• 제목/요약/키워드: Dose response relationship

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Comet assay를 이용한 Ferric Sulfate의 유전자 독성에 대한 연구 (EVALUATION OF THE GENOTOXICITY OF FERRIC SULFATE BY COMET ASSAY)

  • 강호승;김신;정태성;박혜련
    • 대한소아치과학회지
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    • 제27권1호
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    • pp.77-84
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    • 2000
  • 치수절단술은 유치의 치수치료 방법 중 사용빈도가 높은 시술 중 하나로 치수절단 술식에 사용되는 약제는 치수나 주위조직에 무해하여야 하며, 감염이나 내흡수 등의 부작용이 없어야 한다. 본 연구는 임상에서 유치의 지혈적 치수절단 술식의 약제로 사용되는 ferric sulfate의 유전자 독성을 평가할 목적으로 human gingival fibroblast에 ferric sulfate를 다양한 농도와 접촉시간을 설정한 후 comet assay를 이용하여 유전자 독성을 평가하여 보았다. 그 결과는 다음과 같다. 1. 농도에 따른 세포의 유전자 손상정도의 변화는 ferric sulfate의 농도에 비례하여 유전자 손상이 증가하는 양상을 나타내었다. 2. 농도에 따른 세포의 유전자 손상정도는 0.1mM 이상의 농도에서 대조군과 유의한 차이를 나타내었다(p<0.05). 3. 시간경과에 따른 세포의 유전자 독성의 변화는 대조군과 유의한 차이를 보이지 않았다(p>0.05).

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Relationship between the regulation of blood pressure and in vivo noradrenergic neural activities in the locus coeruleus of young Spontaneously Hypertensive Rats

  • Kim, Y.T.;Lee, J.H.;Lee, E.K.;Song, M.J.;Ko, K.H.
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1996년도 춘계학술대회
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    • pp.216-216
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    • 1996
  • The purpose of the present study was to determine whether in vivo noradrenergic neural activity in the locus coeruleus is related to the development of hypertension. Two groups of animals were prepared, 1) young spontaneously hypertensive rats (SHR) and 2) age-matched normotensive wistar kyoto rats (WKY). At il weeks of age, the release of norepinephrine (NE) and 3,4-dihydroxyphenylglycol (DOPEG) from locus coeruleus of young SHR and WKY as an index of neural activity were determined by in vivo microdialysis along with blood pressure (BP) at three conditions : 1) normal; 2) elevated BP by systemic injection of phenylephrine and 3) alpha-1 adrenoceptor stimulated by perfusion of phenylephrine into the locus coeruleus through microdialysis probe. Basal releases of NE and DOPEG from the iocus coeruleus were 0.415+/-0.089pg/20min, 1.311+/-0.293 pg/20min in SHR and 0.204+/-0.078 pg/20min, 1.492+/-0.365 pg/20min in WKY respectively. Basal release of NE from the locus coeruleus of SHR was significantly greater than that of WKY. Phenylephrine systemic injection caused elevation of BP in both SHR and WKY in a dose related manner. Following phenyephrine injection, the releases of NE and DOPEG from the locus coeruleus of SHR were significantly decreased, whereas there were no significant changes in the releases of NE and DOPEG In young WKY. Alpha-1 adrenoceptor stimulation in the locus coeruleus by perfused phenylephrine through microdialysis probe caused pressor responses in both SHR and WKY, but the magnitude of pressor response in SHR was larger compared with that in WKY. The result from the present study suggests that noradrenergic neural activity in locus coeruleus may contribute as one of triggering factors for the expression of hypertension in young SHR.

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Habitual Tea Consumption Reduces Prostate Cancer Risk in Vietnamese Men: a Case-Control Study

  • Hoang, Van Dong;Lee, Andy H;Pham, Ngoc Minh;Xu, Dan;Binns, Colin W
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권11호
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    • pp.4939-4944
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    • 2016
  • Background: An upward trend has been noted for the incidence of prostate cancer (PCa) in Vietnam, but information is limited on modifiable factors associated with this form of cancer. This case-control study was conducted to ascertain any relationship between habitual tea consumption and PCa risk. Materials and Methods: Two hundred and fifty-three incident patients with histologically confirmed PCa and 419 (340 community-based and 79 hospital-based) controls, matched by age, were recruited in Ho Chi Minh City during 2013-2015. Information on frequency, quantity and duration of tea consumption, together with demographics, habitual diet and lifestyle characteristics, was obtained by direct interviews using a validated questionnaire. Logistic regression analyses were performed to assess associations between tea consumption variables and PCa risk. Results: The control subjects reported higher tea consumption levels in terms of cumulative exposure, frequency and quantity of tea drank than the PCa patients. After accounting for confounding factors, increasing tea consumption was found to be associated with reduced risk of PCa. The adjusted odds ratios (95% confidence intervals) were 0.52 (95% CI 0.35-0.79) and 0.30 (95% CI 0.18-0.48) for participants drinking 100-500 ml/day and > 500 ml/day, respectively, relative to those drinking < 100 ml/day. Significant inverse dose-response relationships were also observed for years of drinking and number of cups consumed daily (P <0.01). Conclusion: Habitual tea consumption is associated with a reduced risk of PCa in Vietnamese men.

Mechanism of Glutamate-induced $[Ca^{2+}]i$ Increase in Substantia Gelatinosa Neurons of Juvenile Rats

  • Jung, Sung-Jun;Choi, Jeong-Sook;Kwak, Ji-Yeon;Kim, Jun;Kim, Jong-Whan;Kim, Sang-Jeong
    • The Korean Journal of Physiology and Pharmacology
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    • 제7권2호
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    • pp.53-57
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    • 2003
  • The glutamate receptors (GluRs) are key receptors for modulatory synaptic events in the central nervous system. It has been reported that glutamate increases the intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) and induces cytotoxicity. In the present study, we investigated whether the glutamate-induced $[Ca^{2+}]_i$ increase was associated with the activation of ionotropic (iGluR) and metabotropic GluRs (mGluR) in substantia gelatinosa neurons, using spinal cord slice of juvenile rats (10${\sim}21 day). $[Ca^{2+}]_i$ was measured using conventional imaging techniques, which was combined with whole-cell patch clamp recording by incorporating fura-2 in the patch pipette. At physiological concentration of extracellular $Ca^{2+}$, the inward current and $[Ca^{2+}]_i$ increase were induced by membrane depolarization and application of glutamate. Dose-response relationship with glutamate was observed in both $Ca^{2+}$ signal and inward current. The glutamate-induced $[Ca^{2+}]_i$ increase at holding potential of -70 mV was blocked by CNQX, an AMPA receptor blocker, but not by AP-5, a NMDA receptor blocker. The glutamate-induced $[Ca^{2+}]_i$ increase in $Ca^{2+}$ free condition was not affected by iGluR blockers. A selective mGluR (group I) agonist, RS-3,5-dihydroxyphenylglycine (DHPG), induced $[Ca^{2+}]_i$ increase at holding potential of -70 mV in SG neurons. These findings suggest that the glutamate-induced $[Ca^{2+}]_i$ increase is associated with AMPA-sensitive iGluR and group I mGluR in SG neurons of rats.

Diabetes Mellitus Reduces Prostate Cancer Risk - No Function of Age at Diagnosis or Duration of Disease

  • Xu, Hua;Mao, Shan-Hua;Ding, Guan-Xiong;Ding, Qiang;Jiang, Hao-Wen
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권1호
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    • pp.441-447
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    • 2013
  • Background: Prior studies examining the relation between diabetes mellitus (DM) and prostate cancer risk have reported controversial findings. We examined this association by conducting a detailed meta-analysis of the peer-reviewed literature. Methods: A comprehensive search for articles of MEDLINE and EMBASE databases and bibliographies of retrieved articles published up to November, 2012 was performed. Methodological quality assessment of the trials was based on the Newcastle-Ottawa Scaleq and the meta-analysis was performed using STATA 12.0. Dose-response regression was conducted with SPSS 19.0. Results: We included 29 studies in the meta-analysis (13 case-control studies, 16 cohort studies), and found an inverse association between DM and prostate cancer (relative risk (RR) 0.84, 95% confidence interval (CI), 0.78-0.91). An inverse association was also observed in non-Asian populations (RR 0.81, 95% CI 0.76-0.87) and population-based studies (RR 0.80, 95% CI 0.77-0.91). No statistical significance was found of the association between prostate cancer risk and the duration of DM (p=0.338), and risk seemed not related with the age of DM diagnosis. Conclusions: This study suggested an inverse relationship between DM and prostate cancer, but without links to duration of disease or age of diagnosis.

Interaction of Antihistaminics with Muscarinic Receptor (III) - Relationship between binding and functional in vitro data -

  • Lee, Shin-Woong;Park, Young-Joo
    • Archives of Pharmacal Research
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    • 제14권2호
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    • pp.181-187
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    • 1991
  • The muscarinic antagonist 1-[benzilic 4, 4'-$[^3H]$ QUINUCLIDINYL BENZILATE $([^3H]$ QNB) bound to a single class of muscarinic receptors with high affinity in rabbit ileal membranes. The $K_D\;and\;B_{ max}$ values for $([^3H]$ QNB calculated from analysis of saturation isotherms were 52.5 pM AND 154 fmol/mg, respectively. Chlopheniramine (CHP), histamine $H_1$ blocker, increased $K_D$ vlue for $([^3H]$QNB without affecting the binding site concentrations and Hill coefficient. The $K_i$ value of CHP for inhibition of $([^3H]$QNB binding in ileal membranes was 1.44\mu{M}$ and the pseudo-Hill coefficient for CHP was close to unit. In the functional assay carbachol, muscarinic agonist, increased the contractile force of ileum with $ED_{50}$ value of $0.11\mu{M}$. CHP caused the rightward shift of the dose-response curve to carbachol. The $pA_2$ value of CHP determined from Schild analysis of carbacholinduced contraction was 5.77 and the slope was unity indicating competitive antagonism with carbachol. The dissociation constant $(K_i)$ of CHP obtained in competitive experiments with $([^3H]$ QNB was similar to the $K_A$ value (1.69 \mu{M)}$ of CHP as inhibitor of carbachol induced contraction in rabbit ileum. This result suggest that the binding of $H_i$ blocker. CHP, vs $([^3H]$QNB to muscarinic receptors in ileal membranes represents an interaction with a receptor of physiological relevance.

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Body Mass Index Effects on Risk of Ovarian Cancer: A Meta-Analysis

  • Poorolajal, Jalal;Jenabi, Ensiyeh;Masoumi, Seyyedeh Zahra
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권18호
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    • pp.7665-7671
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    • 2014
  • Objectives: The association between body mass index (BMI) and ovarian cancer risk is unclear and requires further investigation. The present meta-analysis was conducted to assess the effect of overweight and obesity on ovarian cancer risk in the premenopausal and postmenopausal periods. Data sources: Major electronic databases were searched until February 2014 including Medline and Scopus. Reference lists and relevant conference databases were searched and the authors were contacted for additional unpublished references. Review Methods: All cohort and case-control studies addressing the effect of BMI on ovarian cancer were included, irrespective of publication date and language. The effect measure of choice was risk ratio (RR) for cohort studies and odds ratio (OR) for case-control studies. The results were reported using a random effects model with 95% confidence intervals (CIs). Results: Of 3,776 retrieved studies, 19 were ultimately analyzed including 10 cohort studies involving 29,237,219 person-years and 9 case-control studies involving 96,965 people. The results of both cohort and case-control studies showed being overweight and obesity increased the risk of ovarian cancer compared to women with normal weight during both premenopausal and postmenopausal periods: RR=1.08 (95%CI: 0.97, 1.19) and OR=1.26 (95%CI: 0.97, 1.63) for overweight and RR=1.27 (95%CI: 1.16, 1.38) and OR=1.26 (95%CI: 1.06, 1.50) for obesity. Conclusions: There is sufficient evidence that an increase in BMI can increase the risk of ovarian cancer regardless of the menopausal status, mimicking a dose-response relationship although the association is not very strong.

락석등(絡石藤)의 관절염에 대한 염증 및 세포사 억제 작용 (Inhibition Effect of Trachelospermi Caulis on the Inflammation and Cell Death in Arthritis)

  • 황만영;차윤엽
    • 동의생리병리학회지
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    • 제20권2호
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    • pp.436-441
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    • 2006
  • Rheumatoid arthritis is a chronic, systemic, and inflammatory autoimmune disorder that affects 1% of the adult population worldwide. Osteoarthritis is a multifactorial disease with high morbidity that is characterized by degradation of the matrix and destruction of articular cartilage. In this study, we examined the inhibition effect of Trachelospermi Caulis on the inflammation($TNF-{\alpha}$, $IL-1{\beta}$, NO), cartilage protection(MMP-13), and cell death in arthritis. RAW 264.7 and SW 1353 cells were cultivated in DMAE(GibcoBRL, USA) with 5% FBS and Fungizone in $37^{\circ}C$, 5% CO2. THP-1 cells were cultivated in RPMI(GibcoBRL, USA) with 5% FBS and Fungizone in $37^{\circ}C$, 5% CO2. Activity of caspase-3, XIAP, Cytochrome C in the cell was examined by using western blot. The results obtained were as Follows; Concentration of nitric oxide in Trachelospermi Caulis treatment group significantly decreased compared with that of non-treatment group (P<0.05). In treated group, Concentration of Trachelospermi Caulis was not significantly associated with cell death. Concentration of $TNF-{\alpha}$ and $IL-1{\beta}$ in Trachelospermi Caulis treatment group decreased significantly compared with that of none treatment group (P<0.05). Relative density of MMP-13 in Trachelospermi Caulis treatment group decreased significantly compared with that of none treatment group and dose-response relationship was observed. After treatment of staurosporin in SW1353 which increases cell death, in Trachelospermi Caulis treated group, the cell death was effectively decreased. In conclusion, these results suggest that Trachelospermi Caulis inhibit inflammation and cell death in arthritis. More researches about effect of Trachelospermi Caulis are considered to need.

The Role of Immunostimulants in Monogastric Animal and Fish - Review -

  • Sohn, K.S.;Kim, M.K.;Kim, J.D.;Han, In K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제13권8호
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    • pp.1178-1187
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    • 2000
  • Many immunostimulating substances have been developed to improve immunity of domestic animals, although their exact mode of action and effects are not clearly defined, and they are now widely used in feed industry. Bacterial lipopolysaccharides, called endotoxin, in particular may have a profound effect not only on the immune system but also on macrophages of the reticuloendothelial system. Glucans from a variety of yeast cell wall have been shown to stimulate both specific and non-specific immune responses and to increase growth performance in pigs. Recently, there has been great interest in the role of complex carbohydrates in disease prevention and treatment. Mannanoligosaccharide is a glucomannoprotein complex derived from the cell wall of yeast. Generally, it was also known that the deficiencies of some major vitamins (vitamin A, E and C) and minerals (chromium and selenium) lead to impaired immune system and, as a result, immune function is depressed and recovery delayed. On the other hand, many researchers suggested that one possible reason for the superior performance observed in pigs fed plasma protein may be because of the presence of biologically active plasma proteins (e.g., immunoglobulins) which are known to contribute to the health of the starter pig. And, immunoglobulins present in plasma protein have been implicated as contributing to the overall immunocompetence of the newborn pig. Other immunostimulants, lactoferrin and lysozyme, mainly found in milk and egg white, have been known as having bacteriocidal and bacteriolytic effect. When considering practical use of immunostimulants, the concept of using immunostimulants is new to many people and, in most cases, it is poorly understood how and why such compounds act, and how they should be used in practice. Therefore, in order to clarify the reason for discrepancies in results, special attention should be paid to the dose/response relationship of immunostimulants and the duration of the effect.

Population Based Study of the Association Between Binge Drinking and Mortality from Cancer of Oropharynx and Esophagus in Korean Men: the Kangwha Cohort Study

  • Jung, Sang Hyuk;Gombojav, Bayasgalan;Park, Eun-Cheol;Nam, Chung Mo;Ohrr, Heechoul;Won, Jong Uk
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권8호
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    • pp.3675-3679
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    • 2014
  • We assessed the association between frequency of heavy binge drinking and mortality from oropharynx and esophagus cancer after controlling for the total volume of alcohol intake among Korean men. The cohort comprised 2,677 male residents in Kangwha County, aged 55 or older in March 1985, for their upper digestive tract cancer mortality for 20.8 years up to December 31, 2005. For daily binge drinkers versus non-drinkers, the hazard ratios (95% Cls) for mortality were 4.82 (1.36, 17.1) and 6.75 (1.45, 31.4) for oropharyngeal and esophageal cancers, respectively. Even after adjusting for the volume of alcohol intake, we found the hazard ratios for frequency of binge drinking and mortality of oropharyngeal or esophageal cancer to not change appreciably: the hazard ratios were 4.90 (1.00, 27.0) and 7.17 (1.02, 50.6), respectively. For esophageal cancer, there was a strong dose-response relationship. The frequency of heavy binge drinking and not just the volume of alcohol intake may increase the risk of mortality from upper digestive tract cancer, particularly esophageal cancer in Korean men. These findings need to be confirmed in further studies with a larger sample size.