• Title/Summary/Keyword: Surrogate method

Search Result 212, Processing Time 0.032 seconds

Functional outcome predictors following mandibular reconstruction with osteocutaneous fibula free flaps: correlating early postoperative videofluoroscopic swallow studies with long-term clinical results

  • Gonzalez, Santiago R.;Hobbs, Bradley;Vural, Emre;Moreno, Mauricio A.
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.41
    • /
    • pp.30.1-30.8
    • /
    • 2019
  • Background: Advancements in the field of microvascular surgery and the widespread adoption of microvascular surgical techniques have made the use of osteocutaneous fibula free flaps the standard of care in the surgical management of segmental mandibular defects. Although the literature possesses abundant evidence to support the effectiveness of fibula free flaps as a reconstructive method, there are relatively few studies reporting on outcomes as objectively measured by videofluoroscopic swallowing studies (VFSS). The purpose of this study is to explore the potential correlation between early postoperative VFSS and the long-term swallowing outcomes in patients who underwent mandibular reconstruction with fibula free flaps. Methods: We performed a retrospective chart review of 36 patients who underwent mandibular reconstruction with osteocutaneous fibular free flaps between 2009 and 2012. Demographics, clinical variables, VFSS data, and diet information were retrieved. Penetration and aspiration findings on VFSS, long-term oral feeding ability, and the need for gastrostomy tube were statistical endpoints correlated with postoperative clinical outcomes. Results: Thirty-six patients were reviewed (15 females and 21 males) with a mean age of 54 years (7-81). Seventeen cases were treated for malignancy. The size of the bony defect ranged from 3 to 15 cm (mean = 9 cm). The cutaneous paddle, a surrogate for soft tissue defect, ranged from 10 to 125 ㎠ (mean = 52 ㎠). A gastrostomy tube was present in patients preoperatively (n = 8), and postoperatively (n = 14). Seventeen patients had neoadjuvant exposure to radiation. Postoperative VFSS showed penetration in 13 cases (36%) and aspiration in seven (19%). Overall, 29 patients (80.6%) achieved unrestricted diet, and this was statistically correlated with age (p = 0.037), radiation therapy (p = 0.002), and preoperative gastrostomy tube (p = 0.03). The presence of penetration or aspiration on VFSS was a strong predictor for long-term unrestricted oral diet (p < 0.001). Conclusion: Early postoperative VFSS is an excellent predictor for long-term swallowing outcomes in patients undergoing mandibular reconstruction with osteocutaneous fibula free flaps.

Comparative Inactivation of Hepatitis A Virus and Murine Encephalomyocarditis Virus to Various Inactivation Processes (바이러스 불활화 공정에 대한 Hepatitis A Virus와 Murine Encephalomyocarditis Virus의 민감도 비교)

  • Kim, In-Seop
    • Korean Journal of Microbiology
    • /
    • v.39 no.4
    • /
    • pp.242-247
    • /
    • 2003
  • Murine encephalomyocarditis virus (EMCV) has been used as a surrogate for hepatitis A virus (HAV) for the validation of virus removal and/or inactivation during the manufacturing process of biopharmaceuticals. Recently international regulation for the validation of HAV safety has been reinforced because of the reported cases of HAV transmission to hemophiliac patients who had received ntihemophilic factors prepared from human plasma. The purpose of the present study was to compare the resistance of HAV and EMCV to various viral inactivation processes and then to standardize the HAV validation method. HAV was more resistant than EMCV to pasteurization (60oC heat treatment for 10 hr), low pH incubation (pH 3.9 at 25oC for 14 days), 0.1 M NaOH treatment, and lyophilization. EMCV was completely inactivated to undetectable levels within 2 hr of pasteurization, however, HAV was completely inactivated to undetectable levels after 5 hr treatment. EMCV was completely inactivated to undetectable levels within 15 min of 0.1 M NaOH treatment, however, residual infectivity of HAV still remained even after 120 min of treatment. The log reduction factors achieved during low pH incubation were 1.63 for HAV and 3.84 for EMCV. Also the log reduction factors achieved during a lyophilization process of antihemophilic factor VIII were 1.21 for HAV and 4.57 for EMCV. These results indicate that HAV rather than EMCV should be used for the virus validation study and the validation results obtained using EMCV should be precisely reviewed.

Use of Hydrogen Peroxide with Ozone to Simultaneously Reduce MIB and Quench Ozone Residual in Existing Water Treatment Plants Sourcing Water from the Han River (한강을 원수로 하는 오존/과산화수소 고도정수처리공정에서의 MIB제거 및 잔류오존 농도에 관한 연구)

  • McAdams, Stephen R.;Koo, Bon Jin;Jang, Myung Hoon;Lee, Sung Kyoo
    • Journal of Korean Society on Water Environment
    • /
    • v.28 no.5
    • /
    • pp.704-716
    • /
    • 2012
  • This paper provides a detailed account of pilot testing conducted at South Lake Tahoe (California), the Ddukdo (Seoul) water treatment plant (WTP) and the Bokjung (Seongnam) WTP between February, 2010, and February, 2012. The objectives were first, to characterize the reactions of ozone with hydrogen peroxide (Peroxone) for Han River water following sand filtration, second to determine empirical ozone and hydrogen peroxide doses to remove a taste-and-odor surrogate 2-methylisoborneol (MIB) using an advanced oxidation process (AOP) configuration and third, to determine the optimum dosing configuration to reduce residual ozone to a safe level at the exit of the process. The testing was performed in a real-time plant environment at both low- and high seasonal water temperatures. Experimental results including ozone decomposition rates were dependent on temperature and pH, consistent with data reported by other researchers. MIB in post-sand-filtration water was spiked to 40-50 ng/L, and in all cases, it was reduced to below the specified target level (7 ng/liter) and typically non-detect (ND). It was demonstrated that Peroxone could achieve both MIB removal and low effluent ozone residual at ozone+hydrogen peroxide doses less than those for ozone alone. An empirical predictive model, suitable for use by design engineers and operating personnel and for incorporation in plant control systems was developed. Due to a significant reduction in the ozone reaction/decomposition at low winter temperatures, results demonstrate the hydrogen peroxide can be "pre-conditioned" in order to increase initial reaction rates and achieve lower ozone residuals. Results also indicate the method, location and composition of hydrogen peroxide injection is critical to successful implementation of Peroxone without using excessive chemicals or degrading performance.

Precipitation behaviors of Cs and Re(/Tc) by NaTPB and TPPCl from a simulated fission products-$(Na_2CO_3-NaHCO_3)-H_2O_2$ solution (모의 FP-$(Na_2CO_3-NaHCO_3)-H_2O_2$ 용액으로부터 NaTPB 및 TPPCl에 의한 Cs 및 Re(/Tc)의 침전 거동)

  • Lee, Eil-Hee;Lim, Jae-Gwan;Chung, Dong-Yong;Yang, Han-Beum;Kim, Kwang-Wook
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.8 no.2
    • /
    • pp.115-122
    • /
    • 2010
  • In this study, the removal of Cs and Tc from a simulated fission products (FP) solution which were co-dissolved with U during the oxidative-dissolution of spent fuel in a mixed carbonate solution of $(Na_2CO_3-NaHCO_3)-H_2O_2$ was investigated by using a selective precipitation method. As Cs and Tc might cause an unstable behavior due to the high decay heat emission of Cs as well as the fast migration of Tc when disposed of underground, it is one of the important issues to removal them in views of the increase of disposal safety. The precipitation of Cs and Re (as a surrogate for Tc) was examined by introducing sodium tetraphenylborate (NaTPB) and tetraphenylphosponium chloride (TPPCl), respectively. Precipitation of Cs by NaTPB and that of Re by TPPCl were completed within 5 minutes. Their precipitation rates were not influenced so much by the temperature and stirring speed even if they were increased by up to $50^{\circ}C$ and 1,000 rpm. However, the pH of the solution was found to have a great influence on the precipitation with NaTPB and TPPCl. Since Mo tends to co-precipitate with Re at a lower pH, especially, it was effective that a selective precipitation of Re by TPPCl was carried out at pH of above 9 without co-precipitation of Mo and Re. Over 99% of Cs was precipitated when the ratio of [NaTPB]/[Cs]>1 and more than 99% of Re, likewise, was precipitated when the ratio of [TPPCl]/[Re]>1.

Quantitative Analysis of Feline Calicivirus Inactivation using Real-time RT-PCR (Real-time RT-PCR을 이용한 Feline Calicivirus 불활성화의 정량적 분석)

  • Jeong, Hye Mi;Kim, Kwang Yup
    • Journal of Food Hygiene and Safety
    • /
    • v.29 no.1
    • /
    • pp.31-39
    • /
    • 2014
  • Norovirus causes acute gastroenteritis in all age groups and its food poisoning outbreaks are rapidly increasing in Korea. Reverse transcription-polymerase chain reaction (RT-PCR) is most widely used for the rapid detection of foodborne viruses due to high sensitivity. However, the false positive results of RT-PCR obtained against already inactivated viruses could be a serious drawbacks in food safety area. In this study, we investigated a method to yield true positive RT-PCR results only with alive viruses. To decompose the RNA genes from dead viruses, the enzymatic treatments composed of proteinse K and Ribonuclease A were applied to the sanitized and inactivated virus particles. Another aim of this study was to quantify the efficiencies of several major sanitizing treatments using real-time RT-PCR. Feline calicivirus (FCV) that belongs to the same Caliciviridae family with norovirus was used as a surrogate model for norovirus. The initial level of virus in control suspension was approximately $10^4$ PFU/mL. Most of inactivated viruses treated with the enzymatic treatment for 30 min at $37^{\circ}C$ were not detected in RT-PCR, Quantification results to verify the inactivation efficiencies of sanitizing treatments using real-time RT-PCR showed no false positive in most cases. We could successfully develope a numerical quantification process for the inactivated viruses after major sanitizing treatments using real-time RT-PCR. The results obtained in this study could provide a novel basis of rapid virus quantification in food safety area.

Factors Affecting Basilar Artery Pulsatility Index on Transcranial Doppler (뇌혈류 초음파 검사에서 기저동맥 박동지수에 영향을 미치는 인자)

  • Jeong, Ho Tae;Kim, Dae Sik;Kang, Kun Woo;Nam, Yun Teak;Oh, Ji Eun;Cho, Eun Kyung
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.50 no.4
    • /
    • pp.477-483
    • /
    • 2018
  • Transcranial doppler is a non-invasive method that measures the blood flow velocity and the direction of cerebral blood vessels through the doppler principle. The pulsatility index is an index for measuring the transcranial doppler that reflects the distal vascular resistance and is used as an index for the presence and diffusion of cerebral small vessel diseases. The purpose of this study was to evaluate the risk factors affecting the basilar artery pulsatility index in ischemic stroke patients. From January 2014 to May 2015, 422 patients were selected by measuring the transcranial doppler pulsatility index, considering their basilar artery pulsatility index. Univariate analysis was performed using the basilar artery pulsatility index as a dependent variable. Multiple regression analysis was performed considering the factors affecting the pulsatility index as variables. Univariate analysis revealed age, presence of hypertension, presence of diabetes mellitus, presence of hyperlipidemia, and hematocrit (P<0.1) as factors. Multiple regression analysis showed statistically significant results with age (P<0.001), presence of diabetes (P=0.004), and presence of hyperlipidemia (P=0.041). The risk factors affecting the basilar artery pulsatility index of transcranial doppler were age, diabetes, and hyperlipidemia. Further research will be needed to increase the cerebral pulsatility index as a surrogate marker of the elderly, diabetes, and hyperlipidemia.

Blood Biomarkers for Alzheimer's Dementia Diagnosis (알츠하이머성 치매에서 혈액 진단을 위한 바이오마커)

  • Chang-Eun, Park
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.54 no.4
    • /
    • pp.249-255
    • /
    • 2022
  • Alzheimer's disease (AD) represents a major public health concern and has been identified as a research priority. Clinical research evidence supports that the core cerebrospinal fluid (CSF) biomarkers for AD, including amyloid-β (Aβ42), total tau (T-tau), and phosphorylated tau (P-tau), reflect key elements of AD pathophysiology. Nevertheless, advances in the clinical identification of new indicators will be critical not only for the discovery of sensitive, specific, and reliable biomarkers of preclinical AD pathology, but also for the development of tests that facilitate the early detection and differential diagnosis of dementia and disease progression monitoring. The early detection of AD in its presymptomatic stages would represent a great opportunity for earlier therapeutic intervention. The chance of successful treatment would be increased since interventions would be performed before extensive synaptic damage and neuronal loss would have occurred. In this study, the importance of developing an early diagnostic method using cognitive decline biomarkers that can discriminate between normal, mild cognitive impairment (MCI), and AD preclinical stages has been emphasized.

A Narrative Literature Review on the Neural Substrates of Cognitive Reserve: Focusing on the Resting-state Functional Magnetic Resonance Imaging Studies (인지예비능의 신경적 기질에 대한 서술적 문헌고찰 연구 : 휴지기 기능적 자기공명영상 연구를 중심으로)

  • Hyeonsang Shin;Woohyun Seong;Bo-in Kwon;Yeonju Woo;Joo-Hee Kim;Dong Hyuk Lee
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.38 no.1
    • /
    • pp.1-9
    • /
    • 2024
  • Cognitive reserve (CR) is a concept that can explain the discrepancies between the pathologic burden of the disease and clinical manifestations. It refers to the individual susceptibility to age-related brain changes and pathologies related to Alzheimer's disease, thus recognized as a factor affecting the trajectories of the disease. The purpose of this study was to explore the current states of clinical studies on neural substrates of CR in Alzheimer's disease using functional magnetic resonance imaging. We searched for clinical studies on CR using fMRI in the Pubmed, Cochrane library, RISS, KISS and ScienceON on August 14, 2023. Once the online search was finished, studies were selected manually by the inclusion criteria. Finally, we analyzed the characteristics of selected articles and reviewed the neural substrates of CR. Total thirty-four studies were included in this study. As surrogate markers of CR, not only education and occupational complexity, but also composite score and questionnaire-based method, which cover various areas of life, were mainly used. The most utilized methods in resting-state fMRI were independent component analysis, seed-based analysis, and graph theory analysis. Through the analysis, we demonstrated that neuroimaging techniques could capture the neural substrates associated with cognitive reserve. Moreover, functional connectivity of brain regions centered on prefrontal and parietal cortex and network areas such as default mode network showed a significant correlation with CR, which indicated a significant association with cognitive performance. CR may induce differential effects according to the disease status. We hope that this perspective on cognitive reserve would be helpful when conducting clinical researches on the mechanisms of traditional Korean medicine for Alzheimer's disease in the future.

Factors Affecting International Transfer Pricing of Multinational Enterprises in Korea (외국인투자기업의 국제이전가격 결정에 영향을 미치는 환경 및 기업요인)

  • Jun, Tae-Young;Byun, Yong-Hwan
    • Korean small business review
    • /
    • v.31 no.2
    • /
    • pp.85-102
    • /
    • 2009
  • With the continued globalization of world markets, transfer pricing has become one of the dominant sources of controversy in international taxation. Transfer pricing is the process by which a multinational corporation calculates a price for goods and services that are transferred to affiliated entities. Consider a Korean electronic enterprise that buys supplies from its own subsidiary located in China. How much the Korean parent company pays its subsidiary will determine how much profit the Chinese unit reports in local taxes. If the parent company pays above normal market prices, it may appear to have a poor profit, even if the group as a whole shows a respectable profit margin. In this way, transfer prices impact the taxable income reported in each country in which the multinational enterprise operates. It's importance lies in that around 60% of international trade involves transactions between two related parts of multinationals, according to the OECD. Multinational enterprises (hereafter MEs) exert much effort into utilizing organizational advantages to make global investments. MEs wish to minimize their tax burden. So MEs spend a fortune on economists and accountants to justify transfer prices that suit their tax needs. On the contrary, local governments are not prepared to cope with MEs' powerful financial instruments. Tax authorities in each country wish to ensure that the tax base of any ME is divided fairly. Thus, both tax authorities and MEs have a vested interest in the way in which a transfer price is determined, and this is why MEs' international transfer prices are at the center of disputes concerned with taxation. Transfer pricing issues and practices are sometimes difficult to control for regulators because the tax administration does not have enough staffs with the knowledge and resources necessary to understand them. The authors examine transfer pricing practices to provide relevant resources useful in designing tax incentives and regulation schemes for policy makers. This study focuses on identifying the relevant business and environmental factors that could influence the international transfer pricing of MEs. In this perspective, we empirically investigate how the management perception of related variables influences their choice of international transfer pricing methods. We believe that this research is particularly useful in the design of tax policy. Because it can concentrate on a few selected factors in consideration of the limited budget of the tax administration with assistance of this research. Data is composed of questionnaire responses from foreign firms in Korea with investment balances exceeding one million dollars in the end of 2004. We mailed questionnaires to 861 managers in charge of the accounting departments of each company, resulting in 121 valid responses. Seventy six percent of the sample firms are classified as small and medium sized enterprises with assets below 100 billion Korean won. Reviewing transfer pricing methods, cost-based transfer pricing is most popular showing that 60 firms have adopted it. The market-based method is used by 31 firms, and 13 firms have reported the resale-pricing method. Regarding the nationalities of foreign investors, the Japanese and the Americans constitute most of the sample. Logistic regressions have been performed for statistical analysis. The dependent variable is binary in that whether the method of international transfer pricing is a market-based method or a cost-based method. This type of binary classification is founded on the belief that the market-based method is evaluated as the relatively objective way of pricing compared with the cost-based methods. Cost-based pricing is assumed to give mangers flexibility in transfer pricing decisions. Therefore, local regulatory agencies are thought to prefer market-based pricing over cost-based pricing. Independent variables are composed of eight factors such as corporate tax rate, tariffs, relations with local tax authorities, tax audit, equity ratios of local investors, volume of internal trade, sales volume, and product life cycle. The first four variables are included in the model because taxation lies in the center of transfer pricing disputes. So identifying the impact of these variables in Korean business environments is much needed. Equity ratio is included to represent the interest of local partners. Volume of internal trade was sometimes employed in previous research to check the pricing behavior of managers, so we have followed these footsteps in this paper. Product life cycle is used as a surrogate of competition in local markets. Control variables are firm size and nationality of foreign investors. Firm size is controlled using dummy variables in that whether or not the specific firm is small and medium sized. This is because some researchers report that big firms show different behaviors compared with small and medium sized firms in transfer pricing. The other control variable is also expressed in dummy variable showing if the entrepreneur is the American or not. That's because some prior studies conclude that the American management style is different in that they limit branch manger's freedom of decision. Reviewing the statistical results, we have found that managers prefer the cost-based method over the market-based method as the importance of corporate taxes and tariffs increase. This result means that managers need flexibility to lessen the tax burden when they feel taxes are important. They also prefer the cost-based method as the product life cycle matures, which means that they support subsidiaries in local market competition using cost-based transfer pricing. On the contrary, as the relationship with local tax authorities becomes more important, managers prefer the market-based method. That is because market-based pricing is a better way to maintain good relations with the tax officials. Other variables like tax audit, volume of internal transactions, sales volume, and local equity ratio have shown only insignificant influence. Additionally, we have replaced two tax variables(corporate taxes and tariffs) with the data showing top marginal tax rate and mean tariff rates of each country, and have performed another regression to find if we could get different results compared with the former one. As a consequence, we have found something different on the part of mean tariffs, that shows only an insignificant influence on the dependent variable. We guess that each company in the sample pays tariffs with a specific rate applied only for one's own company, which could be located far from mean tariff rates. Therefore we have concluded we need a more detailed data that shows the tariffs of each company if we want to check the role of this variable. Considering that the present paper has heavily relied on questionnaires, an effort to build a reliable data base is needed for enhancing the research reliability.

Clinical Usefulness of the Line Probe Assay for Rapid Detection of Rifampicin-resistant Tuberculosis (Line probe assay를 이용한 신속한 rifampicin내성결핵 진단법의 임상적 유용성)

  • Hong, Sang-Bum;Lim, Chae-Man;Lee, Sang-Do;Koh, Youn-Suck;Kim, Woo-Sung;Kim, Dong-Soon;Kim, Won-Dong;Shim, Tae-Sun
    • Tuberculosis and Respiratory Diseases
    • /
    • v.50 no.3
    • /
    • pp.334-342
    • /
    • 2001
  • Background : RpoB gene mutations have been found in about 96-98% of rifampicin (RMP)-resistant Mycobacterium tuberculosis. Recent reports confirm that the in laboratory settings a rpoB gene mutation can be used as a surrogate marker for multi-drug resistant tuberculosis. However, its usefulness in clinical applications has not been evaluated. This study was performed to confirm whether mutation analysis of the rpoB gene of M. tuberculosis is useful in clinical settings. Methods : The medical records of 33 patients in whom rpoB gene analysis was conducted using an INNOLiPA Rif. TB assay (LiPA) from June, 1998, to July, 2000, at the Asan Medical Center were retrospectively reviewed in 33 patients. The clinical characteristics in addition to the drug susceptibility and LiPA results were analyzed. The drug susceptibility test was considered as a gold standard method for M. tuberculosis susceptibility and these results were compared with those of the rpoB gene study and sequencing analysis. Sequencing analysis of the rpoB gene was done in cases where there was a discrepancy between the results of the drug susceptibility an d rpoB gene study. Results : The mean age and sex ratio was $42{\pm}18$, and 24:9 (M:F), respectively. There were 19 RMP susceptible (58%) and 14 RMP-resistant cases (42%) according to the rpoB gene study. The mean time from the request to reporting the results of the rpoB gene study was $5.2{\pm}2.6$ days. The mean gap from reporting the rpoB gene study to reporting the susceptibility was $56{\pm}35$ days. Twenty-eight cases (85%) showed identical results compared with the drug susceptibility results, whereas five cases (15%) showed contradictory results. When compared with the sequencing analysis, of the five cases that showed contradictory results, two had LiP A analysis errors and the remaining three were identical to the sequencing results. The rpoB gene study was of assistance in choosing the appropriate drugs in 28 cases (85%). Conclusions : An rpoB gene study using an LiP A assay was useful in rapidly diagnosing RMP-resistant tuberculosis, which enabled a proper choice of the appropriate drugs in clinical practices. However, an LiPA assay always should be performed in conjunction with microscopy, culture, and susceptibility tests.

  • PDF