• The Korean Journal of Zoology
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• v.37 no.2
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• pp.232-239
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• 1994

RecA protein plans a central role in homologous recombination and DNA repair in Escherichia cofi (E. colD. The function 8nd structure of this protein are universal in prokarvotes and also conserved in eukaryotes such as yeast. The RecA-like protein with 74 lInDa in size has already been identified and purified from a fission yeast Schizosaccharomyces pombe (5. pommel (Lee, 19911. From this study it was revealed that the RecA-like protein of 5. pombe was highly inducible to various DNA damaging agents and inhibitors of nucleotide pool svnthesizins enzymes. The cellular level of the 5. pombe RecA-like protein wi,u markedly increased, upto 5- to 10-fold, by treatment with various DNA-damains agents including ultraviolet (UV) light, methyl methanesulfonate WS),4-nitroquinoline-1-oxide (4-NQO), and mitomycin-C (MMC), similar to E. cofi RecA protein. Interestingly, the protein level was also increased by inhibitors of nucleotide pool forming enzlwnes such as methotrexate (MTX) and hvdroxvurea (HU). The most effective doses for the inducibility of 4-NQO, MMS, W, MMC, MTX, and HU were 0.2 Ug/ml, 30 mM, 200 J/ma, 0.4 $\mus/ml,$ 1 Ug/ml, and 100 mM, respectively. The range of effective duration time for the inducibilitv of RecA-like protein was from 270 to 450 mins. These results suggest that the 5. pombe RecA-like protein also platys an imortant role in cellular responses to DNA damage as in E. coli system.

• Journal of Yeungnam Medical Science
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• v.40 no.1
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• pp.37-48
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• 2023

Background: Commensal bacteria play an important role in the pathogenesis of inflammatory bowel disease (IBD) and probiotics have been used as treatment options. We aimed to explore the current use of probiotics and factors associated with their prescription in patients with IBD. Methods: This cross-sectional study was conducted on a single hospital-based cohort. Patients were eligible if they were ≥18 years old, visited the IBD clinic as an outpatient more than twice during the study period, and had a confirmed diagnosis of IBD. Patients were divided into two groups based on the prescription of probiotics. Clinical assessments were compared between the two groups. Results: In total, 217 patients were enrolled in this study. In patients with Crohn disease (CD), moderate or severe abdominal pain; prior use of methotrexate (MTX), iron, thiopurines, or biologics; history of IBD-related surgery; and stool frequency were independently associated with the prescription of probiotics. In patients with ulcerative colitis (UC), moderate or severe abdominal pain, hematochezia, stool frequency, and moderate or severe physician global assessment score were independently associated with the prescription of probiotics. Conclusion: Increased disease activity may be associated with fewer prescriptions of probiotics in patients with IBD. However, physicians prescribed probiotics to control symptoms, such as abdominal pain and increased stool frequency in patients with UC and CD, and hematochezia in patients with UC. Additionally, the use of MTX and iron, and a history of IBD-related surgeries were associated with more frequent probiotic prescriptions in patients with CD.

• 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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.3
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• pp.483-489
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• 2002

APA-01, which is an aqueous extract of five Chinese herbs, is a modified formula of Huoxiang-Zhengqi-San. The effect of new herb extract on immune response was investigated. The parameter examined to assess apparent immune response of APA-01 in mice included changes of body weight, relative weight of immune organs, cell proliferation and cytokine gene expression. The body weight and relative weight of immune organs were not significantly changed among the tested groups. In the spleen cell prolijeration assay, APA-01 increased the cell proliferation in a dose-dependent manner. Methotrexate (MTX), an agent of immune suppression, inhibited the spleen cell proliferation (IC/sub 50/: 800㎍/㎖). However, APA-01 significantly inhibited the suppression of mouse spleen cell proliferation. Therefore, it seems that APA-01 has a reducing effect of immune suppression. Immunomodulatory effect of APA-01 was further investigated using reverse transcription polymerase chain reaction (RT-PCR) in mouse spleen cells. In RT-PCR test, APA-01 enhanced the expression of cyclooxygenase-2 (COX-2) mRNA in a dose-dependent manner. In spite of immune suppression by MTX, COX-2 mRNA was induced by co-treatment with APA-01. These results suggest that APA-01 stimulates the proliferation of spleen cells, regulates the expression of COX-2 mRNA, and accelerates the recovery of inhibition of spleen cell proliferation induced by MTX, thus providing the immunological basis for clinical benefit of APA-01.

• Clinical and Experimental Pediatrics
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• v.46 no.6
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• pp.566-571
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• 2003

Purpose : Leukoencephalopathy(LE) is one of the most serious complications in children with hematologic malignancies during the course of treatment. Early recognition is important to reduce the impact and sequelae from LE. We therefore investigated the clinical features of LE following central nervous system(CNS) prophylaxis in children with hematologic malignancies and evaluated the significance of regular check-ups of brain MRI. Methods : We retrospectively reviewed children with hematologic malignancies who had CNS prophylaxis including intrathecal(IT) methotrexate(MTX) and/or cranial irradiation at the Department of Pediatrics, Kyungpook National University Hospital from Oct. 1995 to May 2002. Fifteen cases of acute leukemia and one case of lymphoma who experienced LE following CNS prophylaxis were included in the study. Clinical data were analyzed from the medical records and brain MRIs were reviewed by neuroradiologists. Results : The ages ranged from 1 to 13 years(median age=5.2 years), and the male to female ratio was 3 : 1. The time interval from the beginning of chemotherapy to the time of diagnosis of LE ranged from 2 to 17 months. They all had IT MTX two to 15 times and ten underwent cranial irradiation(1,800 rads). At the time of diagnosis, ten of them had neuropsychiatric symptoms including seizures, personality changes, headache, etc. After the change of treatment modality, four cases showed significant improvement on follow-up MRIs, six cases had no significant changes and two had worsening of LE. Four patients died of infection and bone marrow relapse. Conclusion : CNS prophylaxis with IT therapy and cranial irradiation may cause leukoencephalopathy during the course of treatment. As a result, regular brain MRI check-up is recommended for the early detection and reducing the incidence of LE, along with changes in the treatment modality.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3403-3410
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• 2014

Context: Interest exits in whether TNF-alpha antagonists increase the risk of breast cancer and total malignancies in patients with rheumatoid arthritis (RA). Objectives: To analyze the risk of malignancies, especially breast cancer, in patients with RA enrolled in randomized control trials (RCTs). Methods: A systematic literature search for RCTs from 1 January 1998 to 1 July 2013 from online databases, such as PubMed, WILEY, EMBASE, ISI web of knowledge and Cochrane Library was conducted. Studies included RCTs that compared the safety of at least one dose of the five TNF-${\alpha}$ antagonists with placebo or methotrexate (MTX) (or TNF-${\alpha}$ antagonists plus MTX vs placebo plus MTX) in RA patients for more than 24 weeks and imported all the references into document management software EndNote${\times}6$. Two independent reviewers selected studies and extracted the data about study design, patients' characteristics and the type, number of all malignancies. Results: 28 RCTs from 34 records with 11,741 patients were analyzed. Of the total, 97 developed at least one malignancy during the double-blind trials, and breast cancer was observed in 17 patients (17.5% of total malignancies). However, there was no statistically significant increased risk observed in either the per protocol (PP) model (OR 0.65, 95%CI [0.22, 1.93]) or the modified intention to treat (mITT) model (OR 0.75, 95%CI [0.25, 2.21]). There were also no significant trend for increased risk of total malignancies on anti-TNF-${\alpha}$ therapy administered at approved doses in either model (OR, 1.06, 95%CI [0.64, 1.75], and OR, 1.30, 95%CI [0.80, 2.14], respectively). As to the two models, modified intention to treat model analysis led to higher estimation than per protocol model analysis. Conclusions: This study did not find a significantly increased risk of breast cancer and total malignancies in adults RA patients treated with TNF-${\alpha}$ antagonists at approved doses. However, it cannot be ignored that more patients developed malignancies with TNF-${\alpha}$ antagonists therapy compared with patients with placebo or MTX, in spite of the lack of statistical significance, so that more strict clinical trials and long-term follow-up are needed, and both mITT and PP analyses should be used in such safety analyses.

• Radiation Oncology Journal
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• v.38 no.1
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• pp.35-43
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• 2020

Purpose: This retrospective study compares higher-dose whole-brain radiotherapy (hdWBRT) with reduced-dose WBRT (rdWBRT) in terms of clinical efficacy and toxicity profile in patients treated for primary central nervous system lymphoma (PCNSL). Materials and Methods: Radiotherapy followed by high-dose methotrexate (HD-MTX)-based chemotherapy was administered to immunocompetent patients with histologically confirmed PCNSL between 2000 and 2016. Response to chemotherapy was taken into account when prescribing the radiation dose to the whole brain and primary tumor bed. The whole brain dose was ≤23.4 Gy for rdWBRT (n = 20) and >23.4 Gy for hdWBRT (n = 68). Patients manifesting cognitive disturbance, memory impairment and dysarthria were considered to have neurotoxicity. A median follow-up was 3.62 years. Results: The 3-year overall survival (OS) and progression-free survival (PFS) were 70.0% and 48.9% with rdWBRT, and 63.2% and 43.2% with hdWBRT. The 3-year OS and PFS among patients with partial response (n = 45) after chemotherapy were 77.8% and 53.3% with rdWBRT, and 58.3% and 45.8% with hdWBRT (p > 0.05). Among patients with complete response achieved during follow-up, the 3-year freedom from neurotoxicity (FFNT) rate was 94.1% with rdWBRT and 62.4% with hdWBRT. Among patients aged ≥60 years, the 3-year FFNT rate was 87.5% with rdWBRT and 39.1% with hdWBRT (p = 0.49). Neurotoxicity was not observed after rdWBRT in patients aged below 60 years. Conclusion: rdWBRT with tumor bed boost combined with upfront HD-MTX is less neurotoxic and results in effective survival as higher-dose radiotherapy even in partial response after chemotherapy.

• The Korean Journal of Zoology
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• v.38 no.4
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• pp.565-569
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• 1995

We have previoosly demonstrated that the RecA-like protein of Schizosaccharomyces pombe (S. pombe) is immunologically related to Escherichia coil (E. coil) RecA protein and that the cellular level of the protein is significantly increased by inhibitors of nucleotide pool-forming enzymes such as hydroxyurea (HU) and methotrexate (MTX) (lee and Park, 1994; lee et al., 1994). In this study, we report that the ribonudeotide redudase activity of S. pombe is inhibited by E. coil RecA antibody, as determined by thin layer chromatography using [5-$^3$H]CDP as a substrate. The relative activity of ribonucleotide reductase was dramatically inhibited by 100 mM of flu (26.4% reduction) in in vitro assay, compared to that of non-treated control. The ribonucleotide reductase activity was also inhibited by immunoprecipitation with E. coil RecA antibody (43.3% reduction). These results indicate that the strudure of S. pombe ribonucleotide reductase is in part similar to that of E. coil RecA protein.

• Journal of Korean Neurosurgical Society
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• v.58 no.1
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• pp.1-8
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• 2015

Treatment of Leptomeningeal carcinomatosis (LMC) from solid cancers has not advanced noticeably since the introduction of intra-cerebrospinal fluid (CSF) chemotherapy in the 1970's. The marginal survival benefit and difficulty of intrathecal chemotherapy injection has hindered its wide spread use. Even after the introduction of intraventricular chemotherapy with Ommaya reservoir, frequent development of CSF flow disturbance, manifested as increased intracranial pressure (ICP), made injected drug to be distributed unevenly and thus, the therapy became ineffective. Systemic chemotherapy for LMC has been limited as effective CSF concentration can hardly be achieved except high dose methotrexate (MTX) intravenous administration. However, the introduction of small molecular weight target inhibitors for primary cancer treatment has changed the old concept of 'blood-brain barrier' as the ultimate barrier to systemically administered drugs. Conventional oral administration achieves an effective concentration at the nanomolar level. Furthermore, many studies report that a combined treatment of target inhibitor and intra-CSF chemotherapy significantly prolongs patient survival. Ventriculolumbar perfusion (VLP) chemotherapy has sought to increase drug delivery to the subarachnoid CSF space even in patients with disturbed CSF flow. Recently authors performed phase 1 and 2 clinical trial of VLP chemotherapy with MTX, and 3/4th of patients with increased ICP got controlled ICP and the survival was prolonged. Further trials are required with newly available drugs for CSF chemotherapy. Additionally, new LMC biologic/pharmacodynamic markers for early diagnosis and monitoring of the treatment response are to be identified with the help of advanced molecular biology techniques.

• BMB Reports
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• v.38 no.4
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• pp.414-419
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• 2005

The production of recombinant antibodies has been generally recognized as time-consuming and labor-intensive. The aim of our study is to construct mammalian expression vectors containing the cDNA encoding the human constant regions and murine variable regions to massively and cost-effectively produce full-length chimeric antibodies. Unique restriction sites flanking the Ig variable region were designed to allow for the replacement of variable regions generated by PCR. Western blot analysis of the chimeric antibodies revealed that the expressed products were of the predicted size, structure and specificity. The usefulness of the vectors was confirmed by construction of human-mouse chimeric antibody-HCAb which secretes murine antibody against the human colorectal cancer. Selected in medium containing gradually increasing methotrexate (MTX), clones with increased expression of the product gene can be efficiently generated. The secretion of recombinant chimeric antibody-HCAb yielded $30\;pg\;cell^{-1}\;day^{-1}$ at $10^{-6}\;M$ MTX. With this high-level expression from pools, the convenient and rapid production of over 100 milligram amounts per liter of recombinant antibodies may be achieved, which indicates the significant roles of pYR-GCEVH and pYR-GCEVL in the production of chimeric antibodies.