• Title/Summary/Keyword: drug exposure

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Adaptive Responses on Survival and Mutagenesis during MNNG Pretreatmeat and Lethality to UV MNNG at Different Cell Stages in Aspergillus nidulans (Aspergillus nidulans에서 MNNG 선 처리시의 생존도와 돌연변이 유발에 대한 Adaptive response 및 Cell stage 따른 UV와 MNNG에 대한 치사율 조사)

  • Chae, Suhn-Kee
    • The Journal of Natural Sciences
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    • v.9 no.1
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    • pp.45-52
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    • 1997
  • We have examined the effects of low concentrations of MNNG, alkylating agent, in survival and mutagenesis in Aspergillus nidulans. Pretreatments of cells with nontoxic and submutagenic doses of MNNG did not reduce the cytotoxic and mutagenic effects of exposure to a high concentration of drug. The results imply that adaptive responses on survival and mutagenesis for MNNG treatments do not occur in Aspergillus nidulans. In the first mitotic cell cycle during germination, the sensitivity to MNNG has been investigated at hourly time interval, and compared with that for UV irradiation. In both UV and MNNG treatments, the sensitivity increased till S cell stage, and decreased while DNA replication continued. Different from that show for UV irradiation, lethality to MNNG reached to the maximum at G2 cell stage.

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Synergistic Anticancer Activity of 5-Aminolevulinic Acid Photodynamic Therapy in Combination with Low-dose Cisplatin on Hela Cells

  • Wei, Xiao-Qiang;Ma, Hui-Qing;Liu, Ai-Hong;Zhang, You-Zhong
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.3023-3028
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    • 2013
  • Objective: Photodynamic therapy (PDT ) is a promising modality for the treatment of various tumors. In order to assist in optimizing treatment, we applied 5-ALA/PDT in combination with low-dose cisplatin to evaluate cytotoxicity in Hela cells. Methods: Antiproliferative effects of 5-ALA/PDT and cisplatin, alone and in combination, were assessed using MTT assay. To examine levels of apoptosis, Hela cells treated with 5-ALA/PDT, and combination treatment were assessed with Annexin-V/PI by flow cytometry. To investigate the molecular mechanisms underlying alterations in cell proliferation and apoptosis, Western blot analysis was conducted to determine the expression of p53, p21, Bax and Bcl-2 proteins. Results: MTT assays indicated that combination treatment obviously decreased the viability of Hela cells compared to individual drug treatment. In addition, it was confirmed that exposure of Hela cells to 5-ALA/PDT in combination with low-dose cisplatin resulted in more apoptosis in vitro. Synergistic anticancer activity was related to upregulation p53 expression and alteration in expression of p21, Bcl-2 and Bax. Conclusion: Our findings suggest that administration of 5-ALA/PDT in combination with the low-dose cisplatin may be an effective and feasible therapy for cervical cancer.

Antimicrobial Activity of Vaccinium macrocarpon (Cranberry) Produced Proanthocyanidin (PAC) on the Growth and Adhesion Properties of Staphylococcus aureus

  • Hui, Jonathan;Choy, John;Suwandaratne, Sid P.;Shervill, Jenna;Gan, Bing S.;Howard, Jeffrey C.;Reid, Gregor
    • Preventive Nutrition and Food Science
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    • v.9 no.1
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    • pp.29-33
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    • 2004
  • Cranberries have long been used by lay people to relieve the symptoms of urinary tract infections. Recent research has determined that the component of cranberry called proanthocyanidin (PAC) is the primary mechanism for inhibiting P-fimbriated E.coli adhesion to uroepithelial cells in vitro. A series of experiments were performed to determine the effects of PAC on growth and adhesion of uropathogenic E. coli and Staphylococcus aureus to urinary catheter material. The results showed that PAC-inhibited binding of Gram positive S. aureus to collagen coated surfaces and significantly decreased the growth of these bacteria. P-fimbriated E.coli did not bind well to the biomaterial and their growth was unaffected by the cranberry extract with the exception of some loss in viability at 1000 $\mu\textrm{g}$/mL after 5 to 18 hours of exposure. This is the first report of the potential for cranberries to interfere with the adhesion and growth of S. aureus, a multi-drug resistant organisms responsible for morbidity and mortality especially in hospitalized patients.

Fever and rash (발열과 발진)

  • Kang, Jin Han
    • Clinical and Experimental Pediatrics
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    • v.50 no.2
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    • pp.132-137
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    • 2007
  • Patients with febrile illness and skin rashes need full and immediate attention. In general, these diseases show mild manifestations and good prognosis. However, causalities of some diseases with fever and rash may be life threatening or trivial. So, the differential diagnosis for those patients is extensive. A through history, a careful physical examination and close observation of clinical progress are very helpful and essential to confirming the diagnosis. Histories of recent travel, drug or specific food ingestion, exposure to human or an animal source of infection may be useful to discover the cause. Although laboratory tests can be useful in making the diagnosis, laboratory results usually are not available immediately. Knowledge and experiences of such diseases may be helpful to reduce the differential diagnosis to a few major possibilities. Rashes can be categorized as petechial, maculopapular, vesicular, urticarial and erythematous. Potential causes include infectious pathogens such as virus, bacteria, rickettsiae, spirohetes, connective tissue diseases, allergic diseases and heamto-oncologic diseases. Because the severity of these diseases can vary mild to life threatening, physicians must perform prompt management decisions regarding empirical therapies. In this article, the differential etiological diagnosis of each type rash is reviewed and discussed, and with emphasis on intensive care of life threatening febrile diseases with rashes that are seen in our country.

The Experimental Model Development of Antibiotic Resistance Gene Transfer Characteristics with Various Micropollutants (미량오염물질에 의한 항생제 내성 유전자 전이 특성에 대한 실험모델 개발)

  • Kim, Doocheol;Oh, Junsik;Kim, Sungpyo
    • Journal of Korean Society on Water Environment
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    • v.28 no.6
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    • pp.911-916
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    • 2012
  • Recently, antibiotic resistant genes (ARGs) in the environment are emerging as pollutants, since these genetic contaminants can eventually be transferred to human pathogens. The aim of this study was to develop the experimental model of antibiotic resistant gene (ARG) plasmid transfer as a function of various environmental conditions. For this purpose, the multi drug resistant plasmid pB10, which is known to be originally isolated from a wastewater treatment plant, was selected as a model transfer plasmid and Escherichia coli $DH5{\alpha}$ containing pB10 was used as a model donor. Pseudomonas aeruginosa, an opportunistic pathogen, was selected as the recipient for the conjugation experiment. When the donor and recipient were exposed to various stressors including antibiotics and heavy metal as a function of the concentrations (10, 100 and, 1000 ppb), statistically increased plasmid transfer rate was observed at a concentration of 10 ppb of tetracycline and sulfamethoxazole compared to control (no antibiotic exposure). Accordingly, the developed experimental ARG model by various stressor is a promising tool for evaluating the dissemination of ARGs by micro-contaminants in aquatic environment.

Anaphylactic Shock Care during General Anesthesia -A Case Report- (전신마취 도중 유발된 아나필락시스 -증례보고-)

  • Choi, Byung-Ho;Sul, Sung-Han;Yoo, Jae-Ha
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.6 no.2 s.11
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    • pp.121-126
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    • 2006
  • Generalized anaphylaxis is a most dramatic and acutely life-threatening allergic reaction. Most fatalities from anaphylaxis occur within the first 30 minutes postantigenic exposure. The mechanism of generalized anaphylaxis is the reaction of IgE antibodies to an allergen that causes the release of histamine, bradykinin, and others. These chemical mediators cause the contraction of smooth muscles of the respiratory and intestinal tracts, as well as increased vascular permeability. Four major clinical symptoms are recognized: skin reactions, smooth muscle spasm (gastrointestinal and genitourinary tracts and respiratory smooth muscle), respiratory distress, and cardiovascular collapse. Epinephrine is the drug of choice for the management. Its syrnpathomimetic effects directly counteract most aspects of the attack. Respiration must be immediately supported by the establishment of a patent airway along with artificial ventilation. The circulation should be supported and the existing hypotension overcome by placing the victim in a position to allow gravity to aid venous return and by administering intravenous fluids, vasopressors, and corticosteroids. When an imperceptible pulse is evident, external cardiac compression must also be instituted. This is a case report of anaphylactic shock care during general anesthesia, possibly due to penicillin, pancuronium and others.

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Effect of Metformin on Cell Growth and Differentiation in Cultured Odontoblasts

  • Oh, Chang Young;Kim, Su-Gwan;Go, Dae-San;Yu, Sun-Kyoung;Kim, Tae-Hoon;Kim, Chun Sung;Park, Joo-Cheol;Kim, Do Kyung
    • International Journal of Oral Biology
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    • v.42 no.2
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    • pp.39-45
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    • 2017
  • Metformin (1,1-dimethylbiguanide hydrochloride), derived from French lilac (Galega officinalis), is a first-line anti-diabetic drug prescribed for patients with type 2 diabetes. However, the role of metformin in odontoblastic cell differentiation is still unclear. This study therefore undertook to examine the effect of metformin on regulating odontoblast differentiation in MDPC-23 mouse odontoblastic cells derived from mouse dental papilla cells. As compared to controls, metformin significantly accelerated the mineralization, significantly increased and accelerated the expressions of ALP and Col I mRNAs, and significantly increased the accelerated expressions of DSPP and DMP-1 mRNAs, during differentiation of MDPC-23 cells. There was no alteration in cell proliferation of MDPC-23 cells, on exposure to metformin. These results suggest that the effect of metformin on MDPC-23 mouse odontoblastic cells derived from mouse dental papilla cells, facilitates the odontoblast differentiation and mineralization, without altering the cell proliferation.

Case Report of Facial Nerve Paralysis (안면신경마비의 치험례)

  • Cho, Sang-Hun;Park, June-Sang;Ko, Myung-Yun
    • Journal of Oral Medicine and Pain
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    • v.26 no.2
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    • pp.157-160
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    • 2001
  • Facial nerve paralysis(or Bell's palsy) which commonly occurs unilaterally, gives rise to paralysis of facial expression muscle. This condition is classified into symptomatic facial nerve paralysis due to intracranial tumor, post operative trauma, etc. and idiopathic facial nerve paralysis. To explain the etiology of idiopathic facial nerve paralysis, many hypothesis including ischemic theory, viral infection, exposure to cold, immune theory etc. were suggested, but there is no agreement at this point. The method to evaluate the facial nerve paralysis, when it occurs, consists of three stage scale method, image thechnics like CT and MRI, laboratory test to examine the antibody titers of viral infection, neurophysiologic test to evaluate the degree and prognosis of paralysis. Treatment includes medication, stellate ganglion block(SGB), surgery, physical therapy and other home care therapy. In medication, systemic steroids, vitamins, vasodilating-drug and ATP drugs were used. SGB was also used repeatedly to attempt the improvement of circulation and to stimulate the recovery of nerve function. Physical therapy including electric acupuncture stimulation therapy(EAST) and hot pack was used to prevent the muscle atrophy. When No response was showed to this conservative therapies, surgery was considered. After treating two patients complaining of Bell's palsy with medication(systemic steroids) and EAST, favorable result was obtained. so author report the case of facial nerve paralysis.

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The Association of Increased Lung Resistance Protein Expression with Acquired Etoposide Resistance in Human H460 Lung Cancer Cell Lines

  • Lee, Eun-Myong;Lim, Soo-Jeong
    • Archives of Pharmacal Research
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    • v.29 no.11
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    • pp.1018-1023
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    • 2006
  • Chemoresistance remains the major obstacle to successful therapy of cancer. In order to understand the mechanism of multidrug resistance (MDR) that is frequently observed in lung cancer patients, here we studied the contribution of MDR-related proteins by establishing lung cancer cell lines with acquired resistance against etoposide. We found that human H460 lung cancer cells responded to etoposide more sensitively than A549 cells. Among MDR-related proteins, the expression of p-glycoprotein (Pgp) and lung resistance protein (LRP) were much higher in A549 cells compared with that in H460 cells. When we established H460-R1 and -R2 cell lines by progressive exposure of H460 cells to increasing doses of etoposide, the response against etopbside as well as doxorubicin was greatly reduced in R1 and R2 cells, suggesting MDR induction. Induction of MDR was not accompanied by a decrease in the intracellular accumulation of etoposide and the expression of MDR-related proteins that function as drug efflux pumps such as Pgp and MRP1 was not changed. We found that the acquired resistance paralleled an increased expression of LRP in H460 cells. Taken together, our data suggest the implicative role of LRP in mediating MDR in lung cancer.

Base Specificity for DNA Interstrand Cross-Linking Induced by Anticancer Agent Bizelesin

  • Lee, Chong-Soon;Myung, Pyung-Keun;Gibson, Neil W.
    • Archives of Pharmacal Research
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    • v.19 no.3
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    • pp.191-196
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    • 1996
  • Bizelesin is a promising novel anticancer agent which is known to alkylate N3 of adenine to induce DNA interstrand cross-links (ISC) with in $5^I-TAATTA\; and\; 5^I-TAAAAAA$. We have investigated the base specificity for DNA ISC induced by bizelesin using oligomers containing the cross-linkable sequence $5^I-TAATTA\; and\; 5^I-TAAAAAA$. in which "N" was either A, C, G, or T. An analysis of denaturing polyacrylamide gel showed that bizelesin is able to induce DNA ISC in the duplex oligomer containing sequences $5^I-TAATTA\; and\; 5^I-TAAAAAA$. The formation of interstrand crosslinking did not occur in the sequences $5^I-TAATTA\; and\; 5^I-TAAAAAA$. DNA strand cleavage assay to determine the cross-linking site within $5^I-TAATTA$sequence showed that bizelesin alkylates guanine. These results demonstrate that bizelesin is able to induce DNA ISC at guanine but not at cytosine or thymine. In addition, guanine adducts have been found to be susceptible to DNA strand cleavage by exposure to hot piperidine. The extent of DNA strand cleavage, however, was not 100% efficient in either neutral pH buffer or hot piperidine.

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