• 제목/요약/키워드: Injection site reaction

검색결과 43건 처리시간 0.03초

열오염 혼합 거동 해석을 위한 수평 2차원 유한요소모형 (Horizontal 2-D Finite Element Model for Analysis of Mixing Transport of Heat Pollutant)

  • 서일원;최황정;송창근
    • 대한토목학회논문집
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    • 제31권6B호
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    • pp.507-514
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    • 2011
  • 본 논문에서는 하천에 유입되는 열 오염물질의 혼합거동을 분석하기 위해 2차원 수심 평균된 이송-분산방정식에 유한요소법을 적용하여 수치 모형을 개발하였다. 유한요소법의 여러 수치기법 중 SUPG법을 적용하였으며, 복잡한 하천경계를 보다 정확히 재현할 수 있도록 삼각 및 사각 요소망의 혼용이 가능하도록 하였다. 열 오염물질의 거동을 표현하기 위해서 열 교환을 묘사하는 반응항을 평형온도와 수온과의 차이에 비례하는 식으로 나타내고, 열교환 계수 및 평형온도에 따라 수온의 변화가 적용되도록 방정식을 구성하였다. 모형의 검증을 위하여 직사각형 수로에 선원으로 연속주입하여 얻은 수치해와 1차원 정상상태의 해석해를 비교하였다. 비교결과 수치해와 해석해의 결과가 서로 일치하는 것으로 밝혀졌다. 모형의 현장적용을 위해 상수원 보호구역인 팔당댐 하류부터 잠실수중보까지 22.5 km 구간을 대상영역으로 하였다. 구리하수처리장 방류수에 의한 수온 변화를 모의한 결과 수질측정망 측정자료와 비교적 비슷한 경향이 나타났다. 본 연구에서 개발한 수치모형이 열 오염원 유입으로 인한 수온 변화를 잘 표현하는 것을 알 수 있었다.

활성화된 질산화균 주입에 의한 저온 질산화효율 향상 (Improvement of Nitrification Efficiency by Activated Nitrifying Bacteria Injection at Low Temperature)

  • 임동일;김영희
    • 한국도시환경학회지
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    • 제18권4호
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    • pp.473-483
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    • 2018
  • 본 연구에서는 Lab 규모의 생물반응장치를 제작하여 운전조건 변화(온도, 저해물질(Cl), 활성화된 질산화균 투입 등)가 질산화에 미치는 영향을 파악하여 저온 조건에서 질산화효율을 향상시킬 수 있는 방안을 찾고자 하였다. $NO_2{^-}-N+NO_3{^-}-N$ 농도 실험에서 $20^{\circ}C$의 경우 염소를 투입하여 질산화균을 사멸한 후 활성화된 질산화균을 투입하면, 정상수준까지 회복하는데 약 4일 정도 소요되었다. $10^{\circ}C$의 경우, 활성화된 질산화균을 투입하여 이전 상태로 회복 되는 데는 약 7일 정도 소요되어 $20^{\circ}C$에 비하여 약 3일이 더 소요되었다. 비질산화속도 실험에서는 $10^{\circ}C$ 운전조건에서 활성화된 질산화균 투입 후 1일경과시 비질산화속도는 0029 mgN/gSS/hr에서 6일 경과시 0.767 mgN/gSS/hr까지 증가하였다. 선형 모형식과 지수함수 모형식에 의한 8일 경과후의 비질산화속도는 각각 0.840, 3.625 mgN/gSS/hr로 예측되어 정상수준인 2.592 mgN/gSS/hr을 상회하는 것으로 예상되었다. 본 연구를 통하여 저온 운전시 활성화된 질산화균을 주입하면 질산화효율을 향상시키는데 많은 효과가 있음을 확인하였다. 향후 연구에서 현장별 운전특성을 고려한 ANB 투입량의 결정, 효율적인 ANB reactor의 설계 등에 대한 추가적인 연구가 진행된다면 동절기 질산화효율 향상에 많은 기여를 할 수 있을 것이다.

현무암 CO2 지중저장 해외 연구 사례 조사 및 타당성 분석 (A Comprehensive Review of Geological CO2 Sequestration in Basalt Formations)

  • 전현정;신형철;윤태권;한원식;정재훈;곽재휘
    • 자원환경지질
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    • 제56권3호
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    • pp.311-330
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    • 2023
  • CO2 배출량 증가로 인한 지구온난화 심화에 대한 주요 대책으로 CO2를 포집하여 지중에 저장하는 이산화탄소 포집·저장(Carbon capture storage, CCS) 기술이 주목받고 있다. 최근 현무암의 거대한 체적, 높은 반응성, 풍부한 양이온 함량 등의 특성이 CO2 포획 및 저장 기작에 유리하게 작용한다는 사실이 부각되면서, 현무암층을 대상으로 하는 CO2 지중저장이 다양한 분야에서 연구되고 있다. 본 연구에서는 CO2 지중저장 기작, 현무암의 특성과 더불어 국외 연구 사례들을 조사 및 분석하여, 현무암 CO2 지중저장에 대한 타당성을 검토하였다. 조사한 사례들은 수행 방법을 기준으로 실험, 모델링, 현장 실증 연구로 분류하였다. 연구 사례별 실험 조건의 경우 온도는 20 ~ 250 ℃, 압력은 0.1 ~ 30 MPa, 암석-유체 간 반응 시간은 수 시간에서 4년까지 넓은 범위에서 진행되었다. 모델링 연구에서는 현무암 CO2 지중저장 후보지와 유사한 모델을 구축하여 CO2-유체 주입 전∙후 유체역학적 및 지화학적 요인들에 대한 변화를 살펴본 사례가 다수였다. 검토 결과, 현무암은 잠재 CO2 저장용량이 크고, CO2 광물화 반응이 빠르기 때문에 현무암 CO2 지중저장시 온도와 압력 및 지질구조와 같은 환경적인 제약이 적다. 현장 실증 사례인 CarbFix project, Wallula project가 성공적으로 수행되어 실증 수행가능성 또한 높게 평가되고 있다. 그러나 현무암 대상 CO2 지중저장에서 신중히 고려해야 할 점도 존재한다. 광물화 기작이 현무암의 조성, 주입 지역의 특성 등 여러 요인에 따라 결과가 상이하게 나타나고, 탄산염과 규산염 광물 등의 침전으로 인해 관정 주입성(injectivity) 저하가 발생할 수 있다. CO2 주입 시 저장층 내 압력 증가가 발생할 수 있으며 암석-CO2-유체 반응 과정에서 지중환경 오염의 위험성도 존재한다. 유체에 CO2를 용해시켜 주입하기 때문에 기존 방식과 다른 지중 모니터링 기술 또한 요구된다. 따라서, 현무암에서의 CO2 지중저장을 안정적이고 효율적으로 수행하기 위해서는 적합한 대상 지역을 선별하고, 해당 지역에 대한 여러 자료를 구축하여 이를 기반으로 한 다양한 실험, 모델링, 현장 실증 등의 체계적인 연구 수행이 필요하다.

배양골세포 이식이 치조골재생에 미치는 영향 (Effects Of Cultured Bone Cell On The Regeneration Of Alveolar Bone)

  • 정순준;허익;박준봉;이만섭;권영혁
    • Journal of Periodontal and Implant Science
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    • 제26권1호
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    • pp.1-26
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    • 1996
  • This study was performed to estimate the effects of cultured bone cell inoculated on porous type hydroxyaptite for the regeneration of the artificial alveolar bone defect. In this experiment 3 beagle dogs were used, and each of them were divided into right and left mandible. Every surgical intervention were performed under the general anesthesia by using with intravenous injection of Pentobarbital sodium(30mg/Kg). To reduce the gingival bleeding during surgery, operative site was injected with Lidocaine hydrochloride(l:80,000 Epinephrine) as local anesthesia. After surgery experimental animal were feeded with soft dietl Mighty dog, Frisies Co., U.S.A.) for 1 weeks to avoid irritaion to soft tissue by food. 2 months before surgery both side of mandibular 1st premolar were extracted and bone chips from mandibular body were obtained from all animals. Bone cells were cultured from bone chips obtained from mandible with Dulbecco's Modified Essential Medium contained with 10% Fetal Bovine Serum under the conventional conditions. Porous type hydroxyapatite were immerse into the high concentrated cell suspension solution, and put 4 hours for attachin the cells on the surface of hydroxyapatite. Graft material were inserted on the artificial bone defect after 3 days of culture. Before insertion of cellinoculated graft material, scanning electronic microscopic observation were performed to confirm the attachment and spreading of cell on the hydroxyapatite surface. 3 artificial bone defects were made with bone trephine drill on the both side of mandible of the experimental animal. First defect was designed without insertion of graft material as negative control, second was filled with porous replamineform hydroxyapatite inoculated with cultured bone marrow cells as expermiental site, and third was filled with graft materials only as positive control. The size of every artificial bone defect was 3mm in diameter and 3mm in depth. After the every surgical intervention of animals, oral hygiene program were performed with 1.0% chlorhexidine digluconate. All of the animals were sacrificed at 2, 4, 6 weeks after surgery. For obtaining histological section, tissus were fixed in 10% Buffered formalin and decalcified with Planko - Rycho Solution for 72hr. Tissue embeding was performed in paraffin and cut parallel to the surface of mandibular body. Section in 8um thickness of tissue was done and stained with Hematoxylin - Eosin. All the specimens were observed under the light microscopy. The following results were obtained : 1. In the case of control site which has no graft material, less inflammatory cell infiltration and rapid new bone forming tendency were revealed compared with experimental groups. But bone surface were observed depression pattern on defect area because of soft tissue invasion into the artificial bone defect during the experimental period. 2. In the porous hydroxyapatite only group, inflammatory cell infiltration was prominet and dense connective tissue were encapsulated around grafted materials. osteoblastic activity in the early stage after surgery was low to compared with grafted with bone cells. 3. In the case of porous hydroxyapatite inoculated with bone cell, less inflammatory cell infiltration and rapid new bone formation activity was revealed than hydroxyapatite only group. Active new bone formation were observed in the early stage of control group. 4. The origin of new bone forming was revealed not from the center of defected area but from the surface of preexisting bony wall on every specimen. 5. In this experiment, osteoclastic cell was not found around grafted materials, and fibrovascular invasion into regions with no noticeable foreign body reaction. Conclusively, the cultured bone cell inoculated onto the porous hydroxyapatite may have an important role of regeneration of artificial bone defects of alveolar bone.

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국내 사람유두종바이러스백신 접종 후 자발적 이상반응 보고사례의 Brighton Collaboration 기준 활용 가능성 연구 (Patterns of Spontaneous Adverse Events Reporting on Human Papillomavirus Vaccines according to the Applicability of Brighton Collaboration Criteria in Korea from 2008 to 2017)

  • 김묘송;유승훈;박혜민;이민택;강예진;구현지;정선영
    • 한국임상약학회지
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    • 제30권1호
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    • pp.19-30
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    • 2020
  • Objective: To describe patterns of spontaneous reporting on adverse events following immunization (AEFIs) using the human papilloma virus (HPV) vaccine according to the Brighton Collaboration (BC) criteria. Methods: We used the Korea Adverse Event Reporting System (KAERS) database including vaccinations between 2008 and 2017. To apply BC criteria, we classified 58 BC AEFIs into World Health Organization Adverse Reaction Terminology (WHO-ART) codes. We applied MedDRA standard medical queries that were pre-defined as five BC AEFIs. Terminology mapping between MedDRA and WHO-ART terms was performed by three researchers. Descriptive statistics of individual case safety reports were analyzed according to BC applicability. Disproportionality analyses were performed on each BC AEFI and each preferred AEFI term according to the case-noncase approach; reporting odds ratio (ROR) and 95% confidence intervals (CI) were calculated. Results: Among the 30,266 reports of vaccinations between 2008 and 2017, 2,845 reports included the HPV vaccine. Of these reports, 1,511 (53.1%) included at least one BC AEFI. Reports from physicians or manufacturers included more BC AEFIs than from other reporters. Injection site reactions and fever were frequently reported in BC AEFIs; spontaneous abortion and ectopic pregnancy (ROR, 14.29 [95% CI, 4.30-47.49]) and vasculitic peripheral neuropathy (ROR, 8.57 [95% CI, 2.61-28.10]) showed the highest ROR. Among non-BC AEFIs, dizziness or myalgia were frequently reported; exposure during pregnancy (ROR, 23.95 [95% CI, 16.27-35.25]) and inappropriate schedule of administration (ROR, 22.89 [95% CI, 16.74-31.31]) showed the highest ROR. Conclusion: BC criteria would be applicable for labeled AEFIs, whereas analyzing non-BC AEFIs would be useful for detecting unlabeled AEFIs.

Facial Paralysis and Myositis Following the H3N2 Influenza Vaccine in a Dog

  • Ju-Hyun An;Ye-In Oh;So-Hee Kim;Su-Min Park;Jeong-Hwa Lee;Ga-Hyun Lim;Kyung-Won Seo;Hwa-Young Youn
    • 한국임상수의학회지
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    • 제40권5호
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    • pp.336-340
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    • 2023
  • A dog (2-year old, female, Shih-Tzu) presented with hyperthermia and right-sided facial paralysis characterized by the inability to close the right eye and drooling from the right side of the mouth after H3N2 influenza vaccination [A/Canine/Korea/01/07(H3N2) strain; Caniflu-Max, Bionote, Hwaseong, Gyeonggi-do, ROK]. To determine the cause of the fever and neurological symptoms, physical examination, ophthalmic examination, thoracic and abdominal radiography, abdominal ultrasonography, complete blood counts, serum chemistry values, and electrolyte levels were determined. In addition, Cerebrospinal fluid analysis, antinuclear antibody test, fever of unknown origin polymerase chain reaction (PCR) panel, tick-borne pathogen PCR panel were performed. As a result, hyperthermia, leukocytosis, and elevated C-reactive protein were confirmed. In addition, neurological examination revealed decreased right eyelid reflexes, corneal reflexes, threat response, and facial sensation, it was possible to suspect problems with the trigeminal and facial nerves of the cranial nerve. Magnetic resonance imaging revealed a lesion suggestive of myositis in the right muscular lesion at atlanto-occipital junction level on site of vaccine injection. Therefore, right-sided facial paralysis was tentatively determined to be a secondary cause of nerve damage caused by myositis. The patient was treated with immunosuppressants such as prednisolone and mycophenolate mofetil. After 3 months of immunosuppressant therapy, the patient's symptoms improved.

Correlation between Reactogenicity and Immunogenicity after the ChAdOx1 nCoV-19 and BNT162b2 mRNA Vaccination

  • So Yun Lim;Ji Yeun Kim;Soonju Park;Ji-Soo Kwon;Ji Young Park;Hye Hee Cha;Mi Hyun Suh;Hyun Jung Lee;Joon Seo Lim;Seongman Bae;Jiwon Jung;Nakyung Lee;Kideok Kim;David Shum;Youngmee Jee;Sung-Han Kim
    • IMMUNE NETWORK
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    • 제21권6호
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    • pp.41.1-41.13
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    • 2021
  • Correlation between vaccine reactogenicity and immunogenicity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. Thus, we investigated to determine whether the reactogenicity after coronavirus disease 2019 vaccination is associated with antibody (Ab) titers and T cell responses. This study was prospective cohort study done with 131 healthcare workers at tertiary center in Seoul, South Korea. The degrees of the local reactions after the 1st and 2nd doses of ChAdOx1 nCov-19 (ChAdOx1) vaccination were significantly associated with the S1-specific IgG Ab titers (p=0.003 and 0.01, respectively) and neutralizing Ab (p=0.04 and 0.10, respectively) in age- and sex-adjusted multivariate analysis, whereas those after the BNT162b2 vaccination did not show significant associations. T cell responses did not show significant associations with the degree of reactogenicity after the ChAdOx1 vaccination or the BNT162b2 vaccination. Thus, high degree of local reactogenicity after the ChAdOx1 vaccine may be used as an indicator of strong humoral immune responses against SARS-CoV-2.

Alloxan 투여 가토(家兎)에 대한 골절치유 실험 (Studies on the Fracture Healing in the Alloxan treated Rabbits)

  • 김성준
    • 대한약리학회지
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    • 제7권1호
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    • pp.53-65
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    • 1971
  • It is well known that diabetes mellitus is associated with metabolic derangements, such as hyper-glycemia, ketosis, glycosuria, and also widespread alterations in the blood vessels, kidneys, eyes, peripheral nerves and heart. It is also recognized that healing of skin wound is delayed in diabetics. In bone, according to Aegerter, osteopenia develops in diabetes mellitus and it is chiefly ascribed to overutilization of protein. Shim claims that total blood flow to the entire skeletal system is approximately 4 to 8 percent of resting cardiac output and blood supply to the skeletal system would be decreased on account of secondary arteriosclerotic changes in the diabetics. An adequate blood supply is an essential factor in the healing process of fracture, and disturbed blood flow, either local or systemic, will invariably delay union of the fragments or the fragments from being fused. As the author has encountered several cases of diabetics in whom healing of fracture was delayed or incomplete, this experimental study was undertaken to elucidate the effects of hyperglycemia and diabetes mellitus on the healing process of fracture. In this experiment adult albino rabbits, weighing about 2 kg. were used and divided into 6 groups. The femur of each animal was fractured surgically, and then the healing process of fracture was periodically checked by radiography at an interval of one week for a period of 6 weeks. Thereafter, all the rabbits were killed to obtain tissue preparation of the femur. The experimental groups were as follows; 1) Control group: Six rabbits sustained a surgical fracture to the femur, without being given any other treatment or drug. 2) Alloxan-treated group: For inducing diabetes, alloxan was given intravenously to 17 rabbits in various dose as follows; to 7 of them 40 mg/kg, to 6 rabbits 80 mg/kg and to 4 rabbits 120 mg/kg of body weight, respectively. 3) Insulin-treated group: Protamine-zinc insulin was injected subcutaneously to each of 6 rabbits in a daily dose of 1 unit per kilogram of body weight. 4) Group treated with insulin after alloxan: Four rabbits were given 80 mg of alloxan once and than 1 unit of insulin per kilogram of body weight daily. Another 5 rabbits were injected 1 unit of insulin per kg of body weight daily following administration of alloxan in a dose of 120 mg/kg. 5) Homotransplantation group: Following intravenous injection of alloxan in a dose of 120 mg/kg, 10 rabbits underwent homotransplantation of a short bone segment to the femur. Five of them were subsequently given 1 unit/kg of insulin daily. 6) Sugar-treated group: six rabbits were fed $15{\sim}20$ gm of sugar daily throughout the period of experiment. The results obtained are summarized as follows; 1. Blood sugar level and damage to the pancreatic islet increased proportionately when alloxan was given to the rabbits in various doses. No appreciable change could be observed in the islets when the blood sugar level was altered by either oral administration of sugar or subcutaneous injection of insulin. 2. Comparing with the control group, healing of fracture was delayed in the alloxan-treated group, while callus formation and periosteal reaction were shown to be more prominent in this group and subsequently, the ultimate osseous tissue formed at the fracture site was significantly smaller in amount and less compact. These findings were more marked as the amount of alloxan increased. 3. Administration of insulin prevented the delay in healing process of fracture in the rabbits with alloxan-induced hyperglycemia. In this case, the course and progression of fracture healing were almost similar to those of control group. 4. Union between the host bone and the fragment transplanted from other rabbit of the same species was more delayed in the group treated with alloxan alone than in the group to which insulin was administered after development of alloxan-induced diabetes. In both groups periosteal new bone developed from the ends of the host bone, above and below the transplanted fragment, and directly fused with failure of periosteal callus to bridge the adjacent ends of the host bone and the transplanted fragment. 5. The healing process of fracture was not inhibited by alteration in blood sugar level when the blood sugar was abnormally increased by excessive sugar intake or lowered by administration of insulin alone. The healing of fracture in these groups progressed similarly as in the control group. In brief summary, it appears that the healing process of fracture would be definitely disturbed in diabetic state brought about by damage to the pancreatic islet. As such an inhibition could be overcome with insulin, it seems that insulin plays an important role in healing of fracture, but alteration in blood sugar level alone does not modify healing process of fracture to significant degree.

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경피용 건조 B.C.G. 백신(Tokyo 172주) 접종 후 국소 반응과 투베르쿨린 양전율에 관한 연구 (Observation of Response to PPD Skin Test and Local Side Reactions at Multiple Inoculation Sites after Percutanous Inoculation with BCG Tokyo 172 Strain)

  • 이진수;손영모
    • Pediatric Infection and Vaccine
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    • 제7권2호
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    • pp.201-210
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    • 2000
  • 목 적 : 관침관을 이용한 분산난자 경피용으로 접종하는 일본에서 제조한 Tokyo 172주 냉동건조 비시지 백신의 투베르쿨린 양성율과 피부국소 반응 및 부작용 빈도를 알아보기 위하여 본 조사를 시행하였다. 방 법 : 신생아, 영유아, 소아를 대상으로 영동세브란스병원과 7개 개인 소아과 의원에서 접종 후 3일, 4~6주, 36주, 48주째 국소 변화 및 림프절 종창 여부를 관찰하였다. 접종 후 4개월 후에 5TU 0.1mL를 전박 내측에 피내주사하여 48~72시간 후 판독하였다. 결 과 : 관찰기간 중 총 138명의 접종자 중 96명에서의 48주간 추적이 가능하였으며 5TU 투베르쿨린 반응검사 결과 경결 크기의 분포는 5mm 미만이 6명으로 6.3%, 10mm 이상이 67명으로 70.0%, 12mm 이상이 46명으로 47.9%였다. 접종자 모든 례에서 접종 부위 피부에 염증 반응이 관찰되었으며 대부분 4~6주 후에 구진과 작은 농포 및 궤양이 생겼다. 모든 례에서 8~12주 후에 가피를 형성한 후 증상이 사라졌으며 접종 후 48주에 관찰한 접종 부위 반흔 조사에 의하면 전체의 4.2%(4명)에서는 아무런 흔적도 발견할 수 없었고 약 70% 이상에서 10개 이상의 반흔이 관찰되었다. 접종 후 16주에 관찰된 5TU 투베르쿨린 검사의 경결 크기와 48주에 관찰한 접종부위 반흔의 개수와는 상관관계가 관찰되지 않았다. 접종 후 48주까지 추적한 96례 모두에서 액와부 림프절의 종창이나 화농성 염증 등의 이상 반응은 관찰되지 않았다. 결 론 : 본 연구에 사용된 관침관을 이용한 분산난자 경피용 접종법은 이상 반응이 관찰되지 않았으며, 통상적으로 피내 접종 후에 초래되는 어깨 부위의 작은 흉터는 한 례에서도 관찰되지 않았다. 모든 례에서 접종 후 48주 후가 되면 희미한 접종 자국만이 관찰되어 기존의 피내 접종으로 인한 흉터의 우려에 대한 보호자의 만족도는 비교적 높았다.

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백서에서 Depulpin®과 Formocresol에 대한 치수와 치근단 조직의 반응 (PULPAL AND PERIAPICAL REACT10N TO FORMOCRESOL AND DEPULPIN® IN THE RAT TEETH)

  • 문형인;김선호;황윤찬;오병주;황인남;김선헌;정선와;윤창;오원만
    • Restorative Dentistry and Endodontics
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    • 제27권4호
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    • pp.355-362
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    • 2002
  • One fifth dilution of formocresol is usually used for pulpotomy of the primary teeth and emergency pulpotomy of the permanent teeth. However the use of formaldehyde has been subjected to criticism because it may be absorbed into the blood stream and become distributed systemically, it nay also alter the pulp tissue rendering it immunologically active, and have carcinogenic potential. Recently Depulpin$^{\circledR}$(VoCo., Germany) gains popularity as a devitalizing agent during root canal therapy in spite of high concentration of 49 % paraformaldehyde because it facilitate devitalization of pulp and make root canal therapy easier But there have been not enough publications about the reaction of pulp and periapical tissue caused by Depulpin. This study was performed to evaluate the histological changes in pulp and periapical tissue of rats after pulpotomy using formocresol and Depulpin and to elucidate the toxic effects of these agents. Thirty six Sprague-Dawley rats were anesthetized by intraperitoneal injection of ketamine Maxillary first molar teeth were used for pulpotomy with formocresol and Depulpin. Rats were sacrificed after 2 days, 4 days, 1 week, 2 weeks, 3 weeks and 4 weeks respectively. Specimens were histologically observed by light microscope changes in pulp and periapical tissue. The obtained results were as follows. 1. Formocresol group A zone of fixed tissue. in which odontoblasts could clearly be defined, was present directly underneath the pulpotomy dressing in almost all teeth of this group. This was followed by an area of necrotic tissue which resembled dried out fibrous tissue with no cellular detail except some pyknotic nuclei. In the specimens of after 2 days, 4 days, 1 week, 2 weeks in which vital tissue was present, it was separated from the fibrous area by a zone of inflammation. In the specimens of after 3 weeks and after 4 weeks, inflammatory infiltrate was in the periodontal ligament adjacent to the apical foramina of the teeth. 2. Depulpin$^{\circledR}$ group The area of necrotic tissue which had no cells and fibers, was present adjacent to the dressing. This was followed by dried out fibrous tissue with no cellular details except some pyknotic nuclei, A short stump of vital pulp with odontoblasts was present at the end of the canal after 2 days. Inflammatory infiltrate was in the periodontal ligament after 4 days and after 1week. Severe root resolution and necrosis of periapical tissue opposite the root resorption site were defined after 2 weeks and after 3 weeks. Periapical lesion which consist of necrotic tissue surrounded by a fibrous connective wall, was found after 4 weeks. The results indicated that Depulpin can cause more adverse reaction to the dental pulp and periapical tissue than formocresol, and further studies are needed for its clinical use with safety.