• The Korean Journal of Physiology and Pharmacology
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• 제10권4호
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• pp.193-198
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• 2006

Many gastrointestinal muscles show electrical oscillation, so-called 'slow wave', originated from interstitial cells of Cajal (ICCs). Thus, a technique to freshly isolate the cells is indispensable to explore the electrophysiological properties of the ICCs. To apply an enzyme solution on the serosal surface for cell isolation, the intestine was inverted and 0.02% trypsin solution and 0.04% collagenase solution were applied to serosal cavity. After the enzyme treatment, mucosal layer was removed and longitudinal muscle layer was gently separated from the rest of tissue. The thin layer was stretched in the recording chamber and mounted on an inverted microscope. Using ${\beta}-escine$, perforated whole cell patch clamp technique was used. Under a microscope, the tissue showed smooth muscle cells and interstitial cells around the myenteric plexus. Under voltage clamp condition, three types of membrane potential were recorded. One group of interstitial cells, which were positive to methylene blue and CD34, showed spontaneous outward current. These cells had bipolar shape and were considered as fibroblast-like cells because of their peculiar shape and arrangement. Another group, positive to c-kit and methylene blue, showed spontaneous inward current. These cells had more rounded shape and processes and were considered as ICCs. The third, positive to c-kit and had granules containing methylene blue, showed quiet membrane potentials under the voltage-clamp mode. These cells appeared to be resident macrophages. Therefore, in the freshly isolated thin tissue preparation, methylene blue could easily identify three types of cells rather than morphological properties. Using this method, we were able to study electrical properties of fibroblast and residential macrophage as well as myenteric ICCs.

• 멤브레인
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• 제26권1호
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• pp.26-31
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• 2016

폴리카프로락톤(PCL)에 NaCl을 혼합한 용액을 블레이드법에 의하여 막형태로 제조한 후 NaCl을 추출하는 염출법을 이용하여 조직공학적으로 사용할 3차원 다공망을 갖는 멤브레인 형태의 지지체를 제조하였다. 본 연구에서는 성형된 멤브레인의 건조조건과, NaCl 입자의 크기, NaCl의 혼합량을 각각 다르게 하여 제조하였다. 별도로 제작한 고분자용액 공급장치를 이용하여 PCL/클로로포름($CHCl_3$) 용액에 NaCl 입자가 균일하게 혼합된 용액을 유리판에 분주하여 필름 어플리케이터를 사용하여 블레이드법에 의한 멤브레인을 제조하였다. 멤브레인 지지체에는 NaCl 입자에 의한 거대기공과 거대기공을 이루는 구조벽에서는 $CHCl_3$의 증발에 의한 미세기공이 함께 복합적으로 상호 연결되어 형성되었다.

• 대한관절경학회지
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• 제2권2호
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• pp.124-128
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• 1998

From Feb. 1996 to Feb. 1997. among sixty-four patients of anterior cruciate ligament(ACL) reconstruction using multi-stranded hamstring tendon and EndoButton fixation, twenty-five patients of volunteer, 15 men and 10 women, from 16 to 50 years of age(mean 27.6 years) underwent arthroscopic evaluation. Arthroscopic evaluation was routinely performed one year after surgery along with an examination of stability. The purpose of this study was to arthroscopically evaluate the morphological changes that occurred in hamstring tendon autograft one year after ACL reconstruction. Both of the tendon graft and the adjacent fibrous tissues were observed for gross appearance and physical properties with probing and response to passive anterior translation. Biopsy samples were taken from the surrounding fibrous tissue and the tendon graft. Grossly, we found a well-defined ligamentous structure with good tension tested with a probe. A common finding was that the reconstructed ligaments were embedded in a layer of the synovium, and blood vessels could be seen on the anterior surface of the ligament. The biopsy tissue was placed in formalin solution and subjected to histological preparation by hematoxylin and eosin staining method. The hamstring tendon graft appeared histologically normal under light microscopic finding. There were a few vessels located between existing collagen bundles, and the vessels had an orderly pattern. The surrounding fibrous tissue envelope was covered with synovium. We pleased with preliminary findings in our evaluation.

• 대한치과의사협회지
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• 제55권11호
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• pp.789-799
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• 2017

Ultrasound images are noninvasive, can be observed in real time, have no radiation exposure, do not cause pain, and are not restricted in use depending on the patient's prosthetic implant or medical condition. Since the use of ultrasound in the dental field was first applied for tooth preparation in 1957, the use of diagnostic ultrasound for the first time in 1963 has been reported. Currently, it is used in the diagnosis of soft tissue lesions such as malignant tumor or salivary gland disease, fine needle aspiration test, temporomandibular joint disease, lymph node metastasis, measurement of muscle thickness and inflammatory diseases, differentiation of periapical cyst and granulation tissue, measurement of periodontal tissue thickness. The ultrasound image can be visualized in real time. The clinician can explain the structure to the patient while consulting the patient and consult the patient. When injecting the drug into a specific site or aspirating a specific site or substance, So that it can be confirmed and practiced. Recently, ultrasonic equipment specialized in the dental field has been developed and marketed, and it is expected that the use of ultrasonic waves will become active in the dentistry. In the future, development of popular equipment with size and frequency suitable for dental diagnosis and various researches on maxillofacial ultrasonic anatomy. If clinical studies are continuously carried out to demonstrate efficacy, ultrasound is expected to aid in accurate diagnosis and treatment throughout the dentistry.

• 대한소아치과학회지
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• 제24권2호
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• pp.361-382
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• 1997

The effect of fluoride pretreatment upon root resorption after delayed replantation was studied in beagle dogs. Upper and lower incisors were extracted and bench dried for 45 minutes. 1% Stannous fluoride solution, 2% neutral sodium fluoride gel and 1.23% acidulated phosphate fluoride gel were used for the pre-treatment of replanted root surface in the experimental groups. Replantation was done with no treatment in control group. After of an experimental periods 3 weeks, animals were sacrificed by perfusion followed by sample preparation. A histomorphometric method was applied for evaluation of tissue reactions observed in each group under light microscope. Scanning electron microscopic observation was done to find out any different surface topography between groups. The results were as follows: 1. Fluoride-treated groups showed in general the better healing patterns than untreated control group. 2. Comparisons between three experimental groups revealed the general superiority of APF-treated group over the other groups in terms of tissue healing reaction by showing the highest frequency in uncomplicated healing pattern and surface resorption and the lowest in inflammatory resorption, but with no statistical significance(p>.05). 3. Scanning elecron micrographs showed the irregular distribution of resorption cavities and the attached bone of variable size and shape in all groups. 4. It can be concluded that the types of fluoride did not have significant impact on the early tissue reactions after delayed replantation under the condition of the present experiment.

• Restorative Dentistry and Endodontics
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• 제47권4호
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• pp.35.1-35.9
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• 2022

Although the success rates of microsurgery and micro-resurgery are very high, the influence of a recurrent perforation combined with radicular cyst remains unclear. A 21-year-old white female patient had a history of root perforation in a previously treated right maxillary lateral incisor. Analysis using cone-beam computed tomography (CBCT) revealed an extensive and well-defined periapical radiolucency, involving the buccal and palatal bone plate. The perforation was sealed with bioceramic material (Biodentine) in the pre-surgical phase. In the surgical phase, guided tissue regeneration (GTR) was performed by combining xenograft (lyophilized bovine bone) and autologous platelet-rich fibrin applied to the bone defect. The root-end preparation was done using an ultrasonic tip. The retrograde filling was performed using a bioceramic material (Biodentine). Histopathological analysis confirmed a radicular cyst. The patient returned to her referring practitioner to continue the restorative procedures. CBCT analysis after 1-year recall revealed another perforation in the same place as the first intervention, ultimately treated by micro-resurgery using the same protocol with GTR, and a bioceramic material (MTA Angelus). The 2-year recall showed healing and bone neoformation. In conclusion, endodontic micro-resurgery with GTR showed long-term favorable results when a radicular cyst and a recurrent perforation compromised the success.

• 한국식품영양과학회지
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• 제33권9호
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• pp.1492-1500
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• 2004

저열량 처방을 위한 식사대체제와 식이섬유ㆍ탄수화물 가수분해 억제제ㆍHCA를 주 성분으로 하는 체중감량제의 섭취 효과를 판정하기 위하여 20대∼50대의 BMI 25이상의 여성 자원자를 모집하여 9주간 시험을 실시하였다. 시험기간 동안 1일 1끼 식사는 식사대체제로 대치하고 1일 2회 체중감량제를 섭취하게 한 후 신체계측과 체조성, 배변 상황, 식이섭취 실태, 자각 증상 등의 변화를 조사하여 효과를 판정하였다. 시험 결과는 9주 동안 지속적으로 체중과 체지방, BMI, 허리 및 엉덩이 둘레가 감소한 것으로 나타났으며 체중감소율은 영양학적으로 안전한 범위에 속해 있었다. 혈청 지질에는 유의적인 변화가 없었으며 혈당과 인슐린이나 C-peptide 함량에도 유의적인 차이는 없었으며 BUN이나 ALP는 감소하였고 헤모글로빈은 유의적으로 증가하였으나 모두 정상범위에 있었다. 배변 시간은 단축되었으며 건강에 대한 부정적인 자각증상도 감소되었다. 1일 섭취 열량은 1300 kcal 정도로 유지되었으며 비타민 A, 비타민 $B_2$, 엽산, 칼슘, 철, 아연등의 섭취량은 권장량의 80% 미만으로 나타났다. 그러므로 본 연구의 저열량식사와 체중감량제의 섭취는 체중 및 체지방 감소와 배변에 효과적이었으며 부정수소를 감소시킬 수 있었다.

• Macromolecular Research
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• 제10권3호
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• pp.158-167
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• 2002

In order to endow with new bioactive functionality from small intestine submucosa (SIS) powder as natural source to poly (L-lactide) (PLA) and poly (lactide-co-glycolide) (PLGA) synthetic biodegradable polymer, porous SIS/PLA and SIS/PLGA as natural/synthetic composite scaffolds were prepared by means of the solvent casting/salt leaching methods for the possibility of the application of tissue engineered bone and cartilage. A uniform distribution of good interconnected pores from the surface to core region was observed the pore size of 40~500 ${\mu}{\textrm}{m}$ independent with SIS amount using the solvent casting/salt leaching method. Porosities, specific pore areas as well as pore size distribution also were almost same. After the fabrication of SIS/PLA hybrid scaffolds, the wetting properties was greatly enhanced resulting in more uniform cell seeding and distribution. Five groups as PGA non-woven mesh without glutaraldehyde (GA) treatment, PLA scaffold without or with GA treatment, and SIS/PLA (Code No.3 ; 1 : 12 of salt content, (0.4 : 1 of SIS content, and 144 ${\mu}{\textrm}{m}$ of median pore size) without or with GA treatment were implanted into the back of nude mouse to observe the effect of SIS on the induction of cells proliferation by hematoxylin and eosin, and von Kossa staining for 8 weeks. It was observed that the effect of SIS/PLA scaffolds with GA treatment on bone induction are stronger than PLA scaffolds, that is to say, in the order of PLA/SIS scaffolds with GA treatment > PLA/SIS scaffolds without GA treatment > PGA nonwoven > PLA scaffolds only with GA treatment = PLA scaffolds only without GA treatment for the osteoinduction activity. The possible explanations are (1) many kinds of secreted, circulating, and extracellular matrix-bound growth factors from SIS to significantly affect critical processes of tissue development and differentiation, (2) the exposure of SIS to GA resulted in significantly calcification, and (3) peri-implant fibrosis due to covalent bonding between collagen molecule by crosslinking reaction. In conclusion, it seems that SIS plays an important role for bone induction in SIS/PLA scaffolds for the application of tissue engineering area.

• Carbon letters
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• 제17권1호
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• pp.11-17
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• 2016

Recently, with continuous developments in the field of materials science, graphene oxide (GO) has emerged as a promising material with excellent electrical, thermal, mechanical, and optical properties, which play important roles in most fields. Researchers have achieved considerable progress with graphene. Chitosan (CS) is a natural polymer that has been studied intensively owing to its specific formation, high chemical resistance, and excellent physical properties. These outstanding properties have led to its universal use in applications such as textile fabrics, tissue engineering, medicine and health, coatings, and paints. By combining the advantages of GO and CS, different types of promising materials can be obtained. This review discusses the preparation of GO-CS fibers, hydrogel and aerogel, and the applications of GO-CS nanocomposites. In addition, directions for future research on graphene material composites are discussed.

• 대한치과의사협회지
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• 제56권10호
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• pp.572-580
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• 2018

Adequate access cavity is the key to achieving endodontic success. The aims of the access cavity can be considered as follows: 1) Creation of a smooth unimpeded pathway for instruments to canal orifices 2) Removal of the entire roof of the pulp chamber in order to inspect the pulp floor, 3) Preservation of natural tooth substance consistent with the above. Recently, contracted endodontic cavities based on minimally invasive endodontics has introduced. This has the benefit of preserving the pericervical dentin more than traditional access cavity with achieving long-term success. However, some studies reported controversial results regarding root canal detection, instrumentation efficacy (noninstrumented canal area, hard tissue debris accumulation, canal transportation, and centering ratio) as well as fracture resistance. Therefore, further studies are required for accepting contracted access cavity, and modified form of traditional and contracted access cavity could be considered.