• Title/Summary/Keyword: radiotracer method

Search Result 24, Processing Time 0.022 seconds

Review of the study on the surfactant-induced foliar uptake of pesticide (계면활성제에 의해 유도되는 농약의 엽면 침투성 연구 현황)

  • Yu, Ju-Hyun;Cho, Kwang-Yun;Kim, Jeong-Han
    • The Korean Journal of Pesticide Science
    • /
    • v.6 no.1
    • /
    • pp.16-24
    • /
    • 2002
  • Research trends in the measurement of foliar uptake of pesticides and the recently proposed action mechanism of the surfactant-induced uptake of pesticides were reviewed with the related reports and studies. Major techniques used in those fields are bioassay, radiotracer techniques with leaves or cuticular membrane. Recently, a new method using Congo Red as a tracer was proposed. The limiting factor in the pesticides uptake into leaves is the waxy layer which consists of the epicuticular and cuticular wax. Physico-chemical parameters such as molar volume, water solubility and partition coefficient of pesticides have limited influences on the pesticide uptake into leaves. Polydisperse ethoxylated fatty alcohol surfactants are well known as the good activator for many pesticides. It is now generally agreed that uptake activation is not related to the intrinsic surface active properties of surfactants such as surface activity, solvent property, humectancy and critical micelle concentration. Recent studies using ESR-spectroscopy revealed that the surfactants have an unspecific plasticising effect on the molecular structure of the wax and cuticular matrix, leading to increased mobilities of pesticides. Penetration of surfactants into waxy layer altered the pesticide mobility in wax and the partition coefficient of pesticide, and then the pesticides penetration into leaves was enhanced temporally. The enhancing effect of surfactant could be significantly different depending on the carbon number of aliphatic moiety and the number of ethoxy group in polyoxyethylene chain of surfactants. It is suggested that the rate of penetration of surfactants should have a significant relationship with the rate of penetration of pesticides.

Assessment of the Synovial Inflammation in Rheumatoid Arthritis with $^{99m}Tc$-labelled Polyclonal Human IgG(HIG): Prospective Comparison with Gadolinium Enhanced MRI ($^{99m}Tc$-labelled HIG 스캔을 이용한 류마티스 관절염 환자에서 활막염증의 평가 : 조영증강 자기공명영상과의 전향적인 비교)

  • Ryu, Young-Hoon;Lee, Jong-Doo;Suh, Jin-Suck;Park, Chang-Yun;Jeon, Pyoung;Na, Jae-Beom;Lee, Soo-Kon
    • The Korean Journal of Nuclear Medicine
    • /
    • v.29 no.1
    • /
    • pp.84-91
    • /
    • 1995
  • Many clinical and laboratory tests have been employed to evaluate disease activity in rheumatioid arthritis. $^{99m}Tc$-labelled polyclonal IgG(HIG) has been demonstrated to accumulate in focal sites of infection or inflammation in both animals and human subjects. The purpose of this study was to distinguish arthritis with active inflammation from those without active inflammation and to correlate relative intensities of $^{99m}Tc$-labelled HIG uptake of the rheumatoid arthritis with clinical and MR indices of the joint inflammation. This study included twelve patients with active rheumatoid arthritis, two with ankylosing spondylitis and one with degenerative osteoarthritis without active inflammation. A Whole-body and spot images were obtained 4 hours after intravenous injection of 20mCi of $^{99m}Tc$-labelled HIG. Scintigrams were assessed visually by 3 experienced radiologists, and graded as normal or mildly and markedly increased uptake within the joints, and the degree of uptake was compared with clinical and radiologic severity of synovial inflammation. MRI studies were done on the involved joints consisted of wrist(n = 11), knee(n = 2) and hip joint(n= 2). Active synovitis was defined when marked elevation of ESR and gadolinium enhancement of synovium on MRI were demonstrated. Markedly increased radiotracer uptake was seen in 10 of 11 rheumatoid arthritic patients with active synovitis whereas normal or mildly increased uptakes were noted in others, including rheumatoid arthritic patient(n=1) and non-rheumatoid patients(n = 3) without active synovitis. This study showed that the localization of involved joints in rheumatoid arthritis could be detected with $^{99m}Tc$-labelled HIG and that the degree of uptake correlated well with the degree and activity of inflammation. In conclusion, $^{99m}Tc$-labelled HIG scan is a useful method in the evaluation of active inflammation in rheumatoid arthritis.

  • PDF

Synthesis of a Dopamine Transporter Imaging Agent, N-(3-[$^{18}F$]fluoropropyl)-$2{\beta}$-carbomethoxy-$3{\beta}$-(4-iodophenyl)nortropane (도파민운반체 방사성추적자 N-(3-[$^{18}F$Fluoropropyl)-$2{\beta}$-carbomethoxy-$3{\beta}$-(4-iodophenyl)nortropane의 합성)

  • Choe, Yearn-Seong;Oh, Seung-Jun;Chi, Dae-Yoon;Kim, Sang-Eun;Choi, Yong;Lee, Kyung-Han;Kim, Byung-Tae
    • The Korean Journal of Nuclear Medicine
    • /
    • v.33 no.3
    • /
    • pp.298-305
    • /
    • 1999
  • Purpose: N-(3-[$^{18}F$]Fluoropropyl)-$2{\beta}$-carbomethoxy-$3{\beta}$-(4-iodophenyl)nortropane [$^{18}F$]FP-CIT) has been shown to be very useful for imaging the dopamine transporter. However, synthesis of this radiotracer is somewhat troublesome. In this study, we used a new method for the preparation of [$^{18}F$]FP-CIT to increase radiochemical yield and effective specific activity. Materials and Methods: [$^{18}F$]FP-CIT was prepared by N-alkylation of nor-${\beta}$-CIT (2 mg) with 3-bromo-1-[$^{18}F$]fluoropropane in the presence of $Et_3N$ (5-6 drops of $DMF/CH_3CN$, $140^{\circ}C$, 20 min). 3-Bromo-1-[$^{18}F$]fluoropropane was synthesized from $5{\mu}L$ of 3-bromo-1-trifluoromethanesulfonyloxypropane (3-bromopropyl-1-triflate) and $nBu_4N^{18}F$ at $80^{\circ}C$. The final compound was purified by reverse phase HPLC and formulated in 13% ethanol in saline. Results: 3-Bromo-1-[$^{18}F$]fluoropropane was obtained from 3-bromopropyl-1-triflate and $nBu_4N^{18}F$ in 77-80% yield. N-Alkylation of nor-${\beta}$-CIT with 3-bromo-1-[$^{18}F$]fluoropropane was carried out at $140^{\circ}C$ using acetonitrile containing a small volume of DMF as the solvents. The overall yield of [$^{18}F$]FP-CIT was 5-10% (decay-corrected) with a radiochemical purity higher than 99% and effective specific activity higher than the one reported in the literature based on their HPLC data. The final [$^{18}F$]FP-CIT solution had the optimal pH (7.0) and it was pyrogen-free. Conclusion: In this study, 3-bromopropyl-1-triflate was used as the precursor for the [$^{18}F$]fluorination reaction and new conditions were developed for purification of [$^{18}F$]FP-CIT by HPLC. We established this new method for the preparation of [$^{18}F$]FP-CIT, which gave high effective specific activity and relatively good yield.

  • PDF

Evaluation of Multiple System Atrophy and Early Parkinson's Disease Using $^{123)I$-FP-CIT SPECT ($^{123)I$-FP-CIT SPECT를 이용한 다중계위축증 및 조기 파킨슨병에서의 평가)

  • Oh, So-Won;Kim, Yu-Kyeong;Lee, Byung-Chul;Kim, Bom-Sahn;Kim, Ji-Sun;Kim, Jong-Min;Kim, Sang-Eun
    • Nuclear Medicine and Molecular Imaging
    • /
    • v.43 no.1
    • /
    • pp.10-18
    • /
    • 2009
  • Purpose: We investigated quantification of dopaminergic transporter (DAT) and serotonergic transporter (SERT) on $^{123}I$-FP-CIT SPECT for differentiating between multiple systemic atrophy (MSA) and idiopathic Parkinson's disease (IPD). Materials and Methods: N-fluoropropyl-$2{\beta}$-carbomethoxy-$3{\beta}$-4-[$^{123}I$]-iodophenylnortropane SPECT ($^{123}I$-FP-CIT SPECT) was performed in 8 patients with MSA (mean age: $64.0{\pm}4.5yrs$, m:f=6:2), 13 with early IPD (mean age: $65.5{\pm}5.3yrs$, m:f=9:4), and 12 healthy controls (mean age: $63.3{\pm}5.7yrs$, m:f=8:4). Standard regions of interests (ROls) of striatum to evaluate DAT, and hypothalamus and midbrain for SERT were drawn on standard template images and applied to each image taken 4 hours after radiotracer injection. Striatal specific binding for DAT and hypothalamic and midbrain specific binding for SERT were calculated using region/reference ratio based on the transient equilibrium method. Group differences were tested using ANOVA with the postHoc analysis. Results: DAT in the whole striatum and striatal subregions were significantly decreased in both patient groups with MSA and early IPD, compared with healthy control (p<0.05 in all). In early IPD, a significant increase in the uptake ratio in anterior and posterior putamen and a trend of increase in caudate to putamen ratio was observed. In MSA, the decrease of DAT was accompanied with no difference in the striatal uptake pattern compared with healthy controls. Regarding the brain regions where $^{123}I$-FP-CIT binding was predominant by SERT, MSA patients showed a decrease in the binding of $^{123}I$-FP-CIT in the pons compared with controls as well as early IPD patients (MSA: $0.22{\pm}0.1$ healthy controls: $0.33{\pm}0.19$, IPD: $0.29{\pm}0.19$), however, it did not reach the statistical significance. Conclusion: In this study, the differential patterns in the reduction of DAT in the striatum and the reduction of pontine $^{123}I$-FP-CIT binding predominant by SERT could be observed in MSA patients on $^{123}I$-FP-CIT SPECT. We suggest that the quantification of SERT as well as DAT using $^{123}I$-FP-CIT SPECT is helpful to differentiate parkinsonian disorders in early stage.