• 제목/요약/키워드: Preclinical Study

검색결과 269건 처리시간 0.025초

Adjunctive effect of 470-nm and 630-nm light-emitting diode irradiation in experimental periodontitis treatment: a preclinical study

  • Dongseob Lee;Jungwon Lee;Sun-Hee Ahn;Woosub Song;Ling Li;Yang-Jo Seol;Yong-Moo Lee;Ki-Tae Koo
    • Journal of Periodontal and Implant Science
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    • 제54권1호
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    • pp.13-24
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    • 2024
  • Purpose: This study investigated the adjunctive effect of light-emitting diodes (LEDs) in the treatment of experimental periodontitis. Methods: Experimental periodontitis was induced by placing ligatures around the mandibular second, third, and fourth premolars of 6 beagles for 3 months. After ligature removal, periodontitis progressed spontaneously for 2 months. The animals' hemimandibles were allocated among the following 3 groups: 1) no treatment (control), 2) scaling and root planing (SRP), and 3) SRP with LED irradiation at 470-nm and 630-nm wavelengths (SRP/LED). The probing pocket depth (PPD) and gingival recession (GR) were measured at baseline, 6 weeks, and 12 weeks. The clinical attachment level (CAL) was calculated. After 12 weeks, histological and histomorphometric assessments were performed. The distances from the gingival margin to the apical extent of the junctional epithelium (E) and to the connective tissue (CT) attachment were measured, as was the total length of soft tissue (ST). Results: PPD and CAL increased at 12 weeks compared with baseline in the control group (6.31±0.43 mm to 6.93±0.50 mm, and 6.46±0.60 mm to 7.61±0.78 mm, respectively). PPD and CAL decreased at 12 weeks compared with baseline in the SRP group (6.01±0.59 to 4.81±0.65 mm, and 6.51±0.98 to 5.39±0.93 mm, respectively). PPD and CAL decreased at 12 weeks compared with baseline in the SRP/LED group (6.03±0.39 to 4.46±0.47 mm, and 6.11±0.47 to 4.78±0.57 mm, respectively). The E/ST and CT/ST ratios significantly differed among the 3 groups (P<0.05). The clinical parameters and histologic findings demonstrated that 470-nm and 630-nm wavelength LED irradiation accompanying SRP could improve treatment results. Conclusions: Within the study limitations, 470 nm and 630 nm wavelength LED irradiation might provide additional benefits for periodontitis treatment.

Medical Students Understanding of The Scope of Plastic Surgery

  • Mohammad K.H.B. Abdulaziz;Mohammad Al-Jamali;Sundus Al-Mazidi;Sarah Albuloushi;Ahmad B. Al-Ali
    • Archives of Plastic Surgery
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    • 제51권2호
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    • pp.251-257
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    • 2024
  • Background Plastic surgery has developed to benefit in a variety of challenging areas formerly handled by other disciplines. Medical students do not have a clear picture of plastic surgery as a career due to lacking scope, clinical practice, and understanding of plastic surgery as a clinical area of expertise, including general practitioners, nursing staff, medical trainees, and the general public, and misconceptions about the extent of reconstructive and plastic surgery. Methods A cross-sectional observational study was conducted on Kuwait University Medical students (2nd-7th Years) over a period of 1 month. A questionnaire and a consent form were provided to eligible students. The inclusion criteria were Kuwait University Medical students from 2nd to 7th Years with signed consent form. The response was collected via email sent in coordination with the Vice Dean of Student Affairs in the Faculty of Medicine. Using statistical package for the social sciences, responses were statistically analyzed. Pearson's chi-square test was used to calculate p-values, where p < 0.05 was considered statistically significant. Results A total of 244 eligible medical students, 121 males and 123 females, were included in the study, with a mean age of 21 (±2) years. Similarly, 126 (51.6%) were preclinical students (2nd-4th-year students), while 118 (48.4%) were clinical students (5th-7th-year students). About 79.8% of medical students believed that plastic surgery plays an essential role in trauma management, whereas 9.2% did not consider plastic surgery significant for trauma management. This study found that only 15.5% of medical students were interested in enrolling in plastic surgery residency after graduation, while 47.1% of students did not consider plastic surgery residency after graduation. However, 37.4% were uncertain. The two most driving factors in deciding on plastic surgery residency were expected income (61.8%) and lifestyle (14.3%). Conclusion Improving medical students' education quality can enhance their perception and awareness of plastic surgery. Students should be taught the broader scope of plastic surgery. The inclusion of formal training during undergraduation is the essence of time and should be added to or improved during plastic surgery rotations with more emphasis on reconstructive and hand/peripheral nerve surgery. Student-led interest groups can be a useful tool for educating students about their specialty.

14C-아세트아미노펜 비임상시험을 통한 생체시료 분석용 가속질량분석기의 검증 (Non-clinical Trials using 14C-Acetaminophen to Validate Biomedical Accelerator Mass Spectrometry System)

  • 송진호;심재훈;박정배;여창수;배수현;최민선;권미혜;김경민
    • 방사선산업학회지
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    • 제17권2호
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    • pp.127-134
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    • 2023
  • Pharmacokinetic (PK) data provide pivotal information in drug development, and they are usually first studied in the preclinical stage using various animals. However, quite often, animal PK data may not match with human PK, especially in metabolites. Thus, most regulatory agencies in the world make it mandatory to obtain metabolite information using 14C radiolabeled drug in human for small molecule drug candidates. However, such studies are expensive and time consuming and they are usually done at the end of Phase II trials using ~3.7 MBq of 14C labeled drug in a limited number of human subjects. Introduction of accelerator mass spectrometry (AMS) in this kind of study has revolutionized it. Since AMS can measure 14C level as close as natural abundance, it can quantify the amounts of 14C labeled drugs and their metabolites produced in human body that consumes less than the amount of 0.0037 MBq of 14C labeled drug, a very safe level of radioactive dose in human. Therefore, it is now possible to conduct human 14C studies safely in early clinical trials without spending hefty amount of money and time. Korea Radioisotope Center for Pharmaceuticals(KRICP) at Korea Institute of Biological and Medical Sciences(KIRAMS) has established an AMS facility in 2018, housing a 0.5MV AMS manufactured at the US National Electrostatics Corps (NEC). The AMS instrument has been validated using various standard samples that have been prepared at Lawrence Livermore National Laboratory in the US, a worldly reputable provider of AMS standards. In this paper, we present a mass balance study for acetaminophen in rats using AMS and prove that the study results are equivalent with those of literature, which shows the AMS facilities at KRICP has successfully installed and be ready to be used in the various PK studies using 14C labelled compounds for new drug development.

68Ga-BAPEN 소동물 PET영상 연구 (Small Animal PET Imaging Study of 68Ga-BAPEN)

  • 김지후;이재성;양보연;김수진;김중현;정재민;이동수
    • 한국의학물리학회지:의학물리
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    • 제22권4호
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    • pp.172-177
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    • 2011
  • 본 연구에서는 소동물의 심근에서 $^{68}Ga$-BAPEN PET 영상분석을 통해 심혈 영상 추적자로서의 적용가능성을 보고자 하였다. 소동물용 PET/CT에서 쥐 9마리를 대상으로 120분간의 $^{68}Ga$-BAPEN PET/CT 스캔을 시행하였다. 특별히 킷트를 통해 간편하고 저비용으로 $^{68}Ga$-BAPEN을 합성이 가능하였다. PET 영상은 쥐의 몸통부분에서 $^{68}Ga$-BAPEN의 생체 동적분포를 나타낸다. $^{68}Ga$-BAPEN PET 영상은 처음 수분간 대동맥과 간에서의 섭취가 나타났고 점차 심근에서의 섭취가 이루어졌다. 관심영역은 좌심근, 심혈, 폐, 간에 그렸고 시간-방사능 곡선을 얻었다. 시간-방사능 곡선에서 $^{68}Ga$-BAPEN이 쥐 심근에 잘 결합하는 것을 확인 할 수 있었다. 정확한 약동학적 파라미터 도출을 위한 최소 PET 스캔시간은 타장 기와의 영상 대조도가 일정비에 이르는 주사 후 60분이 적합하였다. 이때 심근의 섭취를 심혈, 간, 폐에서의 섭취로 나누어 얻은 영상 대조도는 각각 1.66, 0.60, 2.82였다. 결론적으로 $^{68}Ga$-BAPEN은 심근 혈류 질환을 진단하기 위한 추적자로서 적합하며 지속적인 연구가 이루어진다면 임상에서의 진단활용에 도움이 될 것이라 예상된다.

The influence of root surface distance to alveolar bone and periodontal ligament on periodontal wound healing

  • Montevecchi, Marco;Parrilli, Annapaola;Fini, Milena;Gatto, Maria Rosaria;Muttini, Aurelio;Checchi, Luigi
    • Journal of Periodontal and Implant Science
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    • 제46권5호
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    • pp.303-319
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    • 2016
  • Purpose: The purpose of this animal study was to perform a 3-dimensional micro-computed tomography (micro-CT) analysis in order to investigate the influence of root surface distance to the alveolar bone and the periodontal ligament on periodontal wound healing after a guided tissue regeneration (GTR) procedure. Methods: Three adult Sus scrofa domesticus specimens were used. The study sample included 6 teeth, corresponding to 2 third mandibular incisors from each animal. After coronectomy, a circumferential bone defect was created in each tooth by means of calibrated piezoelectric inserts. The experimental defects had depths of 3 mm, 5 mm, 7 mm, 9 mm, and 11 mm, with a constant width of 2 mm. One tooth with no defect was used as a control. The defects were covered with a bioresorbable membrane and protected with a flap. After 6 months, the animals were euthanised and tissue blocks were harvested and preserved for micro-CT analysis. Results: New alveolar bone was consistently present in all experimental defects. Signs of root resorption were observed in all samples, with the extent of resorption directly correlated to the vertical extent of the defect; the medial third of the root was the most commonly affected area. Signs of ankylosis were recorded in the defects that were 3 mm and 7 mm in depth. Density and other indicators of bone quality decreased with increasing defect depth. Conclusions: After a GTR procedure, the periodontal ligament and the alveolar bone appeared to compete in periodontal wound healing. Moreover, the observed decrease in bone quality indicators suggests that intrabony defects beyond a critical size cannot be regenerated. This finding may be relevant for the clinical application of periodontal regeneration, since it implies that GTR has a dimensional limit.

Polymorphisms of methylenetetrahydrofolate reductase are not a risk factor for Kawasaki disease in the Korean population

  • Yoon, Kyung-Lim;Ko, Jin-Hee;Shim, Kye-Shik;Han, Mi-Young;Cha, Sung-Ho;Kim, Su-Kang;Jung, Joo-Ho
    • Clinical and Experimental Pediatrics
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    • 제54권8호
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    • pp.335-339
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    • 2011
  • Purpose: Hyperhomocysteinemia is known as a risk factor for atherosclerosis. Preclinical arteriosclerosis is noted and premature atherosclerosis is known to be accelerated in Kawasaki disease (KD) patients. Genetic polymorphisms in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene result in elevated plasma homocysteine concentrations and are known to be associated with the development of coronary artery disease. Our hypothesis is that single nucleotide polymorphisms (SNPs) of the MTHFR gene are related to the development of KD and coronary artery lesions (CALs). Methods: For this study, we selected 3 candidate single nucleotide polymorphisms (SNPs) (rs2274976, rs1801131, and rs1801133) of MTHFR. These SNPs are located on chromosome 1p36.3. We included 101 KD patients and 306 healthy adults as controls in this study. CALs were seen in 38 patients. Genotypes of the selected SNPs were determined by direct sequencing and analyzed with SNPAlyze. Results: The genetic distribution and allelic frequency of the 3 MTHFR SNPs (rs2274976, rs1801131, and rs1801133) were not significantly different in patients with KD compared to the control group (P=0.71, 0.17, and 0.96, respectively). There was no difference in the genetic distribution of the MTHFR SNPs between the normal control group and the CAL group (P=0.43, 0.39, 0.52 respectively). Conclusion: The genetic distribution of the MTHFR SNPs (rs2274976, rs1801131, and rs1801133) was not different in the KD group compared to the control group. In addition, the genetic distribution of these SNPs was not different in the CAL group compared to the control group in the Korean population.

Molecular Mechanism of Crocin Induced Caspase Mediated MCF-7 Cell Death: In Vivo Toxicity Profiling and Ex Vivo Macrophage Activation

  • Bakshi, Hamid A;Hakkim, Faruck Lukmanul;Sam, Smitha
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권3호
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    • pp.1499-1506
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    • 2016
  • Background: Crocus sativus and its major constituent crocin are well established to have anti-cancer properties in breast cancer cells (MCF-7). However the role of C. sativus extract (CSE) and crocin on caspase signaling mediated MCF-7 cell death at molecular level is remains unclear. In this study, we tried to unravel role of CSE and crocin on caspase mediated MCF-7 cells death and their in vivo preclinical toxicity profiling and immune stimulatory effect. Materials and Methods: CSE extract was fractionated by HPLC and crocin was isolated and characterized by NMR, IR, and MS. MCF-7 cells were treated with both CSE and crocin and expression of Bcl-2 and Bax was assessed after 24 and 36 hours. Furthermore, caspase 3, caspase 8 and caspase 9 expression was determined by Western blotting after 24 hours of treatment. DNA fragmentation analysis was performed for genotoxicity of CSE and crocin in MCF-7 cells. The in vivo toxicity profile of CSE (300 mg/kg of b.wt) was investigated in normal Swiss albino mice. In addition, peritoneal macrophages were collected from crocin (1, 1.5 and 2 mg/kg body weight) treated mice and analyzed for ex vivo yeast phagocytosis. Results: Immunoblot analysis revealed that there was time dependent decline in anti-apoptotic Bcl-2 with simultaneous upregulation of Bax in CSE and crocin treated MCF-7 cells. Further CSE and crocin treatment downregulated caspase 8 and 9 and cleaved the caspase 3 after 24 hours. Both CSE and crocin elicited considerable DNA damage in MCF-7 cells at each concentration tested. In vivo toxicity profile by histological studies revealed no observable histopathologic differences in the liver, kidney, spleen, lungs and heart in CSE treated and untreated groups. Crocin treatment elicited significant dose and time dependent ex vivo yeast phagocytosis by peritoneal macrophages. Conclusions: Our study delineated involvement of pro-apoptotic and caspase mediated MCF-7 cell death by CSE and crocin at the molecular level accompanied with extensive DNA damage. Further we found that normal swiss albino mice can tolerate the maximum dose of CSE. Crocin enhanced ex vivo macrophage yeast phagocytic ability.

Radix et Rhizoma Ginseng chemoprevents both initiation and promotion of cutaneous carcinoma by enhancing cell-mediated immunity and maintaining redox homeostasis

  • Yu, Suyun;Wang, Siliang;Huang, Shuai;Wang, Wei;Wei, Zhonghong;Ding, Yushi;Wang, Aiyun;Huang, Shile;Chen, Wenxing;Lu, Yin
    • Journal of Ginseng Research
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    • 제44권4호
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    • pp.580-592
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    • 2020
  • Background: Radix et Rhizoma Ginseng (thereafter called ginseng) has been used as a medicinal herb for thousands of years to maintain people's physical vitality and is also a non-organ-specific cancer preventive and therapeutic traditional medicine in several epidemiologic and preclinical studies. Owing to few toxic side effects and strong enhancement on body immunity, ginseng has admirable application potential and value in cancer chemoprevention. The study aims at investigating the chemopreventive effects of ginseng on cutaneous carcinoma and the underlying mechanisms. Methods: The mouse skin cancer model was induced by 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoylphorbol-13-acetate. Ultraperformance liquid chromatography/mass spectrometry was used for identifying various ginsenosides, the main active ingredients of ginseng. Comprehensive approaches (including network pharmacology, bioinformatics, and experimental verification) were used to explore the potential targets of ginseng. Results: Ginseng treatment inhibited cutaneous carcinoma in terms of initiation and promotion. The content of Rb1, Rb2, Rc, and Rd ginsenosides was the highest in both mouse blood and skin tissues. Ginseng and its active components well maintained the redox homeostasis and modulated the immune response in the model. Specifically, ginseng treatment inhibited the initiation of skin cancer by enhancing T-cell-mediated immune response through upregulating HSP27 expression and inhibited the promotion of skin cancer by maintaining cellular redox homeostasis through promoting nuclear translocation of Nrf2. Conclusion: According to the study results, ginseng can be potentially used for cutaneous carcinoma as a chemopreventive agent by enhancing cell-mediated immunity and maintaining redox homeostasis with multiple components, targets, and links.

Rating criteria to evaluate student performance in digital wax-up training using multi-purpose software

  • Mino, Takuya;Kurosaki, Yoko;Tokumoto, Kana;Higuchi, Takaharu;Nakanoda, Shinichi;Numoto, Ken;Tosa, Ikue;Kimura-Ono, Aya;Maekawa, Kenji;Kim, Tae Hyung;Kuboki, Takuo
    • The Journal of Advanced Prosthodontics
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    • 제14권4호
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    • pp.203-211
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    • 2022
  • PURPOSE. The aim of this study was to introduce rating criteria to evaluate student performance in a newly developed, digital wax-up preclinical program for computer-aided design (CAD) of full-coverage crowns and preliminarily investigate the reliability and internal consistency of the rating system. MATERIALS AND METHODS. This study, conducted in 2017, enrolled 47 fifth-year dental students of Okayama University Dental School. Digital wax-up training included a fundamental practice using computer graphics (CG), multipurpose CAD software programs, and an advanced practice to execute a digital wax-up of the right mandibular second molar (#47). Each student's digital wax-up work (stereolithography data) was evaluated by two instructors using seven qualitative criteria. The total qualitative score (0-90) of the criteria was calculated. The total volumetric discrepancy between each student's digital wax-up work and a reference prepared by an instructor was automatically measured by the CAD software. The inter-rater reliability of each criterion was analyzed using a weighted kappa index. The relationship between the total volume discrepancy and the total qualitative score was analyzed using Spearman's correlation. RESULTS. The weighted kappa values for the seven qualitative criteria ranged from 0.62 - 0.93. The total qualitative score and the total volumetric discrepancy were negatively correlated (ρ = -0.27, P = .09, respectively); however, this was not statistically significant. CONCLUSION. The established qualitative criteria to evaluate students' work showed sufficiently high inter-rater reliability; however, the digitally measured volumetric discrepancy could not sufficiently predict the total qualitative score.

Evaluation of Soil Streptomyces spp. for the Biological Control of Fusarium Wilt Disease and Growth Promotion in Tomato and Banana

  • Praphat, Kawicha;Jariya, Nitayaros;Prakob, Saman;Sirikanya, Thaporn;Thanwanit, Thanyasiriwat;Khanitta, Somtrakoon;Kusavadee, Sangdee;Aphidech, Sangdee
    • The Plant Pathology Journal
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    • 제39권1호
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    • pp.108-122
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    • 2023
  • Fusarium oxysporum f. sp. lycopersici (Fol) and Fusarium oxysporum f. sp. cubense (Foc), are the causal agent of Fusarium wilt disease of tomato and banana, respectively, and cause significant yield losses worldwide. A cost-effective measure, such as biological control agents, was used as an alternative method to control these pathogens. Therefore, in this study, six isolates of the Streptomyces-like colony were isolated from soils and their antagonistic activity against phytopathogenic fungi and plant growth-promoting (PGP) activity were assessed. The results showed that these isolates could inhibit the mycelial growth of Fol and Foc. Among them, isolate STRM304 showed the highest percentage of mycelial growth reduction and broad-spectrum antagonistic activity against all tested fungi. In the pot experiment study, the culture filtrate of isolates STRM103 and STRM104 significantly decreased disease severity and symptoms in Fol inoculated plants. Similarly, the culture filtrate of the STRM304 isolate significantly reduced the severity of the disease and symptoms of the disease in Foc inoculated plants. The PGP activity test presents PGP activities, such as indole acetic acid production, phosphate solubilization, starch hydrolysis, lignin hydrolysis, and cellulase activity. Interestingly, the application of the culture filtrate from all isolates increased the percentage of tomato seed germination and stimulated the growth of tomato plants and banana seedlings, increasing the elongation of the shoot and the root and shoot and root weight compared to the control treatment. Therefore, the isolate STRM103 and STRM104, and STRM304 could be used as biocontrol and PGP agents for tomato and banana, respectively, in sustainable agriculture.