• 제목/요약/키워드: Dose-response

검색결과 2,332건 처리시간 0.027초

Study of the immunosuppressive activity of methanolic extract of Madhuca longifolia (Koenig)

  • V., Chitra;Ganesh, Dhawle;Shrinivas, Sharma
    • Advances in Traditional Medicine
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    • 제10권3호
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    • pp.150-154
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    • 2010
  • The immunosuppressive activity of the Methanol extract of bark of Madhuca longifolia (Koenig) consisting of a mixture of saponins, flavonoids, tannins, steroids, phenol and glycosides was studied on the immune responses in mice. Methanol extract of Madhuca longifolia (MLL) was administered orally at doses of 50, 100 and 150 mg/kg/day to healthy mice divided into four groups consisting of six animals each. The assessment of immunomodulatory activity was carried out by testing the humoral (antibody titre) and cellular (foot pad swelling) immune responses to the antigenic challenge by sheep RBCs. Furthermore, the effect on hematological parameters as well as relative organ weight was determined. On oral administration MML showed a significant decrease delayed type hypersensitivity (DTH) response whereas the humoral response to sheep RBCs was unaffected. Thus MLL significantly suppressed the cellular immunity by decreasing the footpad thickness response to sheep RBCs in sensitized mice. With a dose of 100 and 150 mg/kg/day the DTH response was $7.66{\pm}2.75$ and $6.41{\pm}1.21$ respectively in comparison to corresponding value of $14.50{\pm}2.38$ for untreated control group. These differences in DTH response were statistically significant (P < 0.05). The study demonstrates that MLL shows preferential suppression of the components of cell-mediated immunity and shows no effect on the humoral immunity.

LiF:Mg,Cu,P 열형광선량계의 선량특성을 이용한 눈가림법에 의한 출력선량 평가 (Evaluation the Output Dose of Linear Accelerator Photon Beams by Blind Test with Dose Characteristics of LiF:Mg,Cu,P TLD)

  • 최태진;이호준;예지원;오영기;김진희;김옥배
    • 한국의학물리학회지:의학물리
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    • 제20권4호
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    • pp.308-316
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    • 2009
  • 조사면의 크기와 한계 측정부위의 선량평가에는 형체가 자유로운 열형광분말체를 이용하는 것이 적합함을 뒷받침하기 위하여 LiF:Mg,Cu,P TLD 분말체의 선량특성을 조사하고, 작성된 평가 알고리즘에 따라 선형가속기의 출력선량을 눈가림법으로 조사한 TLD에 적용했을 때 평가 신뢰성을 확인하고자 한다. 열형광분말소자는 PTW 사의 LiF:Mg,Cu,P (200 Mesh)이며, 판독기는 LTM (LTM Co, France)이다. 물의 흡수선량은 전리함과 전위계를 표준선량평가기관에서 교정한 흡수선량계수를 사용하여 구하였으며, TLD 조사는 자체 제작한 미니 프라스틱 수조의 중앙에 삽입하여 조사면 $10{\times}10\;cm^2$로 시행 하였다. 방사선조사는 두 대학병원에 설치된 선형가속기(Oncor, Siemens와 Clinac Ix, Varian)의 6 MV 광자선으로 하였으며, TLD의 눈가림법 선량평가는 glow 곡선의 특성과 분말질량에 의한 감도변화, 선량률의존성, 선량-TL 강도의 비례성과 퇴행성 조사를 통해 시행되었다. LiF:Mg,Cu,P TLD는 3개의 glow peak를 보였고 232도에 나타나는 peak는 선량과 비례성이 높고 감도가 높으며 퇴행현상이 적어 선량계로써 좋은 조건을 보이고 있다. 열형광선량분말체는 1,000 cGy까지 대략적인 선형관계를 유지하였으나, 정밀 측정평가를 위해 비선형 함수를 통해 평균 1% 오차범위에서 평가할 수 있었다. LiF:Mg,Cu,P TLD는 선량률 22.2 cGy/min에서 600 cGy/min까지 TL 감도에 거의 영향을 주지 않았으나, 가열판(Planchette)의 분말체의 량에 따라서는 TL 감도에 변화가 있음을 확인하였다. 눈가림법으로 두 기관의 선형가속기에서 15회와 10회 조사하였고, 선량범위는 15~800 cGy였다. 눈가림법에 의한 양 기관의 TL 선량은 평균 1% 이하의 오차범위에서 일치하고 편차는 각각 ${\pm}1.9%$${\pm}2.58$ 이내에 있었다. 열형광분말소자를 사용하여 눈가림법으로 출력선량을 평가한 결과 실험오차범위에서 표준전리함의 선량과 잘 일치하였으며, 전리함으로 접근할 수 없는 작은 조사면이나 경계성 조사면에 대한 선량평가에 신뢰성 있는 평가를 할 수 있을 것으로 생각한다.

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다중소자 열형광선량계에 의한 수정체 등가선량 평가의 적정성 연구 (A Feasibility Study on the Lens of Eye Dose Assessment Using the System of Multi-Element TLD)

  • 이나래;한승재;이병일;조건우
    • Journal of Radiation Protection and Research
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    • 제37권2호
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    • pp.96-102
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    • 2012
  • 2011년 국제방사선방호위원회(ICRP)는 최근 역학 조사들을 근거로 방사선영향으로 발생할 수 있는 암 외 질환의 위험에 대한 권고를 개정하였다. 특히 수정체 조직반응의 발단선량을 0.5 Gy로 하향 조정하면서, 계획 피폭상황에서 직무 피폭 시 수정체 등가선량한도를 "정해진 5년 기간 동안 평균해서 연간 20 mSv, 그 중 어느 한 해에도 50 mSv를 초과하지 않아야 한다"로 권고하였다. 방사선작업종사자의 외부선량은 개인 열형광선량계(TLD)를 사용하여 감시하고 있으며 판독한 열형광소자별 반응도를 선량평가 알고리즘에 적용하면 개인의 수정체 등가선량을 구할 수 있다. 본 논문에서는 성능검사에 사용된 Harshaw TLD의 소자반응도를 사용하여 현재 사용 중인 알고리즘들에 의한 수정체 등가선량을 평가하였다. 그 결과 성능검사에 사용된 TLD의 소자반응도를 사용하여 수정체 등가선량을 평가한 경우 알고리즘 간의 상대오차는 최대 48.84% 내에 있는 것으로 나타났다.

기분장애에서 risperidone의 양면성 (Risperidone as a Janus in Mood Disorder)

  • 윤도준
    • 생물정신의학
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    • 제4권2호
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    • pp.198-210
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    • 1997
  • To examine the double-faced thymoleptic(antidepressant and antimanic) effects of risperidone in mood disorders, this article reviews the psychotropic-induced mania, thymoleptic effects of antipsychotics, therapeutic effects of risperidone and risperidone(RIS)-induced mania(RIM) in mood disorders, risk factors of RIM, possible neurochemical mechanism of these thymoleptic effects, pathophysiological and clinical significance of thymoleptic effects, and suggestive clinical guideline of RIS in mood disorders. RIS appeared effective for bipolar disorder at a lower dose than that recommended for schizophrenia, especially in the cases of maintenance of mood stabilizers, and gradual titration from low doses. Manic induction/exacerbation can occur by chance during RIS treatment in mood disorders, schizoaffective disorders, and schizophrenias. The possible risk factors for RIM are refractory mood disorder, especially in bipolar I disorder with poor initial response ; refractory schizoaffective disorders, especially in bipolar type with poor initial response ; refractory chronic schizophrenias, especially with initial responses ; psychotic features ; higher initial doses ; rapid titration ; combined therapy with antidepressants in refractory depression ; and RIS monotherapy in mania/hypomania. RIS is a drug that preferentially block 5-HT2 receptors. The effects of low dose are due mainly to the blockade of 5-HT2 receptors. There are more gradual increase in D2 blockade with increasing dose and this D2 blocking properties become apparent at higher doses. This may be related to a modulation of dopaminergic transmission by 5-HT2 antagonism at lower doses with the direct action of RIS on DA receptors coming into play at higher dose. The serotonergic antagonistic effect may be important for its effects on depressive symptoms. This, together with adequate blo-ckade of D2 receptors, may not necessarily lead to destabilization of mood disorder, but rather to more therapeutic effects. Therefore, this dose-receptor affinity relationship with both antidepressant and antimanic effects according to treatment duration can explain a continuum of antidepressant effect, antimanic effect, behavioral stimulation, and manic/hypomanic induction/exacerbation. It was the recognition of a useful psychiatric side effects by a thoughtful observer with fertile minds that led to their ultimate utilization as psychotropic drugs, i.e., phenothiazine, MAOI, TCA, and lithium. And, in vivo pharmacological challenge by novel psychotropics, as a neurochemical probe, with more specific actions is a useful tool to select pharmacologically homogeneous subgroup of the same phenotypical(clinical) condition, to further study the unknown underlying pathogenesis of various mental illnesses. Finally, RIS may be a useful alternative or adjunctive drug for patients with mood disorders without psychotic features or refractory to treatment with standard antipsychotic drugs. The more conservative doses(tirated slowly from 1-3 mg/d) of RIS, and maintenance of mood stabilizer in the cases with risk factors of RIM are recommended in mood disorder.

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자연발생 또는 백신접종후 생긴 HBsAg에 대한 항체의 지속성과 Anamnestic Response (Persistence and Anamnestic Response of Antibody to HBsAg Induced by Natural Immunization or Vaccine Treatment)

  • 정환국;선희식;정규원;노재철;김부성
    • Journal of Preventive Medicine and Public Health
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    • 제20권2호
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    • pp.280-286
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    • 1987
  • For evaluating the boosting (anamnestic) effects of the most recent commercially produced plasma derived heat-inactivated hepatitis B vaccine (A. Co.), 117 adults with naturally acquired antibody to hepatitis B surface antigen (anti-HBs) were selected at random. In addition, out of case immunized at zero and 1 month, and boosted at 6 months (primary boosting) by conventional vaccine (B. Co), inactivated by pepsin digestion and formalin treatment, 11 cases who showed elevated titer after primary boosting were also submitted to the study. The results were as follows: 1) Out of the 117 subjects with naturally acquired anti-HBs, 6(5.1%) showed isolated anti-HBs and the titers were below 10 ratio units (RU). Negative seroconversion was seen in 4(3.4%) of the 117 cases at 12 months after the screening and, of these cases, 3 showed isolated anti-HBs and the titers were below 10 RU. 2) Eighty-three percent of the cases with naturally acquired isolated anti-HBs below 10 RU did not respond to a booster injection with 3 us dose of A. Co. vaccine at all, but 90% of the other subjects responded. 3) The anti-HBs titers of all the 11 cases who showed a rise of more than 10 RU (increased GMT, 28.04) at one month after primary booster injection by $20{\mu}g$ dose of B. Co. vaccine decreased at 19 months after the primary booster. And 3 subjects (27.3%) of the 11 reached negative seroconversion. All of the 11 cases, who had secondary booster injection with $3{\mu}g$ dose of A. Co. vaccine at 19 months after primary boosting, showed increased anti-HBs titer at least 20 RU or more (increased GMT, 57. 72) at one month after the boosting. According to the above results in the anti-HBs screening survey for the purpose of immunization with hepatitis B vaccine, subjects with isolated anti-HBs below 10 RU should be regarded as being in an unimmunized state. In cases who are in risk circumstances, immunized primarily with a $20{\mu}g$ dose of B. Co. vaccine, a secondary booster injection should be given within 2 years after initiation of primary immunization and a $3{\mu}g$ booster dose of A. Co. vaccine can be reliably used.

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Impact of Treatment Time on Chemoradiotherapy in Locally Advanced Cervical Carcinoma

  • Pathy, Sushmita;Kumar, Lalit;Pandey, Ravindra Mohan;Upadhyay, Ashish;Roy, Soumyajit;Dadhwal, Vatsla;Madan, Renu;Chander, Subhash
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권12호
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    • pp.5075-5079
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    • 2015
  • Background: Adverse effects of treatment prolongation beyond 8 weeks with radiotherapy for cervical cancer have been established. Clinical data also show that cisplatin increases the biologically effective dose of radiotherapy. However, there are no data on the effect of overall treatment time in patients with locally advanced cervical cancer treated with concomitant chemo-radiotherapy (CCRT) in an Indian population. The present study concerned the feasibility of concurrent chemotherapy and interspacing brachytherapy during the course of external radiotherapy to reduce the overall treatment time and compare the normal tissue toxicity and loco-regional control with a conventional schedule. Materials and Methods: Between January 2009 and March 2012 fifty patients registered in the Gynaecologic Oncology Clinic of Institute Rotary Cancer Hospital with locally advanced cervical cancer (FIGO stage IIB-IIIB) were enrolled. The patients were randomly allocated to treatment arms based on a computer generated random number. Arm I (n=25) treatment consisted of irradiation of the whole pelvis to a dose of 50 Gy in 27 fractions, and weekly cisplatin $40mg/m^2$. High dose rate intra-cavitary brachytherapy (HDR-ICBT) was performed after one week of completion of external beam radiotherapy (EBRT). The prescribed dose for each session was 7Gy to point A for three insertions at one week intervals. Arm II (n=25) treatment consisted of irradiation of the whole pelvis to a dose of 50 Gy in 27 fractions. Mention HDR-ICBT ICRT was performed after 40Gy and 7Gy was delivered to point A for three insertions (days 23, 30, 37) at one week intervals. Cisplatin $20mg/m^2/day$ was administered from D1-5 and D24-28. Overall treatment time was taken from first day of EBRT to last day of HDR brachytherapy. The overall loco-regional response rate (ORR) was determined at 3 and 6 months. Results: A total of 46 patients completed the planned treatment. The overall treatment times in arm I and arm II were $65{\pm}12$ and $48{\pm}4$ days, respectively (p=0.001). At three and six months of follow-up the ORR for arm I was 96% while that for arm II was 88%. No statistically significant difference was apparent between the two arms. The overall rate of grade ${\geq}3$ toxicity was numerically higher in arm I (n=7) than in arm II (n=4) though statistical significance was not reached. None of the predefined prognostic factors like age, performance status, baseline haemoglobin level, tumour size, lymph node involvement, stage or histopathological subtype showed any impact on outcome. Conclusions: In the setting of concurrent chemoradiotherapy a shorter treatment schedule of 48 days may be feasible by interspacing brachytherapy during external irradiation. The response rates and toxicities were comparable.

안지오텐신 수용체 리간드 KR-31125의 생체 내 활성에 관한 연구 (Pharmacological Profile of KR-31125, an Orally Active AT1 Receptor Antagonist)

  • 이승호
    • 생명과학회지
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    • 제20권7호
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    • pp.969-976
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    • 2010
  • 피리딜 이미다졸 시리즈의 비펩타이드 안지오텐신 수용체 리간드로 새롭게 개발된 KR-31125에 대한 생체 내활성을 동물모델에서 검증하였다. 척수장애 동물모델에서 KR-31125는 비대칭 농도의존적으로 로자탄보다 18배 이상의 경쟁적인 혈압강하 효과를 나타내었으며, 기타 수용체 촉진제들의 영향을 받지 않았다. 안지오텐신으로 유도된 정상혈압 쥐모델에서는 대조화합물인 로자탄과 비교하여 경구효과는 동등하였으나 더 빠른 초기효과가 관찰되었다. 또한 신성고혈압 쥐모델에서 KR-31125는 로자탄보다 3배 이상의 지속형 혈압강하 효과를 나타내었고, 이뇨제를 투여하여 레닌을 활성화시킨 개실험 모델에서 KR-31125는 로자탄보다 20배 이상의 지속적인 경구혈압강하 효과를 나타내었다. 이러한 KR-31125의 생체 내 활성특징은 대사물질을 통하여 효과를 발휘하는 로자탄과 달리 동일물질의 효과에 의한 것으로 고혈압 및 혈관질환과 깊은 관련이 있는 안지오텐신 조절시스템에 대한 세포영상, 비침투성 진단등의 도구물질로서 가능성이 높을 것으로 판단된다.

Camostat 투여 흰쥐 이자 외분비선의 분비자극물질에 대한 반응성 (Exocrine Secretory Responsiveness of Dispersed Pancreatic Acini to Secretagogues in Camostat-treated Rats)

  • 김철;김동구;김경환
    • 대한약리학회지
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    • 제30권2호
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    • pp.205-215
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    • 1994
  • It is well known that chronic stimulation with CCK gives rise to growth of exocrine pancreas and to increased content of enzyme proteins in pancreas. However, littls Is known about changes of the secretory function of exocrine pancreas which has been chronically stimulated with CCK, especially about the responsiveness to secretagogues such as CCK, caerulein and carbachol. The present study was performed to investigate the effect of camostat on secretory profiles and the responsiveness to secretagogues of exocrine pancreas by observing in vitro amylase release stimulated by cholecystokinin-octapeptide(CCK-8) and carbachol in dispersed isolated pancreatic acini from camostat-treated rats for 4 or 10 days. The results summarized as follows : 1) The maximal effective concentration of CCK-8 in amylase release in the camostat treated group was greater than control group, but that of carbachol was not different between groups. 2) Analysis of the stimulated amylase release as the percentage of the maximal response revealed that camostat treatment caused right-shift of the dose-response curve of CCK-8. Camostat did not cause significant changes in the dose-response curve of carbachol. 3) There were considerable increases in the amylase release in the camostat-treated group, compared to the control when acini were stimulated with CCK-8 $10^{-9}\;M$ and carbaochol $10^{-6}\;M$, and higher concentrations. 4) There was a reverse correlation between the tissue content and the maximal release(percent of the total content) of amylase. These results suggest that chronic exposure of exocrine pancreas to increased endogenous CCK can enhance the responsiveness of exocrine enzyme secretion to secretagogues, especially at higher concentrations of CCK and carbachol.

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식도암에 있어서 방사선치료의 역할 (The Role of Radiotherapy in Esophageal Cancer)

  • 최은경;김정수;박찬일
    • Radiation Oncology Journal
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    • 제3권2호
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    • pp.123-129
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    • 1985
  • 1979년 3월부터 1982년 10월까지 식도의 편평상피암으로 진단되어 서울대학교병원 치료방사선과에서 근치적 목적으로 방사선치료를 받았던 46례에 대한 후향성 분석을 시행하여 다음과 같은 결과를 얻었다. 전체 환자의 2년 생존율은 $20\%$이었으며 식도암의 위치, 크기, 병기, 방사선조사량 그리고, 관해정도에 따라 생존율에 차이가 있었다. 식도 촬영상 5cm이하$(39.3\%)$ 또는 적도의 상부 1/3에 종양이 있는 경우$(29.5\%)$에 가장 좋은 2년 생존율을 보였으며 척적방사선 조사량은 $1,600\~l,700ret$였다. 관해정도에 따른 생존율은 완전관해를 보인 경우의 2년 생존율이 $42.2\%$인 반딘 전혀 반응이 없던 경우의 2년 생를율은 $0\%$이었다.

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Early treatment volume reduction rate as a prognostic factor in patients treated with chemoradiotherapy for limited stage small cell lung cancer

  • Lee, Joohwan;Lee, Jeongshim;Choi, Jinhyun;Kim, Jun Won;Cho, Jaeho;Lee, Chang Geol
    • Radiation Oncology Journal
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    • 제33권2호
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    • pp.117-125
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    • 2015
  • Purpose: To investigate the relationship between early treatment response to definitive chemoradiotherapy (CRT) and survival outcome in patients with limited stage small cell lung cancer (LS-SCLC). Materials and Methods: We retrospectively reviewed 47 patients with LS-SCLC who received definitive CRT between January 2009 and December 2012. Patients were treated with systemic chemotherapy regimen of etoposide/carboplatin (n = 15) or etoposide/cisplatin (n = 32) and concurrent thoracic radiotherapy at a median dose of 54 Gy (range, 46 to 64 Gy). Early treatment volume reduction rate (ETVRR) was defined as the percentage change in gross tumor volume between diagnostic computed tomography (CT) and simulation CT for adaptive RT planning and was used as a parameter for early treatment response. The median dose at adaptive RT planning was 36 Gy (range, 30 to 43 Gy), and adaptive CT was performed in 30 patients (63.8%). Results: With a median follow-up of 27.7 months (range, 5.9 to 75.8 months), the 2-year locoregional progression-free survival (LRPFS) and overall survival (OS) rates were 74.2% and 56.5%, respectively. The mean diagnostic and adaptive gross tumor volumes were 117.9 mL (range, 5.9 to 447 mL) and 36.8 mL (range, 0.3 to 230.6 mL), respectively. The median ETVRR was 71.4% (range, 30 to 97.6%) and the ETVRR >45% group showed significantly better OS (p < 0.0001) and LRPFS (p = 0.009) than the other group. Conclusion: ETVRR as a parameter for early treatment response may be a useful prognostic factor to predict treatment outcome in LS-SCLC patients treated with CRT.