preclinical (r = 0.449, p = 0.000) and clerkship (r = 0.437, p = 0.000) each, but the scores of clerkship were not related to OSCE. To make the students skillful for clerkship, more professor's firsthand teaching on treating patients and adequate numbers of clinical professors are required. Patients who come to the university dental hospital prefer to be treated by professors rather than students. In these circumstances, educational conditions should be arranged by ensuring the number of professors for teaching students to improve their clinical competence through direct instruction and feedback to students. In addition, pragmatic improvement plans, which allow continuous education and evaluation about basic techniques to be examined in the clinical practice course, should be compromised with the more concrete evaluation of the curriculum in order to evaluate theoretical knowledge and technical trainings to be well exercised and deepened in the practical clinical field.

Imaging Studies in Mouse Brain Using Clinical 3T MRI Scanner (임상용 3T MRI를 이용한 마우스 뇌의 영상)

  • Lim, Soo-Mee;Park, Eun-Mi
    • Progress in Medical Physics
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    • v.21 no.4
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    • pp.348-353
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    • 2010
  • The purpose of this study was to explore the potentials of a clinical 3T MRI in mouse brains and technical adaptation and optimization. T1-weighted images (T1WI), T2-weighted images (T2WI), FLAIR (Fluid Attenuated Inversion Recovery) images, Gadolinium enhanced T1-weighted images (Gd-T1WI), Diffusion weighted images (DWI) were acquired in brain of 2 mice (weight 20~25 g) with cerebral infarction by occlusion of right middle cerebral artery, 1 hour, 24 hours, 72 hours after infarction and 1 normal mouse brain using clinical 3T MRI scanner. We analyzed differentiation of striatum, ventricle, cerebral cortex, and possibility of detection of acute cerebral infarction. We could differentiate the striatum, ventricle, cerebral cortex on T2WI and on DWI, FLAIR, T1WI, the differentiation of each anatomy of brain was not definite, but acute cerebral infarction was detected on DWI of 1 hour, 24 hours, 72 hours after infarction and on T2WI, FLAIR of 24 hours, 72 hours after infarction. Clinical 3T MRI can be used in differentiation of anatomy of mouse brains and DWI can be helpul in detection of acute cerebral infarction in acute phase. With technical adaptation and optimization clinical 3T MRI can be useful tool for provide preclinical and clinical small animal studies.

Anti-cancer Effect of Hematopoietic Stem Cell-derived Allogeneic-DC Vaccine in Melanoma Metastasis Model (마우스 동종 줄기세포 유래 수지상 세포를 이용한 백신의 흑색종 폐암 전이 모델에서의 항암 효과 및 기전 연구)

  • Kim, Myoung-Joo;Shon, Hye-Jin;Baek, So-Young;Lee, Kang-Eun;Lee, Young-Joon;Lee, Hyun-Ah
    • IMMUNE NETWORK
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    • v.6 no.3
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    • pp.154-162
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    • 2006
  • Background: Dendritic cell (DC)-based cancer immunotherapy is studied for several years. However, it is mainly derived from autologous PBMC or leukapheresis from patient, which has limitations about yield and ability of DC production according to individual status. In order to solve these problems, inquiries about allogeneic DCs are performed but there are no preclinical trial answers for effect or toxicity of allogeneic DC to use for clinical trial. In this study, we compared the anti-tumor effect of allogeneic and autologous DCs from mouse bone marrow stem cells in mouse metastatic melanoma model. Methods: B16F10 melanoma cells ($5{\times}10^4$/mouse) were injected intravenously into the C57BL/6 mouse. Therapeutic DCs were differentiated from autologous (C57BL/6: CDC) or allogeneic (B6C3F1: BDC) bone marrow stem cells with GM-CSF, SCF and IL-4 for 13days and pulsed with B16F10 tumor cell lysate (Blys) for 18hrs. DC intra-peritoneal injections began on the 8th day after the tumor cell injection by twice with one week interval. Results: Anti-tumor response was observed by DC treatment without any toxicity especially in allogeneic DC treated mice (tumor burden score: $2.667{\pm}0.184,\;2.500{\pm}0.463,\;2.000{\pm}0.286,\;1.500{\pm}0.286,\;1.667 {\pm}0.297$ for saline, CDC/unpulsed-DC: U-DC, CDC/Blys-DC, BDC/U-DC and BDC/Blys-DC, respectively). IFN-${\gamma}$ secretion was significantly increased in allogeneic DC group stimulated with B16F10 cell lysate ($2,643.3{\pm}5,89.7,\;8,561.5{\pm}2,204.9.\;6,901.2{\pm}141.1pg/1{\times}10^6$ cells for saline, BDC/U-DC and BDC/Blys-DC, respectively) with increased NK cell activity. Conclusion: Conclusively, promising data was obtained that allogeneic DC can be used for DC-based cancer immunotherapy.

Antioxidant Activity and Inhibitory Effect of Aster scaber Thunb. Extract on Adipocyte Differentiation in 3T3-L1 Cells (참취(Aster scaber Thunb.) 추출물의 항산화 효과와 3T3-L1 지방전구세포에서의 지방분화 억제 효과)

  • Choi, Jun-Hyeok;Park, Yun-Hee;Lee, In-Seon;Lee, Sam-Pin;Yu, Mi-Hee
    • Korean Journal of Food Science and Technology
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    • v.45 no.3
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    • pp.356-363
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    • 2013
  • Clinical and preclinical trials of involving drugs with anti-obesity effects have focused on screening for herbal medicines suspected to have anti-obesity activities. In this study, an extract of Aster scaver Thunb., which was prepared in 80% methanol (ASE), was assessed for its total phenol content, total flavonoid content, antioxidant activity ability to scavenge the ${\alpha}-{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl, 2,2'-azino-bis-[3-ethylbenzthiazoline]-6-sulfonic acid radical, and anti-adipogenic effects. The anti-adipogenic effect of ASE on the differentiation of 3T3-L1 pre-adipocytes to adipocytes was investigated by assaying the suppression of adipocyte differentiation and lipid accumulation by using western blot analysis and the Oil Red-O assay, respectively. The staining results showed that ASE significantly inhibited 3T3-L1. Western blot analysis results showed that ASE decreased the levels of peroxisome proliferator-activated receptor-${\gamma}$, CCAAT/enhancer-binding protein ${\alpha}$, and sterol regulatory element-binding protein 1c. These results demonstrate that ASE directly inhibits the differentiation of preadipocytes, and might be an important adjunct in the therapeutic efforts to reduce adipogenesis.

Serum fatty acids, biochemical indices and antioxidant status in goats fed canola oil and palm oil blend

  • Adeyemi, Kazeem D.;Sabow, Azad B.;Aghwan, Zeiad A.;Ebrahimi, Mahdi;Samsudin, Anjas A.;Alimon, Abdul R.;Sazili, Awis Q.
    • Journal of Animal Science and Technology
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    • v.58 no.2
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    • pp.6.1-6.11
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    • 2016
  • Background: Dietary supplementation of unsaturated fats in ruminants, if not stabilized, can instigate oxidative stress which can have negative impact on production performance and enhance the susceptibility to various diseases. The current study examined the effect of dietary 80 % canola oil and 20 % palm oil blend (CPOB) on serum fatty acids, antioxidant profile and biochemical indices in goats. Thirty Boer bucks (4-5 months old; initial BW, $20.34{\pm}0.77kg$) were randomly assigned to diets containing 0, 4 or 8 % CPOB and fed daily for a period of 90 days. Blood was sampled from the goats on 0, 30, 60 and 90 days of the trial and the serum was analyzed for fatty acids, cholesterol, glucose, total protein, antioxidants and lipid oxidation. Results: Neither diet nor sampling time influenced serum TBARS value, catalase, glutathione peroxidase and superoxide dismutase activities, LDL cholesterol, VLDL cholesterol, triglycerides, glucose and total protein. Goats fed 4 and 8 % CPOB had higher (P < 0.05) total cholesterol and HDL cholesterol than the control goats on day 30, 60 and 90. The proportion of C15:0 decreased with increasing level of CPOB on day 30 and 60. Serum C18:1n-9 increased with increasing level of CPOB in diet on day 60. The proportion of C18:3n-3 and C22:5n-3 increased (P < 0.05), while the proportion of C18:2n-6 decreased (P < 0.05) with increase in the level of CPOB on day 60 and 90. Dietary CPOB did not affect serum total carotenoid and ${\delta}$-tocopherol but did increase (P < 0.05) ${\alpha}$ and ${\gamma}$-tocopherol. Conclusion: Dietary canola oil and palm oil blend could be supplemented in diets without instigating oxidative stress in goats.

Anti-cancer Activity of Paclitaxel, Lenvatinib and Radiation Combination Therapy on Anaplastic Thyroid Cancer in Vitro and in Vivo (Paclitaxel, Lenvatinib 및 방사선 병용 요법의 역형성 갑상선암에서의 항암 작용)

  • Jun, Shiyeol;Kim, Soo Young;Kim, Seok-Mo;Park, Ki Cheong;Kim, Hee Jun;Chang, Ho Jin;Lee, Yong Sang;Chang, Hang-Seok;Park, Cheong Soo
    • Korean Journal of Head & Neck Oncology
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    • v.35 no.2
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    • pp.19-25
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    • 2019
  • Background/Objectives: Although anaplastic thyroid carcinoma (ATC) is rare, it is one of the deadliest forms of thyroid cancer. The fatality rate for ATC is high, and the survival rate at one year after diagnosis is <20%. The present study aimed to investigate the anti-tumor activities of paclitaxel, radiation, and tyrosine kinase inhibitor (TKI) combined therapy in anaplastic thyroid cancer cells both in vitro and in vivo and explore its effects on apoptotic cell death pathways. Materials & Methods: ATC cell line was exposed to TKI, lenvatinib in the presence or absence of paclitaxel with radiation, and cell viability was determined by MTT assay. Effects of the combined treatment on cell cycle and intracellular signaling pathways were assessed by flow cytometry and western blot analysis. The ATC cell line xenograft model was used to examine the anti-tumor activity in vivo. Results: Our data revealed that the combined administration of paclitaxel, TKI, and radiation decreased cell viability in ATC cells, and also significantly increased apoptotic cell death in these cells, as demonstrated by the cleavage of caspase-3 and DNA fragmentation. This combination therapy reduced anti-apoptotic factor levels in ATC cells, while significantly decreasing tumor volume and increasing survival in ATC xenografts. Conclusion: These results indicate that administering the combination of paclitaxel, TKI, and radiation therapy may exert significant anticancer effects in preclinical models, potentially suggesting a new clinical approach for treating patients with ATC.

Variation of Nephrotoxicity Biomarkers by Urinary Storage Condition in Rats

  • Lee, Jung-Min;Han, Young-Hwan;Choi, Su-Jeong;Park, Ju-Seong;Jang, Jeong-Jun;Bae, Re-Ji-Na;Lee, Mi Ju;Kim, Myoung Jun;Lee, Yong-Hoon;Kim, Duyeol;Lee, Hye-Young;Park, Sun-Hee;Park, Cheol-Beom;Kang, Jin Seok;Kang, Jong-Koo
    • Toxicological Research
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    • v.30 no.4
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    • pp.305-309
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    • 2014
  • Recently, there has been an increase in the use of several nephrotoxicity biomarkers in preclinical experiments. In addition, it has been indicated that the result may have been influenced by secondary factors, such as sample storage condition or storage period. In this study, we have assessed the variation in urinary nephrotoxicity biomarkers as a result of urine storage conditions and storage period of the urine. Urine was sampled from specific pathogen-free Sprague-Dawley rats (19 weeks old), which were housed individually in hanged stainless steel wire mesh cages. Urine was stored at $20^{\circ}C$, at $4^{\circ}C$, or at $-70^{\circ}C$ after sampling. The levels of the biomarkers such as beta-2 microglobulin (B2M), cystatin-C (Cys-C), N-acetyl-${\beta}$-D-glucosaminidase (NAG), micro albumin (MA), micro protein (MP) were measured at 6, 24, 48 and 144 hr after sampling. The B2M level was significantly decreased at 6, 24, 48, and 144 hr compared to 0 hr at $-70^{\circ}C$ (p < 0.05, p < 0.01, p < 0.05, and p < 0.05, respectively) and 24 and 144 hr at $20^{\circ}C$ (p < 0.01, p < 0.01, respectively). The Cys-C level was significantly decreased at 144 hr compared to 0 hr at $4^{\circ}C$ (p < 0.01), at $20^{\circ}C$ (p < 0.05) and at $70^{\circ}C$ (p < 0.01). MP and MA levels were not different for 144 hr in all storage conditions. Taken together, B2M and Cys-C levels were modulated by storage temperature and period. For the enhancement of test accuracy, it is suggested that strict protocols be established for samples to minimize the effects of the storage conditions on the detected levels of biomarkers.

Are critical size bone notch defects possible in the rabbit mandible?

  • Carlisle, Patricia L.;Guda, Teja;Silliman, David T.;Hale, Robert G.;Baer, Pamela R. Brown
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.45 no.2
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    • pp.97-107
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    • 2019
  • Objectives: Small animal maxillofacial models, such as non-segmental critical size defects (CSDs) in the rabbit mandible, need to be standardized for use as preclinical models of bone regeneration to mimic clinical conditions such as maxillofacial trauma. The objective of this study is the establishment of a mechanically competent CSD model in the rabbit mandible to allow standardized evaluation of bone regeneration therapies. Materials and Methods: Three sizes of bony defect were generated in the mandibular body of rabbit hemi-mandibles: $12mm{\times}5mm$, $12mm{\times}8mm$, and $15mm{\times}10mm$. The hemi-mandibles were tested to failure in 3-point flexure. The $12mm{\times}5mm$ defect was then chosen for the defect size created in the mandibles of 26 rabbits with or without cautery of the defect margins and bone regeneration was assessed after 6 and 12 weeks. Regenerated bone density and volume were evaluated using radiography, micro-computed tomography, and histology. Results: Flexural strength of the $12mm{\times}5mm$ defect was similar to its contralateral; whereas the $12mm{\times}8mm$ and $15mm{\times}10mm$ groups carried significantly less load than their respective contralaterals (P<0.05). This demonstrated that the $12mm{\times}5mm$ defect did not significantly compromise mandibular mechanical integrity. Significantly less (P<0.05) bone was regenerated at 6 weeks in cauterized defect margins compared to controls without cautery. After 12 weeks, the bone volume of the group with cautery increased to that of the control without cautery after 6 weeks. Conclusion: An empty defect size of $12mm{\times}5mm$ in the rabbit mandibular model maintains sufficient mechanical stability to not require additional stabilization. However, this defect size allows for bone regeneration across the defect. Cautery of the defect only delays regeneration by 6 weeks suggesting that the performance of bone graft materials in mandibular defects of this size should be considered with caution.

The Role of Autophagy in Depression (우울증에서 자가소화작용의 역할)

  • Seo, Mi Kyoung;Park, Sung Woo;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.32 no.10
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    • pp.812-820
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    • 2022
  • Depression is a psychiatric disorder characterized by depressed mood, anhedonia, fatigue, and altered cognitive function, leading to a decline in daily functioning. In addition, depression is a serious and common mental illness not only in an individual's life but also in society, so it must be actively treated. Autophagy is involved in the pathophysiological mechanism of mental illness. According to a recent study, it is known that autophagy-induced apoptosis affects neuroplasticity and causes depression and that antidepressants regulate autophagy. Autophagy is a catabolic process that degradation and removes unnecessary organelles or proteins through a lysosome. And, it is essential for maintaining cellular homeostasis. Autophagy is activated in stress conditions, and depression is a stress-related disease. Stress causes damage to cellular homeostasis. Recently, although the role of autophagy mechanisms in neurons has been investigated, the autophagy of depression has not been fully studied. This review highlights the new evidence for the involvement of autophagy in the pathophysiological mechanisms and treatment of depression. To highlight the evidence, we present results from clinical and preclinical studies showing that autophagy is associated with depression. Understanding the relevance of autophagy to depression and the limitations of research suggest that autophagy regulation may provide a new direction for antidepressant development.

Phosphodiesterase-5 Inhibitor Attenuates Anxious Phenotypes and Movement Disorder Induced by Mild Ischemic Stroke in Rats

  • Yu, Yeon Hee;Kim, Seong-Wook;Kang, Juhyeon;Song, Yejin;Im, yHyuna;Kim, Seo Jeong;Yoo, Dae Young;Lee, Man-Ryul;Park, Dae-Kyoon;Oh, Jae Sang;Kim, Duk-Soo
    • Journal of Korean Neurosurgical Society
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    • v.65 no.5
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    • pp.665-679
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    • 2022
  • Objective : Patients with mild ischemic stroke experience various sequela and residual symptoms, such as anxious behavior and deficits in movement. Few approaches have been proved to be effective and safe therapeutic approaches for patients with mild ischemic stroke by acute stroke. Sildenafil (SIL), a phosphodiesterase-5 inhibitor (PDE5i), is a known remedy for neurodegenerative disorders and vascular dementia through its angiogenesis and neurogenesis effects. In this study, we investigated the efficacy of PDE5i in the emotional and behavioral abnormalities in rats with mild ischemic stroke. Methods : We divided the rats into four groups as follows (n=20, respectively) : group 1, naïve; group 2, middle cerebral artery occlusion (MCAo30); group 3, MCAo30+SIL-pre; and group 4, MCAo30+SIL-post. In the case of drug administration groups, single dose of PDE5i (sildenafil citrate, 20 mg/kg) was given at 30-minute before and after reperfusion of MCAo in rats. After surgery, we investigated and confirmed the therapeutic effect of sildenafil on histology, immunofluorescence, behavioral assays and neural oscillations. Results : Sildenafil alleviated a neuronal loss and reduced the infarction volume. And results of behavior task and immunofluorescence shown possibility that anti-inflammation process and improve motor deficits sildenafil treatment after mild ischemic stroke. Furthermore, sildenafil treatment attenuated the alteration of theta-frequency rhythm in the CA1 region of the hippocampus, a known neural oscillatory marker for anxiety disorder in rodents, induced by mild ischemic stroke. Conclusion : PDE5i as effective therapeutic agents for anxiety and movement disorders and provide robust preclinical evidence to support the development and use of PDE5i for the treatment of mild ischemic stroke residual disorders.