• Title/Summary/Keyword: Kaplan-Meier Analysis

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The Results and Prognostic Factors of Mitomycin C Trabeculectomy in Neovascular Glaucoma (신생혈관녹내장에 대한 Mitomycin C 섬유주절제술의 성적과 예후인자)

  • Kim, Yun-Tae;Cha, Soon-Cheol
    • Journal of Yeungnam Medical Science
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    • v.19 no.2
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    • pp.126-135
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    • 2002
  • Background: Neovascular glaucoma is common secondary glaucoma at high risk for failure of glaucoma filtering surgery. Recently, trabeculectomy with adjunctive mitomycin C trabeculectomy has been tried to improve the surgical success rate of conventional trabeculectomy. But, the long-term effects of mitomycin C trabeculectomy for neovascular glaucoma are unknown. Thus, we evaluated the long-term effects of mitomycin C trabeculectomy and its prognostic factors influencing the outcome. Materials and Methods: Medical records of 62 eyes of 55 neovascular glaucoma who had undergone mitomycin C trabeculectomy were retrospectively reviewed. Surgical success was defined as intraocular pressures of 21 mmHg or less with or without glaucoma medications and no loss of light perception. Surgical failure was defined as postoperative loss of light perception in patients with preoperative vision better than light perception, additional glaucoma surgery, or phthisis bulbi in patients with preoperative vision of no light perception. Results: Postoperative success was obtained in 37 (60%) out of 62 eyes after mean followup period of $23.9{\pm}16.2$ months. Using Kaplan-Meier survival analysis, cumulative success rate at the 6-, 12-, 24- and 36-month intervals were 85%, 71%, 57% and 52%, respectively. Success rate was greater in eyes with diabetic retinopathy than other causes(p=0.005) and in eyes with preoperative panretinal photocoagulation(PRP) than without PRP(p=0.015). However, Cox proportional hazard regression analysis revealed that preoperative PRP was not a significant risk factor for surgical failure. Conclusion: Prognosis of neovascular glaucoma caused by diabetic retinopathy was better than that caused by the other disorders following mitomycin C trabeculectomy. The author would suggest that mitomycin C trabeculectomy could be effective and relatively safe as the first procedure of choice before performing glaucoma drainage device implantation or cyclodestructive procedure.

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A 10-year retrospective study on the risk factors affecting the success rate of internal connection implants after prosthetic restoration (내부연결 임플란트의 보철 수복 후 성공률에 미치는 위험요소에 관한 10년간의 후향적 연구)

  • Seoin Lee;Min-Jeong Kim
    • The Journal of Korean Academy of Prosthodontics
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    • v.61 no.2
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    • pp.113-124
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    • 2023
  • Purpose. The purpose of this study is to help increase the success rate by analyzing the types and characteristics of implant prosthesis and the survival rate. Materials and methods. Among implants placed between 2011 and 2020 at Sanbon Dental Hospital, College of Dentistry, Wonkwang University, a case restored by a prosthetic surgeon was investigated for the characteristics and correlation of failure. The causes of failure were classified as failure of osseointegration, peri-implantitis, fixture fracture, abutment fracture, screw fracture, screw loosening, prosthesis fracture, and loss of prosthesis retention. Prosthetic method, cantilever presence, placement location, etc. were analyzed for their correlation with implant failure. Results analysis was derived through Chi-square test and Kaplan-Meier survival analysis using SPSS ver 25.0 (IBM, Chicago, IL, USA). Results. A total of 2587 implants were placed, of which 1141 implants were restored with Single Crown and 1446 implants with Fixed Partial Denture, and the cumulative survival rate was 88.1%. The success rate of SC was 86.2% (984) and the success rate of FPD was 89.6% (1295), showing statistically significant differences, among which factors that had significant differences were abutment fracture, screw fracture, and screw loosening (P < .05). Conclusion. As a result of the 10-year follow-up, more failures occurred due to biomechanical factors than biological factors. Further studies on the success of implants will be needed in the future.

Determination of Lethal Concentrations and Lethal Times of Extracts from Tanacetum cineariaiaefolium, Derris elliptica, and Sophora flavescens, to Control Green Peach Aphid, Myzus persicae (복숭아혹진딧물, Myzus persicae, 방제를 위한 제충국, 데리스, 고삼 추출물의 살충농도와 살충시간 결정)

  • Ka Hee Cho;Hyo Jung Kim;Song Hee Han;Young Cheol Kim
    • Korean journal of applied entomology
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    • v.62 no.4
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    • pp.267-275
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    • 2023
  • Botanical extracts are employed in management of aphids. Extracts from Tanacetum cineariaiaefolium, Derris elliptica, and Sophora flavescens are widely used to control various insects. In this study, we determined concentrations of insecticidal active ingredients in commercial botanical extracts of these plants, and we investigated the time and concentration for lethal results with the green peach aphid, Myzus persicae. The concentrations of active ingredients, pyrethrins from T. cineariaiaefolium, rotenone from D. elliptica, and matrine and oxymatrine from S. flavescens, were determined after their fractionation by liquid chromatography followed by mass analysis and comparison with standard compounds. The extracts were tested for lethality in a bioassay with green peach aphids. Sprays at defined doses were applied to tobacco leaves infested with aphid nymphs. The lethal concentrations (LC50) were 20.4 ppm for pyrethrins, 34.1 ppm for rotenone, and 29.6 ppm for matrine at 48 h after treatments. At 100 ppm application levels, the lethal time LT50 was 13.4 h for pyrethrin, 15.1 h for rotenone, and 14.4 h for matrine. Kaplan-Meier analysis indicated the lethal times for the three botanical extracts at 100 ppm were significantly faster than application of a chemical insecticide, Sulfoxaflor, applied at the recommended level. These results provide baselines to develop and formulate single or mixed preparations containing botanical extracts to control green peach aphids on commercial crops.

Socio-economic Factors Affect the Outcome of Soft Tissue Sarcoma: an Analysis of SEER Data

  • Cheung, Min Rex;Kang, Josephine;Ouyang, Daniel;Yeung, Vincent
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.1
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    • pp.25-28
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    • 2014
  • Background: This study analyzed whether socio-economic factors affect the cause specific survival of soft tissue sarcoma (STS). Methods: Surveillance, Epidemiology and End Results (SEER) soft tissue sarcoma (STS) data were used to identify potential socio-economic disparities in outcome. Time to cause specific death was computed with Kaplan-Meier analysis. Kolmogorov-Smirnov tests and Cox proportional hazard analysis were used for univariate and multivariate tests, respectively. The areas under the receiver operating curve were computed for predictors for comparison. Results: There were 42,016 patients diagnosed STS from 1973 to 2009. The mean follow up time (S.D.) was 66.6 (81.3) months. Stage, site, grade were significant predictors by univariate tests. Race and rural-urban residence were also important predictors of outcome. These five factors were all statistically significant with Cox analysis. Rural and African-American patients had a 3-4% disadvantage in cause specific survival. Conclusions: Socio-economic factors influence cause specific survival of soft tissue sarcoma. Ensuring access to cancer care may eliminate the outcome disparities.

Racial and Socioeconomic Disparities in Malignant Carcinoid Cancer Cause Specific Survival: Analysis of the Surveillance, Epidemiology and End Results National Cancer Registry

  • Cheung, Rex
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7117-7120
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    • 2013
  • Background: This study hypothesized living in a poor neighborhood decreased the cause specific survival in individuals suffering from carcinoid carcinomas. Surveillance, Epidemiology and End Results (SEER) carcinoid carcinoma data were used to identify potential socioeconomic disparities in outcome. Materials and Methods: This study analyzed socioeconomic, staging and treatment factors available in the SEER database for carcinoid carcinomas. The Kaplan-Meier method was used to analyze time to events and the Kolmogorov-Smirnov test to compare survival curves. The Cox proportional hazard method was employed for multivariate analysis. Areas under the receiver operating characteristic curves (ROCs) were computed to screen the predictors for further analysis. Results: There were 38,546 patients diagnosed from 1973 to 2009 included in this study. The mean follow up time (S.D.) was 68.1 (70.7) months. SEER stage was the most predictive factor of outcome (ROC area of 0.79). 16.4% of patients were un-staged. Race/ethnicity, rural urban residence and county level family income were significant predictors of cause specific survival on multivariate analysis, these accounting for about 5% of the difference in actuarial cause specific survival at 20 years of follow up. Conclusions: This study found poorer cause specific survival of carcinoid carcinomas of individuals living in poor and rural neighborhoods.

Survival Analysis for Prognostic Factors of Occupational Low Back Pain (직업성 요통 근로자의 장애기간에 영향을 미치는 요인 연구)

  • Kim, Ji-Yun
    • Research in Community and Public Health Nursing
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    • v.17 no.1
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    • pp.17-25
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    • 2006
  • Purpose: The goals of this research are to find out factors influencing the duration of work-related disability and to present implications for policies to prevent delayed recovery. Method: The subjects of this study were 238 workers who had been proved to be industrial disaster victims for occupational low back pain between January 1 2000 and December 31 2003. Kaplan-Meier method was used to estimate the proportion of duration of disability associated with low back pain, and Cox proportional hazards analysis was used to identify factors predicting it. The model distinguished main symptom variables affecting acute(${\leq}90\;days$) and chronic phase of disability (>90 days). Result: Fifty percent of the workers had not recovered in 408 days. The results of Cox regression show that delayed duration of disability was predicted by diagnosis, pain radiation (in chronic phase), sex, the size and labor union of the workplace, scheduled rest, compensation from the company, and operation. Conclusion: Duration of disability associated with compensated low back pain is influenced not only by factors related to the company and compensation system but also by individual factors. Thus, future efforts to reduce duration of disability may need to take into account all these factors.

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Low Income and Rural County of Residence Increase Mortality from Bone and Joint Sarcomas

  • Cheung, Min Rex
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.9
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    • pp.5043-5047
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    • 2013
  • Background: This is a part of a larger effort to characterize the effects on socio-economic factors (SEFs) on cancer outcome. Surveillance, Epidemiology and End Result (SEER) bone and joint sarcoma (BJS) data were used to identify potential disparities in cause specific survival (CSS). Materials and Methods: This study analyzed SEFs in conjunction with biologic and treatment factors. Absolute BJS specific risks were calculated and the areas under the receiver operating characteristic (ROC) curve were computed for predictors. Actuarial survival analysis was performed with Kaplan-Meier method. Kolmogorov-Smirnov's 2-sample test was used to for comparing two survival curves. Cox proportional hazard model was used for multivariate analysis. Results: There were 13501 patients diagnosed BJS from 1973 to 2009. The mean follow up time (SD) was 75.6 (90.1) months. Staging was the highest predictive factor of outcome (ROC area of 0.68). SEER stage, histology, primary site and sex were highly significant pre-treatment predictors of CSS. Under multivariate analysis, patients living in low income neighborhoods and rural areas had a 2% and 5% disadvantage in cause specific survival respectively. Conclusions: This study has found 2-5% decrement of CSS of BJS due to SEFs. These data may be used to generate testable hypothesis for future clinical trials to eliminate BJS outcome disparities.

Long-Term Survival Analysis of Unicompartmental Knee Arthroplasty (슬관절 부분 치환술의 장기 생존 분석)

  • Park, Cheol Hee;Lee, Ho Jin;Son, Hyuck Sung;Bae, Dae Kyung;Song, Sang Jun
    • Journal of the Korean Orthopaedic Association
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    • v.54 no.5
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    • pp.427-434
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    • 2019
  • Purpose: This study evaluated the long term clinical and radiographic results and the survival rates of unicompartmental knee arthroplasty (UKA). In addition, the factors affecting the survival of the procedure were analyzed and the survival curve was compared according to the affecting factors. Materials and Methods: Ninety-nine cases of UKA performed between December 1982 and January 1996 were involved: 10 cases with Modular II, 44 cases with Microloc, and 45 cases with Allegretto prostheses. The mean follow-up period was 16.5 years. Clinically, the hospital for special surgery (HSS) scoring system and the range of motion (ROM) were evaluated. Radiographically, the femorotibial angle (FTA) was measured. The survival rate was analyzed using the Kaplan-Meier method. Cox regression analysis was used to identify the factors affecting the survival according to age, sex, body mass index, preoperative diagnosis, and type of implant. The Kaplan-Meier survival curves were compared according to the factors affecting the survival of UKA. Results: The overall average HSS score and ROM was 57.7 and 134.3° preoperatively, 92.7 and 138.4° at 1 year postoperatively, and 79.1 and 138.4° at the last follow-up (p<0.001, respectively). The overall average FTA was varus 0.8° preoperatively, valgus 4.1° at postoperative 2 weeks, and valgus 3.0° at the last follow-up. The overall 5-, 10-, 15- and 20-year survival rates were 91.8%, 82.9%, 71.0%, and 67.0%, respectively. The factors affecting the survival were the age and type of implant. The risk of the failure decreased with age (hazard ratio=0.933). The Microloc group was more hazardous than the other prostheses (hazard ratio=0.202, 0.430, respectively). The survival curve in the patients below 60 years of age was significantly lower than those of the patients over 60 years of age (p=0.003); the survival curve of the Microloc group was lower compared to the Modular II and Allegretto groups (p=0.025). Conclusion: The long-term clinical and radiographic results and survival of UKA using old fixed bearing prostheses were satisfactory. The selection of appropriate patient and prosthesis will be important for the long term survival of the UKA procedure.

Resection and Observation for Brain Metastasis without Prompt Postoperative Radiation Therapy

  • Song, Tae-Wook;Kim, In-Young;Jung, Shin;Jung, Tae-Young;Moon, Kyung-Sub;Jang, Woo-Youl
    • Journal of Korean Neurosurgical Society
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    • v.60 no.6
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    • pp.667-675
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    • 2017
  • Objective : Total resection without consecutive postoperative whole brain radiation therapy is indicated for patients with a single or two sites of brain metastasis, with close follow-up by serial magnetic resonance imaging (MRI). In this study, we explored the effectiveness, usefulness, and safety of this follow-up regimen. Methods : From January 2006 to December 2015, a total of 109 patients (76 males, 33 females) underwent tumor resection as the first treatment for brain metastases (97 patients with single metastases, 12 with two metastases). The mean age was 59.8 years (range 27-80). The location of the 121 tumors in the 109 patients was supratentorial (n=98) and in the cerebellum (n=23). The origin of the primary cancers was lung (n=45), breast (n=17), gastrointestinal tract (n=18), hepatobiliary system (n=8), kidney (n=7), others (n=11), and unknown origin (n=3). The 121 tumors were totally resected. Follow-up involved regular clinical and MRI assessments. Recurrence-free survival (RFS) and overall survival (OS) after tumor resection were analyzed by Kaplan-Meier methods based on clinical prognostic factors. Results : During the follow-up, MRI scans were done for 85 patients (78%) with 97 tumors. Fifty-six of the 97 tumors showed no recurrence without adjuvant local treatment, representing a numerical tumor recurrence-free rate of 57.7%. Mean and median RFS was 13.6 and 5.3 months, respectively. Kaplan-Meier analysis revealed the cerebellar location of the tumor as the only statistically significant prognostic factor related to RFS (p=0.020). Mean and median OS was 15.2 and 8.1 months, respectively. There were no significant prognostic factors related to OS. The survival rate at one year was 8.2% (9 of 109). Conclusion : With close and regular clinical and image follow-up, initial postoperative observation without prompt postoperative radiation therapy can be applied in patients of brain metastasi(e)s when both the tumor(s) are completely resected.

Trabeculectomy Using Mitomycin C in Aphakic and Pseudophakic Eyes (무수정체안과 인공수정체안에 대한 Mitomycin C를 이용한 일차 섬유주절제술의 효과)

  • Son, Jun-Hyuk;Cha, Soon-Cheol
    • Journal of Yeungnam Medical Science
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    • v.24 no.2
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    • pp.232-242
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    • 2007
  • Background : The safety and efficacy of trabeculectomy with Mitomycin C (MMC) for surgical treatment in aphakic and pseudophaic eyes were retrospectively evaluated. Materials and Methods : The authors reviewed 51 eyes of 45 patients who had been followed up for at least 6 months after trabeculectomy using MMC for aphakic and pseudophakic eyes. The success rate and complications were analyzed. The success criteria included intraocular pressures of 21 mmHg or less with or without glaucoma medications and no loss of light perception. Surgical failure was defined as a postoperative loss of light perception in patients with preoperative vision better than light perception, additional glaucoma surgery, or phthisis bulbi in patients with preoperative vision of no light perception. Results : The average follow up period was 27.7 months and the intraocular pressure was controlled under 21 mmHg in 36 eyes of 51 (70.6%) after the procedure with or without medication for glaucoma. Using the Kaplan-Meier survival analysis, the cumulative success rate at the 3-, 6-, 12-, 24- and 36-month intervals were 98.0%, 94.1%, 91.9%, 83.4% and 75.5%, respectively. The complications observed were hyphema (4 eyes), serous choroidal detachment (4 eyes), hypotony (3 eyes), and endophthalmitis (1 eye). Conclusion : Trabeculectomy using Mitomycin C for the treatment of aphakic and pseudophaic eyes was safe and effective.

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