• Journal of Periodontal and Implant Science
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• 제38권3호
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• pp.551-556
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• 2008

Purpose: Cemental tear is an uncommon form of root fracture that can lead to rapid localized attachment loss. When it is exposed in the periodontal pocket, it should be removed to prevent accumulation of dental plaque and calculus. Material and Methods: 2 patients were diagnosed as a cemental tear and they were treated with conventional flap operation and subgingival curettage. Additional treatments such as bone graft or guided tissue regeneration were not performed. Result: Symptoms subsided after the treatment. Periodontal pocket has been reduced but no gain of clinical attachment was observed. Remnant of cemental fragment remained after curettage. However, periodontal pocket was stably maintained and there was no recurrence. Conclusion: Periodontal attachment loss associated with cemental tear can be successfully treated with conventional periodontal surgical and nonsurgical procedures.

• 대한치과의사협회지
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• 제54권5호
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• pp.365-373
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• 2016

Purpose: Cemental tear is a specific type of root surface fracture characterized by a complete separation of a cemental fragment along the cementodentinal junction or a partial split within the cementum along an incremental line. It is suggested to be a factor for periodontal or periapical tissue destruction. The aim of this study is to present a diagnosis and treatment of cemental tear associated with periapical lesion with root canal treatment and regenerative periodontal surgery. Treatments: A 60-year-old male who had a history of sports trauma on the mandibular right central incisor about 10 years ago presented with apical cemental tear. Clinical examination showed a slightly dark yellowish discoloration and sinus tract that was located on the apical labial mucosa. The mobility and percussion were also assessed on the diseased tooth and recorded as $Miller^{\circ}{\phi}s$ Class II and tenderness to percussion. The probing depth was within the normal limit (<3 mm). Radiographic examination revealed a radiolucent lesion at the apical area and extended to distal aspect of the tooth along the fragment of cemental tear. After root canal treatment, periapical surgery was performed. The bony defect was exposed and then the detached root fragment was removed. Apical root resection and retrograde filling with Mineral Trioxide Aggregate (MTA) were accomplished and the bony defect was filled with deproteinized bovine bone mineral (DBBM) and covered with biodegradable collagen membrane. Results: After 9-month follow-up, healing of the mandibular right central incisor was uneventful and no swelling, purulence or pain was revealed in the associated area. Probing pocket depth was favorably stable, and the tooth mobility was decreased to the Miller's Class I. Conclusions: Apical cemental tear associated periapical lesion could be successfully treated with removal of the detached cementum in combination with apical surgery and GTR procedure.

• 구강생물연구
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• 제42권4호
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• pp.248-253
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• 2018

Cemental tears are uncommon form of root fracture that can lead to rapid localized periodontal attachment loss. Studies have described periodontal breakdown as being associated with the separation of the cementum from the underlying tooth structure. The aim of this case report is to assess the outcome of treatment of cemental tear with several surgical treatment regimens. Three patients with cemental tear were treated with different surgical method. In all three cases, the cemental tear occurred on maxillary right central incisors. In each case, the root fragment were removed, the localized defect was treated using different surgical methods including guided tissue regeneration and bone graft followed by scaling and root planting. In all three cases, symptoms subsided after the treatment and clinical attachment level was improved up to 2 mm at 3 month after surgery. Both conventional and regenerative periodontal surgery could achieve successful outcomes.

• Bulletin of the Korean Chemical Society
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• 제24권6호
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• pp.817-823
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• 2003

We have performed ab initio calculation on the active site of HIV-1 protease. The FEP method was used to determine the binding free energy of four different of protonated states of HIV-1 protease with inhibitor. The structure of the active site and hole structure was taken from the X-ray crystallographic coordinates of the C₂ symmetric inhibitor A74704 protease bound. The active site was modeled with the fragment molecules of binding pocket, acetic acid/ acetate anion (Asp25, Asp125), formamide (amide bond of Thr26/Gly27, Thr126/ Gly127), and methanol as inhibitor fragment. All possibly protonated states of the active site were considered, which were diprotonated state (0, 0), monoprotonated (-1, 0),(0, -1) and diunprotonated state (-1, -1). Once the binding energy Debind, of each model was calculated, more probabilistic protonated states can be proposed from binding energy. From ab-initio results, the FEP simulations were performed for the three following mutations: Ⅰ) Asp25 … Asp125 → AspH25 … Asp125, ⅱ) Asp25 … Asp125 → Asp25 … AspH125, ⅲ) AspH25 … Asp125 → AspH25 … AspH125. The free energy difference between the four states gives the information of the more realistic protonated state of active site aspartic acid. These results provide a theoretical prediction of the protonation state of the catalytic aspartic residues for A74707 complex, and may be useful for the evaluation of potential therapeutic targets.

• Journal of Microbiology
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• 제40권3호
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• pp.211-218
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• 2002

A 4.8-kb DNA fragment encoding the P-450 type hydroxylase and ferredoxin genes was cloned from Pseudonocardia autotrophica IFO 12743 that can convert vitamin D$\_$3/ into its hydroxylated active forms. In order to isolate the P-450 gene cluster in this organism, we designed PCR primers on the basis of the regions of an oxygen binding site and a heme ligand pocket that are general characteristics of the P-450 hydroxylase. Sequencing analysis of the BamHI fragment revealed the presence of four complete and one incomplete ORFs, named PauA, PauB, PauC, and PauD, respectively. As a result of computer-based analyses, PauA and PauB have homology with enoyl-CoA hydratase from several organisms and the positive regulators belonging to the tetR family, respectively. PauC and PauD show similarity with SuaB/C proteins and ferredoxins, respectively, which are composed of P-450 monooxygenase systems for metabolizing two sulfonylurea herbicides in Streptomyces griseolus PauC shows the highest similarity with another CytP-450$\_$Sca2/ protein that is responsible for production of a specific HMG-CoA reductase inhibitor, pravastatin, in S. carbophilus. Cultures of Steptomyces lividans transformant, containing the P-450 gene cluster on the pWHM3 plasmid, was unable to convert vitamin D$\_$3/ to its hydroxylated forms.

• 대한두개안면성형외과학회지
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• 제19권4호
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• pp.300-303
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• 2018

Intraorbital wooden foreign bodies may present difficulties in diagnosis due to their radiolucent nature. Delayed recognition and management can cause significant complications. We present a case report that demonstrates these problems and the sequela that can follow. A 56-year-old man presented with a 3-cm laceration in the right upper eyelid, sustained by a slipping accident. After computed tomography (CT) scanning and ophthalmology consultation, which revealed no fractures and suggested only pneumophthalmos, the wound was repaired by a plastic surgery resident. Ten days later, the patient's eyelid displayed signs of infection including pus discharge. Antibiotics and revisional repair failed to solve the infection. Nearly 2 months after the initial repair, a CT scan revealed a large wooden fragment in the superomedial orbit. Surgical exploration successfully removed the foreign body and inflamed pocket, and the patient healed uneventfully. However, the prolonged intraorbital infection had caused irreversible damage to the superior rectus muscle, with upgaze diplopia persisting 1 year after surgery and only minimal muscle function remaining. We report this case to warn clinicians of the difficulties in early diagnosis of intraorbital wooden foreign bodies and the grave prognosis of delayed management.

• 한국지열·수열에너지학회논문집
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• 제14권3호
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• pp.21-28
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• 2018

This paper presents two-step simulations to calculate the influence of blast-induced pressures on explosion-protection valves installed at the boundary between a protection facility and a tunnel entering the facility. The first step is to calculate the respective overpressure on the entrance and exit of the tunnel when an explosion occurs near the tunnel entrance and exit to approach the protection facility. Secondly, the blast pressures on the explosion-protection valves mounted to walls located near the tunnel inside approaching the protection facility are analyzed with a 0.1 ms time variation using the results obtained from the first-step calculations. The following conclusions could be derived as a results: (1) The analysis of the entrance tunnel scenario, P1, leads to the maximum overpressure of 47 kPa, approximately a half of the ambient pressure, at the inner entrance due to the effect of blast barrier. For the scenario, P2, the case not blocked by the barrier, the maximum overpressure is 628 kPa, which is relatively high, namely, 5.2 times the ambient pressure. (2) It is observed that the pressure for the entrance tunnel is effectively mitigated because the initial blast pressures are partially offset from each other according to the geometry of the entrance and a portion of the pressures is discharged to the outside.

• Archives of Plastic Surgery
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• 제35권5호
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• pp.611-614
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• 2008

Purpose: Infection, foreign body reaction and decreased volume of implant are common complications after augmentation rhinoplasty with $Gore-tex^{(R)}$ implant. The author experienced two cases of recurrent foreign body granuloma in the patients who underwent $Gore-tex^{(R)}$ removal because of infection after augmentation rhinoplasty. and treated them with complete removal of$Gore-tex^{(R)}$. Methods: Case 1: A 49 year-old female visited our clinic for recurrent foreign body reaction on nasal dorsum and tip area. The patient underwent augmentation rhinoplasty with $Gore-tex^{(R)}$ 3 years ago and implant was removed due to infection 9 months ago. Excision of the granuloma was performed and a piece of foreign body suspicious to be a $Gore-tex^{(R)}$ implant debris was detected under the subcutaneous pocket. The implant fragments were removed and nasalis muscle rotation flap was performed to cover the lesion. The specimen was proved to be $Gore-tex^{(R)}$ in histological study. Case 2: A 31 year-old-male with recurrent foreign body granuloma on the nasal tip area visited our clinic. 10 years ago, the patient had augmentation rhinoplasty with silicone implant and then, he underwent revisional rhinoplasty five times including nasal implant removal, which was performed 9 months ago. The authors excised the granuloma and found a small sized foreign body suspicious to be a $Gore-tex^{(R)}$ implant debris under the granuloma. The foreign body was excised and identified to be $Gore-tex^{(R)}$ in histological study. Results: In both cases, the lesions were healed without any complications and there were no evidences of recurrence up to 6 months of follow-up. Conclusion: The $Gore-tex^{(R)}$ is known to be weak against mechanical force. These properties of $Gore-tex^{(R)}$ make it difficult to remove the implant completely. In the patient who have infection after augmentation rhinoplasty with $Gore-tex^{(R)}$, the operator should take care to perform the complete removal without remaining fragment of the implant.