• 대한의생명과학회지
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• 제23권1호
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• pp.1-7
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• 2017

It is known that acute myeloid leukemia (AML) is a heterogeneous blood cancer, which is enormously propagated by self-renewing leukemia stem cells (LSCs). The persistence of LSCs after chemotherapy can contribute to minimal residual disease and relapse by LSCs can be evoked promptly. Elucidating special molecules and cellular activity of LSCs is an extremely important to eliminate AML. Despite an increasing understanding of the origin of LSCs by incessant study, AML still remains a notorious disease with high mortality. An exact identification of the LSCs that sustain the proliferation of neoplastic clone is a fundamental issue in AML treatment. CD34+CD38- conventional phenotype is overall regarded as LSCs, but it has a limitation that is still hard to demarcate exactly due to similarity with normal hematopoietic stem cells (HSCs). Not all primary blasts and progenitors have equal function, thus a bona fide marker for identifying LSCs from HSCs is needed in hematologic malignancy, especially in AML. These findings have direct important implications in both in mechanistic study of LSCs as well as in the strategies of more effective therapies. In this review, I briefly summarized current advances in LSCs biology, focusing on membrane markers and a functional behavior of LSCs in AML treatment with monoclonal antibodies. Ultimately, it may be helpful in overviewing the status of LSC research, while expecting the clinic benefits of target therapy by specific inhibition.

• 대한의생명과학회지
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• 제22권2호
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• pp.46-52
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• 2016

Salicornia herbacea L. (S. herbacea) is an annual herbaceous plant of Chenopodiaceae. It grows in groups on the coast or mud flat of Korea is known to be rich in minerals. S. herbacea has potent anti-cancer, antioxidant, anti-obesity, bowel function improvement. However, pharmacological mechanisms of S. herbacea extract (SHE) remain poorly understood. The aim of this study was to investigate the potential acute toxicity of SHE in ICR mice administered a single oral dose of 0, 500, 1,000, and 2,000 mg/kg by gavage. After administration of the extract, signs of toxicity were observed every day for 14 days. No mortality, abnormal clinical signs, body weight, organ weight or pathological changes were observed compared to a control group, and there were no differences in the body weights of the control and treatment groups. Biological serum activities and histological tests were not significantly changed in the treatment group compared to the control group. Especially, treatment of SHE was significantly decreased of total cholesterol and triglyceride levels. These results indicated that a single oral administration of SHE does not exerts any toxic effects at a dose of 2,000 mg/kg and that the $LD_{50}$ of SHE is greater than 2,000 mg/kg. Accordingly, SHE appears to have potential in various functional agents of foods, without toxicity.

• 대한두경부종양학회지
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• 제5권1호
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• pp.5-13
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• 1989

Carotid body paraganglioma is uncommon, with appoximately 900 reports of it in the world literature, and with only 7 documented cases in the Korean literature. The classic carotid body paraganglioma develops in the bifurcation of common carotid artery and involves both the internal and external carotid arteries at it expands. The diagnosis may almost always be established preoperatively by selective angiography which shows a widening of the carotid bifurcation with a well defined vascular mass. Differential consideration of a single, lateral cervical mass in this location include branchial cleft cyst, neurogenic tumor, metastatic thyroid cancer, carotid body aneurysm and salivary gland tumor. Surgical therapy is the preferred method of treatment as these tumors are regarded as radioresistant. Because of their high vascularity and anatomical location, surgical removal of these tumors reguires a considerable degree of caution and a high degree of surgical expertise. With improved diagnostic and surgical technique, the morbidity and mortality has been reduced lately. This report details the management of 3 patients with carotid body paraganglioma who underwent safe resection by subadventitial dissection or using an internal vascular shunt.

• 대한두경부종양학회지
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• 제11권2호
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• pp.167-172
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• 1995

Pharyngocutaneous fistula(PCF) is one of the complications following total laryngectomy in laryngeal and hypopharyngeal cancer. Fistula lead to delayed wound healing, more serious complications such as carotid blow-out, prolonged hospitalization, significant patient morbidity and occasional mortality. Identification of patients at high risk for fistula formation, appropriate preventive measures, and appropriate management are the head and neck surgeon's responsibility. So we analyzed the clinical data of pharyngocutaneous fistula which was developed after total laryngectomy. Following results were obtained: 1) Occurrence of PCF increases with salvage surgery compared to curative surgery. 2) Early detection and effective management of PCF are the key factors to decreasing the hospitalization period. 3) Constructing a pharyngostoma seems to be an ideal method of preventing dangerous complications and ultimately closing the fistula. 4) Simultaneous reconstruction is necessary in the high risk group.

• 대한예방의학회:학술대회논문집
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• 대한예방의학회 1994년도 교수 연수회(환경)
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• pp.417-425
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• 1994

Although animal studies have been used most often for quantitative risk assessment, it is generally recognized that well-conducted epidemiologic studies would provide the best basis for estimating human risk. However, there are several features related to the design and analysis of epidemiologic studies that frequently limit their usefulness for quantitating risks. The lack of accurate information on exposure in epidemiologic studies is perhaps the most frequently cited limitation of these studies for risk assessment. However. other features of epidemiologic study design, such as statistical power, length of follow-up, confounding, and effect modification, may also limit the inferences that can be drawn from these studies. Furthermore, even when the aforementioned limitations are overcome, substantial uncertainty exists concerning the choice of an appropriate statistical (or biologic) model for extrapolation beyond the range of exposures observed in a particular study. This paper focuses on presenting a review and discussion of the methodologic issues involved in using epidemiologic studies for risk assessment. This review concentrates on the use of retrospective, cohort, mortality studies of occupational groups for assessing cancer risk because this is the most common application of epidemiologic data for quantitative risk assessment (QRA). Epidemiologic data should not be viewed as a panacea for the problems inherent in using animal bioassay data for QRA. Rather, information that can be derived from epidemiologic and toxicologic studies complement one another, and both data sources need to be used to provide the best characterization of human risk.

• Journal of Chest Surgery
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• 제10권2호
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• pp.214-218
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• 1977

There appears to be significant problems remained in the treatment of thoracic empyema inspire of the more potent broad spectrum antimicrobial agents available and improved surgical managements. Clinical analysis of 60 patients of thoracic empyema was done who received major and/or minor surgical intervention at the Dept. of Thoracic and Cardiovascular Surgery, Korea University Hospital in the period of 3 years from May 1973 to July 1976. Following was the results: 1. Male was predominent to female with the ratio of 2.16 to 1, and adult to infant was 2.75: 1. 2. Most frequent predisposing factors of thoracic empyema in infancy and childhood was pneumonia [38.3%], and in adult was pulmonary tuberculosis [36.7%]. 3. Cardinal symptoms were dyspnea, fever, chest pain and productive cough etc. 4. Positive result of bacteriological culture study was reported in 26. 7%, and among them, Staph. aureus [10%], Diplo. pneumonia [3.3%], Streptococcal group [1.7%], Pseu. aeruginosa [1.7%], Paracolon bacilli [1.7%] and others [8.3%] in respectively. No growth of pathologic organism was reported in 60.0%, and not requested in 13.3%. Among the negative group, tuberculosis was confirmed on pathological tissue slide in half and other half was not determined bacteriologically and pathologically. 5. Surgical treatment was performed to the almost all of the patients with closed thoracostomy [48.3%], empyemectomy [28.3%], empyemectomy with pulmonary resection [11.7%] and others [I1.6%] in respectively with favorable results. 6. Mortality rate was 8.3% [5 cases], each one with lung cancer, diabetes mellitus, respiratory insufficiency, sepsis and another, two months old infant with asphyxia.

• Journal of Chest Surgery
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• 제28권11호
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• pp.1025-1031
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• 1995

Thirty patients who underwent esophageal resections due to esophageal carcinoma and benign strictures, and esophagovisceral anastomoses were performed by hand suture in 11 patients[Group I and by using the end to end anastomosis[EEA stapler in 19 patients[Group II . Anastomoses were performed in the thoracic cavity in 24 patients[Right 19, Left 5 and in the cervical area in 6 patients. There was one operative mortality[3.3% in a cancer patient who underwent Ivor-Lewis operation using EEA stapler. She expired on POD 38 days due to renal failure and sepsis. There were two anastomotic leakage in the sutured group and no anastomotic leakage in the stapled group. Late anastomotic strictures occurred in 10 patients[52.6% in the stapled group compared to 2 patients[18.1% in the sutured group. Most of the patients with late anastomotic strictures responded to one or two trials of TTS dilations. Using EEA stapler in performing esophagovisceral anastomosis is a safe method with acceptable range of complication rate, and total admission period after the operation for group I was 30.3 days compared to 25.4 days in group II although it had no clinical significance. The follow up was possible in 23 patients; 5 patients in group I died within mean 12.6 months and 9 patients in group II within mean 14.2 months.

• Journal of Korean Neurosurgical Society
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• 제61권3호
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• pp.292-301
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• 2018

Medulloblastoma is the most common malignant brain tumor of childhood and remains a major cause of cancer related mortality in children. Significant scientific advancements have transformed the understanding of medulloblastoma, leading to the recognition of four distinct clinical and molecular subgroups, namely wingless (WNT), sonic hedgehog, group 3, and group 4. Subgroup classification combined with the recognition of subgroup specific molecular alterations has also led to major changes in risk stratification of medulloblastoma patients and these changes have begun to alter clinical trial design, in which the newly recognized subgroups are being incorporated as individualized treatment arms. Despite these recent advancements, identification of effective targeted therapies remains a challenge for several reasons. First, significant molecular heterogeneity exists within the four subgroups, meaning this classification system alone may not be sufficient to predict response to a particular therapy. Second, the majority of novel agents are currently tested at the time of recurrence, after which significant selective pressures have been exerted by radiation and chemotherapy. Recent studies demonstrate selection of tumor sub-clones that exhibit genetic divergence from the primary tumor, exist within metastatic and recurrent tumor populations. Therefore, tumor resampling at the time of recurrence may become necessary to accurately select patients for personalized therapy.

• Journal of Information Processing Systems
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• 제9권1호
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• pp.103-116
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• 2013

Prostate cancer is one of the most frequent cancers in men and is a major cause of mortality in the most of countries. In many diagnostic and treatment procedures for prostate disease accurate detection of prostate boundaries in transrectal ultrasound(TRUS) images is required. This is a challenging and difficult task due to weak prostate boundaries, speckle noise and the short range of gray levels. In this paper a method for automatic prostate segmentation in TRUS images using Gabor feature extraction and snake-like contour is presented. This method involves preprocessing, extracting Gabor feature, training, and prostate segmentation. The speckle reduction for preprocessing step has been achieved by using stick filter and top-hat transform has been implemented for smoothing the contour. A Gabor filter bank for extraction of rotation-invariant texture features has been implemented. A support vector machine(SVM) for training step has been used to get each feature of prostate and nonprostate. Finally, the boundary of prostate is extracted by the snake-like contour algorithm. A number of experiments are conducted to validate this method and results showed that this new algorithm extracted the prostate boundary with less than 10.2% of the accuracy which is relative to boundary provided manually by experts.

• Clinical and Experimental Pediatrics
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• 제52권6호
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• pp.633-642
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• 2009

Neutropenia is defined as an absolute neutrophil count (ANC) of <$1,500/{\mu}L$, and the severity of neutropenia generally can be graded as mild ($1,000-1,500/{\mu}L$), moderate ($500-1,000/{\mu}L$), or severe (<500/$\mu{L}$). This stratification aids in predicting the risk of pyogenic infection because the susceptibility to life-threatening infections is significantly increased in patients with prolonged episodes of severe neutropenia. Especially cancer-related neutropenia carry significant mortality. Neutropenia can develop under various conditions such as decreased bone marrow production, the sequestering of neutrophils, and increased destruction of neutrophils in the peripheral blood. Neutropenia is classified according to the etiology as congenital or acquired, with the latter further defined according to the etiology or pathology. The clinical result is increased risk for infection, which is directly proportional to the severity and duration of the neutropenia. The typical workup of neutropenia starts with a 6-week period in which complete blood counts are measured twice weekly to document the persistence of the neutropenia and whether a cyclic pattern is present. When persistent neutropenia is diagnosed and no spontaneous recovery occurs within 3 months, a more extensive evaluation is advised. Treatment is usually unnecessary for most patients with severe neutropenia, as the majority of patients have a good prognosis. However, for patients who have severe and frequent infections, treatment with filgrastim may prevent infectious complications and improve quality of life.