• Title/Summary/Keyword: Mean Residence Time

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Effect of Analytical Method on the Pharmacokinetic Evaluation of Bromosulfophthalein: Comparison of HPLC and UV Spectroscopy Method (Bromosulfophthalein의 체내동태 평가에 미치는 분석법의 영향: HPLC 법과 UV 흡광광도법의 비교)

  • Oh, Ju-Hee;Cha, You-Kyoung;Lee, Young-Joo
    • Journal of Pharmaceutical Investigation
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    • v.38 no.6
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    • pp.399-403
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    • 2008
  • The aim of this study was to evaluate the difference of analytical methods for the pharmacokinetic study of bromosulfophthalein (BSP), an indicator of hepatobiliary function. The plasma and bile concentrations of BSP after intravenous administration were measured according to custom UV spectroscopy and HPLC, respectively. Plasma concentration of BSP measured by UV spectroscopy was similar to that measured by HPLC. There was no significant difference in the distribution volume, total body clearance, area under the curve and mean residence time of BSP between different analytical method groups. However, bile concentration of BSP measured by UV spectroscopy was overestimated compared with concentration measured by HPLC method. Biliary clearance of BSP obtained from UV spectroscopy method was almost 3 times higher than that obtained from HPLC method. Thus, a feasibility of UV spectroscopy method for high throughput pharmacokinetic evaluation of BSP was limited to the study based on the plasma concentration of BSP, not bile concentration.

Metabolism and Pharmacokinetics of S-(N,N-Diethyldithiocar-bamoyul)-N-acetyl-L-cysteine in Rats

  • Lee, Byung-Hoon;Song, Yun-Seon;Park, Jongsei;Ryu, Jae-Chun
    • Archives of Pharmacal Research
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    • v.17 no.6
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    • pp.428-433
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    • 1994
  • The methabolism and phamacokinetics of a mixed disulfide S-(N, N-diethyldithiocarbamoyl)-N-acetyl-L-cysteine (AC-DDTC) were studied in rats. Two metabolites of AC-DDTC following iv and po administration were indentified in plasma and liver by HPLC and GC, namely N, N-diethyldithiocarbamate (DDTC) and the methyl ester of DDTC (Me-DDTC). AC-DDTC was very unstable in vivo and could not be detected neither in plasma nor in urine. Pharmacokinetic parameters of DDTC following intravenous administration of AC-DDTC (20 mg/kg) were calculated. DDTC has a low affinity to rat tissue and the body clearance was $9.0{\pm}3.4mkl/mim/kg$. The mean residence time (MRT) was $11.5{\pm}16.3 min$. After oral administration of 20 mg/kg AC-DDTC, maximal plasma concenttion ($C_{max}$) was $3.8{\pm}0.2 nmol/ml$ and the bioavailability was 7.04%. $C_{max}$ for DDTC at a dose of 120 mg/kg. AC-DDTC was $40.1{\pm}2.2 nmol/ml$. ART was $47.1{\pm}2.8min$.at a dose of 20 mg/kg and $110.5{\pm}6.0 min$ at 120 mg/kg.

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Effect of Renal Failure on Pharmacokinetics of Atenolol in Rabbits (아테놀올의 체내동태에 대한 신장해의 영향)

  • Lee, Chong Ki;Cho, Sam Sang
    • Korean Journal of Clinical Pharmacy
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    • v.8 no.1
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    • pp.23-28
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    • 1998
  • The pharmacokinetics of atenolol (25 mg/kg, i.v.) in the folate-induced renal failure rabbits was studied. Renal failure was induced by the i.v. injection of folate (50, 100, and 200 mg/kg). At folate dose of 100 and 200 mg/kg, the serum creatinine concentration (Scr) and blood urea nitrogen (BUN) increased significantly compared with control rabbits. Plasma concentrations and AUC of atenolol increased significantly at folate dose of 100 and 200 mg/kg. The elimination rate constant $(K_{el})$ and total body clearance $(CL_t)$ of atenolol decreased significantly, and half-life ($t_{1/2}$) and mean residence time (MRT) of atenolol increased significantly at folate dose of 100 and 200 mg/kg. The serum creatinine concentration $(S_{cr})$ correlated well (p<0.05) with half-life $(t_{1/2})$ and elimination rate constant $(K_{el})$ of atenolol, as well as BUN with AUC and total body clearance $(CL_t)$ of atenolol.

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Production of 3-Ketosteroid-delta-1-Dehydrogenase by a Two-stage Continuous Culture

  • Ryu, D.Y.;Lee, B.K.;Thoma, R.W.
    • Microbiology and Biotechnology Letters
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    • v.2 no.1
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    • pp.29-35
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    • 1974
  • We have studied the applicability of the principles and inherent advantages of the two-stage dontinuous uclture technique to an enzyme process for the purpose of improving and optimizing the productivity of 3-ketosteroid-delta-1-dehydrogenase. By using a two-stage continuous culture system, the growth st ageand enzyme produdtion stage are separated. In each stage an optimal set of toperaing conditions was determined, and this was tested for feasibility for the period of 10 days. During this period, at least 70% of the maximum enzyme productivity could be maintained. The important design parameters studied are: (1) optimal specific growth rate in the first stage which corresponds to the maximal cell productivity, (2) the optimal dilution rate in the second stage which in turn determines the size of second stage fermentor and the mean residence time of cells in the second stage, (3) cell concentration in both stages, add (4) the specific enzyme productivity and enzyme productivity of the second stage. In addition, by using two-stage continuous culture system we have been able to reduce or eliminate the effect of catabolite repression due to high medium concentration and the adverse effect of the solvent used to dissolve the inducer. We have found the balance between the opposing effects of induction and repression in the second stage judging from the observation that the enzyme productivity goes through a maximum.

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A Study of the Health Status of Elderly Residing in Large city, Medium and Small city, Rural areas in Korea (대도시, 중소도시, 농촌 노인의 건강상태에 관한 연구)

  • 최영희;신윤희
    • Journal of Korean Academy of Nursing
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    • v.21 no.3
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    • pp.365-382
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    • 1991
  • This study was designed to measure the physical, mental-emotional and social health status of elderlies according to rural areas, medium - small cities, and large city environment. Data collection was done from July 18 to August 17 1990. The subjects were a convenience sample after their place of residence was stratified into large, medium- small cities and rural areas. Those who attended elderly centers in Seodaemun, Mapo, and Kangnam districts in Seoul were considered to be residents of a large city and interviewed by trained research assistants and student nurses. Elderlies living in Chungju, Jinju, Chuncheon, and Jeonju cities were coded as residents of medium-small cities and were interviewed by professors of nursing colleges. Rural residents were interviewed by the community health practioners working in community health clinics in North and South Kyongsang, North and South Jeolla, and Kyonggi provinces. The tool used in this study was the health assessment tool developed by Choi, Young Hee in 1990. This tool was organized into 20 physical health status, 17 mental - emotional health status, and 37 social health ststus items. Physical health status items consisted of six factors - personal hygiene activity ability, external activity utilizing traffic, mass media, and spare time ability, sexual ability, digestive system related ability, sexual ability, sensory ability, and elimination ability. Mental - emotional health status items consisted of two factors - mental health factor and emotional health factor. Social health status items consisted of seven factors -grandparental role ability, parental role ability, spoused role ability, friendship role ability, kinship role ability, group member role ability, and religious believer role ability. Data Analysis included frequencies, percentage, mean, standard deviation, ANOVA, and chi - square test. The results of the analysis are as follows : 1. The mean physical health status score for large city residents was 4.1132, for rural residents 4.0787, and for medium and small city residents 3.9565. There were significant differences according to residential area for personal hygiene activity ability, external activity ability, sexual ability, and digestive system related ability items 2. The mean mental -emotional health status score for rural residents was 3.8291, for medium and small city residents 3.7967, and for large city residents 3.7807. There was a significant difference according to residential area in the mental health ability item. 3. The mean social health status score for medium and small city residents was 3.0000, for rural residents 2.9362, and for large city residents 2.8960. There were significant differences according to residential area for kinship role ability and religious believer role ability items. The following conclusion was derived from the above results 1. The physical health status of elderlies residing in medium - small cities and in rural areas was lower than that of those residing in Seoul, a large urban area. Therefore, more medical facilities are needed in rural area so as to monitor their health, prevent disease, and promote their health. 2. The mental -emotional ststus and social health status of elderlies residing in the large city were lower than that of those residing in medium - small cities and rural areas. This may reflect weakening of the strong traditional family bond that may happen with urbanization. Continued support for elderly parents is essential and education should emphasize the traditional cultural norm and value of filial piety. 3. Facilities and programs for elderly are needed so that they may spend their time more valuably in their urban environment.

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Effect of Nicardipine on the Pharmacokinetic Parameters of Cyclosporine in Rat (흰쥐에서 Cyclosporine의 약동학적 지표에 대한 Nicardipine의 영향)

  • 김희규;강주섭;이창호;신인철
    • Biomolecules & Therapeutics
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    • v.6 no.4
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    • pp.389-394
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    • 1998
  • Cyclosporine (CsA) is a major immunosuppressive drug used widely to prevent organ allograft rejection. fits potential organotoxicity by prolonged use is known to cause both direct tissue damage and indirect pharmacokinetic interactions with other drugs. This study was performed to determine the effect of nicardipine (NCP) on the pharmacokinetic parameters of CsA in Sprague-Dawley rats. Each rat was administered with CsA in saline-treated group or in NCP-treated group which was pretreated with NCP (5 mg/kg/12 hours, i.p.) for 6 days. The plasma CsA concentration were analyzed by reversed HPLC: UV system at 0.5, 1, 2, 4, 6, and 8 hours after bolus injection of CsA (10 mg/kg). Pharmacokinetic parameters (mean$\pm$ SD, n=7) such as initial plasma concentration (C(0)), mean residence time (MRT), steady-state volume of distribution (Vdss), terminal half-life (t$\frac{1}{2}$($\beta$)) and plasma clearance (CLp) of CsA in each groups (saline-group vs NCP-group) were determined as follows: C(0) (5.66$\pm$ 1.98 vs 17.98$\pm$2.36, p<0.01); Vdss (2.68$\pm$ 1.6 vs 0.94 $\pm$ 0.25, p<0.01); CLp (0.53 $\pm$0.18 vs 0.21 $\pm$0.06, p<0.01). Therefore, Our results indicate that nicardipine significantly affects the pharmacokinetic parameters of cyclosporme, especially C(0), Vdss, and CLp in NCP-treated group. We suggest that the significant pharmacokinetic interaction between cyclosporine and nicardipine should be considered and cyclosporine level should be closely monitored and dosage reduction made as necessary in clinical situation that was coadministered with CsA and NCP.

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Survival of Mesothelioma in a Palliative Medical Care Unit in Egypt

  • Ibrahim, Noha;Abou-Elela, Enas;Darwish, Dalia
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.2
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    • pp.739-742
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    • 2013
  • Background: This study was to evaluate the survival of patients with pleural and intraperitoneal malignant mesothelioma and to investigate the efficacy of chemotherapy (CT) as well as radiotherapy (RTH) and surgery compared to best supportive care (BSC). Materials and Methods: Forty patients with malignant mesothelioma (38 with pleural and 2 with intraperitoneal) were enrolled. Twenty seven patients underwent (CT) chemotherapy of which 2 also received (RTH) and surgery was only for biopsy in 15/40. Combination chemotherapy included cisplatin-gemcitabine, cisplatin-navelbine and cisplatin (or carboplatin) with premetrexed. Thirteen patients received only best supportive care. Results: A total of 12 (30%) patients were male, and 28 (70%) female. Median age was 54.0 years and the male/female ratio was 1/2.33 (P=0.210). Residential exposure played a major role in two regions, Helwan and Shoubra, in 20% and 15%, respectively. Overall mean survival time was $13.9{\pm}2.29$ months. That for patients who had received best supportive care was $7.57{\pm}1.85$ months, for chemotherapy was $16.5{\pm}3.20$ months, and multimodality treatment regimen $27{\pm}21.0$ months (P=0.028). Kaplan-Meier survival did not significantly vary for sex, residence and the pathological types epithelial, mixed and sarcomatous. The median survival for performance status and treatment modalities was significant (P=0.001 and 0.028). Best supportive care using opioids with a mean dose of 147.1 mg (range 0-1680) of morphine sulphate produced good subjective response and reasonable quality of life but did not affect survival. Conclusions: We conclude that CT prolongs survival compared to BSC in patients with malignant mesothelioma. Moreover, using escalating doses of opioids provides good pain relief and subjective responses.

Phosphorus Budget of a River Reservoir, Paldang (하천형 호수인 팔당호의 인 수지)

  • Kong, Dongsoo
    • Journal of Korean Society on Water Environment
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    • v.34 no.3
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    • pp.270-284
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    • 2018
  • Paldang is a river reservoir located in the Midwest of Korea, with a water volume of $244{\cdot}10^6m^3$ and a water surface area of $36.5km^2$. It has eutrophied since the construction of a dam at the end of 1973, and the phosphorus concentration has decreased since 2001. Average hydraulic residence time of the Paldang reservoir is about 10 days during the spring season and 5.6 days as an annual level. The hydraulics and water quality of the reservoir can differ greatly, both temporally and spatially. For the spring period (March to May) in 2001 ~ 2017, the reservoir mean total phosphorus concentration calculated from the budget model based on a plug-flow system (PF) and a continuous stirred-tank reaction system (CSTR) was 13 % higher and 10 % lower than the observed concentration, respectively. A composite flow system (CF) was devised by assuming that the transition zone was plug flow, and that the lacustrine zone was completely mixed. The mean concentration calculated from the model based on CF was not skewed from the observed concentration, and showed just 6 % error. The retention coefficient of the phosphorus derived from the CF was 0.30, which was less than those of the natural lakes abroad or river reservoirs in Korea. The apparent settling velocity of total phosphorus was estimated to be $93m\;yr^{-1}$, which was 6 ~ 9 times higher than those of foreign natural lakes. Assuming CF, the critical load line for the total phosphorus concentration showed a hyperbolic relation to the hydraulic load in the Paldang reservoir. This is different from the previously known straight critical load line. The trophic state of the Paldang reservoir has recently been estimated to be mesotrophic based on the critical-load curve of the phosphorus budget model developed in this study. Although there is no theoretical error in the newly developed budget model, it is necessary to verify the validity of the portion below the inflection point of the critical-load curve afterwards.

The Effect of Preparation Conditions on the Characteristics of Co3O4 Particles Prepared by Spray Pyrolysis (합성 조건이 분무열분해 공정에 의해 합성되는 Co3O4 분말의 특성에 미치는 영향)

  • Kim, Do-Youp;Ju, Seo-Hee;Koo, Hye-Young;Hong, Seung-Kwon;Kang, Yun-Chan
    • Korean Journal of Materials Research
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    • v.16 no.1
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    • pp.11-18
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    • 2006
  • [ $Co_3O_4$ ] particles with non-aggregation characteristics were prepared by various conditions such as preparation temperature, flow rate of carrier gas, and concentration of spray solution using spray pyrolysis. The morphology and crystallinity of the preformed particles obtained by spray pyrolysis at various conditions affected the mean size and morphology of the post-treated $Co_3O_4$ particles. The preformed particles with hollow and porous morphology obtained from spray solution with citric acid and ethylene glycol turned to $Co_3O_4$ particles with nano size, regular morphology and non-aggregation characteristics after post-treatment at $800^{\circ}C$. On the other hand, the preformed particles obtained by the preparation conditions of short residence time of particles inside hot wall reactor and high reactor temperature turned to $Co_3O_4$ particles with aggregated morphology after post-treatment. The mean crystallite size and particle size of the $Co_3O_4$ particles prepared from optimum preparation conditions were 47 nm and 210 nm at post-treatment temperature of $800^{\circ}C$.

The Smartphone Addiction, Self-Efficacy, and Communication Skills of Nursing College Students before Clinical Training Relationship between Communication Skills (임상실습교육 전 간호대학생의 스마트폰 중독, 자기효능감 및 의사소통능력 관계)

  • Mi-Young Kim;Hyo-Jin Park
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.4
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    • pp.157-166
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    • 2023
  • Purpose : The purposes of this study were to determine the relationships of communication skills with smartphone addiction and self-efficacy before clinical practice training among nursing students and to provide basic data for developing and verifying the effectiveness of an intervention program for improving nursing students' communication skills. Methods : This study targeted those who obtained consent to collect data explained the purpose and procedure of the study for the first and second graders of the nursing department at one university located in B city. The data collection period was from April 24 to May 13, 2023. A total of 207 questionnaire responses were included in the analysis. The collected data were analyzed using t-tests and analysis of variance in the SPSS/Win 230 program. The results were reported as real numbers, percentages, mean values, and standard deviations. The correlations between the variables were analyzed using the Pearson correlation coefficient. Results : Smartphone addiction according to the general characteristics of the study subjects showed significant differences in 'residence type' (F=2.91, p=.035) and 'average smartphone usage time' (F=20.15, p=.000). It seemed. self-efficacy was determined by 'age' (F=2.74, p=.045), 'subjective academic level' (F=7.71, p=.001), and 'average smartphone usage time' (F=3.96, p=.009) showed a significant difference. Communication skills showed a significant difference in 'average smartphone usage time' (F=3.83, p=.011). The correlation between the variables of the study subjects showed that self-efficacy was negatively correlated with smartphone addiction (r=-.42, p<.001), and communication ability was positively correlated with self-efficacy. It was found that (r=.55, p<.001). 15) Conclusion : On the basis of the study results, the higher the nursing students' smartphone addiction, the lower their self-efficacy, and the higher their communication ability, the higher their self-efficacy. Therefore, intervention research is necessary to develop interventions for preventing smartphone addiction and increasing communication ability among nursing students.