• Proceedings of the Korean Statistical Society Conference
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• 2005.05a
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• pp.17-23
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• 2005

In this paper we consider the well-known semiparametric proportional hazards models for survival analysis. These models are usually used with few covariates and many observations (subjects). But, for a typical setting of gene expression data from DNA microarray, we need to consider the case where the number of covariates p exceeds the number of samples n. For a given vector of response values which are times to event (death or censored times) and p gene expressions(covariates), we address the issue of how to reduce the dimension by selecting the significant genes. This approach enables us to estimate the survival curve when n ${\ll}$p. In our approach, rather than fixing the number of selected genes, we will assign a prior distribution to this number. The approach creates additional flexibility by allowing the imposition of constraints, such as bounding the dimension via a prior, which in effect works as a penalty To implement our methodology, we use a Markov Chain Monte Carlo (MCMC) method. We demonstrate the use of the methodology to diffuse large B-cell lymphoma (DLBCL) complementary DNA (cDNA) data and Breast Carcinomas data.

• Korean Journal of Veterinary Research
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• v.63 no.3
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• pp.25.1-25.5
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• 2023

Peritoneal lymphomatosis (PL) is a rare lymphoid neoplasm in dogs. A nine-year-old spayed female Labrador retriever presented with pleural and peritoneal effusions. Diagnostic imaging revealed diffuse nodular to massive lesions in the mesentery, particularly in the caudal abdomen. While the superficial lymph nodes did not show significant changes, enlargement was observed in the intra-abdominal and intra-thoracic lymph nodes. Cytological and flow cytometric analyses of the effusion indicated the presence of large B-cell lymphocytes expressing CD3^-/CD5^-/CD14^-/CD21^-/CD34⁺/CD45⁺/CD79a⁺. PL was diagnosed using diagnostic imaging and fluid analysis. This case report highlights the clinical and diagnostic features of canine PL.

• Journal of Life Science
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• v.27 no.2
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• pp.149-154
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• 2017

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-hodgkin lymphoma. Advances in the chemotherapeutic treatment of this disease have improved the outcomes of DLBCL; nonetheless, many patients still die of DLBCL, and therefore, a better understanding of this disease and identification of novel therapeutic targets are urgently required. In a recent gene expression profiling study, PDE (phosphodiesterase) 4B was found to be overexpressed in chemotherapy-resistant tumors. The major function of PDE4B is to inactivate the second messenger cyclic 3',5' monophosphate (cAMP) by catalyzing the hydrolysis of cAMP to 5'AMP. It is known that cAMP induces cell cycle arrest and/or apoptosis in B cells, and PDE4B abolishes cAMP's effect on B cells. However, the mechanism by which PDE4B is overexpressed remains unclear. Here, we show that the aberrant expression of miRNA may be associated with the overexpression of this gene. The PDE4B 3' untranslated region (UTR) has three functional binding sites of miR-23b, as confirmed by luciferase reporter assays. Interestingly, miR-23b-binding sites were evolutionarily conserved from humans to lizards, implying the critical role of PDE4B-miR-23b interaction in cellular physiology. The ectopic expression of miR-2 3b repressed PDE4B mRNA levels and enhanced intracellular cAMP concentrations. Additionally, miR-23b expression inhibited cell proliferation and survival of DLBCL cells only in the presence of forskolin, an activator of adenylyl cyclase, suggesting that miR-23b's effect is via the downregulation of PDE4B. These results together suggest that miR-23b could be a therapeutic target for overcoming drug resistance by repressing PDE4B in DLBCL.

• Journal of Chest Surgery
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• v.40 no.6 s.275
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• pp.435-440
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• 2007

Background: Primary malignant lymphoma of the lung is a very rare neoplasm. Although the prognosis of lymphoma is favorable, the clinical features, prognostic factors and management have not been clearly defined. Material and Method: We retrospectively reviewed the records of 8 patients we managed between 1994 and 2000. They all had malignant lymphoma on the pathologic examination of the lung wit no evidence of mediastinal adenopathy and extrathoracic disease, and no past history of lymphoma. Result: The study group consisted of 3 males and 5 female patients with a mean age of 53.9 years. Three patients were asymtomatic and 5 patients were seer with pulmonary or systemic symptoms. The diagnostic methods were 3 CT needle aspiration biopsies, 1 bronchoscopic biopsy and 4 surgical methods (wedge resection, lobectomy). There were 3 patients with MALT lymphoma, two with diffuse large B-cell lymphoma, two with small lymphocytic lymphom, and one with follicular lymphoma. The 8 patients were treated with a variety of modalities, including surgery, chemotherapy, radiotherapy and combination therapy. The 8 patients have survived for a median follow-up of 38 months. Conclusiian: Although this entity of lymphoma appears to have a good prognosis, further clinical experience and long-term follow-up are needed to identify its clinical features, prognostic factors and management.

• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.334-341
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• 2001

Objective : We have currently changed treatment strategies to methotrexate(MTX)-based preirradiation chemotherapy with subsequent planned radiation for the initial therapy of primary central nervous system lymphoma (PCNSL). The aim of this study was to evaluate the results of treating PCNSL with chemotherapy plus radiotherapy (CRT) or radiotherapy(RT) alone. Method and Material : This study involved 10 females and 3 males patients with a mean age of 54.2 years. All patients underwent surgery, open(8 cases) or stereotactic biopsy(5 cases) for histological diagnosis. Eleven tumors were diffuse large B-cell lymphomas. Tumor volume change in the follow-up images and survival time were evaluated in patients treated with CRT and RT alone. In the beginning, two patients received ProMACE-Cytabom chemotherapeutic regimen, but did not complete the course and died of progressive tumor 8 and 9 months after diagnosis, respectively. One patient died at 6 months before chemotherapy. These three were excluded from the survival analysis. Five patients(RT group) completed full courses of cranial irradiation with or without boost. For the current combined modality treatment, high-dose MTXbased chemotherapy(systemic and intrathecal MTX, IV vincristine, and oral procarbazine) followed by whole brain irrdiation to 45Gy to tumor was introduced in 5 patients of CRT group. Result : A complete response was achieved in three of five who received RT only and in all of five who received CRT. All patients in CRT groups are in disease free status at a mean 23 months following therapy. The RT group patients refused any additional salvage therapy at tumor relapse and survived at mean 20 months from diagnosis. The Karnofsky performance status improved in eight of ten patients with treatment. The treatment toxicity included leukoencephalopathy in RT group and severe leukopenia, transient hepatitis, avascular necrosis of femoral head, hearing loss, and amenorrhea in CRT group, respectively. Conclusion : The combined modality therapy of MTX-based chemotherapy plus radiotherapy for PCNSL may enhance tumor response and improve patient survival. The patients who received CRT should be carefully followed up because of the higher risk of treatment-induced late neurotoxicity.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6715-6717
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• 2015

Background: The purpose of this study was to provide epidemiological and histological data of thyroid cancers in Togo. Materials and Methods: This was a retrospective cross-sectional study of cases of thyroid cancers diagnosed from 2000 to 2014 (15 years) at the pathology laboratory of the Sylvanus Olympio Teaching Hospital of $Lom{\acute{e}}$. All cases of review of a thyroid sample (biopsies, surgical specimens) were collected from the data records of that laboratory. Results: Thyroid cancers represented 1.1% (7930cases) of all cancers registered during the study period. Mean age was $45.4{\pm}0.3$ years and the proportion of females was 78.3%. We identified 92.4% carcinomas and 7.6% lymphomas. Carcinomas were well differentiated in 80 cases and were dominated by the papillary type (47 cases). Metastasis was observed in 13% of patients. The pTNM classification evaluated in 18 cases showed a predominance of grade I (13 cases). Lymphomas were dominated by lymphoma diffuse large B-cell (5 cases). Conclusions: This study is the first global standard for thyroid cancer pathology in Togo. The high frequency of follicular form suggests an unrecognized iodine deficiency. The improvement of the technical platform of the LAP (immunohistochemistry) will increase the diagnosis of rare forms of thyroid cancer.

• Journal of Korean Neurosurgical Society
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• v.67 no.2
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• pp.249-256
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• 2024

The Leksell frame-based transcerebellar approach was proposed with the arc support frame attached upside down to the Z coordinate. This study presented practical tips and considerations for obtaining adequate tissue samples for deep-seated cerebellar lesions or lower brainstem lesions specifically those accessible via the cerebellar peduncle. For practical insights, the Leksell coordinate frame G was fixed to prevent the anterior screw implantation within the temporalis muscle, to avoid interference with the magnetic resonance (MR)-adapter, and taking into account the magnetic field of MR in close proximity to the tentorium. After mounting of indicator box, the MR imaging evaluation should cover both the indicator box and the infratentorial region that deviated from it. The coordinates [X, Y, Za, Arc⁰, Ringa⁰] obtained from Leksell SurgiPlan^® software (Elekta, Stockholm, Sweden) with arc 0⁰ located on the patient's right side were converted to [X, Y, Zb=360-Za, Arc⁰, Ringb⁰=Ringa⁰-180⁰]. The operation was performed in the prone position under general anesthesia in four patients with deep cerebellar (n=3) and brainstem (n=1) tumors. The biopsy results showed two cases of diffuse large B-cell lymphoma, one metastatic braintumor and one glioblastoma. One patient required frame repositioning as a complication. Drawing upon the methodology outlined in existing literature, we anticipate that imparting supplementary expertise could render the stereotactic biopsy of infratentorial tumors more consistent and manageable for the practitioner, thereby facilitating adequate tissue samples and minimizing patient complications.

• Korean Journal of Radiology
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• v.20 no.8
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• pp.1293-1299
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• 2019

Objective: The purpose of this study was to evaluate the diagnostic performance of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) for chronic empyema-associated malignancy (CEAM). Materials and Methods: We retrospectively reviewed the ¹⁸F-FDG PET/CT images of 33 patients with chronic empyema, and analyzed the following findings: 1) shape of the empyema cavity, 2) presence of fistula, 3) maximum standardized uptake value (SUV) of the empyema cavity, 4) uptake pattern of the empyema cavity, 5) presence of a protruding soft tissue mass within the empyema cavity, and 6) involvement of adjacent structures. Final diagnosis was determined based on histopathology or clinical follow-up for at least 6 months. The abovementioned findings were compared between the ¹⁸F-FDG PET/CT images of CEAM and chronic empyema. A receiver operating characteristic (ROC) analysis was also performed. Results: Six lesions were histopathologically proven as malignant; there were three cases of diffuse large B-cell lymphoma, two of squamous cell carcinoma, and one of poorly differentiated carcinoma. Maximum SUV within the empyema cavity (p < 0.001) presence of a protruding soft tissue mass (p = 0.002), and involvement of the adjacent structures (p < 0.001) were significantly different between the CEAM and chronic empyema images. The maximum SUV exhibited the highest diagnostic performance, with the highest specificity (96.3%, 26/27), positive predictive value (85.7%, 6/7), and accuracy (97.0%, 32/33) among all criteria. On ROC analysis, the area under the curve of maximum SUV was 0.994. Conclusion: ¹⁸F-FDG PET/CT can be useful for diagnosing CEAM in patients with chronic empyema. The maximum SUV within the empyema cavity is the most accurate ¹⁸F-FDG PET/CT diagnostic criterion for CEAM.

• Korean Journal of Clinical Pharmacy
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• v.25 no.3
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• pp.151-158
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• 2015

Objective: This study was designed to compare pegfilgrastim and filgrastim in diffuse large B-cell lymphoma (DLBCL) patients treated with a rituximab with cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone (R-CHOP) regimen in terms of clinical efficacy and cost-effectiveness. Method: Clinical efficacy was measured by trough level of absolute neutrophil count (ANC), days of ANC under 50% of baseline value, days of ANC under 90% of baseline value, duration of ANC recovery to baseline value, days of ANC less than $0.5{\times}10^9cells/L$, and difference of peak and trough level of ANC during 1 cycle of R-CHOP regimen. To evaluate cost-effectiveness, total prices of used filgrastim and pegfilgrastim within 1 cycle of R-CHOP were analyzed. Results: In terms of clinical efficacy, trough level of ANC and days to ANC recovery showed statistical significance. The median trough levels of ANC with administration of filgrastim and pegfilgrastim were 0.18 and 1.94 (p = 0.021), respectively, and the median durations of ANC recovery to baseline value were 5.5 days and 2 days (p = 0.023), respectively. For the median days of ANC under 50% of baseline value, days of ANC under 90% of baseline value, days of ANC less than $0.5{\times}10^9cells/L$, and difference of peak and trough level of ANC during 1 cycle of R-CHOP, the pegfilgrastim group performed better than the filgrastim group. However the difference was not statistically significant. In terms of overall expense during 1 cycle of R-CHOP, pegfilgrastim is about 3.43 times more expensive than filgrastim. Conclusion: Pegfilgrastim is more efficient than filgrastim in terms of clinical efficacy. In terms of prices, pegfilgrastim is more expensive than filgrastim for patients, but it is more convenient in clinical use. Therefore, pegfilgrastim should be the preferred choice of G-CSF for neutropenic patients. Further comparative study of pegfilgrastim and filgrastim is needed.