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Park J, Jeon YM, In D, Heo SD, Ban C, Lee JB. Single-Molecule Studies of the ssDNA Binding Activity of E. Coli MutL. Biophys J 2010. [DOI: 10.1016/j.bpj.2009.12.368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Chun JS, Yun SJ, Kim SJ, Lee SC, Won YH, Lee JB. Dapsone hypersensitivity syndrome with circulating 190-kDa and 230-kDa autoantibodies. Clin Exp Dermatol 2009; 34:e798-801. [PMID: 19778310 DOI: 10.1111/j.1365-2230.2009.03527.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dapsone has potent anti-inflammatory effects, and is used in the treatment of leprosy, cutaneous vasculitis, neutrophilic dermatoses, and dermatitis herpetiformis and other blistering disorders. However, it may cause severe adverse reactions such as hypersensitivity syndrome, which is characterized by fever, skin rash, hepatitis and lymphadenopathy. We report a 44-year-old female Korean patient with dapsone hypersensitivity syndrome (DHS) that presented as a bullous skin eruption. The patient had a 1-year history of urticarial vasculitis, treated with antihistamines, prednisolone and dapsone. Although the skin lesions improved, she reported fever, nausea, abdominal pain, jaundice, fatigue and skin rashes. On physical examination, there were generalized erythematous macules and purpura with facial oedema that developed into vesicles on the upper limbs. Histological examination of a skin biopsy of a vesicular lesion found subepidermal oedema with a mixed inflammatory cell infiltrate, including eosinophils in the dermis. Indirect immunofluorescence testing using normal foreskin as substrate revealed IgG deposits in the basement membrane zone. Circulating autoantibodies against antigens of 190 and 230 kDa were found by immunoblotting analysis using epidermal extracts. This case illustrates DHS with the formation of circulating autoantibodies.
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Choo MS, Lee JZ, Lee JB, Kim YH, Jung HC, Lee KS, Kim JC, Seo JT, Paick JS, Kim HJ, Na YG, Lee JG. Efficacy and safety of solifenacin succinate in Korean patients with overactive bladder: a randomised, prospective, double-blind, multicentre study. Int J Clin Pract 2008; 62:1675-83. [PMID: 19143854 PMCID: PMC2680337 DOI: 10.1111/j.1742-1241.2008.01898.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
PURPOSE We assessed the efficacy and safety of solifenacin compared with tolterodine for treatment of overactive bladder (OAB) in Korean patients. MATERIALS AND METHODS The study was randomised, double-blind, tolterodine-controlled trial in Korea. Patients had average frequency of >or= 8 voids per 24 h and episodes of urgency or urgency incontinence >or= 3 during 3-day voiding diary period. Patients were randomised to 12-week double-blind treatment with either tolterodine immediate release (IR) 2 mg twice daily (TOL4) or solifenacin 5 mg (SOL5) or 10 mg (SOL10) once daily. The outcome measure was mean change in daily micturition frequency, volume, daily frequency of urgency incontinence, urgency and nocturia from baseline to week 12. Quality of life was assessed using the King's Health Questionnaire. RESULTS A total of 357 were randomised and 329 were evaluated for efficacy. All voiding parameters recorded in micturition diary improved after treatment in all three groups. Mean changes in volume voided were 19.30 ml (26.69%) in TOL4, 30.37 ml (25.89%) in SOL5 and 37.12 ml (33.36%) in SOL10 group (p = 0.03). Speed of onset of SOL10 efficacy on urgency incontinence was faster than that of SOL5 and TOL4. Quality of life improved in all three groups. Dry mouth was the most common adverse event; its incidence was the lowest in SOL5 group (7.63%, compared with 19.49% and 18.64% in SOL10 and TOL4 groups respectively). CONCLUSIONS Solifenacin succinate 5 and 10 mg once daily improve OAB symptoms with acceptable tolerability levels compared with tolterodine IR 4 mg. Solifenacin 5 mg is a recommended starting dose in Korean patients with OAB.
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Woo SU, Bae JW, Kim HG, Choi SH, Kang DH, Lee JB, Koo BW. Correlation between the in vitro ATP-based chemosensitivity assay and HER2/neu expression in women with breast cancer. J Int Med Res 2008; 35:753-61. [PMID: 18034988 DOI: 10.1177/147323000703500603] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Several in vitro chemosensitivity tests have been developed to predict the chemotherapeutic response of tumours prior to initiation of individualized treatment for breast cancer. This study investigated whether the in vitro chemosensitivity response of cell lines derived from breast cancer patients was affected by HER2/neu expression. We cultured breast cancer cell lines from 50 patients and the adenosine triphosphatebased chemotherapy response assay (ATPCRA) was performed with 5-fluorouracil, gemcitabine, docetaxel, doxorubicin, methotrexate, vinorelbine and paclitaxel. 5-fluorouracil combined a high median cell death rate (32.4%) with the narrowest range of cytotoxic effects (7.3-65.7%). In addition, gemcitabine showed significantly greater activity in HER2/neupositive patients. In contrast, docetaxel was significantly less effective in HER2/neu-positive patients. No significant correlation was found between the other agents and HER2/neu expression. The use of the ATP-CRA test for metastatic tissue from patients with recurrent disease might be a useful approach to determine the most effective chemotherapy regimen.
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80
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Park KH, Heo SJ, Koak JY, Kim SK, Lee JB, Kim SH, Lim YJ. Osseointegration of anodized titanium implants under different current voltages: a rabbit study. J Oral Rehabil 2008; 34:517-27. [PMID: 17559620 DOI: 10.1111/j.1365-2842.2006.01688.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The oxide layer that covers a titanium surface is extremely stable and appears to have excellent biocompatibility, which can result in successful osseointegration. The aim of this study was to analyse the characteristics of an oxide layer formed by anodic oxidation (anodization), and to evaluate the extent of bone healing around the anodized implant. The screw-type implants were made of commercially pure titanium (Grade 2). The Group 1 samples had a turned surface, and three other types of experimental specimens were anodized under constant voltages of 190 V (Group 2), 230 V (Group 3) and 270 V (Group 4). The surface characteristics of each sample type were inspected. Removal torque was measured after a 4-week healing period and the histomorphometric analysis was performed 6 weeks after implantation in rabbit tibiae. There was an increase in both the size and number of pores as the anodizing voltage increased. The Ra value of the Group 4 samples was higher than those in the Group 1 and 2 samples (P < 0.05). Group 3 showed a difference compared with Group 1 (P < 0.05). A thicker oxide layer, which contained crystalline (anatase) TiO(2) with the inclusion of some electrolytes (Ca, P), was formed at the higher anodizing voltage. Group 4 had higher removal torque values and percentages of bone-to-implant contact than the other groups (P < 0.05). The anodized titanium implants showed more intimate and stronger connections with peri-implant bone during early osseointegration than the turned titanium implants in this experimental model.
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81
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Hamdan SM, Johnson DE, Tanner NA, Lee JB, Qimron U, Tabor S, van Oijen AM, Richardson CC. Dynamic DNA helicase-DNA polymerase interactions assure processive replication fork movement. Mol Cell 2007; 27:539-49. [PMID: 17707227 DOI: 10.1016/j.molcel.2007.06.020] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Revised: 05/11/2007] [Accepted: 06/19/2007] [Indexed: 11/20/2022]
Abstract
A single copy of bacteriophage T7 DNA polymerase and DNA helicase advance the replication fork with a processivity greater than 17,000 nucleotides. Nonetheless, the polymerase transiently dissociates from the DNA without leaving the replisome. Ensemble and single-molecule techniques demonstrate that this dynamic processivity is made possible by two modes of DNA polymerase-helicase interaction. During DNA synthesis the polymerase and the helicase interact at a high-affinity site. In this polymerizing mode, the polymerase dissociates from the DNA approximately every 5000 bases. The polymerase, however, remains bound to the helicase via an electrostatic binding mode that involves the acidic C-terminal tail of the helicase and a basic region in the polymerase to which the processivity factor also binds. The polymerase transfers via the electrostatic interaction around the hexameric helicase in search of the primer-template.
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82
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Pelcovits RA, Meyer RB, Lee JB. Dynamics of the molecular orientation field coupled to ions in two-dimensional ferroelectric liquid crystals. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 76:021704. [PMID: 17930051 DOI: 10.1103/physreve.76.021704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2007] [Indexed: 05/25/2023]
Abstract
Molecular orientation fluctuations in ferroelectric smectic liquid crystals produce space charges, due to the divergence of the spontaneous polarization. These space charges interact with mobile ions, so that one must consider the coupled dynamics of the orientation and ionic degrees of freedom. Previous theory and light scattering experiments on thin free-standing films of ferroelectric liquid crystals have not included this coupling, possibly invalidating their quantitative conclusions. We consider the most important case of very slow ionic dynamics, compared to rapid orientational fluctuations, and focus on the use of a short electric field pulse to quench orientational fluctuations. We find that the resulting change in scattered light intensity must include a term due to the quasistatic ionic configuration, which has previously been ignored. In addition to developing the general theory, we present a simple model to demonstrate the role of this added term.
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83
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Woo OH, Yong HS, Lee JB, Kim A, Koo BH, Kang EY. A giant malignant peripheral nerve sheath tumour of the breast: CT and pathological findings. Br J Radiol 2007; 80:e44-7. [PMID: 17495054 DOI: 10.1259/bjr/30984808] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Malignant peripheral nerve sheath tumour (MPNST) is a rare soft tissue sarcoma. In particular, primary MPNST of the breast is extremely rare. We report a case of a giant malignant peripheral nerve sheath tumour involving the entire right breast, which was not associated with neurofibromatosis type 1 (NF-1) or previous radiation therapy. A CT scan showed a huge heterogeneous soft tissue mass with well-enhanced nodules at its periphery and low-density internal necrosis, which was confirmed by modified radical mastectomy.
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84
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Lee JB, Pelcovits RA, Meyer RB. Role of electrostatics in the texture of islands in free-standing ferroelectric liquid crystal films. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 75:051701. [PMID: 17677078 DOI: 10.1103/physreve.75.051701] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2007] [Indexed: 05/16/2023]
Abstract
Curved textures of ferroelectric smectic-C* liquid crystals produce space charge when they involve divergence of the spontaneous polarization field. Impurity ions can partially screen this space charge, reducing long-range interactions to local ones. Through studies of the textures of islands on very thin free-standing smectic films, we see evidence of this effect, in which materials with a large spontaneous polarization have static structures described by a large effective bend elastic constant. To address this issue, we calculated the electrostatic free energy of a free-standing film of ferroelectric liquid crystal, showing how the screened Coulomb interaction contributes a term to the effective bend elastic constant, in the static long-wavelength limit. We report experiments which support the main features of this model.
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85
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Won Y, Hong SH, Yu HY, Kwon YH, Yun SJ, Lee SC, Lee JB. Photodetection of basal cell carcinoma using methyl 5-aminolaevulinate-induced protoporphyrin IX based on fluorescence image analysis. Clin Exp Dermatol 2007; 32:423-9. [PMID: 17459066 DOI: 10.1111/j.1365-2230.2007.02435.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The preferential accumulation of 5-aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) in neoplastic cells supports its potential use in the photodetection of porphyrin fluorescence in tumour cells. Hence, epithelial tumours, including basal cell carcinoma (BCC), might be visualized using the fluorescence of selectively accumulated ALA-induced PpIX. AIM In this study, we evaluated the clinical efficacy of PpIX fluorescence images using fluorescence image analysis (FIA) to define the lateral border between the tumour and tumour-free areas of facial BCC. METHODS FIA was used to define the lateral border between the tumour and tumour-free areas on red fluorescence images induced by the topical application of methyl 5-aminolaevulinate (MAL) ointment. According to the FIA results, 50 tissue samples, obtained from 10 patients with BCC, were divided into three categories: tumour area (n = 10), suspected tumour area (n = 20) and suspected tumour-free area (n = 20). These tissue samples were evaluated by histopathological examination. The FIA tool marked out the PpIX fluorescence image for defining the lateral border between the BCC tumour and tumour-free areas. RESULTS The rate of tumour detection from BCC lesions using PpIX fluorescence with the FIA tool showed a sensitivity of 94.1% and specificity of 82.6%. CONCLUSION These results suggest that MAL-induced PpIX fluorescence imaging using FIA is quite sensitive and specific for detecting tumour and occult tumour in facial BCC lesions. This method of presurgical in vivo imaging is therefore proposed as a useful tool for defining the lateral border between BCC tumour and tumour-free areas.
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Abstract
We describe a 52-year-old man with paraneoplastic pemphigus (PNP) without any evidence of an underlying neoplasm over an 8-year follow-up period. He had a chronic relapsing vesiculobullous eruption for approximately 7 years (from April 1998 to May 2005). Initially, scattered flaccid vesicles with crusts developed on the face and trunk, which waxed and waned several times. Our patient was diagnosed as having PNP based on immunopathological criteria for PNP, i.e. histopathological, immunoblotting and immunoprecipitation analyses. However, physical and laboratory examinations including serial blood tests with peripheral blood smear, whole-body positron emission tomography/computed tomography and abdominal ultrasound were unable to detect any underlying neoplasm over an 8-year follow-up period.
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Choi JW, Heo SJ, Koak JY, Kim SK, Lim YJ, Kim SH, Lee JB. Biological responses of anodized titanium implants under different current voltages. J Oral Rehabil 2006; 33:889-97. [PMID: 17168931 DOI: 10.1111/j.1365-2842.2006.01669.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The oxide layer of a titanium surface is very stable, and seems to result in excellent biocompatibility and successful osseointegration. The purpose of this study was to investigate the effects of high anodic oxidation voltages on the surface characteristics of titanium implants and the biologic response of rabbit tibiae. Bone tissue responses were evaluated by removal torque tests and histomorphometric analysis. Screw-shaped implants with microthreads were made of commercially pure titanium (Grade II). We prepared anodized implants under 300 V (group I), 400 V (group II), 500 V (group III) and 550 V (group IV). The surface characteristics of specimens were inspected according to three categories: surface morphology, surface roughness and oxide layer thickness. The screw-shaped implants were installed in rabbit tibiae. The removal torque values were measured and histomorphometric analysis was done after 1- and 3-month healing periods. Data indicate that as anodic oxidation voltage increased above 300 V, oxide layer thickness increased rapidly and pore size also increased. The roughness values of the implants increased with voltage up to 500 V, but decreased at 550 V. In the removal torque test, group III showed higher values than groups I and II at a statistically significant level (P < 0.05) after a 1-month healing period. In histomorphometric analysis, groups III and IV, after a 3-month healing period, showed greater bone to implant contact ratios for the total implant surface than did group I (P < 0.05).
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Meyer RB, Konovalov D, Kraus I, Lee JB. Equilibrium Size and Textures of Islands in Free-Standing Smectic C* Films. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587250108024982] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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89
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Park GT, Quan G, Lee JB. Sera from patients with toxic epidermal necrolysis contain autoantibodies to periplakin. Br J Dermatol 2006; 155:337-43. [PMID: 16882172 DOI: 10.1111/j.1365-2133.2006.07323.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The pathophysiological mechanism of toxic epidermal necrolysis (TEN) with extensive bullae that is induced suddenly by drugs is not well understood. The individual patterns and distribution of the widespread mucocutaneous reactions of TEN often show striking similarities with those of paraneoplastic pemphigus (PNP), which is known to involve autoantibodies (aAbs) to members of the plakin family. OBJECTIVES To investigate the existence of circulating aAbs to periplakin in the sera of patients with TEN. METHODS The presence of circulating aAbs to periplakin was examined using immunoblotting, immunoabsorption and indirect immunofluorescence (IF) analyses. Recombinant protein expression was used to determine the interaction between periplakin and aAbs in the sera of patients with TEN. RESULTS Indirect IF studies revealed circulating aAbs in the intercellular area in the epidermis. Interestingly, on rat bladder the staining pattern of the IgG deposits was similar to that observed in patients with PNP. Immunoblotting analysis of the epidermal extracts was used to identify the aAbs in the sera of patients with TEN. These contained circulating aAbs to a 190-kDa protein corresponding to periplakin. Recombinant periplakin and domains of periplakin were prepared in order to confirm the existence of aAbs to periplakin. Immunoblotting with these proteins demonstrated that the sera from patients with TEN reacted with each domain as well as with the full-length periplakin. CONCLUSIONS We found that circulating aAbs in the sera of patients with TEN target periplakin. These aAbs might play a role in the pathogenesis of TEN as a humoral autoimmune mechanism.
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Lee JB, Levy M, Walker A. Use of a forensic technique to identify blood contamination of emergency department and ambulance trauma equipment. Emerg Med J 2006; 23:73-5. [PMID: 16373813 PMCID: PMC2564139 DOI: 10.1136/emj.2005.025346] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Using a Kastle-Meyer (KM) technique, the following equipment from the emergency departments of six UK hospitals (four trusts) and three regional ambulance services was tested for blood contamination: extrication ("spinal") boards, cervical collars, straps, box splints, head blocks, and headboards. Only equipment ready for patient use was tested. Over half of trauma equipment (57%) tested positive for blood, including 15% of equipment that was visibly stained with blood. There have been no recorded cases of infection from contaminated trauma equipment but our study has identified the potential risk. Disposable covers for boards, disposable straps, and disposable radiolucent head blocks which are currently available provide a solution but have resource implications.
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91
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Lee JB, Konovalov D, Meyer RB. Textural transformations in islands on free standing smectic-C* liquid crystal films. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 73:051705. [PMID: 16802952 DOI: 10.1103/physreve.73.051705] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Indexed: 05/10/2023]
Abstract
We report on and analyze the textural transformations in islands, thicker circular domains, floating in very thin free standing chiral Smectic-C* liquid crystal films. As an island is growing, an initial pure bend texture of the director changes into a reversing spiral at a critical size. Another distinct spiral texture is induced by changing the boundary condition at the central point defect in the island. To understand these transformations from a pure bend island, a linear stability analysis of the c-director free energy is developed, which predicts a state diagram for the island. Our observations are consistent with the theoretical phase diagram.
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92
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Lee JB, Ahmad S, Gale CP. Detection of coins ingested by children using a handheld metal detector: a systematic review. Emerg Med J 2006; 22:839-44. [PMID: 16299189 PMCID: PMC1726630 DOI: 10.1136/emj.2004.022301] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
To determine if the use of a handheld metal detector (HHMD) can safely reduce the number of radiographs requested in cases of coins ingested by children, a search was performed to identify prospective studies of the ability of an HHMD to identify the presence or absence of ingested coin in children (17 years or younger). Outcome measures were presence or absence of coin on metal detector screening, and accuracy of coin localisation. Inclusion and exclusion criteria were defined. Mantel-Haenszel (fixed effect model) pooling with 95% confidence intervals (CI) was used to calculate overall sensitivities and specificities. In total, 11 studies met the inclusion criteria. The overall sensitivity of the HHMD at detecting the presence of coins was 99.4% (95% CI 98.0 to 99.9%) and accuracy at localisation was 99.8% (98.5 to 100.0%). The overall specificity of the HHMD was 100% (76.8 to 100%). Use of the HHMD is an accurate, radiation free, and cost effective method of identifying and localising coins ingested by children. An algorithm for investigating children with coin ingestion is proposed.
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93
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Lee JB, Hite RK, Hamdan SM, Xie XS, Richardson CC, van Oijen AM. DNA primase acts as a molecular brake in DNA replication. Nature 2006; 439:621-4. [PMID: 16452983 DOI: 10.1038/nature04317] [Citation(s) in RCA: 217] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2005] [Accepted: 10/13/2005] [Indexed: 11/09/2022]
Abstract
A hallmark feature of DNA replication is the coordination between the continuous polymerization of nucleotides on the leading strand and the discontinuous synthesis of DNA on the lagging strand. This synchronization requires a precisely timed series of enzymatic steps that control the synthesis of an RNA primer, the recycling of the lagging-strand DNA polymerase, and the production of an Okazaki fragment. Primases synthesize RNA primers at a rate that is orders of magnitude lower than the rate of DNA synthesis by the DNA polymerases at the fork. Furthermore, the recycling of the lagging-strand DNA polymerase from a finished Okazaki fragment to a new primer is inherently slower than the rate of nucleotide polymerization. Different models have been put forward to explain how these slow enzymatic steps can take place at the lagging strand without losing coordination with the continuous and fast leading-strand synthesis. Nonetheless, a clear picture remains elusive. Here we use single-molecule techniques to study the kinetics of a multiprotein replication complex from bacteriophage T7 and to characterize the effect of primase activity on fork progression. We observe the synthesis of primers on the lagging strand to cause transient pausing of the highly processive leading-strand synthesis. In the presence of both leading- and lagging-strand synthesis, we observe the formation and release of a replication loop on the lagging strand. Before loop formation, the primase acts as a molecular brake and transiently halts progression of the replication fork. This observation suggests a mechanism that prevents leading-strand synthesis from outpacing lagging-strand synthesis during the slow enzymatic steps on the lagging strand.
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Lee JW, Um SH, Lee JB, Mun J, Cho H. Scoring and staging systems using cox linear regression modeling and recursive partitioning. Methods Inf Med 2006; 45:37-43. [PMID: 16482368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
OBJECTIVES Scoring and staging systems are used to determine the order and class of data according to predictors. Systems used for medical data, such as the Child-Turcotte-Pugh scoring and staging systems for ordering and classifying patients with liver disease, are often derived strictly from physicians' experience and intuition. We construct objective and data-based scoring/staging systems using statistical methods. METHODS We consider Cox linear regression modeling and recursive partitioning techniques for censored survival data. In particular, to obtain a target number of stages we propose cross-validation and amalgamation algorithms. We also propose an algorithm for constructing scoring and staging systems by integrating local Cox linear regression models into recursive partitioning, so that we can retain the merits of both methods such as superior predictive accuracy, ease of use, and detection of interactions between predictors. The staging system construction algorithms are compared by cross-validation evaluation of real data. RESULTS The data-based cross-validation comparison shows that Cox linear regression modeling is somewhat better than recursive partitioning when there are only continuous predictors, while recursive partitioning is better when there are significant categorical predictors. The proposed local Cox linear recursive partitioning has better predictive accuracy than Cox linear modeling and simple recursive partitioning. CONCLUSIONS This study indicates that integrating local linear modeling into recursive partitioning can significantly improve prediction accuracy in constructing scoring and staging systems.
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Poolman RW, Goslings JC, Lee JB, Statius Muller M, Steller EP, Struijs PAA. Conservative treatment for closed fifth (small finger) metacarpal neck fractures. Cochrane Database Syst Rev 2005; 2005:CD003210. [PMID: 16034891 PMCID: PMC8711295 DOI: 10.1002/14651858.cd003210.pub3] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Subcapital fractures of the fifth metacarpal bone, meaning fractures just below the knuckle of the little finger, account for approximately 20% of all hand fractures. Currently, there is no consensus concerning the optimal management of these fractures. Traditionally, treatment consists of closed reduction and external splinting in a neutral position using plaster of Paris (POP), involving the metacarpal joint, the proximal interphalangeal joint and the carpo-metacarpal joint. An alternative treatment strategy is functional treatment using taping or bracing that does not restrict movement. OBJECTIVES To compare functional treatment with immobilization, and to compare different periods and types of immobilization, for the treatment of closed fifth metacarpal neck fractures in adults. SEARCH STRATEGY We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialized Register (July 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2004), OVID OldMEDLINE (1951 to 1965), OVID MEDLINE (1966 to July 2004), OVID MEDLINE In-Process (July 2004), EMBASE (1988 to 2004, week 29), the Internet, and reference lists of articles. No language restrictions were applied. SELECTION CRITERIA All randomized and quasi-randomized controlled trials which compare functional treatment with immobilization or different types of immobilization for closed fifth metacarpal neck fractures. DATA COLLECTION AND ANALYSIS Two review authors assessed abstracts of all studies identified by the initial search, identified studies meeting the selection criteria, independently assessed the quality of the trial reports, and extracted and analysed the data. MAIN RESULTS Five studies met the inclusion criteria including a total of 252 participants. Most studies were of poor quality. The primary outcome measure, function of the hand, was not used in any studies. There was no evidence that any of the treatment modalities was statistically significantly superior. AUTHORS' CONCLUSIONS No included studies reported our primary outcome measure of interest, validated hand function. There was heterogeneity between the studies, which were of limited quality and size. No single non-operative treatment regimen for fracture of the neck of the fifth metacarpal can be recommended as superior to another in result. Further research is definitely warranted.
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Huber CD, Lee JB, Yang KH, King AI. Head injuries in airbag-equipped motor vehicles with special emphasis on AIS 1 and 2 facial and loss of consciousness injuries. TRAFFIC INJURY PREVENTION 2005; 6:170-4. [PMID: 16019402 DOI: 10.1080/15389580590931644] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
OBJECTIVES Safety of the airbag supplemental restraint system (airbag) is a well-known concern. Although many lives are saved each year through airbag use, injuries continue to occur, especially to the head. Airbag safety research has focused primarily on severe injuries, while minor and moderate injuries have been largely ignored. METHODS In this study, 205,977 injury cases from the 1995 to 2001 National Automotive Sampling System (NASS)/ Crashworthiness Data System (CDS) were surveyed to determine the prevalence of AIS 1 and 2 facial and brain loss of consciousness (LOC) injuries and determine if these injuries are a concern. The query was focused on frontal impacts in vehicles equipped with airbags. Only occupants wearing appropriate seatbelts were included in this study so that the airbag would provide occupant protection under optimal conditions. Of the 205,977 injury cases studied, 2.4% met this criterion. RESULTS From the data gathered, the trends seem to indicate an increase in these specific injuries, both in terms of the total number and the proportion to all injury cases. In 1995, AIS 1 and 2 head injuries accounted for 96.5% of all head injuries caused by airbags. By 2001, the percentage had risen 3.0% to 99.5%. Injuries occurring in vehicles equipped with first-generation versus second generation airbags were compared, and data seem to suggest that there is a higher rate of minor and moderate head injuries when occupants are in second-generation airbag-equipped vehicles, even when appropriate lap and shoulder belts are used. CONCLUSIONS The short timeframe surveyed prevents drawing meaningful conclusions about statistical significance, but the graphical representations of the data in this study underscore an urgent need for further investigation based on current trends in order to understand the issue of minor and moderate head injury prevention in regard to airbags.
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Snedeker JG, Niederer P, Schmidlin FR, Farshad M, Demetropoulos CK, Lee JB, Yang KH. Strain-rate dependent material properties of the porcine and human kidney capsule. J Biomech 2005; 38:1011-21. [PMID: 15797583 DOI: 10.1016/j.jbiomech.2004.05.036] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2004] [Indexed: 11/29/2022]
Abstract
This study was performed to characterize the mechanical properties of the kidney capsular membrane at strain-rates associated with blunt abdominal trauma. Uniaxial quasi-static and dynamic tensile experiments were performed on fresh, unfrozen porcine and human renal capsules at deformation rates ranging from 0.0001 to 7 m/s (strain-rates of 0.005-250 s(-1)). Single stroke, dynamic tests were performed on samples of porcine renal capsule at strain-rates of 0.005 s(-1) (n = 33), 0.05 s(-1) (n = 17), 0.5 s(-1) (n = 38), 2 s(-1) (n = 10), 4 s(-1) (n = 10), 50 s(-1) (n = 21), 100 s(-1) (n = 18), 150 s(-1) (n = 17), 200 s(-1) (n = 10), and 250 s(-1) (n = 17). Due to limited availability of human tissues, only quasi-static tests were performed (0.005 s(-1), n = 25). Porcine renal capsule properties were found to match the material properties of human capsular tissue sufficiently well such that porcine tissue material can be used as a human test surrogate. The apparent elastic modulus and breaking stress of the porcine renal capsule were observed to increase significantly with increasing strain-rate (p < 0.01). Breaking strain was inversely related to strain-rate (p < 0.01). The effect of increasing strain-rate on material properties diminished appreciably at rates exceeding 150 s(-1). Empirically derived mathematical models of constitutive behavior were developed using a hyperelastic/viscoelastic Ogden formulation, as well as a Cowper-Symonds law material curve multiplication.
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Kim SK, Lee JB, Koak JY, Heo SJ, Lee KR, Cho LR, Lee SS. An abutment screw loosening study of a Diamond Like Carbon-coated CP titanium implant. J Oral Rehabil 2005; 32:346-50. [PMID: 15842243 DOI: 10.1111/j.1365-2842.2004.01475.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The aim of this study was to quantify the extent of abutment screw loosening and thus understand the role of frictional and wear factors in abutment screw loosening by using a cyclic loading device to compare Diamond Like Carbon (DLC)-coated and non-coated implants. The properties of DLC films, including hardness, wear resistance, chemical stability, and biocompatibility, are similar to those of real diamond materials. In this study, a 1-mum thick DLC film served to protect and lubricate a layer of commercially-pure titanium affixed to the top of a dental implant (external hexagon-shaped implant). A cyclic loading force was then applied to the top of the prosthetic portion of the implants in order to determine the difference in looseness of the titanium abutment screw between ten DLC-coated implants and ten non-coated implants. The abutment screw loosening tests were performed with 100 N of force at a frequency of 20 Hz. Data indicate that implants with a DLC coating are more resistant to an applied force (P = 0.002) than are those without the coating. We hope these results will be useful for preventing implant abutment screw loosening.
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Lee JB. NICE head injury guidelines: cost implication for a district general hospital ("six scans to six figures"). Emerg Med J 2004; 21:125-6. [PMID: 14734404 PMCID: PMC1756348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
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Abstract
The present study was designed to develop a microencapsulated L-ascorbic acid and iron that could be used to fortify milk and to determine the sensory properties of milk fortified with microencapuslation. Coating material was medium-chain triacylglycerol (MCT), and selected core material was ferric ammonium sulfate and L-ascorbic acid. The highest efficiency of microencapsulation was 95.0% in the ratio of 15:1 as coating to core material. Ascorbic acid release was increased sharply up to 5 d storage as 6.5%. TBA value was the lowest when both capsulated iron and ascorbic acid were added during 12 d storage, compared with other treatments. In sensory analysis, most aspects were not significantly different between control and capsulated ascorbic acid fortified milk at 5 d storage. The present study indicated that the use of microencapsulated ascorbic acid with MCT is effective for fortifying milk. In addition, these results suggest that acceptable milk products can be prepared with microencapsulated ascorbic acid and iron.
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