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Sample records for 125i seed localization

  1. Localization of linked {sup 125}I seeds in postimplant TRUS images for prostate brachytherapy dosimetry

    SciTech Connect

    Xue Jinyu . E-mail: Jinyu.Xue@mail.tju.edu; Waterman, Frank; Handler, Jay; Gressen, Eric

    2005-07-01

    Purpose: To demonstrate that {sup 125}I seeds can be localized in transrectal ultrasound (TRUS) images obtained with a high-resolution probe when the implant is performed with linked seeds and spacers. Adequate seed localization is essential to the implementation of TRUS-based intraoperative dosimetry for prostate brachytherapy. Methods and Materials: Thirteen preplanned peripherally loaded prostate implants were performed using {sup 125}I seeds and spacers linked together in linear arrays that prevent seed migration and maintain precise seed spacing. A set of two-dimensional transverse images spaced at 0.50-cm intervals were obtained with a high-resolution TRUS probe at the conclusion of the procedure with the patient still under anesthesia. The image set extended from 1.0 cm superior to the base to 1.0 cm inferior to the apex. The visible echoes along each needle track were first localized and then compared with the known construction of the implanted array. The first step was to define the distal and proximal ends of each array. The visible echoes were then identified as seeds or spacers from the known sequence of the array. The locations of the seeds that did not produce a visible echo were interpolated from their known position in the array. A CT scan was obtained after implantation for comparison with the TRUS images. Results: On average, 93% (range, 86-99%) of the seeds were visible in the TRUS images. However, it was possible to localize 100% of the seeds in each case, because the locations of the missing seeds could be determined from the known construction of the arrays. Two factors complicated the interpretation of the TRUS images. One was that the spacers also produced echoes. Although weak and diffuse, these echoes could be mistaken for seeds. The other was that the number of echoes along a needle track sometimes exceeded the number of seeds and spacers implanted. This was attributed to the overall length of the array, which was approximately 0.5 cm

  2. CT-guided 125I seed implantation for inoperable retroperitoneal sarcoma: A technique for delivery of local tumor brachytherapy

    PubMed Central

    Yang, Biao; Guo, Wen-Hao; Lan, Ting; Yuan, Fang; Liu, Guan-Jian; Zan, Rui-Yu; You, Xin; Tan, Qiao-Yue; Liao, Zheng-Yin

    2016-01-01

    Radical surgery is currently the first treatment of choice for retroperitoneal soft tissue sarcoma (RSTS). However, the prognosis of RSTS remains poor due to ineffective local control and a high incidence of metastasis after surgical resection. Brachytherapy has been shown to safely provide local radiotherapy for numerous types of cancer when used alone or in combination with surgical resection, but has not been well characterized in the management of RSTS. The aim of this study was to evaluate CT-guided 125I seed implantation for local control and pain relief in the treatment of inoperable RSTS. A total of 23 patients with RSTS were treated with 125I implantation. Pain was assessed using a visual analog scale. Other endpoints were evaluated via computed tomography scan or phone call/e-mail records. The occurrence of complications was assessed preoperatively (baseline) and during postoperatively follow-up or until patient succumbed. All patients were successfully treated with 125I implantation. A mean number of 70.87 radioactive seeds were applied in each patient. During the follow-up, two patients were unaccounted for, local recurrence occurred in three patients, five succumbed and complications were observed in sixteen. The patient's VAS score changed from 7.4 preoperatively to 7.6, 2.3, 2.0, 1.2, 1.5, 1.4 and 2.5 at 24 h, 1, 3, 6, 12, 24 and 36 months after the procedure, respectively. Good local control and significant pain relief after 125I seed implantation was observed in patients with inoperable RSTS. Thus, the present results suggest that this method could be an effective treatment option for patients with inoperable RSTS. PMID:28101168

  3. Radioactive seed localization with 125I for nonpalpable lesions prior to breast lumpectomy and/or excisional biopsy: methodology, safety, and experience of initial year.

    PubMed

    Dauer, Lawrence T; Thornton, Cynthia; Miodownik, Daniel; Boylan, Daniel; Holahan, Brian; King, Valencia; Brogi, Edi; Morrow, Monica; Morris, Elizabeth A; St Germain, Jean

    2013-10-01

    The use of radioactive seed localization (RSL) as an alternative to wire localizations (WL) for nonpalpable breast lesions is rapidly gaining acceptance because of its advantages for both the patient and the surgical staff. This paper examines the initial experience with over 1,200 patients seen at a comprehensive cancer center. Radiation safety procedures for radiology, surgery, and pathology were implemented, and radioactive material inventory control was maintained using an intranet-based program. Surgical probes allowed for discrimination between 125I seed photon energies from 99mTc administered for sentinel node testing. A total of 1,127 patients (median age of 57.2 y) underwent RSL procedures with 1,223 seeds implanted. Implanted seed depth ranged from 10.3-107.8 mm. The median length of time from RSL implant to surgical excision was 2 d. The median 125I activity at time of implant was 3.1 MBq (1.9 to 4.6). The median dose rate from patients with a single seed was 9.5 µSv h-1 and 0.5 µSv h-1 at contact and 1 m, respectively. The maximum contact dose rate was 187 µSv h-1 from a superficially placed seed. RSL performed greater than 1 d before surgery is a viable alternative to WL, allowing flexibility in scheduling, minimizing day of surgery procedures, and improving workflow in breast imaging and surgery. RSL has been shown to be a safe and effective procedure for preoperative localization under mammographic and ultrasound guidance, which can be managed with the use of customized radiation protection controls.

  4. Intercomparison of ionisation chamber measurements from (125)I seeds.

    PubMed

    Davies, J B; Enari, K F; Baldock, C

    2007-05-01

    The reference air kerma rates of a set of individual (125)I seeds were calculated from current measurements of a calibrated re-entrant ionisation chamber. Single seeds were distributed to seven Australian brachytherapy centres for the same measurement with the user's instrumentation. Results are expressed as the ratio of the reference air kerma rate measured by the Australian Nuclear Science & Technology Organisation (ANSTO) to the reference air kerma rate measured at the centre. The intercomparison ratios of all participants were within +/-5% of unity.

  5. Novel Silicone-Coated 125I Seeds for the Treatment of Extrahepatic Cholangiocarcinoma.

    PubMed

    Lin, Lizhou; Guo, Lili; Zhang, Weixing; Cai, Xiaobo; Chen, Dafan; Wan, Xinjian

    2016-01-01

    125I seeds coated with titanium are considered a safe and effective interstitial brachytherapy for tumors, while the cost of 125I seeds is a major problem for the patients implanting lots of seeds. The aim of this paper was to develop a novel silicone coating for 125I seeds with a lower cost. In order to show the radionuclide utilization ratio, the silicone was coated onto the seeds using the electro-spinning method and the radioactivity was evaluated, then the anti-tumor efficacy of silicone 125I seeds was compared with titanium 125I seeds. The seeds were divided into four groups: A (control), B (pure silicone), C (silicone 125I), D (titanium 125I) at 2 Gy or 4 Gy. Their anti-tumour activity and mechanism were assessed in vitro and in vivo using a human extrahepatic cholangiocarcinoma cell line FRH-0201 and tumor-bearing BALB/c nude mice. The silicone 125I seeds showed higher radioactivity; the rate of cell apoptosis in vitro and the histopathology in vivo demonstrated that the silicone 125I seeds shared similar anti-tumor efficacy with the titanium 125I seeds for the treatment of extrahepatic cholangiocarcinoma, while they have a much lower cost.

  6. Novel Silicone-Coated 125I Seeds for the Treatment of Extrahepatic Cholangiocarcinoma

    PubMed Central

    Zhang, Weixing; Cai, Xiaobo; Chen, Dafan; Wan, Xinjian

    2016-01-01

    125I seeds coated with titanium are considered a safe and effective interstitial brachytherapy for tumors, while the cost of 125I seeds is a major problem for the patients implanting lots of seeds. The aim of this paper was to develop a novel silicone coating for 125I seeds with a lower cost. In order to show the radionuclide utilization ratio, the silicone was coated onto the seeds using the electro-spinning method and the radioactivity was evaluated, then the anti-tumor efficacy of silicone 125I seeds was compared with titanium 125I seeds. The seeds were divided into four groups: A (control), B (pure silicone), C (silicone 125I), D (titanium 125I) at 2 Gy or 4 Gy. Their anti-tumour activity and mechanism were assessed in vitro and in vivo using a human extrahepatic cholangiocarcinoma cell line FRH-0201 and tumor-bearing BALB/c nude mice. The silicone 125I seeds showed higher radioactivity; the rate of cell apoptosis in vitro and the histopathology in vivo demonstrated that the silicone 125I seeds shared similar anti-tumor efficacy with the titanium 125I seeds for the treatment of extrahepatic cholangiocarcinoma, while they have a much lower cost. PMID:26840346

  7. 125I Seed Permanent Implantation as a Palliative Treatment for Stage III and IV Hypopharyngeal Carcinoma

    PubMed Central

    Li, Lei; Yang, Jie; Li, Xiaojiang; Wang, Xiaoli; Ren, Yanxin; Fei, Jimin; Xi, Yan; Sun, Ruimei; Ma, Jing

    2016-01-01

    Objectives. The aim of this study was to investigate the feasibility and safety of percutaneous 125I seed permanent implantation for advanced hypopharyngeal carcinoma from toxicity, tumor response, and short-term outcome. Methods. 125I seeds implant procedures were performed under computed tomography for 34 patients with advanced hypopharyngeal carcinoma. We observed the local control rate, overall survival, and acute or late toxicity rate. Results. In the 34 patients (stage III, n=6; stage IV, n=28), the sites of origin were pyriform sinus (n=29) and postcricoid area (n=5). All patients also received one to four cycles of chemotherapy after seed implantation. The post-plan showed that the actuarial D90 of 125I seeds ranged from 90 to 158 Gy (median, 127 Gy). The mean follow-up was 12.3 months (range, 3.4 to 43.2 months). The local control was 2.1–31.0 months with a median of 17.7 months (95% confidence interval [CI], 13.4 to 22.0 months). The 1-, 2-, and 3-year local controls were 65.3%, 28.6%, and 9.5% respectively. Twelve patients (35%) died of local recurrence, fourteen patients (41%) died of distant metastases, and three patients (9%) died of recurrence and metastases at the same time. Five patients (15%) still survived to follow-up. At the time of analysis, the median survival time was 12.5 months (95% CI, 9.5 to 15.4 months). The 1-, 2-, and 3-year overall survival rates were 55.2%, 20.3%, and 10.9%, respectively. Five patients (15%) experienced grade 3 toxic events and nine patients (26%) have experienced grade 2 toxic events. Conclusion. This review shows relatively low toxicity for interstitial 125I seed implantation in the patients with advanced stage hypopharyngeal cancer. The high local control results suggest that 125I seed brachytherapy implant as a salvage or palliative treatment for advanced hypopharyngeal carcinoma merit further investigation. PMID:27440132

  8. The Protective Roles of ROS-Mediated Mitophagy on 125I Seeds Radiation Induced Cell Death in HCT116 Cells

    PubMed Central

    Hu, Lelin; Wang, Hao; Huang, Li; Zhao, Yong

    2016-01-01

    For many unresectable carcinomas and locally recurrent cancers (LRC), 125I seeds brachytherapy is a feasible, effective, and safe treatment. Several studies have shown that 125I seeds radiation exerts anticancer activity by triggering DNA damage. However, recent evidence shows mitochondrial quality to be another crucial determinant of cell fate, with mitophagy playing a central role in this control mechanism. Herein, we found that 125I seeds irradiation injured mitochondria, leading to significantly elevated mitochondrial and intracellular ROS (reactive oxygen species) levels in HCT116 cells. The accumulation of mitochondrial ROS increased the expression of HIF-1α and its target genes BINP3 and NIX (BINP3L), which subsequently triggered mitophagy. Importantly, 125I seeds radiation induced mitophagy promoted cells survival and protected HCT116 cells from apoptosis. These results collectively indicated that 125I seeds radiation triggered mitophagy by upregulating the level of ROS to promote cellular homeostasis and survival. The present study uncovered the critical role of mitophagy in modulating the sensitivity of tumor cells to radiation therapy and suggested that chemotherapy targeting on mitophagy might improve the efficiency of 125I seeds radiation treatment, which might be of clinical significance in tumor therapy. PMID:28119765

  9. CT-Guided Radioactive {sup 125}I Seed Implantation Therapy of Symptomatic Retroperitoneal Lymph Node Metastases

    SciTech Connect

    Wang, Zhongmin; Lu, Jian; Gong, Ju; Zhang, Liyun; Xu, Yingjia; Song, Shaoli; Chen, Kemin; Liu, Fenju; Gang, Huang

    2013-04-12

    PurposeThis study explored the clinical efficacy of CT-guided radioactive {sup 125}I seed implantation in treating patients with symptomatic retroperitoneal lymph node metastases.MethodsTwenty-five patients with pathologically confirmed malignant tumors received CT-guided radioactive {sup 125}I seed implantation to treat metastatic lymph nodes. The diameter of the metastatic lymph nodes ranged from 1.5 to 4.5 cm. Treatment planning system (TPS) was used to reconstruct the three-dimensional image of the tumor and then calculate the corresponding quantity and distribution of {sup 125}I seeds.ResultsFollow-up period for this group of patients was 2–30 months, and median time was 16 months. Symptoms of refractory pain were significantly resolved postimplantation (P < 0.05), and Karnofsky score rose dramatically (P < 0.05). Most patients reported pain relief 2–5 days after treatment. Follow-up imaging studies were performed 2 months later, which revealed CR in 7 patients, PR in 13 patients, SD in 3 patients, and PD in 2 patients. The overall effective rate (CR + PR) was 80 %. Median survival time was 25.5 months. Seven patients died of recurrent tumor; 16 patients died of multiorgan failure or other metastases. Two patients survived after 30 months follow-up. Two patients reported localized skin erythema 1 week postimplantation, which disappeared after topical treatment.ConclusionsCT-guided radioactive {sup 125}I seed implantation, which showed good palliative pain relief with acceptable short-term effects, has proved in our study to be a new, safe, effective, and relatively uncomplicated treatment option for symptomatic retroperitoneal metastatic lymph nodes.

  10. [Relief effect of CT-guided (125)I seed implantation on patients with spinal and paraspinal osteolytic metastatic tumors].

    PubMed

    Huang, H; Li, F S; Wang, L; Du, Z G; Xu, S N

    2017-03-23

    Objective: To evaluate the clinical value of computed tomography (CT)-guided (125)I seed implantation in the treatment of patients with spinal and/or paraspinal osteolytic metastatic tumors. Methods: The radiation dose distribution was planned for 27 patients with 35 spinal and paraspinal osteolytic metastatic tumors by a treatment planning system (TPS). CT-guided (125)I seed implantation was carried out in the patients, and the quality of treatment was evaluated based on CT-imaging follow-up. Results: All the 27 patients underwent CT-guided (125)I seed implantation successfully. 12 to 50 (125)I seeds were injected into each spinal or paraspinal metastatic tumor, 39.15 on average, and the specific radioactive activity of the particles ranged from 0.60 to 0.80 mCi, 0.73 mCi on average. The minimal percentage of the dose received by 90% of the target volume (D(90)) of the spinal and paraspinal metastatic tumors ranged from 90 to 165 Gy, 115.03 Gy on average. Among the 27 patients, 21 (77.8%) had partial remission (PR) and 6(22.2%)had stable disease (SD). The Numerical Rating Scale (NRS) scores before implantation and at postoperative 3 and 6 months were 7.81±0.74, 2.04±1.10 and 1.81±0.79, respectively, (P<0.05). The assessment of pain intensity before (125)I seed implantation and at 3 postoperative months showed obvious improvements in the patients evaluated according to the American Spinal Injury Association (ASIA) impairment scale: 12 (44.4%) patients with ASIA grade C were changed to grade D, 3 (11.1%) from grade C to grade E, 8 (29.6%) from grade D to grade E, 3 (11.1%) with a stable grade D, and 1 (3.7%)with a stablegrade C. The Karnovsky performance scale (KPS) scores before treatment and at 3 months and 6 months postoperatively were 66.30±6.88, 85.93±9.31 and 87.91±8.56, respectively (P<0.05). Their local control rate (LCR) at 3 months, 6 months and 1 year postoperatively were 100%, 92.6% and 51.9%, respectively, and the overall survival rates(OSR) were

  11. Polymer gel dosimetry close to an 125I interstitial brachytherapy seed

    NASA Astrophysics Data System (ADS)

    Pantelis, E.; Lymperopoulou, G.; Papagiannis, P.; Sakelliou, L.; Stiliaris, E.; Sandilos, P.; Seimenis, I.; Kozicki, M.; Rosiak, J. M.

    2005-09-01

    Despite its advantages, the polymer gel-magnetic resonance imaging (MRI) method has not, as yet, been successfully employed in dosimetry of low energy/low dose rate photon-emitting brachytherapy sources such as 125I or 103Pd interstitial seeds. In the present work, two commercially available 125I seed sources, each of approximately 0.5 U, were positioned at two different locations of a polymer gel filled vial. The gel vial was MR scanned with the sources in place 19 and 36 days after seed implantation. Calibration curves were acquired from the coupling of MRI measurements with accurate Monte Carlo dose calculations obtained simulating the exact experimental setup geometry and materials. The obtained gel response data imply that while linearity of response is sustained, sensitivity (calibration curve slope) is significantly increased (approximately 60%) compared to its typical value for the 192Ir (or 60Co and 6 MV LINAC) photon energies. Water equivalence and relative energy response corrections of the gel cannot account for more than 3-4% of this increase, which, therefore, has to be mainly attributed to physicochemical processes related to the low dose rate of the sources and the associated prolonged irradiation time. The calibration data obtained from one 125I source were used to provide absolute dosimetry results for the other 125I source, which were found to agree with corresponding Monte Carlo calculations within experimental uncertainties. It is therefore suggested that, regardless of the underlying factors accounting for the gel dose response to 125I irradiations, polymer gel dosimetry of new 125I or 103Pd sources should be carried out as originally proposed by Heard and Ibbot (2004 J. Phys.: Conf. Ser. 3 221-3), i.e., by irradiating the same gel sample with the new low dose rate source, as well as with a well-characterized low dose rate source which will provide the dose calibration curve for the same irradiation conditions.

  12. CT-Guided 125I Seed Interstitial Brachytherapy as a Salvage Treatment for Recurrent Spinal Metastases after External Beam Radiotherapy

    PubMed Central

    Yao, Lihong; Cao, Qianqian; Yang, Jiwen; Meng, Na; Guo, Fuxin; Jiang, Yuliang; Tian, Suqing; Sun, Haitao

    2016-01-01

    The aim of this study is to evaluate the feasibility, safety, and clinical efficacy of CT-guided 125I seed interstitial brachytherapy in patients with recurrent spinal metastases after external beam radiotherapy (EBRT). Between August 2003 and September 2015, 26 spinal metastatic lesions (24 patients) were reirradiated by this salvage therapy modality. Treatment for all patients was preplanned using a three-dimensional treatment planning system 3–5 days before 125I seed interstitial brachytherapy; dosimetry verification was performed immediately after seed implantation. Median actual D90 was 99 Gy (range, 90–176), and spinal cord median Dmax was 39 Gy (range, 6–110). Median local control (LC) was 12 months (95% CI: 7.0–17.0). The 6- and 12-month LC rates were 52% and 40%, respectively. Median overall survival (OS) was 11 months (95% CI: 7.7–14.3); 6-month and 1-, 2-, and 3-year OS rates were 65%, 37%, 14%, and 9%, respectively. Pain-free survival ranged from 2 to 42 months (median, 6; 95% CI: 4.6–7.4). Treatment was well-tolerated, with no radiation-induced vertebral compression fractures or myelopathy reported. Reirradiation with CT-guided 125I seed interstitial brachytherapy appears to be feasible, safe, and effective as pain relief or salvage treatment for patients with recurrent spinal metastases after EBRT. PMID:28105434

  13. Computed tomography (CT)-guided interstitial permanent implantation of (125)I seeds for refractory chest wall metastasis or recurrence.

    PubMed

    Jiang, Ping; Liu, Chen; Wang, Junjie; Yang, Ruijie; Jiang, Yuliang; Tian, Suqing

    2015-02-01

    To evaluate the efficacy and safety of 125I seeds implantation for refractory chest wall (CW) metastasis or recurrence under CT guidance. In addition we assessed initial data obtained on the therapeutic response for refractory CW metastasis or recurrence. Twenty consecutive patients underwent permanent implantation of 125I seeds (from Jul. 2004 to Jan. 2011) under computed tomography (CT) guidance. Postoperative dosimetry was routinely performed for all patients. The actuarial D90 of the implanted 125I seeds ranged from 100 Gy to 160 Gy (median: 130 Gy). The activity of 125I seeds ranged from 0.5 mCi to 0.78 mCi (median: 0.71 mCi). The total number of seeds implanted ranged from 8 to 269 (median: 53). The follow-up period ranged from 3 to 54 months (median: 11.5 months). The survival and local control probabilities were calculated by the Kaplan-Meier method. Among all the 20 patients, 3 patients had complete remission CR (15%), 12 patients had partial remission PR (60%), 5 patients had stable disease SD. The 1-, 2-, 3- and 4-year tumor control rates were all 88.7% respectively. The 1- and 2-, 3-, 4-year cancer specific survival rates were 56.5% and 47.1%, 47.1%, 47.1% respectively. The 1- and 2-, 3-, 4-year overall survival rates were 53.3% and 35.6%, 35.6%, 35.6% respectively, with a median survival of 15 months (95% CI, 7.0-22.9). Mild brachial plexus injury was seen in one patient; grade 1 or 2 skin reactions were seen in 6 patients (30%) who had received external beam radiation therapy (EBRT) before. No grade 3 and 4 skin side effects were found. Rib fracture, ulceration, pneumothorax or hemopneumothorax were not seen. Interstitial permanent implantation of 125I seeds under CT guidance is feasible, efficacious and safe for refractory CW metastasis or recurrence.

  14. Preventive effects of 125I seeds on benign restenosis following esophageal stent implantation in a dog model

    PubMed Central

    GAN, ZHEN; JING, JIAN; ZHU, GUANGYU; QIN, YONGLIN; TENG, GAOJUN; GUO, JINHE

    2015-01-01

    The present study aimed to evaluate the effects of iodine-125 (125I) seeds on the proliferation of primary esophageal fibroblasts in dogs, and to assess the safety and preventive efficacy of 125I seed-pre-loaded esophageal stents in benign restenosis following implantation. Primary fibroblasts were cultured with various 125I seed activities, which were then evaluated using cell proliferation and apoptosis assays as well as cell cycle analysis using Annexin V/propidium iodide (PI) double staining and PI staining. Prior to sacrification, animals were submitted to esophageal radiography under digital subtraction angiography. Esophageal tissues were collected and examined for macroscopic, microscopic and pathological alterations. The results demonstrated a significant and dose-dependent inhibition of fibroblast proliferation and increased apoptosis following exposure to 125I seeds. G0/G1 fibroblast populations increased in a dose-dependent manner following treatment with 125I seeds, in contrast to cells in S phase. Four weeks following implantation, α-smooth muscle actin and proliferating cell nuclear antigen expression levels in the experimental group were significantly lower compared with those in the control group; in addition, eight weeks following implantation, esophageal inner diameters were increased in the experimental group. 125I seeds inhibited proliferation of dog esophageal fibroblasts via cell cycle arrest and apoptosis. In conclusion, 125I seed-pre-loaded esophageal stents inhibited benign hyperplasia in the upper edge of the stent to a certain extent, which relieved benign restenosis following implantation with a good safety profile. PMID:25543838

  15. Effects of gold and silver backings on the dose rate around an 125I seed.

    PubMed

    Cygler, J; Szanto, J; Soubra, M; Rogers, D W

    1990-01-01

    Measurements of the effect of either gold or silver backing on the dose rate around an 125I seed were performed using a Therados RFA7 dosimetry system and a small diode detector which was 2.5 mm in diameter and 0.06 mm thick. It was found that the presence of the gold or silver backing modifies the diode response on the side of the 125I seed away from the backing. The effect depends on the backing material and the distance from the seed. There is a small increase close to the gold backing but a decrease further away. This decrease at distances greater than 10 mm from the seed is uniformly 10%, the same as found when the seed is backed by air. There is an increase of up to 25% observed with silver backing the seed and this increase remains significant more than 30 mm from the seed. When the response increases, the results are hard to interpret quantitatively because of variations in the diode response per unit dose with photon energy and extreme sensitivity to geometric changes. Nonetheless, except for the increase at close distances with the gold, the results are in agreement with EGS4 Monte Carlo photon transport simulations which are for a simplified geometry and account for x-ray fluorescence from the K-shell. Furthermore, the increase in the gold-backed case is qualitatively explained by Williamson's Monte Carlo calculations which take into account the L-shell fluorescent x-rays from gold.

  16. The effect of lead, gold, and silver backings on dose near 125I seeds.

    PubMed

    Meli, J A; Motakabbir, K A

    1993-01-01

    Brachytherapy for ocular melanoma uses 125I seeds backed by a gold shield. Conflicting results are reported in the literature on the effect of the gold on dose close to the seeds. In this work, a small lucite jig was constructed such that the seed-to-detector separation remained fixed as high-Z materials of lead, silver, and gold were moved in and out of position behind the seed. The jig was clamped in place in the water filled tank of a beam scanning system. The response of two p-type silicon diodes was measured at several distances from the seed with and without the high-Z backings. The response with the high-Z backing relative to water, found to be the same for each diode and the same for lead and gold, decreased from about 1.01 at 1.5 mm to about 0.92 at 20 mm. It has been suggested in the literature that L-shell fluorescent x rays of approximately 10 keV from the gold backing might contribute significantly to the dose within 7 mm of the seed. To test this, the response with the gold backing relative to water was measured with an aluminum cap of 1-mm wall thickness covering the diode. The cap transmits about 70% of the 125I influence but is essentially infinitely thick to 10-keV photons. The relative response (gold/water) was the same with and without the cap showing that the contribution of 10-keV x rays is negligible. Compared to water, the silver backing was found to enhance the diode response by about 14% between 5 to 10 mm from the seed.

  17. Effect of pedicle fixation combined with 125I seed implantation for metastatic thoracolumbar tumors

    PubMed Central

    Qian, Jiale; Bao, Zhaohua; Zou, Jun; Yang, Huilin

    2016-01-01

    Purpose The aim of this study was to investigate the clinical efficacy of pedicle fixation combined with 125I brachytherapy in treating metastatic thoracolumbar tumors. Patients and methods A retrospective analysis of the clinical data of seven metastatic thoracolumbar tumor patients who received pedicle fixation combined with radioactive 125I seed implantation brachytherapy in our department between January 2009 and December 2013 was performed. The visual analog scale (VAS) for pain and the Karnofsky performance status (KPS) score before the operation and 1, 6, and 12 months after the operation were observed and recorded. The changes in the scores at each time point were compared. Results All the patients underwent a successful operation, without any complications during their hospitalization. All the patients received postoperative follow-up, and the duration of follow-up was 15–50 months, with an average of 32.2 months. One pancreatic cancer patient died of liver failure and hypoproteinemia 28 months post surgery. The VAS scores of patients before the operation and 1, 6, and 12 months after the operation were 7.43±0.98, 2.71±0.49, 3.00±0.82, and 4.29±0.98, respectively; the KPS scores were 52.9±9.5, 84.3±5.3, 75.7±5.3, and 72.9±4.9, respectively. These results suggest that the VAS score at each time point was significantly decreased compared with that before the operation, while the KPS score was significantly increased compared with that before the operation. Both differences had statistical significance (P<0.05). Conclusion As a therapy for advanced malignant tumors with thoracolumbar metastasis, pedicle fixation combined with 125I brachytherapy can effectively relieve short-term pain and improve patient’s quality of life. PMID:27274307

  18. New National Air-Kerma-Strength Standards for (125)I and (103)Pd Brachytherapy Seeds.

    PubMed

    Seltzer, Stephen M; Lamperti, Paul J; Loevinger, Robert; Mitch, Michael G; Weaver, James T; Coursey, Bert M

    2003-01-01

    The new U.S. measurement standard for the air-kerma strength from low-energy photon-emitting brachytherapy seed sources is formally described in detail. This instrument-based standard was implemented on 1 January 1999, with its salient features and the implications of differences with the previous standard given only through a series of informal communications. The Wide-Angle Free-Air Chamber (WAFAC) is specially designed to realize air kerma from a single-seed source emitting photons with energies up to about 40 keV, and is now used to measure the wide variety of seeds used in prostate-cancer therapy that has appeared in the last few years. For the two (125)I seed models that have been subject to both the old and new standards, the new standard reduces the air-kerma strength by 10.3 %. This change is mainly due to the removal of the influence on the measurement of the Ti K x rays produced in the source encapsulation, a component with no clinical significance.

  19. Acute urinary morbidity after a permanent 125I implantation for localized prostate cancer.

    PubMed

    Ohga, Saiji; Nakamura, Katsumasa; Shioyama, Yoshiyuki; Tatsugami, Katsunori; Sasaki, Tomonari; Nonoshita, Takeshi; Yoshitake, Tadamasa; Asai, Kaori; Hirata, Hideki; Naito, Seiji; Honda, Hiroshi

    2014-11-01

    We evaluated the predictive factors of acute urinary morbidity (AUM) after prostate brachytherapy. From November 2005 to January 2007, 62 patients with localized prostate cancer were treated using brachytherapy. The (125)Iodine ((125)I) seed-delivering method was a modified peripheral pattern. The prescribed dose was 144 Gy. Urinary morbidity was scored at 3 months after implantation. The clinical and treatment parameters were analysed for correlation with AUM. In particular, in this study, Du90 (the minimal dose received by 90% of the urethra), Dup90 (the minimal dose received by 90% of the proximal half of the urethra on the bladder side) and Dud90 (the minimal dose received by 90% of the distal half of the urethra on the penile side) were analysed. We found that 43 patients (69.4%) experienced acute urinary symptoms at 3 months after implantation. Of them, 40 patients had Grade 1 AUM, one patient had Grade 2 pain, and two patients had Grade 2 urinary frequency. None of the patients had ≥Grade 3. Univariate and multivariate analysis revealed that Du90 and Dup90 were significantly correlated with AUM. In this study, Du90 and Dup90 were the most significant predictors of AUM after prostate brachytherapy.

  20. Radiofrequency ablation versus 125I-seed brachytherapy for painful metastases involving the bone

    PubMed Central

    Jiao, Dechao; Wu, Gang; Ren, Jianzhuang; Han, Xinwei

    2016-01-01

    This retrospective study aimed to demonstrate and compare the safety and effectiveness of computed tomography-guided radiofrequency ablation (RFA) and 125I-seed brachytherapy for painful bone metastases after failure of external beam radiotherapy (EBRT). From June 2013 to October 2015, 79 patients with moderate-to-severe pain caused by metastatic bone lesions who underwent either RFA (n = 41) or 125I-seed brachytherapy (n = 38) were enrolled. Pain in patients was measured using the brief pain inventory (BPI) before treatment, 1 week after treatment, and 3 months after treatment. Response rates were assessed by measuring the changes in pain and incorporation of changes in the analgesic requirements. At baseline, 1 week, and 3 months, the mean worst pain scores of BPI were 7.8, 5.4, and 2.7, respectively, for the RFA group and 7.7, 6.1, and 2.8, respectively, for the brachytherapy group. At 1 week, the complete and partial response rates were 12% and 59%, respectively, in the RFA group compared with 3% and 45%, respectively, in the brachytherapy group. At 3 months, the complete and partial response rates were 23% and 58%, respectively, in the RFA group compared with 24% and 52% in the brachytherapy group (p = 0.95). The response rates in the RFA group were significantly higher than those in the brachytherapy group at 1 week (p = 0.32), but comparable at 3 weeks (p = 0.95). Both groups had low rates of complications and no treatment-related mortality. In conclusion, the short-term curative efficiency of RFA was better than that of brachytherapy, but the log-term efficiency of both treatments was equal. PMID:27636995

  1. Monte Carlo dosimetry for {sup 125}I and {sup 103}Pd eye plaque brachytherapy with various seed models

    SciTech Connect

    Thomson, R. M.; Rogers, D. W. O.

    2010-01-15

    Purpose: Dose distributions are calculated for various models of {sup 125}I and {sup 103}Pd seeds in the standardized plaques of the Collaborative Ocular Melanoma Study (COMS). The sensitivity to seed model of dose distributions and dose distributions relative to TG-43 are investigated. Methods: Monte Carlo simulations are carried out with the EGSnrc user-code BrachyDose. Brachytherapy seeds and eye plaques are fully modeled. Simulations of one seed in the central slot of a 20 mm Modulay (gold alloy) plaque backing with and without the Silastic (silicone polymer) insert and of a 16 mm fully loaded Modulay/Silastic plaque are performed. Dose distributions are compared to those calculated under TG-43 assumptions, i.e., ignoring the effects of the plaque backing and insert and interseed attenuation. Three-dimensional dose distributions for different {sup 125}I and {sup 103}Pd seed models are compared via depth-dose curves, isodose contours, and tabulation of doses at points of interest in the eye. Results are compared to those of our recent BrachyDose study for COMS plaques containing model 6711 ({sup 125}I) or 200 ({sup 103}Pd) seeds [R. M. Thomson et al., Med. Phys. 35, 5530-5543 (2008)]. Results: Along the central axis of a plaque containing one seed, variations of less than 1% are seen in the effect of the Modulay backing alone for different seed models; for the Modulay/Silastic combination, variations are 2%. For a 16 mm plaque fully loaded with {sup 125}I ({sup 103}Pd) seeds, dose decreases relative to TG-43 doses are 11%-12% (19%-20%) and 14%-15% (20%) at distances of 0.5 and 1 cm from the inner sclera along the plaque's central axis, respectively. For the same prescription dose, doses at points of interest vary by up to 8% with seed model. Doses to critical normal structures are lower for all {sup 103}Pd seed models than for {sup 125}I with the possible exception of the sclera adjacent to the plaque; scleral doses vary with seed model and are not always higher

  2. Clinical research on the treatment effects of radioactive (125)I seeds interstitial brachytherapy on children with primary orbital rhabdomyosarcoma.

    PubMed

    Ge, Xin; Ma, Jianmin; Dai, Haojie; Ren, Ling; Li, Quan; Shi, Jitong

    2014-09-01

    Rhabdomyosarcoma (RMS) is one of the most common primary orbital malignancies. However, orbital RMS is a very rare disease, especially in childhood, and the tumor has a high degree of malignancy and rapid development. The objective of the present study was to investigate the clinical treatment effects of radioactive (125)I seeds interstitial brachytherapy on children with primary orbital RMS, which may provide a new method for treating RMS in clinical applications. Radioactive (125)I seeds were used in the present study. Primary lesions from ten children with orbital RMS, including three male and seven female patients, were selected as the targeted areas. The activity, number and spatial location of the seeds were optimized and simulated by applying computer three-dimensional treatment planning system (TPS) software. The interstitial implantation of the radioactive (125)I seeds was conducted on children under general anesthesia according to the TPS simulation results. Quality verifications of the operation were conducted by orbital computed tomography and X-ray plain film at the early stage after operation, and the children were followed up. The patients were followed up by October 2012 with an average follow-up time of 57 ± 17.43 months and a median follow-up time of 55 months. Nine cases achieved complete remission, and one case achieved partial remission, resulting in a total efficiency and survival rate of 100.0 % (10/10). Most patients recovered after treatment or had no radiotherapy side effect after the operations, though 20.0 % of the patients (2/10) experienced corneal opacity, eyeball movement disorder, or loss of sight. Radioactive (125)I seeds interstitial brachytherapy was an effective treatment for children with primary orbital RMS. Results from this study may provide a new clinical approach for the treatment of child patients with primary orbital RMS.

  3. Autoradiographic localization of (/sup 125/I)-angiotensin II binding sites in the rat adrenal gland

    SciTech Connect

    Healy, D.P.; Maciejewski, A.R.; Printz, M.P.

    1985-03-01

    To gain greater insight into sites of action of circulating angiotensin II (Ang II) within the adrenal, we have localized the (/sup 125/I)-Ang II binding site using in vitro autoradiography. Autoradiograms were generated either by apposition of isotope-sensitive film or with emulsion-coated coverslips to slide-mounted adrenal sections labeled in vitro with 1.0 nM (/sup 125/I)-Ang II. Analysis of the autoradiograms showed that Ang II binding sites were concentrated in a thin band in the outer cortex (over the cells of the zona glomerulosa) and in the adrenal medulla, which at higher power was seen as dense patches. Few sites were evident in the inner cortex. The existence of Ang II binding sites in the adrenal medulla was confirmed by conventional homogenate binding techniques which revealed a single class of high affinity Ang II binding site (K/sub d/ . 0.7nM, B/sub max/ . 168.7 fmol/mg). These results suggest that the adrenal medulla may be a target for direct receptor-mediated actions of Ang II.

  4. The use of new GAFCHROMIC EBT film for {sup 125}I seed dosimetry in Solid Water phantom

    SciTech Connect

    Chiu-Tsao, Sou-Tung; Medich, David; Munro, John III

    2008-08-15

    Radiochromic film dosimetry has been extensively used for intravascular brachytherapy applications for near field within 1 cm from the sources. With the recent introduction of new model of radiochromic films, GAFCHROMIC EBT, with higher sensitivity than earlier models, it is promising to extend the distances out to 5 cm for low dose rate (LDR) source dosimetry. In this study, the use of new model GAFCHROMIC EBT film for {sup 125}I seed dosimetry in Solid Water was evaluated for radial distances from 0.06 cm out to 5 cm. A multiple film technique was employed for four {sup 125}I seeds (Implant Sciences model 3500) with NIST traceable air kerma strengths. Each experimental film was positioned in contact with a {sup 125}I seed in a Solid Water phantom. The products of the air kerma strength and exposure time ranged from 8 to 3158 U-h, with the initial air kerma strength of 6 U in a series of 25 experiments. A set of 25 calibration films each was sequentially exposed to one {sup 125}I seed at about 0.58 cm distance for doses from 0.1 to 33 Gy. A CCD camera based microdensitometer, with interchangeable green (520 nm) and red (665 nm) light boxes, was used to scan all the films with 0.2 mm pixel resolution. The dose to each {sup 125}I calibration film center was calculated using the air kerma strength of the seed (incorporating decay), exposure time, distance from seed center to film center, and TG43U1S1 recommended dosimetric parameters. Based on the established calibration curve, dose conversion from net optical density was achieved for each light source. The dose rate constant was determined as 0.991 cGy U{sup -1} h{sup -1} ({+-}6.9%) and 1.014 cGy U{sup -1} h{sup -1} ({+-}6.8%) from films scanned using green and red light sources, respectively. The difference between these two values was within the uncertainty of the measurement. Radial dose function and 2D anisotropy function were also determined. The results obtained using the two light sources corroborated each

  5. Ejaculatory Function After Permanent {sup 125}I Prostate Brachytherapy for Localized Prostate Cancer

    SciTech Connect

    Huyghe, Eric Delannes, Martine; Wagner, Fabien M.; Delaunay, Boris; Nohra, Joe; Thoulouzan, Matthieu; Shut-Yee, J. Yeung; Plante, Pierre; Soulie, Michel; Thonneau, Patrick; Bachaud, Jean Marc

    2009-05-01

    Purpose: Ejaculatory function is an underreported aspect of male sexuality in men treated for prostate cancer. We conducted the first detailed analysis of ejaculatory function in patients treated with permanent {sup 125}I prostate brachytherapy for localized prostate cancer. Patients and Methods: Of 270 sexually active men with localized prostate cancer treated with permanent {sup 125}I prostate brachytherapy, 241 (89%), with a mean age of 65 years (range, 43-80), responded to a mailed questionnaire derived from the Male Sexual Health Questionnaire regarding ejaculatory function. Five aspects of ejaculatory function were examined: frequency, volume, dry ejaculation, pleasure, and pain. Results: Of the 241 sexually active men, 81.3% had conserved ejaculatory function after prostate brachytherapy; however, the number of patients with rare/absent ejaculatory function was double the pretreatment number (p < .0001). The latter finding was correlated with age (p < .001) and the preimplant International Index of Erectile Function score (p < .001). However, 84.9% of patients with maintained ejaculatory function after implantation reported a reduced volume of ejaculate compared with 26.9% before (p < .001), with dry ejaculation accounting for 18.7% of these cases. After treatment, 30.3% of the patients experienced painful ejaculation compared with 12.9% before (p = .0001), and this was associated with a greater number of implanted needles (p = .021) and the existence of painful ejaculation before implantation (p < .0001). After implantation, 10% of patients who continued to be sexually active experienced no orgasm compared with only 1% before treatment. in addition, more patients experienced late/difficult or weak orgasms (p = .001). Conclusion: Most men treated with brachytherapy have conserved ejaculatory function after prostate brachytherapy. However, most of these men experience a reduction in volume and a deterioration in orgasm.

  6. Calibration of the NPL secondary standard radionuclide calibrator for 125I seeds used for prostate brachytherapy. National Physical Laboratory.

    PubMed

    Baker, M; Bass, G A; Woods, M J

    2002-01-01

    In the therapeutic use of radionuclides, by far the most rapid growth in recent years is that of 125I seeds used for the treatment of prostate cancer. Large numbers of these seeds are used in each treatment and there is a need for a simple but accurate means of confirming their dose rates. This mechanism requires a transfer device for which the calibration factors are traceable to national standards. The NPL secondary standard radionuclide calibrator, because of its guaranteed reproducibility and traceable calibration procedure, is ideally suited for this purpose. A series of characterisation measurements have been performed on the NPL radionuclide calibrator in order to estimate the uncertainty levels that can be achieved and these are presented together with the relevant calibration factors for some typical seeds.

  7. 125I Seeds Radiation Induces Paraptosis-Like Cell Death via PI3K/AKT Signaling Pathway in HCT116 Cells

    PubMed Central

    Hu, Lelin; Wang, Hao; Zhao, Yong

    2016-01-01

    125I seeds brachytherapy implantation has been extensively performed in unresectable and rerecurrent rectal carcinoma. Many studies on the cancer-killing activity of 125I seeds radiation mainly focused on its ability to trigger apoptosis, which is the most well-known and dominant type of cell death induced by radiation. However our results showed some unique morphological features such as cell swelling, cytoplasmic vacuolation, and plasma membrane integrity, which is obviously different to apoptosis. In this study, clonogenic proliferation was carried out to assay survival fraction. Transmission electron microscopy was used to analyze ultrastructural and evaluate morphologic feature of HCT116 cells after exposure to 125I seeds radiation. Immunofluorescence analysis was used to detect the origin of cytoplasmic vacuoles. Flow cytometry analysis was employed to detect the size and granularity of HCT116 cells. Western blot was performed to measure the protein level of AIP1, caspase-3, AKT, p-Akt (Thr308), p-Akt (Ser473), and β-actin. We found that 125I seeds radiation activated PI3K/AKT signaling pathway and could trigger paraptosis-like cell death. Moreover, inhibitor of PI3K/AKT signaling pathway could inhibit paraptosis-like cell death induced by 125I seeds radiation. Our data suggest that 125I seeds radiation can induce paraptosis-like cell death via PI3K/AKT signaling pathway. PMID:28078301

  8. Polymer gel dosimetry for the TG-43 dosimetric characterization of a new 125I interstitial brachytherapy seed.

    PubMed

    Papagiannis, P; Pantelis, E; Georgiou, E; Karaiskos, P; Angelopoulos, A; Sakelliou, L; Stiliaris, S; Baltas, D; Seimenis, I

    2006-04-21

    In this work, a polymer gel-magnetic resonance (MR) imaging method is employed for the dosimetric characterization of a new 125I low dose rate seed (IsoSeed model I25.S17). Two vials filled with PABIG gel were prepared in-house and one new seed as well as one commercially available 125I seed of similar dose rate and well-known dosimetric parameters (IsoSeed model I25.S06) were positioned in each vial. Both seeds in each vial were MR scanned simultaneously on days 11 and 26 after implantation. The data obtained from the known seed in each vial are used to calibrate the gel dose response which, for the prolonged irradiation duration necessitated by the investigated dose rates, depends on the overall irradiation time. Data for this study are presented according to the AAPM TG-43 dosimetric formalism. Polymer gel results concerning the new seed are compared to corresponding, published dosimetric results obtained, for the purpose of the new seed clinical implementation, by our group using the established methods of Monte Carlo (MC) simulation and thermo-luminescence dosimetry (TLD). Polymer gel dosimetry yields an average dose rate constant value of lambda = (0.921 +/- 0.031) cGy h(-1) U(-1) relative to (MC)lambda = (0.929 +/- 0.014) cGy h(-1) U(-1), (TLD)lambda = (0.951 +/- 0.044) cGy h(-1) U(-1) and the average value of Lambda = (0.940 +/- 0.051) cGy h(-1) U(-1) proposed for the clinical implementation of the new seed. Results for radial dose function, g(L)(r), and anisotropy function, F(r, theta), also agree with corresponding MC calculations within experimental uncertainties which are smaller for the polymer gel method compared to TLD. It is concluded that the proposed polymer gel-magnetic resonance imaging methodology could be used at least as a supplement to the established techniques for the dosimetric characterization of new low energy and low dose rate interstitial brachytherapy seeds.

  9. /sup 125/I implants as an adjuvant to surgery and external beam radiotherapy in the management of locally advanced head and neck cancer

    SciTech Connect

    Martinez, A.; Goffinet, D.R.; Fee, W.; Goode, R.; Cox, R.S.

    1983-03-15

    /sup 125/I seeds either individually placed or inserted into absorbable Vicryl suture carriers were utilized in conjunction with surgery and external beam radiotherapy in an attempt to increase local control rates in patients with advanced oropharyngeal and laryngopharyngeal cancers (T3-T4, N2-N3), massive cervical lymphadenopathy (N3) and an unknown primary site and locally recurrent head and neck cancers. Forty-eight patients were treated with 55 implants. The carotid artery was implanted in 15 patients, while seven patients had seeds inserted into the base of the skull region, and another three patients had implants near cranial nerves. Eighteen of the 48 patients were treated for cure. The actuarial survival at five years in this subgroup was 50%. The overall local control in the head and neck area was 58%. In this group no patients to date have had a local failure in the implanted volume. Seventeen patients with comparable stage of disease treated prior to 1974 with curative intent without /sup 125/I implants were analyzed retrospectively for comparison with the implanted patients. The actuarial survival of these patients was 18% and the overall head and neck control was 21%. These differences are statistically significant at a P value of 0.01 and 0.007, respectively. Seventeen patients received implants for local recurrence. The local control in the head and neck area was 50%; however, the 2.5 year actuarial survival was only 17%. The complication rate was 11% (six of 55 implants). The improved survival, the high local control, and the minimal complication rates in this series makes the intraoperative implantation of /sup 125/I seeds and effective adjunctive treatment to surgery and external beam irradiation.

  10. Characteristics and autoradiographic localization of 2-( sup 125 I)iodomelatonin binding sites in Djungarian hamster brain

    SciTech Connect

    Duncan, M.J.; Takahashi, J.S.; Dubocovich, M.L. )

    1989-08-01

    These studies investigated the characteristics and regional distribution of 2-({sup 125}I)iodomelatonin binding in Djungarian hamster brain. The results showed that 2-({sup 125}I)iodomelatonin labels two types of binding sites, which resemble the ML-1 and ML-2 melatonin subtypes previously described in other tissues. The 2-({sup 125}I)iodomelatonin binding site identified in whole brain membranes has a nanomolar affinity (Kd = 1.48 +/- 0.26 nM) and biochemical and pharmacological characteristics identical to those of the ML-2 site of Syrian hamster whole brain. The 2-({sup 125}I)iodomelatonin site in the hypothalamus has a picomolar affinity (Kd = 43.4 +/- 5.1 pM) and resembles the ML-1 site of chicken retina. The localization of 2-({sup 125}I)iodomelatonin labeling in autoradiographic studies of the Djungarian hamster brain includes the suprachiasmatic nuclei, the median eminence, the reuniens nucleus, and the paraventricular nucleus of the thalamus.

  11. Sequential Comparison of Seed Loss and Prostate Dosimetry of Stranded Seeds With Loose Seeds in {sup 125}I Permanent Implant for Low-Risk Prostate Cancer

    SciTech Connect

    Saibishkumar, Elantholi P.; Borg, Jette; Yeung, Ivan; Cummins-Holder, Cheryl; Landon, Angela; Crook, Juanita

    2009-01-01

    Purpose: To compare stranded seeds (SSs) with loose seeds (LSs) in terms of prostate edema, dosimetry, and seed loss after {sup 125}I brachytherapy. Methods and Materials: Two prospective cohorts of 20 men participated in an institutional review board-approved protocols to study postimplant prostate edema and its effect on dosimetry. The LS cohort underwent brachytherapy between September 2002 and July 2003 and the SS cohort between April 2006 and January 2007. Both cohorts were evaluated sequentially using computed tomography-magnetic resonance imaging fusion-based dosimetry on Days 0, 7, and 30. No hormonal therapy or supplemental beam radiotherapy was used. Results: Prostate edema was less in the SS cohort at all points (p = NS). On Day 0, all the prostate dosimetric factors were greater in the LS group than in the SS group (p = 0.003). However, by Days 7 and 30, the dosimetry was similar between the two cohorts. No seeds migrated to the lung in the SS cohort compared with a total of five seeds in 4 patients in the LS cohort. However, the overall seed loss was greater in the SS cohort (24 seeds in 6 patients; 1.1% of total vs. 0.6% for LSs), with most seeds lost through urine (22 seeds in 5 patients). Conclusion: Despite elimination of venous seed migration, greater seed loss was observed with SSs compared with LSs, with the primary site of loss being the urinary tract. Modification of the technique might be necessary to minimize this. Prostate dosimetry on Days 7 and 30 was similar between the SS and LS cohorts.

  12. Monte Carlo and thermoluminescence dosimetry of the new IsoSeed registered model I25.S17 {sup 125}I interstitial brachytherapy seed

    SciTech Connect

    Lymperopoulou, G.; Papagiannis, P.; Sakelliou, L.; Karaiskos, P.; Sandilos, P.; Przykutta, A.; Baltas, D.

    2005-11-15

    Monte Carlo simulation and experimental thermoluminescence dosimetry were utilized for the dosimetric characterization of the new IsoSeed registered model I25.S17 {sup 125}I interstitial brachytherapy seed. The new seed design is similar to that of the selectSeed and 6711 seeds, with the exception of its molybdenum marker. Full dosimetric data are presented following the recommendations in the Update of the AAPM Task Group 43 report (TG-43U1). A difference of 3.3% was found between Monte Carlo dose rate constant results calculated by air kerma strengths from simulations using a point detector and a detector resembling the solid angle subtended to the seed by the Wide Angle Free Air Chamber (WAFAC) in the primary standard calibration geometry. Following the TG-43U1 recommendations, an average value of {lambda}{sub MC}=(0.929{+-}0.014) cGy h{sup -1} U{sup -1} was adopted for the new seed. This value was then averaged with the measured value of {lambda}{sub EXP}=(0.951{+-}0.044) cGy h{sup -1} U{sup -1} to yield the proposed dose rate constant for the new seed that is equal to {lambda}=(0.940{+-}0.051) cGy h{sup -1} U{sup -1}. The Monte Carlo calculated radial dose function and two-dimensional (2-D) anisotropy function results for the new seed were found in agreement with experimental results to within statistical uncertainty of repeated measurements. Monte Carlo simulations were also performed for {sup 125}I seeds of similar geometry and dimensions for the purpose of comparison. The new seed presents dosimetric characteristics that are very similar to that of the selectSeed. In comparison to the most extensively studied Amersham 6711 seed, the new one presents similar dosimetric characteristics with a slightly reduced dose rate constant (1.5%)

  13. Comparison of permanent 125I seeds implants with two different techniques in 500 cases of prostate cancer

    PubMed Central

    Ricós, Jose Vicente; Tortajada, Maria Isabel; Santos, Miguel Angel; Casanova, Juan; Clemente, Jose; Samper, Josefa; Santamaría, Paula; Arribas, Leoncio

    2015-01-01

    Purpose To perform a comparative study of 500 consecutive 125I seeds implants for intracapsular prostate carcinoma with two techniques differing in terms of both strand implantation and planning. Material and methods From 2002 to 2007 we performed 250 implants with fixed stranded seeds (RapidStrand™) and a preplanning system and from 2007 to 2010, 250 with real-time and ProLink™ system. Mean age was 68 and 66, respectively, median PSA (prostate-specific antigen) 7.3 and 7.2, stage T1-T2a in 98% and 94%, and Gleason ≤ 6 in 96% and 86%. Low risk cases were 81% and 71%. The prescribed dose was 145 Gy to the prostate volume, or 108 Gy plus EBRT 46 Gy in some intermediate risk cases. Hormonal treatment was given to 42% and 28%. Results Median follow-up was 48 and 47 months, respectively, 14 patients in the first group and 7 patients in the second developed biochemical failure (BF). Actuarial biochemical relapse-free survival (bRFS) at 5 years increased from 90.2% to 97.2% (low risk from 91.3% to 97.2%, intermediate risk from 84.2% to 97.1%). Biochemical failure was independent of hormone treatment. Rectal complications were G1-2 in 1.2% and 5.2%, respectively. A urinary catheter was necessary in 6.9% and 9.6%, and urethral resection in 1.9% and 4.4%. Genitourinary toxicity was G1-2 in 4.6% and 12%, G3-4 in 1.9% and 4.8%. An assessment of mean D90 in a sample of patients showed that the dosimetry in postoperative planning based on CT improved from a mean D90 of 143 Gy to 157 Gy. Conclusions The outcome of patients with low risk prostate carcinoma treated with 125I seed is very good with low complications rate. The real-time approach in our hands achieved a more precise seed implantation, better dosimetry, and a statistically non-significant better biochemical control. We have made this our standard technique. PMID:26622228

  14. Y-configured metallic stent combined with 125I seed strands cavity brachytherapy for a patient with type IV Klatskin tumor

    PubMed Central

    Dechao, Jiao; Yanli, Wang; Zhen, Li

    2016-01-01

    We report a case in an inoperable patient with type IV Klatskin tumor treated by the use of a novel, two piece, Y-configured self-expandable metallic stent (SEMS) combined with two 125I seed strands via bilateral approach. The placement of the Y-shaped SEMS was successful and resulted in adequate biliary drainage. After 2 months of intraluminal brachytherapy (ILBT), both 125I seed strands and temporary drainage catheter were removed after patency of the expanded stents was confirmed by the cholangiogram. This technique was feasible and could be considered for the treatment of patients with Bismuth type IV Klatskin tumors. PMID:27648091

  15. Autoradiographic localization of (/sup 125/I-Tyr4)bombesin-binding sites in rat brain

    SciTech Connect

    Zarbin, M.A.; Kuhar, M.J.; O'Donohue, T.L.; Wolf, S.S.; Moody, T.W.

    1985-02-01

    The binding of (/sup 125/I-Tyr/sub 4/)bombesin to rat brain slices was investigated. Radiolabeled (Tyr/sub 4/)bombesin bound with high affinity (K/sub d/ . 4 nM) to a single class of sites (B/sub max/ . 130 fmol/mg of protein); the ratio of specific to nonspecific binding was 6/1. Also, pharmacology studies indicated that the C-terminal of bombesin was important for the high affinity binding activity. Autoradiographic studies indicated that the (/sup 125/I-Tyr4)bombesin-binding sites were discretely distributed in certain gray but not white matter regions of rat brain. Highest grain densities were present in the olfactory bulb and tubercle, nucleus accumbens, suprachiasmatic and periventricular nuclei of the hypothalamus, central medial thalamic nucleus, medial amygdaloid nucleus, hippocampus, dentate gyrus, subiculum, nucleus of the solitary tract, and substantia gelatinosa. Moderate grain densities were present in the parietal cortex, deep layers of the neocortex, rhinal cortex, caudate putamen, stria terminalis, locus ceruleus, parabrachial nucleus, and facial nucleus. Low grain densities were present in the globus pallidus, lateral thalamus, and midbrain. Negligible grain densities were present in the cerebellum, corpus callosum, and all regions treated with 1 microM unlabeled bombesin. The discrete regional distribution of binding suggests that endogenous bombesin-like peptides may function as important regulatory agents in certain brain loci.

  16. [CT guidance (125)I seed implantation for pelvic recurrent rectal cancer assisted by 3D printing individual non-coplanar template].

    PubMed

    Wang, H; Wang, J J; Jiang, Y L; Tian, S Q; Ji, Z; Guo, F X; Sun, H T; Fan, J H; Xu, Y P

    2016-12-20

    Objective: To analyze the difference of dosimetric parameters between pre-plan and post-plan of (125)I radioactive seed implantation assisted by 3D printing individual non-coplanar template (3D printing template) for locally recurrent rectal cancer (LRRC). Methods: From February 2016 to April 2016, a total of 10 patients with locally recurrent rectal cancer received (125)I seeds implantation under CT guidance assisted by 3D printing template in Department of Radiation Oncology, Peking University Third Hospital.Each patient underwent CT simulation, three-dimentional treatment planning pre-implantation, 3D printing template design, radioactive seed implantation assisted by 3D printing template and dosimetric verification post implantation. The median activity of seed was 0.63 mCi (0.58 to 0.7 mCi) (2.15- 2.59×10(7) Bq), and the median number of seeds was 80 (19 to 192). D90, D100, V100, V150, CI, EI, HI, D5cc, D2cc of bladder and bowel of pre-plan and post-plan were calculated, respectively.Paired t test was used to evaluate the difference of dosimetric parameters between pre-plan and post-plan. Results: The median D90 of pre-plan and post-plan were 13 761.0 and 12 798.8 cGy, respectively.The median D100 of pre-plan and post-plan were 5 293.6 and 5 397.9 cGy, respectively.The median V100 of pre-plan and post-plan were 90.0% and 90.0%, respectively.The median V150 of pre-plan and post-plan were 63.8% and 62.4%, respectively.The median CI of pre-plan and post-plan were 0.73 and 0.67.The median EI of pre-plan and post-plan were 0.22 and 0.30, respectively. The median HI of pre-plan and post-plan were 0.29 and 0.31.The median bladder D2cc of pre-plan and post-plan were 3 088.8 and 4 240.4 cGy, respectively.The median bowel D2cc of pre-plan and post-plan were 7 051.6 and 7 903.9 cGy, respectively. Conclusions: 3D printing template might be helpful for locally recurrent rectal cancer patients who received (125)I radioactive seed implantation assisted by 3D printing

  17. Effect of improved TLD dosimetry on the determination of dose rate constants for {sup 125}I and {sup 103}Pd brachytherapy seeds

    SciTech Connect

    Rodriguez, M.; Rogers, D. W. O.

    2014-11-01

    Purpose: To more accurately account for the relative intrinsic energy dependence and relative absorbed-dose energy dependence of TLDs when used to measure dose rate constants (DRCs) for {sup 125}I and {sup 103}Pd brachytherapy seeds, to thereby establish revised “measured values” for all seeds and compare the revised values with Monte Carlo and consensus values. Methods: The relative absorbed-dose energy dependence, f{sup rel}, for TLDs and the phantom correction, P{sub phant}, are calculated for {sup 125}I and {sup 103}Pd seeds using the EGSnrc BrachyDose and DOSXYZnrc codes. The original energy dependence and phantom corrections applied to DRC measurements are replaced by calculated (f{sup rel}){sup −1} and P{sub phant} values for 24 different seed models. By comparing the modified measured DRCs to the MC values, an appropriate relative intrinsic energy dependence, k{sub bq}{sup rel}, is determined. The new P{sub phant} values and relative absorbed-dose sensitivities, S{sub AD}{sup rel}, calculated as the product of (f{sup rel}){sup −1} and (k{sub bq}{sup rel}){sup −1}, are used to individually revise the measured DRCs for comparison with Monte Carlo calculated values and TG-43U1 or TG-43U1S1 consensus values. Results: In general, f{sup rel} is sensitive to the energy spectra and models of the brachytherapy seeds. Values may vary up to 8.4% among {sup 125}I and {sup 103}Pd seed models and common TLD shapes. P{sub phant} values depend primarily on the isotope used. Deduced (k{sub bq}{sup rel}){sup −1} values are 1.074 ± 0.015 and 1.084 ± 0.026 for {sup 125}I and {sup 103}Pd seeds, respectively. For (1 mm){sup 3} chips, this implies an overall absorbed-dose sensitivity relative to {sup 60}Co or 6 MV calibrations of 1.51 ± 1% and 1.47 ± 2% for {sup 125}I and {sup 103}Pd seeds, respectively, as opposed to the widely used value of 1.41. Values of P{sub phant} calculated here have much lower statistical uncertainties than literature values, but

  18. Disease-related effects of perioperative blood transfusions associated with sup 125 I seed implantation for prostate carcinoma

    SciTech Connect

    Petersen, J.P.; Schellhammer, P.F.; el-Mahdi, A.M. )

    1990-08-01

    In some retrospective studies perioperative transfusions during oncologic surgery have been shown to decrease the time interval between surgery and local and/or distant recurrence of cancer. This study examines the disease-related effect, if any, of perioperative blood transfusions among 108 patients with localized carcinoma of the prostate treated by radioactive iodine-125 seed implantation of the prostate and lymphadenectomy. When all subjects were analyzed, there was no statistical difference of local and distant failure between the transfused and nontransfused groups. Patients with well-differentiated tumors had statistically fewer local recurrences (0% vs 22%, p = 0.036) if they were transfused perioperatively. However, the difference in distant metastases (0% vs 11%) was not statistically significant (p = 0.21). In contrast, patients with moderately and poorly differentiated disease receiving transfusions had more local recurrences and metastases, though this was not statistically significant. Our data suggest that there is no obvious evidence that perioperative blood transfusions have an adverse effect on local recurrence or distant metastases for iodine-125 seed implantation of carcinoma of the prostate.

  19. Evaluation of material heterogeneity dosimetric effects using radiochromic film for COMS eye plaques loaded with {sup 125}I seeds (model I25.S16)

    SciTech Connect

    Acar, Hilal; Chiu-Tsao, Sou-Tung; Oezbay, Ismail; Kemikler, Goenuel; Tuncer, Samuray

    2013-01-15

    Purpose: (1) To measure absolute dose distributions in eye phantom for COMS eye plaques with {sup 125}I seeds (model I25.S16) using radiochromic EBT film dosimetry. (2) To determine the dose correction function for calculations involving the TG-43 formalism to account for the presence of the COMS eye plaque using Monte Carlo (MC) method specific to this seed model. (3) To test the heterogeneous dose calculation accuracy of the new version of Plaque Simulator (v5.3.9) against the EBT film data for this seed model. Methods: Using EBT film, absolute doses were measured for {sup 125}I seeds (model I25.S16) in COMS eye plaques (1) along the plaque's central axis for (a) uniformly loaded plaques (14-20 mm in diameter) and (b) a 20 mm plaque with single seed, and (2) in off-axis direction at depths of 5 and 12 mm for all four plaque sizes. The EBT film calibration was performed at {sup 125}I photon energy. MC calculations using MCNP5 code for a single seed at the center of a 20 mm plaque in homogeneous water and polystyrene medium were performed. The heterogeneity dose correction function was determined from the MC calculations. These function values at various depths were entered into PS software (v5.3.9) to calculate the heterogeneous dose distributions for the uniformly loaded plaques (of all four sizes). The dose distributions with homogeneous water assumptions were also calculated using PS for comparison. The EBT film measured absolute dose rate values (film) were compared with those calculated using PS with homogeneous assumption (PS Homo) and heterogeneity correction (PS Hetero). The values of dose ratio (film/PS Homo) and (film/PS Hetero) were obtained. Results: The central axis depth dose rate values for a single seed in 20 mm plaque measured using EBT film and calculated with MCNP5 code (both in ploystyrene phantom) were compared, and agreement within 9% was found. The dose ratio (film/PS Homo) values were substantially lower than unity (mostly between 0.8 and 0

  20. Reversible and irreversible labeling and autoradiographic localization of the cerebral histamine H2 receptor using ( sup 125 I)iodinated probes

    SciTech Connect

    Ruat, M.; Traiffort, E.; Bouthenet, M.L.; Schwartz, J.C.; Hirschfeld, J.; Buschauer, A.; Schunack, W. )

    1990-03-01

    Iodoaminopotentidine (I-APT)--i.e., N-(2-(4-amino-3-iodobenzamido)ethyl)-N'-cyano-N''-(3-(3- (1-piperidinylmethyl)phenoxy)propyl)guanidine--represents one of the most potent H2-receptor antagonists known so far. In membranes of guinea pig brain 125I-APT bound reversibly, selectively, and with high affinity (Kd = 0.3 nM) to a homogeneous population of sites unambiguously identified as H2 receptors by inhibition studies conducted with a large panel of antagonists. 125I-APT binding was also inhibited by histamine, and the effect was modulated by a guanyl nucleotide, which is consistent with the association of the H2 receptor with a guanine nucleotide binding regulatory protein. The low nonspecific binding of 125I-APT generated high contrast autoradiographic pictures in brain sections and established the precise distribution of H2 receptors. Their highly heterogeneous distribution and laminated pattern in some areas suggest their major association with neuronal elements. These localizations were more consistent than those of H1 receptors with the distribution of histaminergic projections, indicating that H2 receptors mediate a larger number of postsynaptic actions of histamine--e.g., in striatum. Colocalizations of H1 and H2 receptors in some areas account for their known synergistic interactions in cAMP formation induced by histamine. The distribution of 125I-APT binding sites did not strictly parallel that of the H2-receptor-linked adenylate cyclase activity, which may reflect heterogeneity among H2 receptors. After UV irradiation and SDS/PAGE analysis, (125I)iodoazidopotentidine (125I-AZPT), a photoaffinity probe derived from 125I-APT, was covalently incorporated in several peptides, among which the labeling of two peptides of 59 and 32 kDa was prevented by H2 antagonists, suggesting that they correspond to H2-receptor binding peptides or proteolysis products of the latter.

  1. Autoradiographic localization of putative nicotinic receptors in the rat brain using sup 125 I-neuronal bungarotoxin

    SciTech Connect

    Schulz, D.W.; Loring, R.H.; Aizenman, E.; Zigmond, R.E. )

    1991-01-01

    Neuronal bungarotoxin (NBT), a snake venom neurotoxin, selectively blocks nicotinic receptors in many peripheral and central neuronal preparations. alpha-Bungarotoxin (alpha BT), on the other hand, a second toxin isolated from the venom of the same snake, is an ineffective nicotinic antagonist in most vertebrate neuronal preparations studied thus far. To examine central nicotinic receptors recognized by NBT, we have characterized the binding of 125I-labeled NBT (125I-NBT) to rat brain membranes and have mapped the distribution of 125I-NBT binding in brain sections using quantitative light microscopic autoradiography. The binding of 125I-NBT was found to be saturable, of high affinity, and heterogeneously distributed in the brain. Pharmacological studies suggested that more than one population of sites is labeled by 125I-NBT. For example, one component of 125I-NBT binding was also recognized by alpha BT, while a second component, not recognized by alpha BT, was recognized by the nicotinic agonist nicotine. The highest densities of these alpha BT-insensitive, nicotine-sensitive sites were found in the fasciculus retroflexus, the lateral geniculate nucleus, the medial terminal nucleus of the accessory optic tract, and the olivary pretectal nucleus. alpha BT-sensitive NBT binding sites were found in highest density in the lateral geniculate nucleus, the subthalamic nucleus, the dorsal tegmental nucleus, and the medial mammillary nucleus (lateral part). The number of brain regions with a high density of 125I-NBT binding sites, blocked either by alpha BT or by nicotine, is low when compared with results obtained using other approaches to studying the central distribution of nicotinic receptors, such as labeling with 3H-nicotine or labeling with cDNA probes to mRNAs coding for putative receptor subunits.

  2. Distribution of sup 125 I-neurotensin binding sites in human forebrain: Comparison with the localization of acetylcholinesterase

    SciTech Connect

    Szigethy, E.; Quirion, R.; Beaudet, A. )

    1990-07-22

    The distribution of 125I-neurotensin binding sites was compared with that of acetylcholinesterase reactivity in the human basal forebrain by using combined light microscopic radioautography/histochemistry. High 125I-neurotensin binding densities were observed in the bed nucleus of the stria terminalis, islands of Calleja, claustrum, olfactory tubercle, and central nucleus of the amygdala; lower levels were seen in the caudate, putamen, medial septum, diagonal band nucleus, and nucleus basalis of Meynert. Adjacent sections processed for cholinesterase histochemistry demonstrated a regional overlap between the distribution of labeled neurotensin binding sites and that of intense acetylcholinesterase staining in all of the above regions, except in the bed nucleus of the stria terminalis, claustrum, and central amygdaloid nucleus, where dense 125I-neurotensin labeling was detected over areas containing only weak to moderate cholinesterase staining. At higher magnification, 125I-neurotensin-labeled binding sites in the islands of Calleja, supraoptic nucleus of the hypothalamus, medial septum, diagonal band nucleus, and nucleus basalis of Meynert were selectively associated with neuronal perikarya found to be cholinesterase-positive in adjacent sections. Moderate 125I-neurotensin binding was also apparent over the cholinesterase-reactive neuropil of these latter three regions. These data suggest that neurotensin (NT) may directly influence the activity of magnocellular cholinergic neurons in the human basal forebrain, and may be involved in the physiopathology of dementing disorders such as Alzheimer's disease, in which these neurons have been shown to be affected.

  3. Assaying multiple 125I seeds with the well-ionization chamber SourceCheck4π 33005 and a new insert

    PubMed Central

    Ballester, Facundo; Perez-Calatayud, Jose; Vijande, Javier

    2015-01-01

    Purpose To provide a practical solution that can be adopted in clinical routine to fulfill the AAPM-ESTRO recommendations regarding quality assurance of seeds used in prostate permanent brachytherapy. The aim is to design a new insert for the well-ionization chamber SourceCheck4π 33005 (PTW, Germany) that allows evaluating the mean air-kerma strength of up to ten 125I seeds with one single measurement instead of measuring each seed individually. Material and methods The material required is: a) the SourceCheck4π 33005 well-ionization chamber provided with a PTW insert to measure the air-kerma strength S K of one single seed at a time; b) a newly designed insert that accommodates ten seeds in one column, which allows measuring the mean S K of the ten seeds in one single measurement; and c) a container with ten seeds from the same batch and class of the seeds used for the patient implant, and a set of nine non-radioactive seeds. The new insert is characterized by determining its calibration coefficient, used to convert the reading of the well-chamber when ten seeds are measured to their mean S K. The proposed method is validated by comparing the mean S K of the ten seeds obtained from the new insert with the individual measurement of S K of each seed, evaluated with the PTW insert. Results The ratio between the calibration coefficient of the new insert and the calibration coefficient of the PTW insert for the SourceCheck4π 33005 is 1.135 ± 0.007 (k = 1). The mean S K of a set of ten seeds evaluated with this new system is in agreement with the mean value obtained from measuring independently the S K of each seed. Conclusions The new insert and procedure allow evaluating the mean S K of ten seeds prior to the implant in a single measurement. The method is faster and more efficient from radiation protection point of view than measuring the individual S K of each seed. PMID:26816507

  4. A modern Monte Carlo investigation of the TG-43 dosimetry parameters for an {sup 125}I seed already having AAPM consensus data

    SciTech Connect

    Aryal, Prakash; Molloy, Janelle A.; Rivard, Mark J.

    2014-02-15

    Purpose: To investigate potential causes for differences in TG-43 brachytherapy dosimetry parameters in the existent literature for the model IAI-125A{sup 125}I seed and to propose new standard dosimetry parameters. Methods: The MCNP5 code was used for Monte Carlo (MC) simulations. Sensitivity of dose distributions, and subsequently TG-43 dosimetry parameters, was explored to reproduce historical methods upon which American Association of Physicists in Medicine (AAPM) consensus data are based. Twelve simulation conditions varying{sup 125}I coating thickness, coating mass density, photon interaction cross-section library, and photon emission spectrum were examined. Results: Varying{sup 125}I coating thickness, coating mass density, photon cross-section library, and photon emission spectrum for the model IAI-125A seed changed the dose-rate constant by up to 0.9%, about 1%, about 3%, and 3%, respectively, in comparison to the proposed standard value of 0.922 cGy h{sup −1} U{sup −1}. The dose-rate constant values by Solberg et al. [“Dosimetric parameters of three new solid core {sup 125}I brachytherapy sources,” J. Appl. Clin. Med. Phys. 3, 119–134 (2002)], Meigooni et al. [“Experimental and theoretical determination of dosimetric characteristics of IsoAid ADVANTAGE™ {sup 125}I brachytherapy source,” Med. Phys. 29, 2152–2158 (2002)], and Taylor and Rogers [“An EGSnrc Monte Carlo-calculated database of TG-43 parameters,” Med. Phys. 35, 4228–4241 (2008)] for the model IAI-125A seed and Kennedy et al. [“Experimental and Monte Carlo determination of the TG-43 dosimetric parameters for the model 9011 THINSeed™ brachytherapy source,” Med. Phys. 37, 1681–1688 (2010)] for the model 6711 seed were +4.3% (0.962 cGy h{sup −1} U{sup −1}), +6.2% (0.98 cGy h{sup −1} U{sup −1}), +0.3% (0.925 cGy h{sup −1} U{sup −1}), and −0.2% (0.921 cGy h{sup −1} U{sup −1}), respectively, in comparison to the proposed standard

  5. 125I brachytherapy of locally advanced non-small-cell lung cancer after one cycle of first-line chemotherapy: a comparison with best supportive care

    PubMed Central

    Song, Jingjing; Fan, Xiaoxi; Zhao, Zhongwei; Chen, Minjiang; Chen, Weiqian; Wu, Fazong; Zhang, Dengke; Chen, Li; Tu, Jianfei; Ji, Jiansong

    2017-01-01

    Objectives The objective of this study was to assess the efficacy of computed tomography (CT)-guided 125I brachytherapy alone in improving the survival and quality of life of patients with unresectable locally advanced non-small-cell lung cancer (NSCLC) after one cycle of first-line chemotherapy. Patients and methods Sixteen patients with locally advanced NSCLC were treated with CT-guided 125I brachytherapy after one cycle of first-line chemotherapy (group A). Sixteen patients who received only best supportive care (group B) were matched up with the patients in group A. Primary end point included survival, and secondary end point included assessment of safety, effectiveness of CT-guided 125I brachytherapy, and improvement in the quality of life. Results The two groups were well balanced in terms of age, disease histology, tumor stage, tumor location, and performance status (P>0.05). The median follow-up time was 16 months (range, 3–30). The total tumor response rate was 75.0% in group A, which was significantly higher than that in group B (0.0%) (P<0.01). The median progression-free survival time was 4.80 months for patients in group A and 1.35 months for patients in group B (P<0.001). Kaplan–Meier survival analysis showed that the median survival time of group A was 9.4±0.3 months versus 8.4±0.1 months in group B (P=0.013). Tumor-related symptoms of patients were significantly relieved, and the quality of life was markedly improved in group A than in group B. Conclusion CT-guided 125I brachytherapy improved the survival of patients with locally advanced NSCLC and quality of life after one cycle of first-line chemotherapy compared with best supportive care. PMID:28280369

  6. Localization of axonally transported 125I-wheat germ agglutinin beneath the plasma membrane of chick retinal ganglion cells

    PubMed Central

    1983-01-01

    The distribution of 125I-wheat germ agglutinin (WGA) transported by axons of chick retinal ganglion cells to layer d of the optic tectum was studied by electron microscopic autoradiography. We found that 52% of the radioactivity was located in axons and axon terminals in the contralateral optic tectum 22 h after intravitreal injection of affinity-purified 125I-WGA. Axons comprised 43% of the volume of layer d. Dendrites, glial cells, and neuron cell bodies contained 20%, 17%, and 3% of the label, whereas these structures comprised 24%, 21%, and 2% of the tissue volume, respectively. We also measured the distances between the autoradiographic silver grains and the plasma membranes of these profiles, and compared observed distributions of grains to theoretical distributions computed for band-shaped sources at various distances from the plasma membranes. This analysis revealed that the radioactive source within axons was distributed in a band of cytoplasm extending in from the plasma membrane a distance of 63 nm. Because WGA is known to bind to specific membrane glycoconjugates, we infer that at least some glycoconjugates may be concentrated within an annular region of cytoplasm just beneath the axonal plasma membrane after axoplasmic transport from the neuron cell body. PMID:6187749

  7. Preparation of (125)I-ricin suitable as a probe for the autoradiographic localization of toxin binding sites

    SciTech Connect

    Doebler, J.A.; Mayer, T.W.; Traub, R.K.; Broomfield, C.A.; Calamaio, C.A.

    1993-05-13

    The long term objectives of this research are to identify cellular binding sites for ricin and examine its organ distribution in mice following aerosol inhalation exposure. Preliminary studies relating to the synthesis and evaluation of (125 I)-ricin as an autoradiographic probe have been conducted. Non-radioactive (I)-ricin prepared using the Iodogen method was found to be non-toxic both in vivo and in vitro. Lactose was then added to the Iodogen reaction medium to block galactose-binding site associated tyrosines in an attempt to retain toxicity. However, this did not prevent iodination-induced loss of biological potency. We then switched to the lactoperoxidase method of iodination, which yielded an (I)-ricin preparation with toxicity comparable to that of native toxin.

  8. Autoradiographic localization of delta opioid receptors within the mesocorticolimbic dopamine system using radioiodinated (2-D-penicillamine, 5-D-penicillamine)enkephalin ( sup 125 I-DPDPE)

    SciTech Connect

    Dilts, R.P.; Kalivas, P.W. )

    1990-01-01

    The enkephalin analog (2-D-penicillamine, 5-D-penicillamine)enkephalin was radioiodinated (125I-DPDPE) and shown to retain a pharmacological selectivity characteristic of the delta opioid receptor in in vitro binding studies. The distributions of 125I-DPDPE binding, using in vitro autoradiographic techniques, were similar to those previously reported for the delta opioid receptor. The nucleus accumbens, striatum, and medial prefrontal cortex contain dense gradients of 125I-DPDPE binding in regions known to receive dopaminergic afferents emanating from the mesencephalic tegmentum. Selective chemical lesions of the ventral tegmental area and substantia nigra were employed to deduce the location of the 125I-DPDPE binding within particular regions of the mesocorticolimbic dopamine system. Unilateral lesions of dopamine perikarya (A9 and A10) within the ventral tegmental area and substantia nigra produced by mesencephalic injection of 6-hydroxydopamine resulted in significant (20-30%) increases in 125I-DPDPE binding contralateral to the lesion within the striatum and nucleus accumbens. Lesions of the perikarya (dopaminergic and nondopaminergic) of the ventral tegmental area, induced by quinolinic acid injections, caused increases of less magnitude within these same nuclei. No significant alterations in 125I-DPDPE binding were observed within the mesencephalon as a result of either treatment. The specificity of the lesions was confirmed by immunocytochemistry for tyrosine hydroxylase. These results suggest that the enkephalins and opioid agonists acting through delta opioid receptors do not directly modulate dopaminergic afferents but do regulate postsynaptic targets of the mesocorticolimbic dopamine system.

  9. Uptake and ultrastructural localization of a (125I) growth hormone releasing factor agonist in male rat pituitary gland: Evidence for internalization

    SciTech Connect

    Morel, G. )

    1991-09-01

    GRF was isolated from a human tumor of the pancreas and characterized. GRF stimulates the in vivo and in vitro secretion of GH. The present study was designed to find out whether human (h) GRF agonist could be internalized and to determine the subcellular localization of internalized peptide in somatotrophs. Autoradiography was performed on rat anterior pituitary glands removed at specific time intervals (2-60 min) after iv injection of monoradioiodinated (125I) (His1,Nle27) hGRF (1-32) NH2. Administration of an excess of unlabeled hGRF agonist along with the radioiodinated hormone prevented the uptake, indicating the specificity of the reaction. At the ultrastructural level only the somatotrophs appeared to contain silver grains. The main effect of hGRF agonist injection on the cytological aspect of the somatotrophs was a decrease in the area occupied by secretory granules, accompanied inversely, by an increase in that of the Golgi complex. The time course study in somatotrophs showed that five compartments (plasma membrane, secretory granules, cytoplasmic matrix, nuclear membrane, and lysosomes) have distinct marked labeling patterns. Plasma membrane, secretory granules, and nuclear membrane were labeled throughout the time course studied (2-60 min after injection). Cytoplasmic matrix was labeled 5 min post injection and lysosomes 15 and 30 min after injection. The Golgi complex, mitochondria, rough endoplasmic reticulum, and nucleus matrix were not labeled. The findings show the cellular specificity of GRF uptake by somatotrophs and the internalization process from the plasma membrane to the intracellular organelles (secretory granules, lysosomes, and nuclear membrane). Labeling of the secretory granule compartment suggests that granules may bind and protect internalized peptide from lysosomal degradation.

  10. 125I-LSD autoradiography confirms the preferential localization of caudate-putamen S2 receptors to the caudal (peripallidal) region.

    PubMed

    Altar, C A; Boyar, W C; Marien, M R

    1986-04-30

    The in vitro binding of 125I-lysergic acid diethylamide (LSD) to horizontal sections of rat brain was quantified with computer-assisted autoradiography. Specific binding of 125I-LSD to D2 and S2 sites, defined with 5 microM (+)-butaclamol, was 65-94% of the total binding. Identification of S2 sites with 50 nM ketanserin showed that over 90% of the butaclamol-displaced 125I-LSD binding in the frontal, cingulate and parietal neocortex was to S2 sites (22-55 fmol/mg protein). 125I-LSD also labeled a dense population of S2 sites (16 fmol/mg protein) in the caudal caudate-putamen at the level of the globus pallidus which exceeded by 5-fold the concentration of S2 sites (3 fmol/mg protein) in more rostral portions of the caudate-putamen. The peripallidal distribution of S2 sites was identical to that observed previously with the less selective S2 label, [3H]spiperone. The dense concentration of S2 sites in the caudal caudate-putamen and their overlap with D2 binding sites indicates that the peripallidal neostriatum may play an important role in interactions between dopamine and serotonin.

  11. Dosimetric characteristic of a new 125I brachytherapy source.

    PubMed

    Sadeghi, Mahdi; Khanmohammadi, Zahra

    2011-11-01

    A new brachytherapy (125)I source has been investigated at Iranian Agricultural, Medical and Industrial Research School. Dosimetric characteristics [dose-rate constant Λ, radial dose function g(l)(r) and anisotropy function F(r,)] of IRA-(125)I were theoretically determined in terms of the updated AAPM task group 43 (TG-43U1) recommendations. Versions 5 and 4C of the Monte Carlo radiation transport code were used to calculate the dosimetry parameters around the source. The Monte Carlo calculated dose-rate constant of the (125)I source in water was found to be 92×10(-4) Gy h(-1) U(-1) with an approximate uncertainty of ±3 %. Brachytherapy seed model, 6711-(125)I, carrying (125)I radionuclides, was modelled and benchmarked against previously published values. Finally, the calculated results were compared with the published results of those of other source manufacturers.

  12. Reevaluation of the AAPM TG-43 brachytherapy dosimetry parameters for an 125I seed, and the influence of eye plaque design on dose distributions and dose-volume histograms

    NASA Astrophysics Data System (ADS)

    Aryal, Prakash

    The TG-43 dosimetry parameters of the Advantage(TM) 125I model IAI-125A brachytherapy seed were studied. An investigation using modern MCNP radiation transport code with updated cross-section libraries was performed. Twelve different simulation conditions were studied for a single seed by varying the coating thickness, mass density, photon energy spectrum and cross-section library. The dose rate was found to be 6.3% lower at 1 cm in comparison to published results. New TG-43 dosimetry parameters are proposed. The dose distribution for a brachytherapy eye plaque, model EP917, was investigated, including the effects of collimation from high-Z slots. Dose distributions for 26 slot designs were determined using Monte Carlo methods and compared between the published literature, a clinical treatment planning system, and physical measurements. The dosimetric effect of the composition and mass density of the gold backing was shown to be less than 3%. Slot depth, width, and length changed the central axis (CAX) dose distributions by < 1% per 0.1 mm in design variation. Seed shifts in the slot towards the eye and shifts of the 125I-laden silver rod within the seed had the greatest impact on the CAX dose distribution, changing it by 14%, 9%, 4.3%, and 2.7% at 1, 2, 5, and 10 mm, respectively, from the inner scleral surface. The measured, full plaque slot geometry delivered 2.4% +/- 1.1% higher dose along the plaque's CAX than the geometry provided by the manufacturer and 2.2%+/-2.3% higher than Plaque Simulator(TM) (PS) treatment planning software (version 5.7.6). The D10 for the simulated tumor, inner sclera, and outer sclera for the measured slot plaque to manufacturer provided slot design was 9%, 10%, and 19% higher, respectively. In comparison to the measured plaque design, a theoretical plaque having narrow and deep slots delivered 30%, 37%, and 62% lower D 10 doses to the tumor, inner sclera, and outer sclera, respectively. CAX doses at --1, 0, 1, and 2 mm were also

  13. Fragmentation of chromatin with 125I radioactive disintegrations.

    PubMed Central

    Turner, G N; Nobis, P; Dewey, W C

    1976-01-01

    The DNA in Chinese hamster cells was labeled first for 3 h with [3H]TdR and then for 3 h with [125I]UdR. Chromatin was extracted, frozen, and stored at -30 degrees C until 1.0 X 10(17) and 1.25 X 10(17) disintegrations/g of labeled DNA occurred for 125I and 3H respectively. Velocity sedimentation of chromatin (DNA with associated chromosomal proteins) in neutral sucrose gradients indicated that the localized energy from the 125I disintegrations, which gave about 1 double-strand break/disintegration plus an additional 1.3 single strand breaks, selectively fragmented the [125I] chromatin into pieces smaller than the [3H] chromatin. In other words, 125I disintegrations caused much more localized damage in the chromatin labeled with 125I than in the chromatin labeled with 3H, and fragments induced in DNA by 125I disintegrations were not held together by the associated chromosomal proteins. Use of this 125I technique for studying chromosomal proteins associated with different regions in the cellular DNA is discussed. For these studies, the number of disintegrations required for fragmenting DNA molecules of different sizes is illustrated. PMID:963201

  14. Interaction of 125I-labeled botulinum neurotoxins with nerve terminals. I. Ultrastructural autoradiographic localization and quantitation of distinct membrane acceptors for types A and B on motor nerves

    PubMed Central

    1986-01-01

    The labeling patterns produced by radioiodinated botulinum neurotoxin (125I-BoNT) types A and B at the vertebrate neuromuscular junction were investigated using electron microscopic autoradiography. The data obtained allow the following conclusions to be made. 125I-BoNT type A, applied in vivo or in vitro to mouse diaphragm or frog cutaneous pectoris muscle, interacts saturably with the motor nerve terminal only; silver grains occur on the plasma membrane, within the synaptic bouton, and in the axoplasm of the nerve trunk, suggesting internalization and retrograde intra-axonal transport of toxin or fragments thereof. 125I-BoNT type B, applied in vitro to the murine neuromuscular junction, interacts likewise with the motor nerve terminal except that a lower proportion of internalized radioactivity is seen. This result is reconcilable with the similar, but not identical, pharmacological action of these toxin types. The saturability of labeling in each case suggested the involvement of acceptors; on preventing the internalization step with metabolic inhibitors, their precise location became apparent. They were found on all unmyelinated areas of the nerve terminal membrane, including the preterminal axon and the synaptic bouton. Although 125I-BoNT type A interacts specifically with developing terminals of newborn rats, the unmyelinated plasma membrane of the nerve trunk is not labeled, indicating that the acceptors are unique components restricted to the nerve terminal area. BoNT types A and B have distinct acceptors on the terminal membrane. Having optimized the conditions for saturation of these binding sites and calibrated the autoradiographic procedure, we found the densities of the acceptors for types A and B to be approximately 150 and 630/micron 2 of membrane, respectively. It is proposed that these membrane acceptors target BoNT to the nerve terminal and mediate its delivery to an intracellular site, thus contributing to the toxin's selective inhibitory action

  15. Interaction of /sup 125/I-labeled botulinum neurotoxins with nerve terminals. I. Ultrastructural autoradiographic localization and quantitation of distinct membrane acceptors for types A and B on motor nerves

    SciTech Connect

    Black, J.D.; Dolly, J.O.

    1986-01-01

    The labeling patterns produced by radioiodinated botulinum neurotoxin (/sup 125/I-BoNT) types A and B at the vertebrate neuromuscular junction were investigated using electron microscopic autoradiography. The data obtained allow the following conclusions to be made. (a) /sup 125/I-BoNT type A, applied in vivo or in vitro to mouse diaphragm or frog cutaneous pectoris muscle, interacts saturably with the motor nerve terminal only; silver grains occur on the plasma membrane, within the synaptic bouton, and in the axoplasm of the nerve trunk, suggesting internalization and retrograde intra-axonal transport of toxin or fragments thereof. (b) /sup 125/I-BoNT type B, applied in vitro to the murine neuromuscular junction, interacts likewise with the motor nerve terminal except that a lower proportion of internalized radioactivity is seen. This result is reconcilable with the similar, but not identical, pharmacological action of these toxin types. (c) The saturability of labeling in each case suggested the involvement of acceptors; on preventing the internalization step with metabolic inhibitors, their precise location became apparent. They were found on all unmyelinated areas of the nerve terminal membrane, including the preterminal axon and the synaptic bouton. (d) It is not proposed that these membrane acceptors target BoNT to the nerve terminal and mediate its delivery to an intracellular site, thus contributing to the toxin's selective inhibitory action on neurotransmitter release.

  16. More accurate fitting of {sup 125}I and {sup 103}Pd radial dose functions

    SciTech Connect

    Taylor, R. E. P.; Rogers, D. W. O.

    2008-09-15

    In this study an improved functional form for fitting the radial dose functions, g(r), of {sup 125}I and {sup 103}Pd brachytherapy seeds is presented. The new function is capable of accurately fitting radial dose functions over ranges as large as 0.05 cm{<=}r{<=}10 cm for {sup 125}I seeds and 0.10 cm{<=}r{<=}10 cm for {sup 103}Pd seeds. The average discrepancies between fit and calculated data are less than 0.5% over the full range of fit and maximum discrepancies are 2% or less. The fitting function is also capable of accounting for the sharp increase in g(r) (upturn) seen for some sources for r<0.1 cm. This upturn has previously been attributed to the breakdown of the approximation of the sources as a line, however, in this study we demonstrate that another contributing factor is the 4.5 keV characteristic x-rays emitted from the Ti seed casing. Radial dose functions are calculated for 18 {sup 125}I seeds and 9 {sup 103}Pd seeds using the EGSnrc Monte Carlo user-code BrachyDose. Fitting coefficients of the new function are tabulated for all 27 seeds. Extrapolation characteristics of the function are also investigated. The new functional form is an improvement over currently used fitting functions with its main strength being the ability to accurately fit the rapidly varying radial dose function at small distances. The new function is an excellent candidate for fitting the radial dose function of all {sup 103}Pd and {sup 125}I brachytherapy seeds and will increase the accuracy of dose distributions calculated around brachytherapy seeds using the TG-43 protocol over a wider range of data. More accurate values of g(r) for r<0.5 cm may be particularly important in the treatment of ocular melanoma.

  17. Relative biologic effectiveness in terms of tumor response of {sup 125}I implants compared with {sup 60}Co gamma rays

    SciTech Connect

    Lehnert, Shirley . E-mail: shirley.lehnert@mcgill.ca; Reniers, Brigitte; Verhaegen, Frank

    2005-09-01

    Purpose: To measure the relative biologic effectiveness (RBE) for {sup 125}I seeds compared with external beam radiotherapy using a clinically relevant in vivo system. Methods and Materials: Photon emission from a detailed source model was simulated using the Monte Carlo code MCNP4C, sampling from a {sup 125}I spectrum. The mouse RIF-1 tumor was treated with either temporary implant of an {sup 125}I seed or with {sup 60}Co gamma rays. The tumors were always the same size at the initiation of treatment, and the endpoint was growth inhibition. Results: The dose-response curve for both modalities was close to linear and was independent of the initial {sup 125}I activity (dose rate) for the range investigated. Calculation of the RBE for tumor response requires assigning a unique value for the tumor dose that is not homogenous but depends on the distance from the {sup 125}I source. Because tumor regrowth will depend on the subpopulation of cells that have the greatest probability of survival (i.e., those at the greatest distance from the {sup 125}I source), one approach is to use the dose to this population. On this basis, the RBE for {sup 125}I compared with {sup 60}Co gamma rays is 1.5. If the {sup 125}I dose is computed as the average dose to the tumor, corrected for the dose that is wasted as overkill in the cell population closest to the center of the {sup 125}I seed, the RBE is 1.4. Conclusion: The result, an RBE of 1.4-1.5 is similar to findings obtained by other methods, supporting the validity of this approach to derive an RBE with validity in a clinical context.

  18. Evaluation of the dose distribution for prostate implants using various {sup 125}I and {sup 103}Pd sources

    SciTech Connect

    Meigooni, Ali S.; Luerman, Christine M.; Sowards, Keith T.

    2009-04-15

    Recently, several different models of {sup 125}I and {sup 103}Pd brachytherapy sources have been introduced in order to meet the increasing demand for prostate seed implants. These sources have different internal structures; hence, their TG-43 dosimetric parameters are not the same. In this study, the effects of the dosimetric differences among the sources on their clinical applications were evaluated. The quantitative and qualitative evaluations were performed by comparisons of dose distributions and dose volume histograms of prostate implants calculated for various designs of {sup 125}I and {sup 103}Pd sources. These comparisons were made for an identical implant scheme with the same number of seeds for each source. The results were compared with the Amersham model 6711 seed for {sup 125}I and the Theragenics model 200 seed for {sup 103}Pd using the same implant scheme.

  19. Model-based dose calculations for {sup 125}I lung brachytherapy

    SciTech Connect

    Sutherland, J. G. H.; Furutani, K. M.; Garces, Y. I.; Thomson, R. M.

    2012-07-15

    Purpose: Model-baseddose calculations (MBDCs) are performed using patient computed tomography (CT) data for patients treated with intraoperative {sup 125}I lung brachytherapy at the Mayo Clinic Rochester. Various metallic artifact correction and tissue assignment schemes are considered and their effects on dose distributions are studied. Dose distributions are compared to those calculated under TG-43 assumptions. Methods: Dose distributions for six patients are calculated using phantoms derived from patient CT data and the EGSnrc user-code BrachyDose. {sup 125}I (GE Healthcare/Oncura model 6711) seeds are fully modeled. Four metallic artifact correction schemes are applied to the CT data phantoms: (1) no correction, (2) a filtered back-projection on a modified virtual sinogram, (3) the reassignment of CT numbers above a threshold in the vicinity of the seeds, and (4) a combination of (2) and (3). Tissue assignment is based on voxel CT number and mass density is assigned using a CT number to mass density calibration. Three tissue assignment schemes with varying levels of detail (20, 11, and 5 tissues) are applied to metallic artifact corrected phantoms. Simulations are also performed under TG-43 assumptions, i.e., seeds in homogeneous water with no interseed attenuation. Results: Significant dose differences (up to 40% for D{sub 90}) are observed between uncorrected and metallic artifact corrected phantoms. For phantoms created with metallic artifact correction schemes (3) and (4), dose volume metrics are generally in good agreement (less than 2% differences for all patients) although there are significant local dose differences. The application of the three tissue assignment schemes results in differences of up to 8% for D{sub 90}; these differences vary between patients. Significant dose differences are seen between fully modeled and TG-43 calculations with TG-43 underestimating the dose (up to 36% in D{sub 90}) for larger volumes containing higher proportions of

  20. Interstitial brachytherapy for pancreatic cancer: Report of seven cases treated with 125I and a review of the literature

    SciTech Connect

    Montemaggi, P.; Dobelbower, R.; Crucitti, F.; Caracciolo, F.; Morganti, A.G.; Smaniotto, D.; Luzi, S.; Cellini, N. )

    1991-07-01

    Since 1975, seven groups of investigators have reported clinical results of interstitial brachytherapy (IBT) for pancreatic cancer. The reports are comprised of data from 254 patients, 21 of whom died in the postoperative period for an overall operative mortality rate of 8.7%. Operative mortality rate range from 0% to 32% in individual reports. Most patients have been treated with 125I, although 25 patients were treated with 198Au seeds. Most investigators report combining IBT with external beam radiation therapy (EBRT) {plus minus} adjuvant chemotherapy. In general, IBT has been associated with considerable morbidity. Median patient survival time has not exceeded 15 months. This report describes an additional seven patients with locally unresectable pancreatic cancer, without distant metastases, treated primarily with 60 to 100 Gy matched peripheral dose (MPD) by 125I IBT. One patient died postoperatively of a pulmonary embolus. Four of the remaining six patients were also treated with modest doses (10.5 to 30 Gy) of EBRT late in the course of the disease for local tumor progression. One developed a pancreaticocutaneous fistula, and one developed exacerbation of pre-existing diabetes mellitus. The median patient survival time from the date of IBT was 7 months (range: 0 to 21 months). One patient is alive without clinical evidence of cancer 9 months after IBT. 25 refs.

  1. Autoradiographic localization of voltage-dependent sodium channels on the mouse neuromuscular junction using /sup 125/I-alpha scorpion toxin. I. Preferential labeling of glial cells on the presynaptic side

    SciTech Connect

    Boudier, J.L.; Jover, E.; Cau, P.

    1988-05-01

    Alpha-scorpion toxins bind specifically to the voltage-sensitive sodium channel in excitable membranes, and binding is potential-dependent. The radioiodinated toxin II from the scorpion Androctonus australis Hector (alpha ScTx) was used to localize voltage-sensitive sodium channels on the presynaptic side of mouse neuromuscular junctions (NMJ) by autoradiography using both light and electron microscopy. Silver grain localization was analyzed by the cross-fire method. At the light-microscopic level, grain density over NMJ appeared 6-8x higher than over nonjunctional muscle membrane. The specificity of labeling was verified by competition/displacement with an excess of native alpha ScTx. Labeling was also inhibited by incubation in depolarizing conditions, showing its potential-dependence. At the electron-microscopic level, analysis showed that voltage-sensitive sodium channels labeled with alpha ScTx were almost exclusively localized on membranes, as expected. Due to washout after incubation, appreciable numbers of binding sites were not found on the postsynaptic membranes. However, on the presynaptic side, alpha ScTx-labeled voltage-sensitive sodium channels were localized on the membrane of non-myelin-forming Schwann cells covering NMJ. The axonal presynaptic membrane was not labeled. These results show that voltage-sensitive sodium channels are present on glial cells in vivo, as already demonstrated in vitro. It is proposed that these glial channels could be indirectly involved in the ionic homeostasis of the axonal environment.

  2. Spectroscopic output of {sup 125}I and {sup 103}Pd low dose rate brachytherapy sources

    SciTech Connect

    Usher-Moga, Jacqueline; Beach, Stephen M.; DeWerd, Larry A.

    2009-01-15

    The spectroscopic output of low dose rate (LDR) brachytherapy sources is dependent on the physical design and construction of the source. Characterization of the emitted photons from 12 {sup 125}I and 3 {sup 103}Pd LDR brachytherapy source models is presented. Photon spectra, both along the transverse bisector and at several polar angles, were measured in air with a high-purity reverse electrode germanium (REGe) detector. Measured spectra were corrected to in vacuo conditions via Monte Carlo and analytical methods. The tabulated and plotted spectroscopic data provide a more complete understanding of each source model's output characteristics than can be obtained with other measurement techniques. The variation in fluorescence yield of the {sup 125}I sources containing silver caused greater differences in the emitted spectra and average energies among these seed models than was observed for the {sup 103}Pd sources or the {sup 125}I sources that do not contain silver. Angular spectroscopic data further highlighted the effects of source construction unique to each model, as well as the asymmetric output of many seeds. These data demonstrate the need for the incorporation of such physically measured output characteristics in the Monte Carlo modeling process.

  3. Near-field dosimetry of {sup 125}I sources for interstitial brachytherapy implants measured using thermoluminescent sheets

    SciTech Connect

    Iwata, Kazuro; Yue, Ning J.; Nath, Ravinder

    2004-12-01

    The dosimetric characteristics were measured for two types of {sup 125}I low-energy photon-emitting sources by using a wide and highly sensitive thermoluminescent (TL) sheet film, which was developed for two-dimensional dose distribution measurements. The TL film is made of Teflon homogeneously mixed with small powders of thermoluminescence (BaSO{sub 4}:Eu doped). Various dosimetric parameters (i.e., radial dose function, 2D and 1D anisotropy functions) of model 6711 and 6702 {sup 125}I sources were obtained at various distances from the source surfaces to 15 mm. These parameters obtained with TL sheet were compared with the data recommended in the updated AAPM TG-43 report. The radial dose functions measured with TL sheet are in agreement with those established data of model 6711 {sup 125}I seed and model 6702 {sup 125}I seed at most of the distances within 5% and 7%, respectively. All the measured anisotropy functions showed symmetry about the longitudinal source axis. The anisotropy of dose distributions was clearly present in the immediate vicinity of the source edges. The measured 2D anisotropy function values at 1 cm are in reasonably good agreement with the recommended values. The differences at two points in the 1D anisotropy functions measured with TL sheet and the established data at 1 cm from source center were 0.7% and 1.9% for model 6711 and 6702 {sup 125}I sources, respectively; the differences at 0.5 cm were 1.5% and 1.7% for model 6711 and 6702 {sup 125}I sources, respectively. The relative dosimetric characteristics in the vicinity of actual interstitial brachytherapy sources containing {sup 125}I have been experimentally determined by using the TL sheet as a 2D dosimeter.

  4. High affinity binding of 125I-angiotensin II to rat glomerular basement membranes.

    PubMed Central

    Sraer, J; Baud, L; Cosyns, J P; Verroust, P; Nivez, M P; Ardaillou, R

    1977-01-01

    125I-angiotensin II (AII) specifically bound to rat glomerular basement membrane (GBM). The kinetics of binding were similar to those obtained with the total glomeruli. The apparent dissociation constant was close to 50 pM with both preparations. The number of sites related to the amount of protein was two times greater with GBM than with total glomeruli. Since the amount of GBM protein extracted from a given amount of glomerular protein was about 10%, it was possible to estimate the share of the GBM binding sites for AII as representing 20% of the total number present in the entire glomerulus. Binding studies at equilibrium as a function of 125I-AII concentration and competitive binding experiments suggested either multiplicity of the binding sites or cooperativity in the binding reaction. Degradation of 125I-AII in the presence of GBM was slight and did not increase with time. The difference in the degrees of degradation of 125I-AII was too small to account for the observed difference in binding when the results obtained with GBM and isolated glomeruli preparations were compared. 125I-AII binding to GBM was increased after treatment of these membranes with collagenase, slightly diminished with neuraminidase, and almost completely abolished with trypsin suggesting the proteic nature of the receptor. 125I-AII binding to GBM was diminished after incubation of GBM with anti-GBM antibodies as a result of a decrease in the number of binding sites. 125I-AII binding was even more diminished in preparations of glomeruli isolated from rats passively immunized with anti-GBM antibodies when compared with glomeruli from control animals. This resulted from both smaller affinity for AII and decrease in the number of the binding sites. The present data provides evidence for specific binding sites for AII localized on GBM. This is noteworthy since receptors for polypeptide hormones are currently observed on the surface of cell membranes. These findings also suggest a new

  5. Identification and characterization of alpha 1 adrenergic receptors in the canine prostate using (/sup 125/I)-Heat

    SciTech Connect

    Lepor, H.; Baumann, M.; Shapiro, E.

    1987-11-01

    We have recently utilized radioligand receptor binding methods to characterize muscarinic cholinergic and alpha adrenergic receptors in human prostate adenomas. The primary advantages of radioligand receptor binding methods are that neurotransmitter receptor density is quantitated, the affinity of unlabelled drugs for receptor sites is determined, and receptors can be localized using autoradiography on slide-mounted tissue sections. Recently, (/sup 125/I)-Heat, a selective and high affinity ligand with high specific activity (2200 Ci/mmole) has been used to characterize alpha 1 adrenergic receptors in the brain. In this study alpha 1 adrenergic receptors in the dog prostate were characterized using (/sup 125/I)-Heat. The Scatchard plots were linear indicating homogeneity of (/sup 125/I)-Heat binding sites. The mean alpha 1 adrenergic receptor density determined from these Scatchard plots was 0.61 +/- 0.07 fmol/mg. wet wt. +/- S.E.M. The binding of (/sup 125/I)-Heat to canine prostate alpha 1 adrenergic binding sites was of high affinity (Kd = 86 +/- 19 pM). Steady state conditions were reached following an incubation interval of 30 minutes and specific binding and tissue concentration were linear within the range of tissue concentrations assayed. The specificity of (/sup 125/I)-Heat for alpha 1 adrenergic binding sites was confirmed by competitive displacement assays using unlabelled clonidine and prazosin. Retrospective analysis of the saturation experiments demonstrated that Bmax can be accurately calculated by determining specific (/sup 125/I)-Heat binding at a single ligand concentration. (/sup 125/I)-Heat is an ideal ligand for studying alpha 1 adrenergic receptors in the prostate and its favorable properties should facilitate the autoradiographic localization of alpha 1 adrenergic receptors in the prostate.

  6. Local Evolution of Seed Flotation in Arabidopsis

    PubMed Central

    Saez-Aguayo, Susana; Rondeau-Mouro, Corinne; Macquet, Audrey; Kronholm, Ilkka; Ralet, Marie-Christine; Berger, Adeline; Sallé, Christine; Poulain, Damien; Granier, Fabienne; Botran, Lucy; Loudet, Olivier; de Meaux, Juliette; Marion-Poll, Annie; North, Helen M.

    2014-01-01

    Arabidopsis seeds rapidly release hydrophilic polysaccharides from the seed coat on imbibition. These form a heavy mucilage layer around the seed that makes it sink in water. Fourteen natural Arabidopsis variants from central Asia and Scandinavia were identified with seeds that have modified mucilage release and float. Four of these have a novel mucilage phenotype with almost none of the released mucilage adhering to the seed and the absence of cellulose microfibrils. Mucilage release was modified in the variants by ten independent causal mutations in four different loci. Seven distinct mutations affected one locus, coding the MUM2 β-D-galactosidase, and represent a striking example of allelic heterogeneity. The modification of mucilage release has thus evolved a number of times independently in two restricted geographical zones. All the natural mutants identified still accumulated mucilage polysaccharides in seed coat epidermal cells. Using nuclear magnetic resonance (NMR) relaxometry their production and retention was shown to reduce water mobility into internal seed tissues during imbibition, which would help to maintain seed buoyancy. Surprisingly, despite released mucilage being an excellent hydrogel it did not increase the rate of water uptake by internal seed tissues and is more likely to play a role in retaining water around the seed. PMID:24625826

  7. Local evolution of seed flotation in Arabidopsis.

    PubMed

    Saez-Aguayo, Susana; Rondeau-Mouro, Corinne; Macquet, Audrey; Kronholm, Ilkka; Ralet, Marie-Christine; Berger, Adeline; Sallé, Christine; Poulain, Damien; Granier, Fabienne; Botran, Lucy; Loudet, Olivier; de Meaux, Juliette; Marion-Poll, Annie; North, Helen M

    2014-03-01

    Arabidopsis seeds rapidly release hydrophilic polysaccharides from the seed coat on imbibition. These form a heavy mucilage layer around the seed that makes it sink in water. Fourteen natural Arabidopsis variants from central Asia and Scandinavia were identified with seeds that have modified mucilage release and float. Four of these have a novel mucilage phenotype with almost none of the released mucilage adhering to the seed and the absence of cellulose microfibrils. Mucilage release was modified in the variants by ten independent causal mutations in four different loci. Seven distinct mutations affected one locus, coding the MUM2 β-D-galactosidase, and represent a striking example of allelic heterogeneity. The modification of mucilage release has thus evolved a number of times independently in two restricted geographical zones. All the natural mutants identified still accumulated mucilage polysaccharides in seed coat epidermal cells. Using nuclear magnetic resonance (NMR) relaxometry their production and retention was shown to reduce water mobility into internal seed tissues during imbibition, which would help to maintain seed buoyancy. Surprisingly, despite released mucilage being an excellent hydrogel it did not increase the rate of water uptake by internal seed tissues and is more likely to play a role in retaining water around the seed.

  8. Scintillation Proximity Radioimmunoassay Utilizing 125I-Labeled Ligands

    NASA Astrophysics Data System (ADS)

    Udenfriend, Sidney; Diekmann Gerber, Louise; Brink, Larry; Spector, Sydney

    1985-12-01

    A unique type of radioimmunoassay is described that does not require centrifugation or separation. Microbeads containing a fluorophor are covalently linked to antibody. When an 125I-labeled antigen is added it binds to the beads and, by its proximity, the emitted short-range electrons of the 125I excite the fluorophor in the beads. The light emitted can be measured in a standard scintillation counter. Addition of unlabeled antigen from tissue extracts displaces the labeled ligand and diminishes the fluorescent signal. Application of scintillation proximity immunoassay to tissue enkephalins, serum thyroxin, and urinary morphine is described. Applications of the principle to study the kinetics of interaction between receptors and ligands are discussed.

  9. Scintillation proximity radioimmunoassay utilizing 125I-labeled ligands

    SciTech Connect

    Udenfriend, S.; Gerber, L.D.; Brink, L.; Spector, S.

    1985-12-01

    A unique type of radioimmunoassay is described that does not require centrifugation or separation. Microbeads containing a fluorophor are covalently linked to antibody. When an /sup 125/I-labeled antigen is added it binds to the beads and, by its proximity, the emitted short-range electrons of the /sup 125/I excite the fluorophor in the beads. The light emitted can be measured in a standard scintillation counter. Addition of unlabeled antigen from tissue extracts displaces the labeled ligand and diminishes the fluorescent signal. Application of scintillation proximity immunoassay to tissue enkephalins, serum thyroxin, and urinary morphine is described. Applications of the principle to study the kinetics of interaction between receptors and ligands are discussed.

  10. Renal catabolism of /sup 125/I-glicentin

    SciTech Connect

    Lopez-Novoa, J.M.; Santos, J.C.; Villamediana, L.M.; Garrote, F.J.; Thim, L.; Moody, A.J.; Valverde, I.

    1986-05-01

    The renal catabolism of /sup 125/I-glicentin has been studied in vivo by the disappearance of this peptide from the plasma of bilaterally nephrectomized, ureteral-ligated, or normal rats and by using tubular microinfusion techniques. In addition the catabolism of glicentin by the isolated, perfused kidney has been studied. Results from in vivo studies demonstrated that half-disappearance time was lower in control (59.5 +/- 1.8 min) than in bilaterally nephrectomized rats (97.2 +/- 2.6 min), and this value was significantly higher than that of ureteral-ligated animals (83.2 +/- 1.1 min, P less than 0.005). Microinfusion experiments revealed that when /sup 125/I-glicentin was injected into the proximal tubule, no trichloroacetic-precipitable radioactivity was recovered in the urine, whereas most of inulin injected was recovered. By contrast most of the /sup 125/I-glicentin injected into the distal tubule was recovered in the urine. In isolated kidney experiments, organ clearance rate of /sup 125/I-glicentin averaged 0.88 +/- 0.10 ml/min, a value significantly higher than that of glomerular filtration rate (0.72 +/- 0.06 ml/min, P less than 0.005, paired data), and both parameters showed a close linear relationship (r = 0.90). Urinary clearance of glicentin was negligible. These results demonstrate that the kidney plays a major role in the catabolism of glicentin, mainly by glomerular filtration and tubular catabolism. The site of tubular catabolism appears to be the proximal tubule. Peritubular uptake was minimal.

  11. Range of high LET effects from /sup 125/I decays

    SciTech Connect

    Charlton, D.E.

    1986-08-01

    Track structure techniques are applied to calculate energy depositions in cylindrical targets 20 A in diameter (simulating the DNA duplex) containing, or near, /sup 125/I decays. Two problems are examined: (1) The possible effects of incorporated versus nonincorporated /sup 125/I are evaluated; (2) the extent of the radiological damage along the DNA is described and discussed for individual decays taking place in the DNA. The results of three different calculations are presented: (1) The distribution of the total energy deposited in the target per decay: Here it is shown that the /sup 125/I decays deposit considerably more energy than 5-MeV alpha particles when the decay occurs on the central axis of the cylinder. When the decay occurs at 40 A from the axis, the energy depositions are small and infrequent, showing that the iodine decay must occur within this distance to produce a high LET-like effect. (2) The distribution of average energy depositions around a curved cylinder simulating the DNA duplex encircling the nucleosome: There is a rapid decrease in the energy deposited in elements (of size resembling a base pair) away from the location of the decay. At approximately 17 A (approximately 5 bp) from the decay the mean energy deposited in an element is reduced by a factor of 10. (3) The energy deposited in individual elements of the cylinder is presented for single decays: The smooth decrease in average energy depositions with distance from the decay ((2) above) is not reflected in individual decays.

  12. 2( sup 125 I)Iodomelatonin binding sites in spleens of guinea pigs

    SciTech Connect

    Poon, A.M.S. ); Pang, S.F. )

    1992-01-01

    2-({sup 125}I)Iodomelatonin was found to bind specifically to the membrane preparations of the spleens of guinea pigs with high affinity. The binding was rapid, stable, saturable and reversible. Scatchard analysis of the binding assays revealed an equilibrium dissociation constant (Kd) of 49.8{plus minus}4.12 pmol/l and binding site density (Bmax) of 0.69{plus minus}0.082 fmol/mg protein at mid-light. There was no significant change in the Kd or the Bmax at mid-dark. Kinetic analysis showed a Kd of 23.13{plus minus}4.81 pmol/l, in agreement to that derived from the saturation studies. The 2-({sup 125}I)iodomelatonin binding sites have the following order of potency: 2-iodomelatonin > melatonin > 6-chloromelatonin {much gt} N-acetylserotonin, 6-hydroxymelatonin > 5-methoxytryptamine, 5-methoxytryptophol > serotonin, 5-methoxyindole-3-acetic acid > 5-hydroxytryptophol, 3-acetylindole, 1-acetylindole-3-carboxyaldehyde, L-tryptophan > tryptamine, 5-hydroxyindole-3-acetic acid. Differential centrifugation studies showed that the binding sites are localized mainly in the nuclear fraction, the rest are distributed in the microsomal fraction, mitochondrial fraction and cytosolic fraction. The demonstration of 2-({sup 125}I)iodomelatonin binding sites in the spleen suggests the presence of melatonin receptors and a direct mechanism of action of melatonin on the immune system.

  13. Monte Carlo dosimetry for {sup 125}I and {sup 103}Pd eye plaque brachytherapy

    SciTech Connect

    Thomson, R. M.; Taylor, R. E. P.; Rogers, D. W. O.

    2008-12-15

    A Monte Carlo study of dosimetry for eye plaque brachytherapy is performed. BrachyDose, an EGSnrc user code which makes use of Yegin's multi-geometry package, is used to fully model {sup 125}I (model 6711) and {sup 103}Pd (model 200) brachytherapy seeds and the standardized plaques of the Collaborative Ocular Melanoma Study (COMS). Three-dimensional dose distributions in the eye region are obtained. In general, dose to water is scored; however, the implications of replacing water with eye tissues are explored. The effect of the gold alloy (Modulay) backing is investigated and the dose is found to be sensitive to the elemental composition of the backing. The presence of the silicone polymer (Silastic) seed carrier results in substantial dose decreases relative to water, particularly for {sup 103}Pd. For a 20 mm plaque with a Modulay backing and Silastic insert, fully loaded with 24 seeds, the dose decrease relative to water is of the order of 14% for {sup 125}I and 20% for {sup 103}Pd at a distance of 1 cm from the inner sclera along the plaque's central axis. For the configurations of seeds used in COMS plaques, interseed attenuation is a small effect within the eye region. The introduction of an air interface results in a dose reduction in its vicinity which depends on the plaque's position within the eye and the radionuclide. Introducing bone in the eye's vicinity also causes dose reductions. The dose distributions in the eye for the two different radionuclides are compared and, for the same prescription dose, {sup 103}Pd generally offers a lower dose to critical normal structures. BrachyDose is sufficiently fast to allow full Monte Carlo dose calculations for routine clinical treatment planning.

  14. Practical application of /sup 125/I-fibrinogen leg scanning

    SciTech Connect

    Hull, R.D.; Hirsh, J.

    1981-07-01

    The diagnosis of venous thrombosis by radioiodine-labeled fibrinogen scanning depends upon the incorporation of circulating labeled fibrinogen into a developing or established thrombus which is then detected by measuring the increase of overlying surface radioactivity with an isotope detector. The scanning procedure is simple and rapid, and one technician can screen 15 to 20 patients daily. A single intravenous injection of 100 ..mu..Ci of /sup 125/I-fibrinogen enables scanning to be performed for approximately 7 days. leg scanning has been a valuable research tool and is also useful for the clinical management of patients with venous thrombosis. Its limitations are its insensitivity to iliac vein thrombosis and relative insensitivity to thrombi in the upper thigh, and when used diagnostically in patients with clinically suspected venous thrombosis there is a delay of up to 2 days before a positive result is obtained. For these reasons leg scanning should not be used alone in patients with clinically suspected venous thrombosis. The practical indications for using /sup 125/I-fibrinogen leg scanning are (1) for diagnosis of clinically suspected venous thrombosis when used in combination with impedance plethysmography; (2) detection of acute venous thrombosis in patients with chronic venous insufficiency; (3) screening patients who develop calf vein thrombosis when there is contraindication to anticoagulant therapy; and (4) screening certain high-risk patients and patient groups in whom the prophylaxis is either contraindicated or ineffective.

  15. {sup 125}I Measurements for Occupational Exposure Assessment

    SciTech Connect

    Silva, L.; Pinhao, N. R.

    2008-08-14

    Whenever there is a risk of occupational exposure to dispersible radioactive material, it is necessary to have a monitoring program to assess the effective dose arising from the intake of radionuclides by workers. In this paper we present our experience in bioassay measurements of {sup 125}I in urine samples of workers using high resolution gamma spectrometry. For a 24-hour excretion period, we found activity values of the order of one Bq and estimated the committed effective doses to be less than one {mu}Sv. Although very small, these values led to a re-evaluation and improvement of the laboratory safety conditions. We discuss the calibration procedure followed for the activity measurements, the estimation of the uncertainty in the excreted activity, the calculation of detection and quantification limits and estimation of performance indicators. Aspects regarding the spectral analysis, true coincidence summing and matrix effects are also considered.

  16. Approaches to sequence analysis of 125I-labeled RNA.

    PubMed Central

    Dickson, E; Pape, L K; Robertson, H D

    1979-01-01

    A method is described for the initial steps of sequence analysis of RNase T1-and pancreatic RN-ase-resistant oligonucleotides of RNA containing cytidylate residues labeled in vitro with 125I. In many cases an oligonucleotide sequence can be deduced from a consideration of (i) its relative position in the two-dimensional fingerprint (with DEAE thin layer homochromatographic second dimension), (ii) its electrophoretic mobility on DEAE paper at pH 1.9, and (iii) identification of its products of further enzymatic digestion by comparison with a set of marker oligonucleotides. Additional methods including analysis of oligonucleotides following chemical blocking of uridylate residues with CMCT and analysis of products of incomplete enzymatic digestion are also discussed. Images PMID:106369

  17. Radiation complications and tumor control after {sup 125}I plaque brachytherapy for ocular melanoma

    SciTech Connect

    Jensen, Ashley W.; Petersen, Ivy A. . E-mail: petersen.ivy@mayo.edu; Kline, Robert W.; Stafford, Scott L.; Schomberg, Paula J.; Robertson, Dennis M.

    2005-09-01

    Purpose: To determine the outcome of {sup 125}I plaque brachytherapy at our institution and identify the risk factors associated with the development of radiation complications, tumor recurrence, and metastasis. Patients and Methods: From 1986 to 2000, 156 patients underwent {sup 125}I episcleral plaque (COMS design) application for the treatment of ocular melanoma. Chart analysis of follow-up ophthalmologic appointments assessed the incidence of ocular side effects after therapy. Statistical analysis assessed outcomes and significant influencing factors. Results: With a median follow-up of 6.2 years, the 5-year overall survival was 83%. The 5-year disease-specific survival was 91%. Initial local control at 5 years was 92%, with 100% ultimate local control after secondary therapy that included 9 enucleations. The risk of metastasis was 10% at 5 years and 27% at 10 years. Vision stayed the same or improved in 25% of patients, and 44% of patients maintained visual acuity better than 20/200. Thirteen percent of patients experienced chronic pain or discomfort in the treated eye. Dose rates to the tumor apex greater than 90 to 100 cGy/h were associated with increased systemic control but worse radiation toxicity. Conclusion: Patients in our series experienced excellent local tumor control. Higher dose rates to the tumor apex were associated with reduced rates of distant metastases but worse ocular function.

  18. /sup 125/I iothalamate an ideal marker for glomerular filtration

    SciTech Connect

    Odlind, B.; Haellgren, R.S.; Sohtell, M.; Lindstroem, B.

    1985-01-01

    The triiodinated angiographic contrast medium, iothalamate (usually labelled /sup 125/I), has been used extensively as a marker for glomerular filtration. The authors have studied the renal handling of /sup 125/I iothalamate (IOT) in vivo and in vitro in several species. In renal cortical slices from chicken, rabbit, rat, and monkey, the tissue-to-medium ratio of IOT was twice that of /sup 51/Cr-EDTA (EDTA) at 37 degrees C; a difference that was abolished at 0 degree C and markedly reduced by added o-iodohippurate or iodipamide. In five chickens the steady-state renal clearance of IOT (CIOT) was twice that of EDTA (CEDTA) or /sup 3/H inulin (C1); a difference that was abolished by administration of 100 mg/kg/hr of novobiocin, an organic anion transport inhibitor. CEDTA was similar to C1 before as well as after transport inhibition. Utilizing the Sperber technique the mean apparent tubular excretion fraction (ATEF) of IOT was 8%, while that of EDTA was 1%. After novobiocin coinfusion (new steady-state) ATEFIOT was significantly reduced and not different from that of EDTA (-1%). In the same animals the total urinary recovery of IOT was 84 and 57% before and after novobiocin, respectively, while corresponding values for EDTA was unchanged by the inhibitor. In seven rats the renal extraction of IOT was reduced from 29 to 17% by coinfusion of probenecid (5 mg/kg/hr). Corresponding extractions were 82 to 34% and 22% (unchanged) for PAH and EDTA, respectively.

  19. Modified COMS Plaques for {sup 125}I and {sup 103}Pd Iris Melanoma Brachytherapy

    SciTech Connect

    Thomson, Rowan M.; Furutani, Keith M.; Pulido, Jose S.; Stafford, Scott L.; Rogers, D.W.O.

    2010-11-15

    Purpose: Novel plaques are used to treat iris melanoma at the Mayo Clinic Rochester. The plaques are a modification of the Collaborative Ocular Melanoma Study (COMS) 22 mm plaque design with a gold alloy backing, outer lip, and silicone polymer insert. An inner lip surrounds a 10 mm diameter cutout region at the plaque center. Plaques span 360{sup o}, 270{sup o}, and 180{sup o} arcs. This article describes dosimetry for these plaques and others used in the treatment of anterior eye melanomas. Methods and Materials: The EGSnrc user-code BrachyDose is used to perform Monte Carlo simulations. Plaques and seeds are fully modeled. Three-dimensional dose distributions for different plaque models, TG-43 calculations, and {sup 125}I (model 6711) and {sup 103}Pd (model 200) seeds are compared via depth-dose curves, tabulation of doses at points of interest, and isodose contours. Results: Doses at points of interest differ by up to 70% from TG-43 calculations. The inner lip reduces corneal doses. Matching plaque arc length to tumor extent reduces doses to eye regions outside the treatment area. Maintaining the same prescription dose, {sup 103}Pd offers lower doses to critical structures than {sup 125}I, with the exception of the sclera adjacent to the plaque. Conclusion: The Mayo Clinic plaques offer several advantages for anterior eye tumor treatments. Doses to regions outside the treatment area are significantly reduced. Doses differ considerably from TG-43 predictions, illustrating the importance of complete Monte Carlo simulations. Calculations take a few minutes on a single CPU, making BrachyDose sufficiently fast for routine clinical treatment planning.

  20. Brachytherapy seed and applicator localization via iterative forward projection matching algorithm using digital X-ray projections

    NASA Astrophysics Data System (ADS)

    Pokhrel, Damodar

    Interstitial and intracavitary brachytherapy plays an essential role in management of several malignancies. However, the achievable accuracy of brachytherapy treatment for prostate and cervical cancer is limited due to the lack of intraoperative planning and adaptive replanning. A major problem in implementing TRUS-based intraoperative planning is an inability of TRUS to accurately localize individual seed poses (positions and orientations) relative to the prostate volume during or after the implantation. For the locally advanced cervical cancer patient, manual drawing of the source positions on orthogonal films can not localize the full 3D intracavitary brachytherapy (ICB) applicator geometry. A new iterative forward projection matching (IFPM) algorithm can explicitly localize each individual seed/applicator by iteratively matching computed projections of the post-implant patient with the measured projections. This thesis describes adaptation and implementation of a novel IFPM algorithm that addresses hitherto unsolved problems in localization of brachytherapy seeds and applicators. The prototype implementation of 3-parameter point-seed IFPM algorithm was experimentally validated using a set of a few cone-beam CT (CBCT) projections of both the phantom and post-implant patient's datasets. Geometric uncertainty due to gantry angle inaccuracy was incorporated. After this, IFPM algorithm was extended to 5-parameter elongated line-seed model which automatically reconstructs individual seed orientation as well as position. The accuracy of this algorithm was tested using both the synthetic-measured projections of clinically-realistic Model-6711 125I seed arrangements and measured projections of an in-house precision-machined prostate implant phantom that allows the orientations and locations of up to 100 seeds to be set to known values. The seed reconstruction error for simulation was less than 0.6 mm/3o. For the physical phantom experiments, IFPM absolute accuracy for

  1. Metabolism and placental transfer of /sup 125/I-proinsulin and /sup 125/I-tyrosylated C-peptide in the pregnant rhesus monkey

    SciTech Connect

    Gruppuso, P.A.; Susa, J.B.; Sehgal, P.; Frank, B.; Schwartz, R.

    1987-10-01

    /sup 125/I-Proinsulin or /sup 125/I-tyrosylated-C-peptide (/sup 125/I-tyr-CP) was administered to pregnant Rhesus monkeys by bolus followed by constant infusion to examine placental transfer of these peptides. At the end of each infusion, fetuses were exsanguinated in situ via the umbilical vein. The bolus-constant infusion technique produced a steady state in maternal plasma of immunoprecipitable label, measured using excess insulin or C-peptide antiserum. In animals infused with /sup 125/I-proinsulin, analysis of umbilical venous plasma revealed no apparent transfer to the fetus of immunoprecipitable label. In animals infused with /sup 125/I-tyr-CP, 3-13% of the umbilical venous plasma radioactivity was immunoprecipitable, representing 1.4-5.8% of the immunoprecipitable radioactivity in maternal plasma at delivery. Gel filtration chromatography of umbilical venous plasma revealed that the immunoprecipitated moiety was a fragment of /sup 125/I-tyr-CP. Analysis of maternal plasma showed that the predominant peak of radioactivity represented intact C-peptide. A peak corresponding to the fetal immunoprecipitable peak was also present. Analysis of simultaneous maternal arterial and uterine vein plasma samples showed that degradation of /sup 125/I-tyr-CP occurred across the uterus. Studies in one nonpregnant and three postpartum animals indicated that pregnancy increased the rate of metabolism of /sup 125/I-tyr-CP. When /sup 125/I-tyr-CP was incubated with trophoblastic cells in culture, degradation to a species corresponding on gel filtration to the immunoprecipitable fetal metabolite was found. We conclude that proinsulin, like insulin, does not traverse the placenta. Immunoreactive fragments of C-peptide do cross, however, and pregnancy alters the metabolism of /sup 125/I-tyr-CP, probably owing to placental degradation.

  2. Microbial contamination detection at low levels by [125]I radiolabeling

    NASA Astrophysics Data System (ADS)

    Summers, David; Karouia, Fathi

    Contamination of mission spacecraft is an ongoing issue. A broad diversity of microorganisms have been detected in clean rooms where spacecraft are assembled. Some of which, depicted as oligotroph, are of special regard, as they are capable of colonizing inorganic surfaces like metal, and have been shown to be a concern for forward contamination of pristine celestial bodies. Currently, the NASA standard assay is the only approved assay intended for the enumeration of spores and heterotrophic microbial populations. However, culture-based microbial detection methods underestimate the viable microbial population. More recently, adenosine triphosphate (ATP) bioluminescence and limulus amebocyte lysate (LAL) assays, which employ measure-ments of selected metabolic products as a proxy of biomass, have been used successfully to circumvent the necessity of the growth of microorganisms in order to estimate the biodurdens associated with spacecraft assembly facility. However, these methods have limitation in the amount of cells that can be detected, i.e., 103 cells, and the type of microorganisms respec-tively. This work seeks to develop a new highly sensitive method for the determination of bioburdens (and the detection of microorganisms and life) that is independant of the type of organism while preserving a good turn-around time for analysis for planetary protection purposes. The assay is based on the detection of the organism's protein by labeling them by radioiodination, 125 I, of aromatic rings on tyrosine amino acids residues. Radiolabeling techniques are inherently sensitive and 125 I, in particular, benefits from a 60 day half-life, providing greater activity and signal per unit number of labels. Furthermore, microorganisms can contain over 50% of protein by dry weight. Thus, just one label per protein increases the sensitivity, compared to the ATP and LAL assays, by one and three orders of magnitude by using standard detection methods and the use of multiphoton

  3. Quantitative pharmacological analysis of 2-125I-iodomelatonin binding sites in discrete areas of the chicken brain

    SciTech Connect

    Siuciak, J.A.; Krause, D.N.; Dubocovich, M.L. )

    1991-09-01

    The authors have localized and characterized 2-125I-iodomelatonin binding sites in the chicken brain using in vitro quantitative autoradiography. Binding sites were widely distributed throughout the chicken brain, predominantly in regions associated with the visual system. The specific binding of 2-125I-iodomelatonin to discrete chicken brain areas was found to be saturable, reversible, and of high affinity. The specific binding of 2-125I-iodomelatonin (75 pm) was quantitated for 40 identifiable brain regions. Eight brain regions were chosen for binding characterization and pharmacological analysis: optic tectum, Edinger-Westphal nucleus, oculomotor nucleus, nucleus rotundus, ventral supraoptic decussation, ventrolateral geniculate nucleus, neostriatum, and ectostriatum. These regions showed no rostral-caudal gradient in 2-125I-iodomelatonin specific binding, and saturation analysis revealed a single class of high-affinity sites with KD values in the range of 33-48 pM and receptor site density (Bmax) ranging from 31 to 58 fmol/mg protein. Competition experiments carried out with various indoles revealed a similar order of pharmacological affinities in these areas: melatonin greater than 6-chloromelatonin greater than methoxyluzindole greater than N-acetylserotonin greater than luzindole much greater than 5-HT greater than 5-methoxytryptamine. The affinity constants determined by quantitative autoradiography for these compounds to compete for 2-125I-iodomelatonin binding in the optic tectum correlated well with the affinities in chicken brain membranes at 25 degrees C (r = 0.966; slope = 0.845; n = 7) and 0 degree C (r = 0.946; slope = 0.379; n = 7), chicken retinal membranes (r = 0.973; slope = 0.759; n = 7), and the potency or affinity of these compounds to affect the calcium-dependent release of 3H-dopamine from the rabbit retina (r = 0.902; slope = 0.506; n = 6).

  4. Differential dose contributions on total dose distribution of 125I brachytherapy source

    PubMed Central

    Camgöz, B.; Yeğin, G.; Kumru, M.N.

    2010-01-01

    This work provides an improvement of the approach using Monte Carlo simulation for the Amersham Model 6711 125I brachytherapy seed source, which is well known by many theoretical and experimental studies. The source which has simple geometry was researched with respect to criteria of AAPM Tg-43 Report. The approach offered by this study involves determination of differential dose contributions that come from virtual partitions of a massive radioactive element of the studied source to a total dose at analytical calculation point. Some brachytherapy seeds contain multi-radioactive elements so the dose at any point is a total of separate doses from each element. It is momentous to know well the angular and radial dose distributions around the source that is located in cancerous tissue for clinical treatments. Interior geometry of a source is effective on dose characteristics of a distribution. Dose information of inner geometrical structure of a brachytherapy source cannot be acquired by experimental methods because of limits of physical material and geometry in the healthy tissue, so Monte Carlo simulation is a required approach of the study. EGSnrc Monte Carlo simulation software was used. In the design of a simulation, the radioactive source was divided into 10 rings, partitioned but not separate from each other. All differential sources were simulated for dose calculation, and the shape of dose distribution was determined comparatively distribution of a single-complete source. In this work anisotropy function was examined also mathematically. PMID:24376927

  5. Synthesis of [{sup 125}I]iodoDPA-713: A new probe for imaging inflammation

    SciTech Connect

    Wang, Haofan; Pullambhatla, Mrudula; Guilarte, Tomas R.; Mease, Ronnie C.; Pomper, Martin G.

    2009-11-06

    [{sup 125}I]IodoDPA-713 [{sup 125}I]1, which targets the translocator protein (TSPO, 18 kDa), was synthesized in seven steps from methyl-4-methoxybenzoate as a tool for quantification of inflammation in preclinical models. Preliminary in vitro autoradiography and in vivo small animal imaging were performed using [{sup 125}I]1 in a neurotoxicant-treated rat and in a murine model of lung inflammation, respectively. The radiochemical yield of [{sup 125}I]1 was 44 {+-} 6% with a specific radioactivity of 51.8 GBq/{mu}mol (1400 mCi/{mu}mol) and >99% radiochemical purity. Preliminary studies showed that [{sup 125}I]1 demonstrated increased specific binding to TSPO in a neurotoxicant-treated rat and increased radiopharmaceutical uptake in the lungs of an experimental inflammation model of lung inflammation. Compound [{sup 125}I]1 is a new, convenient probe for preclinical studies of TSPO activity.

  6. Dosimetric effect of tissue heterogeneity for 125I prostate implants

    PubMed Central

    Oliveira, Susana Maria; Teixeira, Nuno José; Fernandes, Lisete; Teles, Pedro; Vaz, Pedro

    2014-01-01

    Aim To use Monte Carlo (MC) together with voxel phantoms to analyze the tissue heterogeneity effect in the dose distributions and equivalent uniform dose (EUD) for 125I prostate implants. Background Dose distribution calculations in low dose-rate brachytherapy are based on the dose deposition around a single source in a water phantom. This formalism does not take into account tissue heterogeneities, interseed attenuation, or finite patient dimensions effects. Tissue composition is especially important due to the photoelectric effect. Materials and methods The computed tomographies (CT) of two patients with prostate cancer were used to create voxel phantoms for the MC simulations. An elemental composition and density were assigned to each structure. Densities of the prostate, vesicles, rectum and bladder were determined through the CT electronic densities of 100 patients. The same simulations were performed considering the same phantom as pure water. Results were compared via dose–volume histograms and EUD for the prostate and rectum. Results The mean absorbed doses presented deviations of 3.3–4.0% for the prostate and of 2.3–4.9% for the rectum, when comparing calculations in water with calculations in the heterogeneous phantom. In the calculations in water, the prostate D90 was overestimated by 2.8–3.9% and the rectum D0.1cc resulted in dose differences of 6–8%. The EUD resulted in an overestimation of 3.5–3.7% for the prostate and of 7.7–8.3% for the rectum. Conclusions The deposited dose was consistently overestimated for the simulation in water. In order to increase the accuracy in the determination of dose distributions, especially around the rectum, the introduction of the model-based algorithms is recommended. PMID:25337412

  7. Interaction of cultured mammalian cells with [125I] diphtheria toxin.

    PubMed Central

    Bonventre, P F; Saelinger, C B; Ivins, B; Woscinski, C; Amorini, M

    1975-01-01

    The characteristics of cell adsorption and pinocytotic uptake of diphtheria toxin by several mammalian cell types were studied. Purified toxin iodinated by a solid-state lactoperoxidase method provided preparations of high specific activity and unaltered biological activity. Dephtheria toxin-sensitive HEp-2 cells and guinea pig macrophage cultures were compared with resistant mouse L-929 cells. At 37 C the resistant cells in monolayer adsorbed and internalized [125I] toxin to a greater extent than did the HEp-2 cell cultures; no significant differences were observed at 5 C. Ammonium chloride protection levels did not alter uptake of toxin by either L-929 OR HEp-2 cells. Biological activity of the iodinated toxin, however, was negated provided the presence of ammonium chloride was maintained. The ammonium salt appears to maintain toxin in a state amenable to antitoxin neutralization. Guinea pig macrophages internalized iodinated toxin to a level 10 times greater than the established cell lines. In spite of the increased uptake of toxin by the endocytic cells, ammonium chloride prevented expression of toxicity. In an artificial system, toxin adsorbed to polystyrene latex spheres and internalized by guinea pig macrophages during phagocytosis did express biological activity. Ammonium chloride afforded some but not total protection against toxin present in the phagocytic vacuoles. The data suggest that two mechanisms of toxin uptake by susceptible cells may be operative. Toxin taken into the cell by a pinocytotic process probably is not ordinarily of physiological significance since it is usually degraded by lysosomal enzymes before it can reach cytoplasmic constituents on which it acts. When large quantities of toxin are pinocytized, toxicity may be expressed before enzymatic degradation is complete. A more specific uptake involving direct passage of the toxin through the plasma membrane may be the mechanism leading to cell death in the majority of instances. PMID

  8. COMS eye plaque brachytherapy dosimetry simulations for {sup 103}Pd, {sup 125}I, and {sup 131}Cs

    SciTech Connect

    Melhus, Christopher S.; Rivard, Mark J.

    2008-07-15

    Monte Carlo (MC) simulations were performed to estimate brachytherapy dose distributions for Collaborative Ocular Melanoma Study (COMS) eye plaques. Brachytherapy seed models 200, 6711, and CS-1 Rev2 carrying {sup 103}Pd, {sup 125}I, and {sup 131}Cs radionuclides, respectively, were modeled and benchmarked against previously published values. Calculated dose rate constants {sub MC}{lambda} were 0.684, 0.924, and 1.052 cGy h{sup -1} U{sup -1} ({+-}2.6%, k=1 uncertainty) for models 200, 6711, and CS-1 Rev2, respectively. The seeds were distributed into 10, 12, 14, 16, 18, 20, and 22 mm-diameter COMS eye plaques. Simulations were performed in both heterogeneous and homogeneous environments, where the latter were in-water and the former included the silastic seed carrier insert and gold-alloy plaque. MC-based homogenous central axis dose distributions agreed within 2%{+-}1% ({+-}1 s.d.) to hand-calculated values. For heterogeneous simulations, notable photon attenuation was observed, with dose reduction at 5 mm of 19%, 11%, and 9% for {sup 103}Pd, {sup 125}I, and {sup 131}Cs, respectively. A depth-dependent correction factor was derived to correct homogenous central-axis dose distributions for plaque component heterogeneities, which were found to be significant at short radial distances.

  9. An (125)I-labeled octavalent peptide fluorescent nanoprobe for tumor-homing imaging in vivo.

    PubMed

    Luo, Haiming; Shi, Jiyun; Jin, Honglin; Fan, Di; Lu, Lisen; Wang, Fan; Zhang, Zhihong

    2012-06-01

    Targeting radiopeptides are promising agents for radio-theranostics. However, in vivo evaluation of their targeting specificity is often obscured by their short biologic half-lives and low binding affinities. Here, we report an approach to efficiently examine targeting radiopeptides with a new class of octavalent peptide fluorescent nanoprobe (Octa-FNP) platform, which is composed of candidate targeting peptides and a tetrameric far-red fluorescent protein (tfRFP) scaffold. To shed light on this process, (125)I-Octa-FNP, (125)I-tfRFP and (125)I-peptide were synthesized, and their targeting functionalities were compared. Both fluorescence imaging and radioactive quantification results confirmed that (125)I-Octa-FNP had a significantly higher cellular binding capability than (125)I-tfRFP. In vivo biodistribution studies show that at 6 h post-injection, (125)I-Octa-FNP had 2-fold and 30-fold higher tumor uptake than that of (125)I-tfRFP and (125)I-peptide, respectively. Moreover, γ-imaging at 24 h post-injection revealed a remarkable accumulation of (125)I-Octa-FNP in the tumor while maintaining an extremely low background contrast, which was further confirmed by immunofluorescence analysis. These data suggested that, as an engineered and multivalent platform, Octa-FNP could enhance the tumor targeting of a designed peptide and provide excellent contrast radioimaging, making it a valuable tool for the evaluation of the targeting ability of specifically designed radiopeptides for cancer theranostics.

  10. Determination of the intrinsic energy dependence of LiF:Mg,Ti thermoluminescent dosimeters for {sup 125}I and {sup 103}Pd brachytherapy sources relative to {sup 60}Co

    SciTech Connect

    Reed, J. L. Micka, J. A.; Culberson, W. S.; DeWerd, L. A.; Rasmussen, B. E.; Davis, S. D.

    2014-12-15

    Purpose: To determine the intrinsic energy dependence of LiF:Mg,Ti thermoluminescent dosimeters (TLD-100) for {sup 125}I and {sup 103}Pd brachytherapy sources relative to {sup 60}Co. Methods: LiF:Mg,Ti TLDs were irradiated with low-energy brachytherapy sources and with a {sup 60}Co teletherapy source. The brachytherapy sources measured were the Best 2301 {sup 125}I seed, the OncoSeed 6711 {sup 125}I seed, and the Best 2335 {sup 103}Pd seed. The TLD light output per measured air-kerma strength was determined for the brachytherapy source irradiations, and the TLD light output per air kerma was determined for the {sup 60}Co irradiations. Monte Carlo (MC) simulations were used to calculate the dose-to-TLD rate per air-kerma strength for the brachytherapy source irradiations and the dose to TLD per air kerma for the {sup 60}Co irradiations. The measured and MC-calculated results for all irradiations were used to determine the TLD intrinsic energy dependence for {sup 125}I and {sup 103}Pd relative to {sup 60}Co. Results: The relative TLD intrinsic energy dependences (relative to {sup 60}Co) and associated uncertainties (k = 1) were determined to be 0.883 ± 1.3%, 0.870 ± 1.4%, and 0.871 ± 1.5% for the Best 2301 seed, OncoSeed 6711 seed, and Best 2335 seed, respectively. Conclusions: The intrinsic energy dependence of TLD-100 is dependent on photon energy, exhibiting changes of 13%–15% for {sup 125}I and {sup 103}Pd sources relative to {sup 60}Co. TLD measurements of absolute dose around {sup 125}I and {sup 103}Pd brachytherapy sources should explicitly account for the relative TLD intrinsic energy dependence in order to improve dosimetric accuracy.

  11. Isolation of /sup 125/I-concanavalin A-labeled plasma membrane from unfertilized mouse eggs

    SciTech Connect

    Boldt, J.; Wolf, D.P.

    1987-04-01

    A procedure was developed for isolation of plasma membrane (PM) preparations from unfertilized mouse eggs. Zona-free mouse eggs prepared by the method of Boldt and Wolf (Gamete Res 13:213-222, 1986) were labeled with 125I-concanavalin A (ConA) prior to sonication and fractionation on iso-osmotic self-generated Percoll density gradients. Experiments using the ConA-specific sugar alpha-methylmannoside (alpha MM) indicated that 125I-ConA bound specifically to the egg PM. Greater than 95% of 125I-ConA binding to zona-free eggs was blocked in the presence of 0.1 M alpha MM, and incubation of eggs in alpha MM after 125I-ConA labeling caused release of 85-90% of bound label. Fractionation of 125I-ConA-labeled eggs by Percoll density gradient centrifugation yielded a single radioactive peak at density = 1.025, corresponding to egg PM material. Prolonged incubation of 125I-ConA-labeled eggs or egg sonicates prior to fractionation did not alter the location of the radioactive peak, indicating that 125I-ConA did not label other organelles. As a control, human erythrocytes were labeled with 125I-ConA and fractionated under identical experimental conditions and yielded a single radioactive peak at density (1.020) comparable to that observed for 125I-ConA-labeled eggs. These results indicate that 125I-ConA can be used as a specific marker to support PM isolation from small numbers of zona-free mouse eggs.

  12. Preferential reduction of binding of sup 125 I-iodopindolol to beta-1 adrenoceptors in the amygdala of rat after antidepressant treatments

    SciTech Connect

    Ordway, G.A.; Gambarana, C.; Tejani-Butt, S.M.; Areso, P.; Hauptmann, M.; Frazer, A. )

    1991-05-01

    This study utilized quantitative receptor autoradiography to examine the effects of repeated administration of antidepressants to rats on the binding of the beta adrenoceptor antagonist, {sup 125}I-iodopindolol ({sup 125}I-IPIN) to either beta-1 or beta-2 adrenoceptors in various regions of brain. Antidepressants were selected to represent various chemical and pharmacological classes including tricyclic compounds (desipramine and protriptyline), monoamine oxidase inhibitors (clorgyline, phenelzine and tranylcypromine), atypical antidepressants (mianserin and trazodone) and selective inhibitors of the uptake of serotonin (citalopram and sertraline). Additionally, rats were treated with various psychotropic drugs that lack antidepressant efficacy (cocaine, deprenyl, diazepam and haloperidol). Repeated treatment of rats with desipramine, protriptyline, clorgyline, phenelzine, tranylcypromine or mianserin reduced the binding of {sup 125}I-IPIN to beta-1 adrenoceptors in many brain areas. Only in the basolateral and lateral nuclei of the amygdala did all six of these antidepressants significantly reduce {sup 125}I-IPIN binding to beta-1 adrenoceptors. In these amygdaloid nuclei, the magnitude of the reduction in the binding of {sup 125}I-IPIN caused by each of these drugs was comparable to or greater than the reduction in binding produced in any other region of brain. Reductions of binding of {sup 125}I-IPIN after antidepressant treatments were not consistently observed in the cortex, the area of brain examined most often in homogenate binding studies. Only the monoamine oxidase inhibitors caused reductions in the binding of {sup 125}I-IPIN to beta-2 adrenoceptors, and this effect was generally localized to the amygdala and hypothalamus.

  13. 125I-labeled anti-bFGF monoclonal antibody inhibits growth of hepatocellular carcinoma

    PubMed Central

    Hu, Peng-Hui; Pan, Lan-Hong; Wong, Patrick Ting-Yat; Chen, Wen-Hui; Yang, Yan-Qing; Wang, Hong; Xiang, Jun-Jian; Xu, Meng

    2016-01-01

    AIM: To investigate the inhibitory efficacy of 125I-labeled anti-basic fibroblast growth factor (bFGF) monoclonal antibody (mAb) in hepatocellular carcinoma (HCC). METHODS: bFGF mAb was prepared by using the 1G9B9 hybridoma cell line with hybridization technology and extracted from ascites fluid through a Protein G Sepharose affinity column. After labeling with 125I through the chloramine-T method, bFGF mAb was further purified by a Sephadex G-25 column. Gamma radiation counter GC-1200 detected radioactivity of 125I-bFGF mAb. The murine H22 HCC xenograft model was established and randomized to interventions with control (phosphate-buffered saline), 125I-bFGF mAb, 125I plus bFGF mAb, bFGF mAb, or 125I. The ratios of tumor inhibition were then calculated. Expression of bFGF, fibroblast growth factor receptor (FGFR), platelet-derived growth factor, and vascular endothelial growth factor (VEGF) mRNA was determined by quantitative reverse transcriptase real-time polymerase chain reaction. RESULTS: The purified bFGF mAb solution was 8.145 mg/mL with a titer of 1:2560000 and was stored at -20 °C. After coupling, 125I-bFGF mAb was used at a 1: 1280000 dilution, stored at 4 °C, and its specific radioactivity was 37 MBq/mg. The corresponding tumor weight in the control, 125I, bFGF mAb, 125I plus bFGF mAb, and 125I-bFGF mAb groups was 1.88 ± 0.25, 1.625 ± 0.21, 1.5 ± 0.18, 1.41 ± 0.16, and 0.98 ± 0.11 g, respectively. The tumor inhibition ratio in the 125I, bFGF mAb, 125I plus bFGF mAb, and 125I-bFGF mAb groups was 13.6%, 20.2%, 25.1%, and 47.9%, respectively. Growth of HCC xenografts was inhibited significantly more in the 125I-bFGF mAb group than in the other groups (P < 0.05). Expression of bFGF and FGFR mRNA in the 125I-bFGF mAb group was significantly decreased in comparison with other groups (P < 0.05). Groups under interventions revealed increased expression of VEGF mRNA (except for 125I group) compared with the control group. CONCLUSION: 125I-bFGF m

  14. Iron in seeds – loading pathways and subcellular localization

    PubMed Central

    Grillet, Louis; Mari, Stéphane; Schmidt, Wolfgang

    2014-01-01

    Iron (Fe) is one of the most abundant elements on earth, but its limited bioavailability poses a major constraint for agriculture and constitutes a serious problem in human health. Due to an improved understanding of the mechanisms that control Fe homeostasis in plants, major advances toward engineering biofortified crops have been made during the past decade. Examples of successful biofortification strategies are, however, still scarce and the process of Fe loading into seeds is far from being well understood in most crop species. In particular in grains where the embryo represents the main storage compartment such as legumes, increasing the seed Fe content remains a challenging task. This review aims at placing the recently identified actors in Fe transport into the unsolved puzzle of grain filling, taking the differences of Fe distribution between various species into consideration. We summarize the current knowledge on Fe transport between symplasmic and apoplasmic compartments, and provide models for Fe trafficking and localization in different seed types that may help to develop high seed Fe germplasms. PMID:24427161

  15. Effects of hyperthermia on binding, internalization, and degradation of epidermal growth factor. [/sup 125/I

    SciTech Connect

    Magun, B.E.; Fennie, C.W.

    1981-04-01

    /sup 125/I-epidermal growth factor was used as a molecular probe to study the effects of hyperthermia and local anesthetics on cultured Rat-1 cells. Heating cells at 45/sup 0/C for times up to 1 h caused a continuous decrease in EGF binding. Scatchard analysis showed that the decreased binding resulted from a decrease in the affinity of the EGF receptors rather than from a decrease in receptor number. Exposure to 42/sup 0/C had no effect on degradation. We compared the effects of heat to those caused by the local anesthetics procaine the lidocaine, which have been shown to prevent EGF degradation. Because procaine and lidocaine have been shown by others to potentiate the killing effects of hyperthermia on tumors and in cultured cells, we suggest that hyperthermia and the local anesthetics may act at the same cellular site. By inhibiting the action of lysosomes, hyperthermia and local anesthetics may permit potentially toxic materials to enter the cell by endocytosis, where they would accumulate and induce lethal damage.

  16. Assessment of [125I]WYE-230949 as a Novel Histamine H3 Receptor Radiopharmaceutical

    PubMed Central

    Lewis, David Y.; Champion, Sue; Wyper, David; Dewar, Deborah; Pimlott, Sally

    2014-01-01

    Histamine H3 receptor therapeutics have been proposed for several diseases such as schizophrenia, attention deficit hyperactivity disorder, Alzheimer's disease and obesity. We set out to evaluate the novel compound, [125I]WYE-230949, as a potential radionuclide imaging agent for the histamine H3 receptor in brain. [125I]WYE-230949 had a high in vitro affinity for the rat histamine H3 receptor (Kd of 6.9 nM). The regional distribution of [125I]WYE-230949 binding sites in rat brain, demonstrated by in vitro autoradiography, was consistent with the known distribution of the histamine H3 receptor. Rat brain uptake of intravenously injected [125I]WYE-230949 was low (0.11 %ID/g) and the ratio of specific: non-specific binding was less than 1.4, as determined by ex vivo autoradiography. In plasma, metabolism of [125I]WYE-230949 into a less lipophilic species occurred, such that less than 38% of the parent compound remained 30 minutes after injection. Brain uptake and metabolism of [125I]WYE-230949 were increased and specific binding was reduced in anaesthetised compared to conscious rats. [125I]WYE230949 is not a potential radiotracer for imaging rat histamine H3 receptors in vivo due to low brain uptake, in vivo metabolism of the parent compound and low specific binding. PMID:25542008

  17. ( sup 125 I)Iodoazidococaine, a photoaffinity label for the haloperidol-sensitive sigma receptor

    SciTech Connect

    Kahoun, J.R.; Ruoho, A.E. )

    1992-02-15

    A carrier-free radioiodinated cocaine photoaffinity label, (-)-3-({sup 125}I)iodo-4-azidococaine (({sup 125}I)IACoc), has been synthesized and used as a probe for cocaine-binding proteins. Photoaffinity labeling with 0.5 nM ({sup 125}I)IACoc resulted in selective derivatization of a 26-kDa polypeptide with the pharmacology of a sigma receptor in membranes derived from whole rat brain, rat liver, and human placenta. ({sup 125}I)IACoc labeling of the 26-kDa polypeptide was also inhibited by 10 {mu}M imipramine, amitriptyline, fluoxetine, benztropine, and tetrabenazine. The size of the ({sup 125}I)I-ACoc-labeled proteins is consistent with the size of proteins photolabeled in guinea pig brain and liver membranes by using the sigma photolabel azido-({sup 3}H)DTG. Kinetic analysis of ({sup 125}I)IACoc binding to rat liver microsomes revealed two sites with K{sub d} values of 19 and 126 pM, respectively. The presence or absence of proteolytic inhibitors during membrane preparation did not alter the size of the photolabeled sigma receptor, indicating that the 26-kDa polypeptide was not derived from a larger protein. In summary, ({sup 125}I)IACoc is a potent and highly specific photoaffinity label for the haloperidol-sensitive sigma receptor and will be useful for its biochemical and molecular characterization.

  18. Assessment of [125I]WYE-230949 as a novel histamine H3 receptor radiopharmaceutical.

    PubMed

    Lewis, David Y; Champion, Sue; Wyper, David; Dewar, Deborah; Pimlott, Sally

    2014-01-01

    Histamine H3 receptor therapeutics have been proposed for several diseases such as schizophrenia, attention deficit hyperactivity disorder, Alzheimer's disease and obesity. We set out to evaluate the novel compound, [125I]WYE-230949, as a potential radionuclide imaging agent for the histamine H3 receptor in brain. [125I]WYE-230949 had a high in vitro affinity for the rat histamine H3 receptor (Kd of 6.9 nM). The regional distribution of [125I]WYE-230949 binding sites in rat brain, demonstrated by in vitro autoradiography, was consistent with the known distribution of the histamine H3 receptor. Rat brain uptake of intravenously injected [125I]WYE-230949 was low (0.11 %ID/g) and the ratio of specific: non-specific binding was less than 1.4, as determined by ex vivo autoradiography. In plasma, metabolism of [125I]WYE-230949 into a less lipophilic species occurred, such that less than 38% of the parent compound remained 30 minutes after injection. Brain uptake and metabolism of [125I]WYE-230949 were increased and specific binding was reduced in anaesthetised compared to conscious rats. [125I]WYE230949 is not a potential radiotracer for imaging rat histamine H3 receptors in vivo due to low brain uptake, in vivo metabolism of the parent compound and low specific binding.

  19. Tissue uptake and catabolic studies of /sup 125/I SS-B (La) injected into mice

    SciTech Connect

    Schrieber, L.; Melsom, R.D.; Venables, P.J.; Maini, R.N.

    1984-04-01

    The radiolabeled soluble cellular antigen /sup 125/I SS-B (La) has a plasma half-life of 3 min following iv injection into BALB/C mice. Uptake by Kupffer cells (KC) and proximal renal tubular (PRT) cells was demonstrated by autoradiography (ARG). That trichloracetic acid (TCA)-soluble products of /sup 125/I SS-B appeared in plasma within 1 min of iv injection suggests rapid in vivo breakdown. Activated peritoneal macrophages (APM) degraded /sup 125/I SS-B in a time- and cell-dose-dependent fashion. These findings suggest that the plasma clearance and catabolism of /sup 125/I SS-B may be dependent on its interaction with phagocytic cells. This rapid antigen elimination may protect against harmful autoantibody responses.

  20. Intramolecular effects of /sup 125/I decay in o-iodotyrosine

    SciTech Connect

    Berridge, M.S.; Jiang, V.W.; Welch, M.J.

    1980-06-01

    As a model for iodinated proteins, 3-(/sup 125/I)iodo(U-/sup 14/C)tyrosine was synthesized by the chloramine-T method from (U-/sup 14/C)tyrosine. The products remaining after the iodine had decayed were characterized chromatographically. A reference system was used to correct for hydrolysis and secondary radiolytic effects. All products due to /sup 125/I decay were small polar molecules. The results demonstrate that after the Auger cascade accompanying /sup 125/I decay, a distribution of charge throughout the molecule occurs before disruption of the molecule. A coulombic explosion mechanism with some contributions due to internal radiolysis and charge neutralization is proposed for the destruction of the aromatic ring. Implications of these results for proteins labeled with /sup 125/I are also discussed.

  1. (125I)iodoazidococaine, a photoaffinity label for the haloperidol-sensitive sigma receptor.

    PubMed Central

    Kahoun, J R; Ruoho, A E

    1992-01-01

    A carrier-free radioiodinated cocaine photo-affinity label, (-)-3-(125I)iodo-4-azidococaine [(125I)IACoc], has been synthesized and used as a probe for cocaine-binding proteins. Photoaffinity labeling with 0.5 nM (125I)IACoc resulted in selective derivatization of a 26-kDa polypeptide with the pharmacology of a sigma receptor in membranes derived from whole rat brain, rat liver, and human placenta. Covalent labeling of the 26-kDa polypeptide was inhibited by 1 microM haloperidol, di(2-tolyl)guanidine (DTG), 3-(3-hydroxyphenyl)-N-(1-propyl)piperidine (3-PPP), dextromethorphan, and carbetapentane. Stereoselective protection of (125I)IACoc photolabeling by 3-PPP [(+)-3-PPP more potent than (-)-3-PPP] was observed. (125I)IACoc labeling of the 26-kDa polypeptide was also inhibited by 10 microM imipramine, amitriptyline, fluoxetine, benztropine, and tetrabenazine. The size of the (125I)I-ACoc-labeled proteins is consistent with the size of proteins photolabeled in guinea pig brain and liver membranes by using the sigma photolabel azido-[3H]DTG. Kinetic analysis of (125I)IACoc binding to rat liver microsomes revealed two sites with Kd values of 19 and 126 pM, respectively. The presence or absence of proteolytic inhibitors during membrane preparation did not alter the size of the photolabeled sigma receptor, indicating that the 26-kDa polypeptide was not derived from a larger protein. In summary, (125I)IACoc is a potent and highly specific photoaffinity label for the haloperidol-sensitive sigma receptor and will be useful for its biochemical and molecular characterization. Images PMID:1311097

  2. Ornithine decarboxylase activity and: [125I]iododeoxyuridine incorporation in rat prostate.

    PubMed Central

    Fuller, D J; Donaldson, L J; Thomas, G H

    1975-01-01

    The relationship between ornithine decarboxylase activity and [125I]iododexyuridine incorporation was studied in prostates from castrated rats (aged 5, 26 and 80 weeks) injected daily with testosterone for up to 10 days. The results suggest that ornithine decarboxylase activity is a parameter of secretory activity, rather than growth, in the ventral prostate. In the dorsolateral prostate, ornithine decarboxylase activity tends to parallel [125I]iododeoxyuridine incorporation. PMID:1212206

  3. Evidence for multiple pathways of sup 125 I-insulin internalization in isolated rat hepatocytes

    SciTech Connect

    Moss, A.L.

    1988-01-01

    Insulin internalization has been characterized frequently as occurring by the coated pit pathway of receptor-mediated endocytosis. The present study in rat hepatocytes demonstrates that insulin internalization is, in part, receptor-mediated, but also occurs by nonreceptor-mediated or fluid-phase endocytosis. Endocytosis was probed with four perturbations: depletion of metabolic energy with anoxia, inhibition of endocytosis with phenylarsine oxide, disruption of coated pits with hyperosmolar sucrose, and inhibition of receptor recycling or ligand-receptor dissociation with monensin. Internalization of {sup 125}I-epidermal growth factor and {sup 125}I-asialofetuin was compared to {sup 125}I-insulin internalization. Pretreatment of cells with anoxia or hyperosmolarity inhibited {sup 125}I-insulin internalization by 40%; pretreatment with phenylarsine oxide resulted in inhibition by 54%. Monensin has no effect on uptake or degradation of a high insulin concentration, but inhibited degradation of a low insulin concentration resulting in intracellular accumulation of insulin. In contract, all four perturbations inhibited {sup 125}I-asialofetuin internalization by greater than 90%. Phenylarsine oxide almost completely abolished {sup 125}I-epidermal growth factor uptake; the other perturbations caused partial inhibition. Competition studies demonstrated that insulin internalization was receptor-mediated over a wide concentration range.

  4. Heparin blocks /sup 125/I-calmodulin internalization by isolated rat renal brush border membrane vesicles

    SciTech Connect

    Meezan, E.; Elgavish, A.; Roden, L.; Wallace, R.W.

    1986-03-05

    /sup 125/I-Calmodulin is internalized by isolated rat renal brush border membrane vesicles (BBV) in a time, temperature and calcium dependent manner. Internalization of /sup 125/I-calmodulin into the osmotically sensitive space of BBV was distinguished from binding of the ligand to the outer BBV surface by examining the interaction of ligand and BBV at different medium osmolarities (300-1100 mosm), uptake was inversely proportional to medium osmolarity. Internalized /sup 125/I-calmodulin was intact and Western blots of solubilized BBV with /sup 125/I-calmodulin demonstrated the presence of several calmodulin-binding proteins of 143, 118, 50, 47.5, 46.5 and 35 kilodaltons which could represent potential intravesicular binding sites for the ligand. Heparin and the related glycosaminoglycan heparin sulfate both showed a dose-dependent inhibition (0.5-50 ..mu..g/ml) of /sup 125/I-calmodulin uptake by BBV, but other sulfated and nonsulfated glycosaminoglycans including chondroitin sulfates, keratan sulfate and hyaluronic acid showed little or no inhibitory effect. Desulfation of heparin virtually abolished the inhibition of uptake while depolymerization reduced it. Heparin did not block the binding of /sup 125/I-calmodulin to BBV proteins as assessed by Western blotting technique suggesting its effect was on internalization of the ligand rather than on its association with internal membrane proteins.

  5. Partition of 125I-iodoantipyrine among erythrocytes, plasma, and renal cortex in the dog.

    PubMed

    Clausen, G; Hope, A; Aukland, K

    1979-09-01

    The tissue/blood partition coefficient, lambda tb, defined as the amount of blood having the same tracer content as one unit of tissue at diffusion equilibrium, was determined for 125I-iodoantipyrine (I-Ap) and tritiated water (THO) in the dog kidney cortex. Measurements were made after in vivo equilibration for 75 to 300 s and with liver circulation excluded. In 18 kidneys, lambda tb for I-Ap averaged 1.38 (S.D. 0.13) w/w (weight/weight), without significant correlation to hematocrit (range: 23-43) or to urine pH (range 5.5-8.6). The lambda tb for THO averaged 0.97 (S.D. 0.06) v/w (volume/weight), close to the relative water contents. Erythrocyte/plasma partition for I-Ap was 0.82 w/w, compared to a water partition of 0.72. Thus, at diffusion equilibrium the apparent I-Ap concentration in renal cortical and red cell water exceeds that of plasma water by 14 and 60%, respectively. It follows that I-Ap cannot be used as a general indicator for total tissue water content. When used for measurement of local blood flow and modum Kety, lambda tb must be determined for each tissue and species.

  6. The Mechanism of Computed Tomography-Guided 125I Particle in Treating Lung Cancer

    PubMed Central

    Cheng, Jianzhong; Ma, Shaozeng; Yang, Guanghua; Wang, Lisen; Hou, Wei

    2017-01-01

    Background The incidence of malignant tumor has gradually increased. How to improve the survival and quality of life of patients who lose the opportunity for surgery or who are unwilling to receive surgery remains an obstacle. At present, 125I particle interstitial implant therapy has been applied in a variety of treatments of tumors. However, the mechanism of computed tomography (CT)-guided 125I particle therapy in lung cancer has not been fully elucidated. Material/Methods A total of 42 patients with advanced non-small cell lung cancer were retrospectively analyzed between January 2013 and December 2013, including 19 patients who received CT-guided 125I particle therapy and 23 patients who received chemotherapy. Curative effect and adverse reactions at 6 months and 12 months were compared and analyzed. A rabbit lung cancer VX2 model was treated by 125I particle implantation therapy under CT guidance. The change in tumor volume was detected. Tumor cell apoptosis was tested by flow cytometry. Bcl-2 and Bax expression were determined by real-time polymerase chain reaction (PCR) and Western blot. Results 125I particle therapy obviously reduced tumor volume after 6 months and 12 months. It showed significantly higher efficiency (57.9%, 57.9%) and control (78.9%, 73.7%) than the rates of efficiency and control in the chemotherapy group (P<0.05). 125I particle implantation therapy markedly suppressed rabbit VX2 transplanted tumor cell proliferation, promoted tumor regression, induced tumor cell apoptosis, reduced Bcl-2 expression, and upregulated Bax expression level (P<0.05). Conclusions CT-guided 125I particle implantation therapy can inhibit tumor proliferation and growth by regulating the expression of apoptosis-related genes and proteins, which is a promising approach in lung cancer treatment. PMID:28095393

  7. Tritiated-nicotine and /sup 125/I-alpha-bungarotoxin-labeled nicotinic receptors in the interpeduncular nucleus of rats. I. Subnuclear distribution

    SciTech Connect

    Hamill, G.S.; Clarke, P.B.; Pert, A.; Jacobowitz, D.M.

    1986-09-15

    The distribution of nicotinic receptors within the interpeduncular nucleus (IPN) was determined in male rats following in vitro labeling with the cholinergic ligands /sup 3/H-nicotine and /sup 125/I-alpha-bungarotoxin (BTX). Autoradiographic images of two rostrocaudal levels of IPN were analyzed by computer-assisted densitometry and the optical density contributed by displaceable labeling was determined in the rostral, central, intermediate, and lateral subnuclei. /sup 3/H-nicotine labeling density within the four subnuclei differs significantly at both levels of IPN. The greatest density of labeling is localized in the rostral subnucleus, followed in order of diminishing density by the central, intermediate, and lateral subnuclei. Labeling within the rostral subnucleus is prominently localized within its central zone. In the central subnucleus, a dense concentration of binding sites is apparent in the middle region, adjacent to less dense vertically oriented columns; /sup 3/H-nicotine binding sites in the lateral subnuclei appear to be most concentrated medially, adjacent to the intermediate subnuclei. /sup 125/I-BTX labeling density within the four subnuclei also differs significantly at both levels of IPN. The greatest density of labeling is found in the rostral subnucleus, followed in order of decreasing density by the lateral, central, and intermediate subnuclei. The ovoid regions of the rostral subnucleus contain dense /sup 125/I-BTX labeling. In the lateral subnuclei, /sup 125/I-BTX binding appears to be predominantly along the lateral margins of the subnucleus. The present data indicate that the IPN contains two distinct populations of putative cholinergic nicotinic receptors identified, respectively, by /sup 3/H-nicotine and /sup 125/I-BTX labeling. Each population of labeled receptors is uniquely localized in patterns that suggest differences in density within and across subnuclei.

  8. Radioimmunoassay for etorphine in horses with a /sup 125/I analog of etorphine

    SciTech Connect

    Tai, C.L.; Wang, C.; Weckman, T.J.; Popot, M.A.; Woods, W.E.; Yang, J.M.; Blake, J.; Tai, H.H.; Tobin, T.

    1988-05-01

    To improve the sensitivity and specificity of screening for etorphine in horses, an /sup 125/I-labeled etorphine analog was synthesized and an antibody to etorphine was raised in rabbits. A radioimmunoassay (RIA) for etorphine was developed, using these reagents. Bound and free /sup 125/I-labeled etorphine was separated by a double-antibody method that reduced interference from materials associated with equine urine. The /sup 125/I-labeled etorphine binding was rarely greater than 250 pg of background etorphine equivalents/ml in raw urine and was 100 pg/ml in hydrolyzed urine. The /sup 125/I-RIA was capable of detecting etorphine equivalents in urine above these background values. Etorphine equivalents were detected in equine urine samples for about 7 days after 4 mares were dosed with 0.22 microgram of etorphine/kg of body weight, IV. The stability of etorphine in urine from these mares was evaluated. Urine from these dosed mares was held in constant -20 C storage, and aliquots were repeatedly frozen and thawed. When analyzed for etorphine equivalents using an /sup 125/I-RIA, etorphine and its metabolites in urine samples were stable for less than or equal to 38 days if continuously frozen and also were resistant to repeated freezing and thawing.

  9. Radioimmunoassay of salivary cyclosporine with use of /sup 125/I-labeled cyclosporine

    SciTech Connect

    Coates, J.E.; Lam, S.F.; McGaw, W.T.

    1988-08-01

    We prepared /sup 125/I-labeled cyclosporine (/sup 125/I-CS) by modifying the procedure of Mahoney and Orf and characterized it with regards to maximal immunoreactivity (greater than 90%), trichloroacetic acid precipitability (greater than 90%), and stability (90% immunoreactive after five half-lives of /sup 125/I). For a particular preparation of /sup 125/I-CS, we estimated its immunoreaction concentration (50 pmol/L) and the equilibrium constant for its reaction with Sandoz polyclonal antiserum (K = 3.9 X 10(9) L/mol). By substituting /sup 125/I-CS as tracer in the Sandoz radioimmunoassay and by modifying other aspects of the assay, we developed a procedure that is sufficiently sensitive (0.34 micrograms/L) to allow measurement of trough (lowest inter-dose) cyclosporine concentrations in parotid saliva. Of 38 kidney-transplant patients, 35 had measurable concentrations in saliva (mean 8.3, SD 5.2 micrograms/L), and these correlated moderately with paired serum concentrations (r = 0.68, P less than 0.001). We believe that measurement of salivary cyclosporine may offer a simple way of estimating the free fraction of the drug in serum or plasma.

  10. Biodistribution and dosimetry of free 211At, 125I- and 131I- in rats.

    PubMed

    Spetz, Johan; Rudqvist, Nils; Forssell-Aronsson, Eva

    2013-11-01

    131I is widely used for therapy in the clinic and 125I and 131I, and increasingly 211At, are often used in experimental studies. It is important to know the biodistribution and dosimetry for these radionuclides to determine potential risk organs when using radiopharmaceuticals containing these radionuclides. The purpose of this study was to investigate the biodistribution of 125I-, 131I-, and free 211At in rats and to determine absorbed doses to various organs and tissues. Male Sprague Dawley rats were injected simultaneously with 0.1-0.3 MBq 125I- and 0.1-0.3 MBq 131I-, or 0.05-0.2 MBq 211At and sacrificed 1 hour to 7 days after injection. The activities and activity concentrations in organs and tissues were determined and mean absorbed doses were calculated. The biodistribution of 125I- was similar to that of 131I- but the biodistribution of free 211At was different compared to 125I- and 131I-. The activity concentration of radioiodine was higher compared with 211At in the thyroid and lower in all extrathyroidal tissues. The mean absorbed dose per unit injected activity was highest to the thyroid. 131I gave the highest absorbed dose to the thyroid, and 211At gave the highest absorbed dose to all other tissues studied.

  11. A sensitive radioimmunoassay for corticotropin using a fully biologically active 125I-labeled ligand

    SciTech Connect

    Buckley, D.I.; Hagman, J.; Ramachandran, J.

    1981-07-01

    The human corticotropin (ACTH) analog, Phe2,Nle4-ACTH-(1-38) was iodinated by the chloramine-T procedure and the product was purified by reverse phase high performance liquid chromatography. The specific radioactivity of (/sup 125/I)Tyr23,Phe2,Nle4-ACTH-(1-38) was determined by comparing the antiserum binding curves of the iodinated peptide and (3H)ACTH of known specific activity. This method gave a value of 1800 +/- 75 Ci/mmol, which is close to the theoretical radioactivity expected for the introduction of a single /sup 125/I atom into the peptide. (/sup 125/I)Tyr23,Phe2,Nle4-ACTH-(1-38) was as potent as ACTH in stimulating corticosterone production in isolated rat adrenocortical cells. The concentrations for half-maximal steroidogenesis were 36.5 +/- 6.1 pM for the /sup 125/I derivative and 37.6 +/- 6.7 pM for ACTH. By the use of this /sup 125/I-labeled ligand, a highly sensitive RIA capable of detecting 1 pg ACTH was developed.l The antiserum employed in this study appeared to be directed against residues 11-13 of ACTH.

  12. /sup 125/I-spiperone: a novel ligand for D/sub 2/ dopamine receptors

    SciTech Connect

    Gundlach, A.L.; Largent, B.L.; Synder, S.H.

    1984-11-05

    /sup 125/I-Spiperone binds with high affinity K/sub D/ 0.3 nM) to a single specific site (B/sub max/ 34 pmole/g wet weight) in homogenates of rat corpus striatum. Specific binding is about 40-60 percent of total binding and is displaced stereo-specifically by butaclamol and clopenthixol. Neuroleptic drugs of various classes are potent inhibitors of /sup 125/I-spiperone binding (/sub i/'s 1-10 nM). Selective dopamine antagonists such as sulpiride (K/sub i/ 50 nM) and dopamine agonists such as apomorphine (K/sub i/ 200 nM) are also potent inhibitors. The drugs specificity of /sup 125/I-spiperone binding correlates well with that of /sup 3/H-spiperone binding, providing good evidence that /sup 125/I-spiperone labels D/sub 2/ dopamine receptors in striatal membranes. /sup 125/I-Spiperone, with its high specific activity (2200 Ci/mmol) may prove to be a useful ligand in studies examining D/sub 2/ dopamine receptors in soluble preparations and by autoradiography. Furthermore iodinated spiperone may be useful in radioreceptor assays of neuroleptic drug levels and, in a /sup 123/I-labeled form for imaging of dopamine receptors, in vivo, using single photon tomography. 18 references, 4 figures, 1 table.

  13. E-17 alpha(/sup 125/I)iodovinylestradiol: an estrogen-receptor-seeking radiopharmaceutical

    SciTech Connect

    Hanson, R.N.; Seitz, D.E.; Botarro, J.C.

    1982-05-01

    Through the use of radioiododestannylation, the specifically labeled E-17 alpha-(/sup 125/I)iodovinylestradiol ((/sup 125/I)VE2) was synthesized rapidly and in high yield from the stable precursor E-17 alpha-tributylstannylvinylestradiol (SnVE2), and its biodistribution was determined in immature female rats. The agent accumulated in the uterus, achieving a peak uptake of 0.465% ID-kg/g at 2 hr. Uterus-to-blood ratios of 19 and 16 occurred at 1 and 2 hr, respectively, declining to 7 by 4 hr after injection. The uptake of (/sup 125/I)VE2 by the uterus at 2 hr was reduced 58--65% by pretreatment of the immature rats with estradiol (5 micrograms) or tamoxifen (100 micrograms), and compared with 16 alpha-(/sup 125/I)iodoestradiol, (/sup 125/I)VE2 showed greater uterine uptake and similar uterus-to-blood ratios. The ease of preparation of the radioligand represents an advantage over the synthetic procedures for other estrogen-receptor-seeking agents.

  14. Fast radioactive seed localization in intraoperative cone beam CT for low-dose-rate prostate brachytherapy

    NASA Astrophysics Data System (ADS)

    Hu, Yu-chi; Xiong, Jian-ping; Cohan, Gilad; Zaider, Marco; Mageras, Gig; Zelefsky, Michael

    2013-03-01

    A fast knowledge-based radioactive seed localization method for brachytherapy was developed to automatically localize radioactive seeds in an intraoperative volumetric cone beam CT (CBCT) so that corrections, if needed, can be made during prostate implant surgery. A transrectal ultrasound (TRUS) scan is acquired for intraoperative treatment planning. Planned seed positions are transferred to intraoperative CBCT following TRUS-to-CBCT registration using a reference CBCT scan of the TRUS probe as a template, in which the probe and its external fiducial markers are pre-segmented and their positions in TRUS are known. The transferred planned seeds and probe serve as an atlas to reduce the search space in CBCT. Candidate seed voxels are identified based on image intensity. Regions are grown from candidate voxels and overlay regions are merged. Region volume and intensity variance is checked against known seed volume and intensity profile. Regions meeting the above criteria are flagged as detected seeds; otherwise they are flagged as likely seeds and sorted by a score that is based on volume, intensity profile and distance to the closest planned seed. A graphical interface allows users to review and accept or reject likely seeds. Likely seeds with approximately twice the seed volume are automatically split. Five clinical cases are tested. Without any manual correction in seed detection, the method performed the localization in 5 seconds (excluding registration time) for a CBCT scan with 512×512×192 voxels. The average precision rate per case is 99% and the recall rate is 96% for a total of 416 seeds. All false negative seeds are found with 15 in likely seeds and 1 included in a detected seed. With the new method, updating of calculations of dose distribution during the procedure is possible and thus facilitating evaluation and improvement of treatment quality.

  15. Simulation of 125I induced DNA strand breaks in a CAP-DNA complex.

    PubMed

    Li, W; Friedland, W; Jacob, P; Paretzke, H G; Panyutin, I; Neumann, R D

    2002-01-01

    The E. coli catabolite gene activator protein (CAP)-DNA complex with 125I located at the position of the H5 atom of the cytosine near the centre was incorporated into the PARTRAC track structure code. DNA strand breaks due to irradiation were calculated by track structure and radical attack simulations; strand breaks due to neutralisation of the highly charged 125Te ion were derived from a semi-empirical distribution. According to the calculations, the neutralisation effect dominates the strand breakage frequency at 2 bases away from the 125I decay site on both strands. The first breakage distribution counted from a 32P labelled end on the strand with 125I agreed well with experimental data, but on the opposite strand, the calculated distribution is more concentrated around the decay site and its yield is about 20% larger than the measured data.

  16. Non-Repairable Strand Breaks Induced by 125I Incorporated into Mammalian DNA

    PubMed Central

    Painter, R. B.; Young, B. R.; Burki, H. J.

    1974-01-01

    When 125I is incorporated into Chinese hamster DNA (via 125I-labeled iododeoxyuridine) and the cells are stored at 77°K, the resulting decays of the isotope cause 4 to 5 breaks/single-strand per disintegration. On the average, about 50% of these breaks are repaired. In contrast, under the same conditions of storage and in the same range of total strand breaks/cell, 70-100% of the breaks induced by x-radiation are repaired. Thus, the extreme toxicity of 125I when incorporated into DNA is correlated with the unrepaired breaks caused by decay of this isotope. These results suggest that unrepaired DNA strand breaks may be important in cell killing after treatments which damage DNA. PMID:4531021

  17. Specific autoantibody slows the rapid plasma clearance of 125I-SS-B (La) in mice.

    PubMed Central

    Schrieber, L; Melsom, R D; Venables, P J; McCarthy, D A; Maini, R N

    1984-01-01

    In BALB/c mice the plasma clearance of intravenously (i.v.) injected 125I-SS-B (La) (T 1/2 = 3 min) is markedly delayed when complexed in vitro to specific autoantibody (T 1/2 = 60 min) and is associated with diminished hepatic and renal uptake. The in vivo behaviour of 11S 125I-SS-B-IgG-anti-SS-B complexes was similar to that of 20-30S 125I-heat-aggregated IgG. The presence of anti-SS-B antibodies in systemic lupus erythematosus and Sjögren's syndrome could similarly result in persistence of SS-B containing immune complexes and provide a mechanism which may perpetuate autoimmunity. PMID:6611229

  18. Distribution of progesterone receptor in the 20-day-old fetal mouse: an autoradiographic study with (/sup 125/I)progestin

    SciTech Connect

    Shughrue, P.J.; Stumpf, W.E.; Sar, M.

    1988-11-01

    The distribution of progestin target sites in 20-day-old fetuses of estrogen-primed pregnant mice was investigated by thaw-mount autoradiography. Pregnant mice received a Silastic estradiol implant on day 17 and were ovariectomized on day 19 of pregnancy. Twenty-four hours after ovariectomy 10 prematurely delivered fetuses were each injected with 0.33 microgram/100 g BW (/sup 125/I)progestin (SA, 2200 Ci/mM). To show specificity of progestin localization two additional fetuses were each injected sc with 20 micrograms R5020, a synthetic progestin, 1 h before the injection of (/sup 125/I)progestin. The fetuses were frozen 2 h after injection of (/sup 125/I)progestin, sectioned, and processed for thaw-mount autoradiography. Cells with nuclear uptake and retention of radioactivity were observed in numerous tissues, including certain regions of the oral mucosa and developing teeth, esophagus, larynx, skin, mammary gland, skeletal muscle, kidney, and reproductive glands and ducts. Injection of unlabeled R5020 1 h before (/sup 125/I)progestin prevented nuclear concentration of radioactivity in all target tissues. The results indicate that progesterone receptors are expressed with a regional, cellular, and subcellular distribution in term fetal mouse tissues and suggest that progesterone is important to the growth and development of certain fetal tissues.

  19. Use of 2-(/sup 125/I)iodomelatonin to characterize melatonin binding sites in chicken retina

    SciTech Connect

    Dubocovich, M.L.; Takahashi, J.S.

    1987-06-01

    2-(/sup 125/I)Iodomelatonin binds with high affinity to a site possessing the pharmacological characteristics of a melatonin receptor in chicken retinal membranes. The specific binding of 2-(/sup 125/I)iodomelatonin is stable, saturable, and reversible. Saturation experiments indicated that 2-(/sup 125/I)iodomelatonin labeled a single class of sites with an affinity constant (Kd) of 434 +/- 56 pM and a total number of binding sites (Bmax) of 74.0 +/- 13.6 fmol/mg of protein. The affinity constant obtained from kinetic analysis was in close agreement with that obtained in saturation experiments. Competition experiments showed a monophasic reduction of 2-(/sup 125/I)iodomelatonin binding with a pharmacological order of indole amine affinities characteristic of a melatonin receptor: 2-iodomelatonin greater than 6-chloromelatonin greater than or equal to melatonin greater than or equal to 6,7-dichloro-2-methylmelatonin greater than 6-hydroxymelatonin greater than or equal to 6-methoxymelatonin much greater than N-acetyltryptamine greater than N-acetyl-5-hydroxytryptamine greater than 5-methoxytryptamine greater than 5-hydroxytryptamine (inactive). The affinities of these melatonin analogs in competing for 2-(/sup 125/I)iodomelatonin binding sites were correlated closely with their potencies for inhibition of the calcium-dependent release of (3H)dopamine from chicken and rabbit retinas, indicating association of the binding site with a functional response regulated by melatonin. The results indicate that 2-(/sup 125/I)iodomelatonin is a selective, high-affinity radioligand for the identification and characterization of melatonin receptor sites.

  20. p-( sup 125 I)iodoclonidine is a partial agonist at the alpha 2-adrenergic receptor

    SciTech Connect

    Gerhardt, M.A.; Wade, S.M.; Neubig, R.R. )

    1990-08-01

    The binding properties of p-(125I)iodoclonidine (( 125I)PIC) to human platelet membranes and the functional characteristics of PIC are reported. (125I)PIC bound rapidly and reversibly to platelet membranes, with a first-order association rate constant (kon) at room temperature of 8.0 +/- 2.7 x 10(6) M-1 sec-1 and a dissociation rate constant (koff) of 2.0 +/- 0.8 x 10(-3) sec-1. Scatchard plots of specific (125I)PIC binding (0.1-5 nM) were linear, with a Kd of 1.2 +/- 0.1 nM. (125I)PIC bound to the same number of high affinity sites as the alpha 2-adrenergic receptor (alpha 2-AR) full agonist (3H) bromoxidine (UK14,304), which represented approximately 40% of the sites bound by the antagonist (3H)yohimbine. Guanosine 5'-(beta, gamma-imido)triphosphate greatly reduced the amount of (125I)PIC bound (greater than 80%), without changing the Kd of the residual binding. In competition experiments, the alpha 2-AR-selective ligands yohimbine, bromoxidine, oxymetazoline, clonidine, p-aminoclonidine, (-)-epinephrine, and idazoxan all had Ki values in the low nanomolar range, whereas prazosin, propranolol, and serotonin yielded Ki values in the micromolar range. Epinephrine competition for (125I)PIC binding was stereoselective. Competition for (3H)bromoxidine binding by PIC gave a Ki of 1.0 nM (nH = 1.0), whereas competition for (3H)yohimbine could be resolved into high and low affinity components, with Ki values of 3.7 and 84 nM, respectively. PIC had minimal agonist activity in inhibiting adenylate cyclase in platelet membranes, but it potentiated platelet aggregation induced by ADP with an EC50 of 1.5 microM. PIC also inhibited epinephrine-induced aggregation, with an IC50 of 5.1 microM. Thus, PIC behaves as a partial agonist in a human platelet aggregation assay. (125I)PIC binds to the alpha 2B-AR in NG-10815 cell membranes with a Kd of 0.5 +/- 0.1 nM.

  1. 2-([sup 125]I) iodomelatonin binding sites in rat adrenals: Pharmacological characteristics and subcellular distribution

    SciTech Connect

    Persengiev, S.P. )

    1992-01-01

    Specific binding sites for 2-[[sup 125]I] iodomelatonin, a selective radiolabeled melatonin receptor ligand, were detected and characterized in rat adrenal membranes. Saturation studies demonstrated that 2-[[sup 125]I]iodomelatonin binds to a single class of sites with an affinity constant (Kd) of 541 pM and a total binding capacity (Bmax) of 3.23 fmol/mg protein. Competition experiments revealed that the relative order of potency of compounds tested was as follows: 6-chloromelatonin > 2-iodomelatonin > melatonin > 5-methoxytryptamine > 5-methoxytryptophol. The highest density of binding sites was found in membranes from nuclear and mitochondrial subcellular fractions.

  2. Increased /sup 125/I-labelled concanavalin A binding to erythrocytes in diabetes mellitus

    SciTech Connect

    Okada, Y.; Arima, T.; Okazaki, S.; Nakata, K.; Nagashima, H.; Yamabuki, T.

    1982-03-01

    Percentage binding of /sup 125/I-labelled concanavalin A to erythrocytes in diabetic patients was significantly higher than that in normal subjects (12.2 +- 2.8 versus 8.1 +- 1.8%, mean +- SD, p < 0.001). Insulin-dependent diabetic patients showed significantly higher concanavalin A binding than non-insulin-dependent diabetic subjects (15.0 +- 1.4 versus 11.4 +- 2.5%, p < 0.01). There was a highly significant correlation between percentage binding of /sup 125/I-labelled concanavalin A and glycosylated haemoglobin.

  3. Detection of glycosaminoglycans at the one-nanogram level by 125I-cytochrome c

    SciTech Connect

    Sampson, P.M.; Heimer, R.; Fishman, A.P.

    1985-12-01

    The basic protein cytochrome c forms stable ionic complexes with all known glycosaminoglycans. When labeled with 125I, cytochrome c is capable of detecting exceptionally small quantities of glycosaminoglycans. Subsequent to electrophoresis on cellulose acetate strips using pyridine formate buffer at pH 3, followed by ethanol fixation, and treatment with 125I-cytochrome c, all the known glycosaminoglycans are detected at minimum levels of 1 ng/0.25-microliter application. The method can be used for quantification of glycosaminoglycans in other electrophoretic buffer systems also.

  4. Metabolism of 125I-labeled lipoproteins by the isolated rat lung

    PubMed Central

    1976-01-01

    The capacity of the isolated perfused rat lung to metabolize the protein moieties of serum lipoproteins was assessed using homologous (rat) and heterologous (human) plasma lipoproteins. The protein and lipid moieties of the plasma lipoproteins were labeled in vivo with Na[125I]. In selected cases the lipoprotein peptides were labeled in vivo with 14C- or 3H-labeled amino acids. Uptake of lipoprotein label during perfusion was monitored by measure of losses in perfusate label and by rises in pulmonary tissue labeling as shown by radioassay and by light and electron microscope radioautography. Lipoprotein degradation was assessed by fractionation of perfusate and lung tissue radioactive material into trichloroacetic acid (TCA)-isoluble, TCA-soluble, and ether-ethanol-soluble fractions. When heparin was included in the perfusion medium, there was selective degradation of the protein portion of very low density lipoprotein (VLDL) in the perfusate and concomitant uptake of radioactive label by the lungs. Low density lipoprotein (LDL)) was neither taken up nor catabolized by the isolated rat lung in the absence or presence of heparin. By light and electron microscopy, the label was localized over the interalveolar septa, predominantly the capillary endothelium. Disappearance of TCA-insoluble radioactivity from the perfusate was associated with the generation of both TCA-soluble iodide and noniodide radioactivity. Greater than 50% of the radioactive label taken up by the lungs was found in the delipidated TCA-insoluble fraction. This study provides in vitro evidence for pulmonary catabolism of VLDL apolipoproteins and uptake of peptide catabolic products of VLDL by the lung. PMID:180034

  5. Labelled dyes, a new 125I-indomonocarbocyanine and 125I-BSP, in the exploration of experimental cholestasis and steatosis in the rat.

    PubMed Central

    Lapalus, F.; Moreau, M. F.; Meyniel, G.

    1981-01-01

    A new dye, an indomonocarbocyanine labelled with radioactive iodine, was studied in normal rats and in rats with experimental diseases. After i.v. injection, the cyanine was selectively concentrated in the liver and eliminated in the bile; urinary excretion was found to be minimal but increased in rats with ligated bile duct. In addition, the blood clearance kinetics of the labelled dyes were significantly modified in cases of hepatic cholestasis or steatosis. A comparative study was carried out with 125I-BSP; the results showed that these 2 dyes may be considered as complementary in the exploration of liver function. PMID:7225289

  6. Dopamine transport sites selectively labeled by a novel photoaffinity probe: 125I-DEEP

    SciTech Connect

    Grigoriadis, D.E.; Wilson, A.A.; Lew, R.; Sharkey, J.S.; Kuhar, M.J. )

    1989-08-01

    The dopamine transporter was labeled using a photosensitive compound related to GBR-12909, {sup 125}I-1-(2-(diphenylmethoxy)ethyl)-4-(2- (4-azido-3-iodophenyl)ethyl)piperazine ({sup 125}I-DEEP). {sup 125}I-DEEP bound reversibly and with high affinity to the dopamine transport protein in the absence of light and could be covalently attached to the protein following exposure to UV light. In rat striatal homogenates, {sup 125}I-DEEP was found to incorporate covalently into a protein with apparent molecular weight of 58,000 Da. The properties of this binding protein were characteristic of the dopamine transporter since covalent attachment could be inhibited by dopamine-uptake blockers with the proper pharmacological rank order of potencies. Covalent binding was also inhibited in a stereospecific manner by (+) and (-) cocaine, as well as other cocaine analogs. The protein was not found in the cerebellum. The dopamine transporter appears to exist in a glycosylated form since photoaffinity-labeled transport sites could adsorb to wheat germ-agglutinin and could be specifically eluted from the column by beta-N-acetylglucosamine.

  7. Synthesis and biodistribution of [125I]iodo- and [75Se]seleno-ergoline derivatives.

    PubMed

    Sadek, S; Basmadjian, G; Patel, A

    1987-01-01

    (8 beta)-8-([125]Iodomethyl)-6-propylergoline (125I-3) was prepared by refluxing the mesyl analog with Na125I in methyl-ethyl-ketone, followed by HPLC, in a radiochemical yield greater than 70%. [75Se]Selenopergolide (75Se-2) was prepared in 74% yield starting with H75(2) SeO3. The biodistribution studies of the two compounds in male rats show good uptake by the adrenals and the brain. Compound 75Se-2 had higher adrenal uptake and adrenal-to-blood ratios (4.2% dose/g and 70:1) than 125I-3 (3.6% dose/g and 23.8:1) at 15 min post injection. The two compounds had almost equal brain uptake (0.91% dose/g for 75Se-2 and 1.14% dose/g for 125I-3), but 75Se-2 showed higher brain-to-blood ratios (15.2:1 vs 7.3:1) at 15 min post injection. This study indicates that 75Se-2 and 123I-3 may be useful agents for imaging the adrenal and the brain.

  8. Photoaffinity labelling of the rat liver nuclear thyroid hormone receptor with (/sup 125/I)triiodothyronine

    SciTech Connect

    David-Inouye, Y.; Somack, R; Nordeen, S.K.; Apriletti, J.W.; Baxter, J.D.; Eberhardt, N.L.

    1982-11-01

    (/sup 125/I)Triiodothyronine (T/sub 3/) was used as a photoreactive probe for the thyroid hormone nuclear receptor in photoaffinity labelling experiments. Autoradiograms of photolysis products electrophoresed on either one or two-dimensional gels showed that (/sup 125/I)T/sub 3/ covalently, but nonspecifically, labelled many proteins in the partially purified receptor preparations used. However, one of these proteins with an estimated molecular weight of 47,000 and an isoelectric point of approximately 6.2 +/- 0.5 pH units appears to be the thyroid hormone receptor, since, in contrast to the other proteins, its photoinduced labelling was blocked by concentrations of T/sub 3/ and thyroxine (T/sub 4/) similar to those that inhibit binding of (/sup 125/I)T/sub 3/ by the receptor in equilibrium binding assays. In addition, the isoelectric point of the photolabelled protein agrees with that determined in separate equilibrium isoelectric focusing studies. These results indicate that (/sup 125/I)T/sub 3/ can serve as a photoreactive probe for the thyroid hormone nuclear receptor, and they suggest that this receptor is a single polypeptide chain of molecular weight 47,000 with an isoelectric point of 6.2 +/- 0.5 pH units.

  9. Uptake and modification of 125I-lipopolysaccharide by isolated rat Kupffer cells.

    PubMed

    Fox, E S; Thomas, P; Broitman, S A

    1988-01-01

    While it is generally believed that hepatic clearance of lipopolysaccharide involves Kupffer cells, the mechanism involved has not been fully elucidated. This study assesses this phenomenon in terms of in vitro uptake and post-uptake modification experiments with an 125I-labeled Salmonella minnesota lipopolysaccharide. 125I-Lipopolysaccharide was added to Kupffer cells in suspension cultures under a variety of conditions. In vitro uptake of 125I-Lipopolysaccharide was not saturable up to concentrations of 33.33 micrograms per ml. Kinetics experiments performed at 16.67 micrograms per ml demonstrated that Kupffer cells were unsaturable after 60 min of incubation. The kinetics of uptake could be inhibited, however, by incubation in the presence of a 10-fold excess of unlabeled lipopolysaccharide, indicating that a component of the uptake process may be limited. Energy dependence in this process was demonstrated by incubation in the presence of 1 mM 2-deoxyglucose which inhibited 125I-lipopolysaccharide uptake by approximately 30%. Pretreatment with 7.5 x 10(-5) M colchicine had no effect on kinetics, implying no role for the cell cytoskeleton in lipopolysaccharide uptake. These results are inconsistent with a receptor-mediated process as previously suggested. Modification of internalized label has been demonstrated by changes in buoyant density in CsCl isopyknic density gradients following overnight incubation with Kupffer cells. These results indicate that Kupffer cells clear bacterial endotoxin in vitro and post-uptake degradation occurs within 20 hr of incubation.

  10. Solid-phase receptor binding assay for /sup 125/I-hCG

    SciTech Connect

    Bortolussi, M.; Selmin, O.; Colombatti, A.

    1987-01-01

    A solid-phase radioligand-receptor assay (RRA) to measure the binding of /sup 125/I-labelled human chorionic gonadotropin (/sup 125/I-hCG) to target cell membranes has been developed. The binding of /sup 125/I-hCG to membranes immobilized on the wells of microtitration plates reached a maximum at about 3 hours at 37 degrees C, was saturable, displayed a high affinity (Ka = 2.4 X 10(9) M-1) and was specifically inhibited by unlabelled hCG. In comparison with RRAs carried out with membranes in suspension, the solid-phase RRA is significantly simpler and much faster to perform as it avoids centrifugation or filtration procedures. The solid-phase RRA was adapted profitably to process large numbers of samples at the same time. It proved particularly useful as a screening assay to detect anti-hCG monoclonal antibodies with high inhibitory activity for binding of /sup 125/I-hCG to its receptors.

  11. Use of immunoaffinity chromatography for purification of /sup 125/I-labeled human prolactin

    SciTech Connect

    Stuart, M.C.; Boscato, L.M.; Underwood, P.A.

    1983-02-01

    Researchers assessed a simple method for purifying /sup 125/I-labeled human prolactin, taking advantage of the abundant supplies of monoclonal antibodies available. /sup 125/I-labeled human prolactin purified by immunoaffinity chromatography is compared with that purified by gel filtration on Sephadex G-100. Researchers used monoclonal antibodies to prolactin to prepare the affinity chromatography columns. Prolactin was radiolabeled by the Chloramine T method, purified by each of the above procedures, and the binding and displacement characteristics were studied in radioimmunoassays in which either monoclonal antibodies or a rabbit anti-prolactin serum was the first antibody. A nonimmune fraction of /sup 125/I-labeled prolactin that co-eluted with the immunoreactive hormone from Sephadex G-100 was removed by affinity chromatography, which increased the antibody binding of /sup 125/I-labeled prolactin in the radioimmunoassay in the absence of unlabeled antigen (B/T0, in percent) twofold or more, increased the assay sensitivity, and increased the slope of antigen displacement measured by the 50% intercept. Several advantages make this the purification method of choice.

  12. Dosimetric analysis of 123I, 125I and 131I in thyroid follicle models

    PubMed Central

    2014-01-01

    Background Radioiodine is routinely used or proposed for diagnostic and therapeutic purposes: 123I, 125I and 131I for diagnostics and 125I and 131I for therapy. When radioiodine-labelled pharmaceuticals are administered to the body, radioiodide might be released into the circulation and taken up by the thyroid gland, which may then be an organ at risk. The aim of this study was to compare dosimetric properties for 123I, 125I and 131I in previously developed thyroid models for man, rat and mouse. Methods Dosimetric calculations were performed using the Monte Carlo code MCNPX 2.6.0 and nuclear decay data from ICRP 107. Only the non-radiative transitions in the decays were considered. The S value was determined for the cell nuclei in species-specific thyroid follicle models for mouse, rat and man for different spatial distributions of radioiodine. Results For the species-specific single follicle models with radioiodine homogeneously within the follicle lumen, the highest S value came from 131I, with the largest contribution from the β particles. When radioiodine was homogeneously distributed within the follicle cells or the follicle cell nucleus, the highest contribution originated from 125I, about two times higher than 123I, with the largest contribution from the Auger electrons. The mean absorbed dose calculated for our human thyroid multiple follicle model, assuming homogenous distribution of for 123I, 125I, or 131I within the follicle lumens and follicle cells, was 9%, 18% and 4% higher, respectively, compared with the mean absorbed dose according to Medical Internal Radiation Dose (MIRD) formalism and nuclear decay data. When radioiodine was homogeneously distributed in the follicle lumens, our calculations gave up to 90% lower mean absorbed dose for 125I compared to MIRD (20% lower for 123I, and 2% lower for 131I). Conclusions This study clearly demonstrates the importance of using more detailed dosimetric methods and models than MIRD formalism for radioiodine

  13. (R)-N-Methyl-3-(3-125I-pyridin-2-yloxy)-3-phenylpropan-1-amine ([125I]PYINXT) : a novel probe for norepinephrine transporters (NET)

    PubMed Central

    Lakshmi, B.; Kung, M-P.; Lieberman, B.; Zhao, J.; Waterhouse, R.; H.F.Kung

    2008-01-01

    Alterations in the serotonin and norepinephrine neuronal functions have been observed in patients with major depression. Several antidepressants bind to both serotonin transporters (SERT) and norepinephrine transporters (NET). The ability to image NET in the human brain would be a useful step toward understanding how alterations in NET relate to disease. In this study, we report the synthesis and characterization of a new series of derivatives of iodo-nisoxetine (INXT), a known radioiodinated probe. The most promising, (R)-N-methyl-3-(3-iodopyridin-2-yloxy)-3-phenylpropylamine (PYINXT) 9, displayed a high and saturable binding to NET with a Kd value of 0.53 ± 0.03 nM. Biodistribution studies of [125I]PYINXT in rats showed moderate initial brain uptake (0.54 %dose/organ at 2 min) with a relatively fast washout from the brain (0.16 %dose/organ at 2 hr) as compared to [125I]INXT, 7. The hypothalamus (a NET rich region) to striatum (a region devoid of NET) ratio was found to be 2.14 at 4 hr post i.v. injection. The preliminary results suggest that this improved iodinated ligand, when labeled with 123I, may be useful for mapping NET binding sites with SPECT in the living human brain. PMID:18158942

  14. Monte Carlo dosimetry for {sup 103}Pd, {sup 125}I, and {sup 131}Cs ocular brachytherapy with various plaque models using an eye phantom

    SciTech Connect

    Lesperance, Marielle; Martinov, M.; Thomson, R. M.

    2014-03-15

    Purpose: To investigate dosimetry for ocular brachytherapy for a range of eye plaque models containing{sup 103}Pd, {sup 125}I, or {sup 131}Cs seeds with model-based dose calculations. Methods: Five representative plaque models are developed based on a literature review and are compared to the standardized COMS plaque, including plaques consisting of a stainless steel backing and acrylic insert, and gold alloy backings with: short collimating lips and acrylic insert, no lips and silicone polymer insert, no lips and a thin acrylic layer, and individual collimating slots for each seed within the backing and no insert. Monte Carlo simulations are performed using the EGSnrc user-code BrachyDose for single and multiple seed configurations for the plaques in water and within an eye model (including nonwater media). Simulations under TG-43 assumptions are also performed, i.e., with the same seed configurations in water, neglecting interseed and plaque effects. Maximum and average doses to ocular structures as well as isodose contours are compared for simulations of each radionuclide within the plaque models. Results: The presence of the plaque affects the dose distribution substantially along the plaque axis for both single seed and multiseed simulations of each plaque design in water. Of all the plaque models, the COMS plaque generally has the largest effect on the dose distribution in water along the plaque axis. Differences between doses for single and multiple seed configurations vary between plaque models and radionuclides. Collimation is most substantial for the plaque with individual collimating slots. For plaques in the full eye model, average dose in the tumor region differs from those for the TG-43 simulations by up to 10% for{sup 125}I and {sup 131}Cs, and up to 17% for {sup 103}Pd, and in the lens region by up to 29% for {sup 125}I, 34% for {sup 103}Pd, and 28% for {sup 131}Cs. For the same prescription dose to the tumor apex, the lowest doses to critical

  15. Dexamethasone effects on (/sup 125/I)albumin distribution in experimental RG-2 gliomas and adjacent brain

    SciTech Connect

    Nakagawa, H.; Groothuis, D.R.; Owens, E.S.; Fenstermacher, J.D.; Patlak, C.S.; Blasberg, R.G.

    1987-12-01

    A total of 72 RG-2 transplanted gliomas were studied in 58 rats at three time points (1, 30, 240 min) after intravenous injection of (/sup 125/I)radioiodinated serum albumin ((/sup 125/I)RISA). The animals were divided into two groups: a control group that received no treatment and a second group that was treated with five doses of 1.5 mg/kg of dexamethasone over 2.5 days. Local tissue concentrations of (/sup 125/I)RISA were measured with quantitative autoradiography based on morphological features of the tumors and used to calculate the tissue distribution space. Two models were used to analyze the data. A two compartment model yielded estimates of local blood-to-tissue influx constants (K1), lower limit extracellular volumes (Ve), and plasma vascular volumes (Vp) in different tumor regions. Treatment with dexamethasone consistently reduced the RISA distribution space in the RG-2 tumors; the reduction in Ve was statistically significant in almost all tumor regions: whole tumor Ve (mean +/- SE) was reduced from 0.14 +/- 0.02 ml g-1 in control animals to 0.08 +/- 0.01 ml g-1 in dexamethasone treated animals. K1 and Vp were also decreased in all tumor regions after treatment with dexamethasone (whole tumor K1 decreased from 2.36 +/- 0.89 to 0.83 +/- 0.29 microliter g-1 min-1 and Vp decreased slightly from 0.016 +/- 0.013 to 0.010 +/- 0.005 ml g-1 after dexamethasone treatment), but these changes were not statistically significant. A comparison of the tumor influx constants in control animals and the aqueous diffusion constants of two different size molecules (RISA and aminoisobutyric acid) suggests that the ''pores'' across RG-2 capillaries are large and may not restrict the free diffusion of RISA (estimated minimum pore diameter greater than 36 nm) and that the total pore area is approximately 6.2 X 10(-5) cm2 g-1 in RG-2 tumor tissue.

  16. Automated localization of implanted seeds in 3D TRUS images used for prostate brachytherapy

    SciTech Connect

    Wei Zhouping; Gardi, Lori; Downey, Donal B.; Fenster, Aaron

    2006-07-15

    An algorithm has been developed in this paper to localize implanted radioactive seeds in 3D ultrasound images for a dynamic intraoperative brachytherapy procedure. Segmentation of the seeds is difficult, due to their small size in relatively low quality of transrectal ultrasound (TRUS) images. In this paper, intraoperative seed segmentation in 3D TRUS images is achieved by performing a subtraction of the image before the needle has been inserted, and the image after the seeds have been implanted. The seeds are searched in a 'local' space determined by the needle position and orientation information, which are obtained from a needle segmentation algorithm. To test this approach, 3D TRUS images of the agar and chicken tissue phantoms were obtained. Within these phantoms, dummy seeds were implanted. The seed locations determined by the seed segmentation algorithm were compared with those obtained from a volumetric cone-beam flat-panel micro-CT scanner and human observers. Evaluation of the algorithm showed that the rms error in determining the seed locations using the seed segmentation algorithm was 0.98 mm in agar phantoms and 1.02 mm in chicken phantoms.

  17. Increased (/sup 125/I)trypsin-binding in serum from cystic fibrosis patients

    SciTech Connect

    Cox, K.L.; Frates, R.C. Jr.; Sheikholislam, B.M.; Iwahashi-Hosoda, C.K.

    1982-01-01

    The capacities of normal and cystic fibrosis (CF) sera to bind to exogenous human (/sup 125/I)trypsin were compared. Sera from eight older CF patients bound significantly more exogenous human (/sup 125/I)trypsin than did sera from eight normal subjects (p less than 0.001). Disregarding the increased trypsin-binding (TB) of CF sera, serum immunoreactive trypsinogen (SIRT) levels were not detectable in these eight older CF patients. However, when SIRT levels were corrected for TB, four CF patients had normal SIRT concentrations and four had low but detectable SIRT levels. As compared to five normal newborns' sera, serum from a newborn with CF had normal TB and the SIRT levels were very high. In conclusion, increased TB in CF serum lowers results of SIRT assays. Therefore, unless SIRT levels are corrected for TB, results obtained from currently available SIRT kits may be invalid.

  18. Effects of hypothyroidism on vascular /sup 125/I-albumin permeation and blood flow in rats

    SciTech Connect

    Tilton, R.G.; Pugliese, G.; Chang, K.; Speedy, A.; Province, M.A.; Kilo, C.; Williamson, J.R.

    1989-05-01

    Effects of hypothyroidism on vascular 125I-albumin permeation and on blood flow were assessed in multiple tissues of male Sprague-Dawley rats rendered hypothyroid by dietary supplementation with 0.5% (wt/wt) 2-thiouracil or by thyroidectomy. In both thiouracil-treated and thyroidectomized rats, body weights, kidney weight, arterial blood pressure, and pulse rate were decreased significantly v age-matched controls. After 10 to 12 weeks of thiouracil treatment, 125I-albumin permeation was increased significantly in the kidney, aorta, eye (anterior uvea, choroid, retina), skin, and new granulation tissue, remained unchanged in brain, sciatic nerve, and heart, and was decreased in forelimb skeletal muscle. A similar pattern was observed in thyroidectomized rats, except that increases in 125I-albumin permeation for all tissues were smaller than those observed in thiouracil-treated rats, and 125I-albumin permeation in retina did not differ from controls. In both thiouracil-treated and thyroidectomized rats, changes in blood flow (assessed with 15-microns, 85Sr-labeled microspheres) relative to the decrease in arterial blood pressure were indicative of a decrease in regional vascular resistance except in the choroid and in the kidney, in which vascular resistance was increased significantly. Glomerular filtration rate was decreased, but filtration fraction and urinary excretion of albumin remained unchanged by thiouracil treatment and thyroidectomy. These results indicate that vascular hemodynamics and endothelial cell barrier functional integrity are modulated in many different tissues by the thyroid. In view of the correspondence of hypothyroid- and diabetes-induced vascular permeability changes, these results raise the possibility that altered thyroid function in diabetes may play a role in the pathogenesis of diabetic vascular disease.

  19. Quantitative autoradiography of the binding sites for ( sup 125 I) iodoglyburide, a novel high-affinity ligand for ATP-sensitive potassium channels in rat brain

    SciTech Connect

    Gehlert, D.R.; Gackenheimer, S.L.; Mais, D.E.; Robertson, D.W. )

    1991-05-01

    We have developed a high specific activity ligand for localization of ATP-sensitive potassium channels in the brain. When brain sections were incubated with ({sup 125}I)iodoglyburide (N-(2-((((cyclohexylamino)carbonyl)amino)sulfonyl)ethyl)-5-{sup 125}I-2- methoxybenzamide), the ligand bound to a single site with a KD of 495 pM and a maximum binding site density of 176 fmol/mg of tissue. Glyburide was the most potent inhibitor of specific ({sup 125}I)iodoglyburide binding to rat forebrain sections whereas iodoglyburide and glipizide were slightly less potent. The binding was also sensitive to ATP which completely inhibited binding at concentrations of 10 mM. Autoradiographic localization of ({sup 125}I)iodoglyburide binding indicated a broad distribution of the ATP-sensitive potassium channel in the brain. The highest levels of binding were seen in the globus pallidus and ventral pallidum followed by the septohippocampal nucleus, anterior pituitary, the CA2 and CA3 region of the hippocampus, ventral pallidum, the molecular layer of the cerebellum and substantia nigra zona reticulata. The hilus and dorsal subiculum of the hippocampus, molecular layer of the dentate gyrus, cerebral cortex, lateral olfactory tract nucleus, olfactory tubercle and the zona incerta contained relatively high levels of binding. A lower level of binding (approximately 3- to 4-fold) was found throughout the remainder of the brain. These results indicate that the ATP-sensitive potassium channel has a broad presence in the rat brain and that a few select brain regions are enriched in this subtype of neuronal potassium channels.

  20. Autoradiographic evidence of sup 125 I-. beta. -endorphin binding sites in the articular cartilage of the rat

    SciTech Connect

    Castano, M.T.; Freire-Garabal, M.; Giraldez, M.; Nunez, M.J.; Belmonte, A.; Couceiro, J.; Jorge, J. )

    1991-01-01

    After {sup 125}I-{beta}-endorphin was intravenously injected to rats, an autoradiographic study of distal femur articular cartilage was performed. Results show a specific binding of {sup 125}I-{beta}-endorphin to chondrocytes, suggesting the possible existence of an opiate modulation of articular cartilage.

  1. Photoaffinity labelling of the rat liver nuclear thyroid hormone receptor with (/sup 125/I)triiodothyronine

    SciTech Connect

    David-Inouye, Y.; Somack, R.; Nordeen, S.K.; Apriletti, J.W.; Baxter, J.D.; Eberhardt, N.L.

    1982-11-01

    (/sup 125/I)Triiodothyronine (T3) was used as a photoreactive probe for the thyroid hormone nuclear receptor in photoaffinity labelling experiments. Autoradiograms of photolysis products electrophoresed on either one or two-dimensional gels showed that (/sup 125/I)T3 covalently, but nonspecifically, labelled many proteins in the partially purified receptor preparations used. However, one of these proteins with an estimated molecular weight of 47,000 and an isoelectric point of approximately 6.2 +/- 0.5 pH units appears to be the thyroid hormone receptor, since, in contrast to the other proteins, its photoinduced labelling was blocked by concentrations of T3 and thyroxine (T4) similar to those that inhibit binding of (/sup 125/I)T3 by the receptor in equilibrium binding assays. In addition, the isoelectric point of the photolabelled protein agrees with that determined in separate equilibrium isoelectric focusing studies. These results indicate that (/sup 125/)T3 can serve as a photoreactive probe for the thyroid hormone nuclear receptor, and they suggest that this receptor is a single polypeptide chain of molecular weight 47,000 with an isoelectric point of 6.2 +/- 0.5 pH units.

  2. Correlation of 125I-LSD autoradiographic labeling with serotonin voltage clamp responses in Aplysia neurons

    SciTech Connect

    Evans, M.L.; Kadan, M.J.; Hartig, P.R.; Carpenter, D.O. )

    1991-05-01

    Autoradiographic receptor binding studies using 125I-LSD (2-(125I)lysergic acid diethyamide) revealed intense labelling on the soma of a symmetrically located pair of cells in the abdominal ganglion of Aplysia californica. This binding was blocked by micromolar concentrations of serotonin and lower concentrations of the serotonergic antagonists, cyproheptadine and mianserin. Electrophysiological investigation of responses to serotonin of neurons in the left upper quadrant, where one of the labeled neurons is located, revealed a range of serotonin responses. Cells L3 and L6 have a K+ conductance increase in response to serotonin that is not blocked by cyproheptadine or mianserin. Cells L2 and L4 have a biphasic response to serotonin: a Na+ conductance increase, which can be blocked by cyproheptadine and mianserin, followed by a voltage dependent Ca2+ conductance which is blocked by Co2+ but not the serotonergic antagonists. Cell L1, and its symmetrical pair, R1, have in addition to the Na+ and Ca2+ responses observed in L2 and L4, a Cl- conductance increase blocked by LSD, cyproheptadine and mianserin. LSD had little effect on the other responses. The authors conclude that the symmetrically located cells L1 and R1 have a Cl- channel linked to a cyproheptadine- and mianserin-sensitive serotonin receptor that is selectively labelled by 125I-LSD. This receptor has many properties in common with the mammalian serotonin 1C receptor.

  3. Glucocorticoid interactions with ethanol effects on synaptic plasma membranes: influence on [125I]calmodulin binding.

    PubMed

    Sze, P Y

    1996-02-01

    Ca(++)-dependent binding of calmodulin (CaM) to brain synaptic plasma membranes is known to be inhibited by ethanol and stimulated by glucocorticoids. These opposite neurochemical actions between ethanol and the steroids in vitro are consistent with glucocorticoid antagonism of ethanol-induced sedation reported to occur in vivo. The present study was undertaken to characterize the interactions of corticosterone with ethanol effects on [125I]CaM binding in synaptic plasma membranes. From the shift of concentration-response curves when corticosterone and ethanol were present in combination, the interaction between steroid stimulation and ethanol inhibition occurred in an additive relationship over the range of their effective concentrations. From Scatchard analyses, ethanol-induced decrease in membrane affinity for [125I]CaM was antagonized by steroid-induced increase in the membrane affinity, indicating that the convergent event in their interaction was the alteration of membrane affinity for CaM. Glucocorticoid antagonism of ethanol inhibition of [125I]CaM binding exhibited a high degree of steroid specificity; steroids with glucocorticoid activity including cortisol, dexamethasone and triamcinolone were effective, whereas gonadal steroids and excitatory neuroactive steroid metabolites were ineffective. The demonstration that glucocorticoids antagonized the inhibition of CaM binding by ethanol provides support for the hypothesis that these steroids are among the endogenous factors that modulate neuronal sensitivity to ethanol.

  4. Embryo Localization Enhances the Survival of Acidovorax citrulli in Watermelon Seeds.

    PubMed

    Dutta, Bhabesh; Schneider, Raymond W; Robertson, Clark L; Walcott, Ronald R

    2016-04-01

    Acidovorax citrulli, the causal agent of bacterial fruit blotch (BFB) of cucurbits has been observed to survive for >34 years in stored melon and watermelon seeds. To better understand this remarkable longevity, we investigated the bacterium's tolerance to desiccation and the effect of bacterial localization in different watermelon seed tissues on its survival. We compared the ability of A. citrulli to tolerate desiccation on filter paper discs and on host (watermelon) and nonhost (cabbage, corn and tomato) seeds to two seedborne (Xanthomonas campestris pv. campestris and Pantoea stewartii subsp. stewartii) and one soilborne (Ralstonia solanacearum) plant-pathogenic bacteria. A. citrulli survival on dry filter paper (>12 weeks) was similar to that of X. campestris pv. campestris but longer than P. stewartii subsp. stewartii. Ralstonia solanacearum survived longer than all other bacteria tested. On all seeds tested, A. citrulli and X. campestris pv. campestris populations declined by 5 orders of magnitude after 12 weeks of incubation at 4°C and 50% relative humidity, while R. solanacearum populations declined by 3 orders. P. stewartii subsp. stewartii was not recovered after 12 weeks of incubation. To determine the effect of tissue localization on bacterial survival, watermelon seeds infested with A. citrulli by flower stigma inoculation (resulting in bacterial localization in the embryo/endosperm) or by ovary pericarp inoculations (resulting in bacterial localization under the testa) were treated with peroxyacetic acid or chlorine (Cl2) gas. Following these treatments, a significantly higher reduction in BFB seed-to-seedling transmission was observed for seeds generated by ovary pericarp inoculation (≥89.5%) than for those generated by stigma inoculation (≤76.5%) (P<0.05). Additionally, higher populations of A. citrulli survived when the bacteria were localized to the embryo/endosperm versus the seed coat, suggesting that tissue localization is important for

  5. Comparative cost-effectiveness of focal and total salvage 125I brachytherapy for recurrent prostate cancer after primary radiotherapy

    PubMed Central

    Piena, Marjanne A.; Steuten, Lotte M.G.; van der Voort van Zyp, Jochem R.N.; Moerland, Marinus A.; van Vulpen, Marco

    2016-01-01

    Purpose Focal salvage (FS) iodine 125 (125I) brachytherapy could be an effective treatment for locally radiorecurrent prostate cancer (PCa). Toxicity is often reduced compared to total salvage (TS) while cancer control can be maintained, which could increase cost-effectiveness. The current study estimates the incremental cost per quality-adjusted life year (QALY) of FS compared to TS. Material and methods A decision analytic Markov model was developed, which compares costs and QALYs associated with FS and TS. A 3-year time horizon was adopted with six month cycles, with a hospital perspective on costs. Probabilities for genitourinary (GU) and gastrointestinal (GI) toxicity and their impact on health-related quality of life (SF-36) were derived from clinical studies in the University Medical Center Utrecht (UMCU). Probabilistic sensitivity analysis, using 10,000 Monte Carlo simulations, was performed to quantify the joint decision uncertainty up to the recommended maximum willingness-to-pay threshold of €80,000/QALY. Results Focal salvage dominates TS as it results in less severe toxicity and lower treatment costs. Decision uncertainty is small, with a 97-100% probability for FS to be cost-effective compared to TS (€0-€80,000/QALY). Half of the difference in costs between FS and TS was explained by higher treatment costs of TS, the other half by higher incidence of severe toxicity. One-way sensitivity analyses show that model outcomes are most sensitive to utilities and probabilities for severe toxicity. Conclusions Focal salvage 125I brachytherapy dominates TS, as it has lower treatment costs and leads to less toxicity in our center. Larger comparative studies with longer follow-up are necessary to assess the exact influence on (biochemical disease free) survival and toxicity. PMID:28115953

  6. Direct linkage of /sup 125/I-EGF to cell surface receptors: a useful artifact of chloramine-T treatment

    SciTech Connect

    Comens, P.G.; Simmer, R.L.; Baker, J.B.

    1982-01-01

    A study is presented which shows that /sup 125/I-EGF that was iodinated by lactoperoxidase treatment bound to cells but did not become linked to EGF receptors. /sup 125/I-EGF that was iodinated by chloramine-T treatment or /sup 125/I-EGF that was iodinated by lactoperoxidase treatment and then exposed to chloramine-T, formed linked /sup 125/I-EGF-receptor complexes. Chloramine-T-treated /sup 125/I-EGF remained able to couple to EGF receptors many hours after chloramine-T was removed. These results indicate that chloramine-T ''activates'' /sup 125/I-EGF to a new stable form that couples specifically to EGF receptors. This activation did not occur when Tris middle dot Cl was present during the chloramine-T incubation. Because Tris middle dot Cl is nucleophilic and could moderate the oxidizing effects of chloramine-T, this finding suggests that chloramine-T activates EGF as a result of its ability to oxidize certain amino acid residues in proteins. The specific linkage of chloramine-T-treated /sup 125/I-EGF to EGF receptors provides a convenient, effective method for radiolabeling EGF receptors. The percentage of human fibroblast EGF receptors cross-linked by /sup 125/I-EGF increased to 60% when turnover of EGF receptors at the cell surface was blocked by inhibiting endocytosis with phenylarsine oxide. The linkage of /sup 125/I-thrombin to protease-nexin, a cell-released factor that mediates the binding of /sup 125/I-thrombin to human fibroblasts, is not a chloramine-T artifact. (JMT)

  7. In vivo binding of /sup 125/I-LSD to serotonin 5-HT/sub 2/ receptors in mouse brain

    SciTech Connect

    Hartig, P.R.; Scheffel, U., Frost, J.J.; Wagner, H.N. Jr.

    1985-08-19

    The binding of /sup 125/I-LSD (2-(/sup 125/I)-lysergic acid diethylamide) was studied in various mouse brain regions following intravenous injection of the radioligand. The high specific activity of /sup 125/I-LSD enabled the injection of low mass doses (14ng/kg), which are well below the threshold for induction of any known physiological effect of the probe. The highest levels of /sup 125/I-LSD binding were found in the frontal cortex, olfactory tubercles, extra-frontal cortex and striatum while the lowest level was found in the cerebellum. Binding was saturable in the frontal cortex but increased linearly in the cerebellum with increasing doses of /sup 125/I-LSD. Serotonergic compounds potently inhibited /sup 125/I-LSD binding in cortical regions, olfactory tubercles, and hypothalamus but had no effect in the cerebellum. Dopaminergic compounds caused partial inhibition of binding in the striatum while adrenergic compounds were inactive. From these studies the authors conclude that /sup 125/I-LSD labels serotonin 5-HT/sub 2/ receptor sites in cortical regions with no indication that other receptor sites are labeled. In the olfactory tubercles and hypothalamus, /sup 125/I-LSD labeling occurs predominantly or entirely at serotonic 5-HT/sub 2/ sites. In the striatum, /sup 125/I-LSD labels approximately equal proportions of serotonergic and dopaminergic sites. These data indicate that /sup 125/I-LSD labels serotonin receptors in vivo and suggests that appropriate derivatives of 2I-LSD may prove useful for tomographic imaging of serotonin 5-HT/sub 2/ receptors in the mammalian cortex.

  8. Placement of {sup 125}I implants with the da Vinci robotic system after video-assisted thoracoscopic wedge resection: A feasibility study

    SciTech Connect

    Pisch, Julianna . E-mail: jpisch@bethisraelny.org; Belsley, Scott J.; Ashton, Robert; Wang Lin; Woode, Rudolph; Connery, Cliff

    2004-11-01

    Purpose: To evaluate the feasibility of using the da Vinci robotic system for radioactive seed placement in the wedge resection margin of pigs' lungs. Methods and materials: Video-assisted thoracoscopic wedge resection was performed in the upper and lower lobes in pigs. Dummy {sup 125}I seeds embedded in absorbable sutures were sewn into the resection margin with the aid of the da Vinci robotic system without complications. In the 'loop technique,' the seeds were placed in a cylindrical pattern; in the 'longitudinal,' they were above and lateral to the resection margin. Orthogonal radiographs were taken in the operating room. For dose calculation, Variseed 66.7 (Build 11312) software was used. Results: With looping seed placement, in the coronal view, the dose at 1 cm from the source was 97.0 Gy; in the lateral view it was 107.3 Gy. For longitudinal seed placement, the numbers were 89.5 Gy and 70.0 Gy, respectively. Conclusion: Robotic technology allows direct placement of radioactive seeds into the resection margin by endoscopic surgery. It overcomes the technical difficulties of manipulating in the narrow chest cavity. With the advent of robotic technology, new options in the treatment of lung cancer, as well as other malignant tumors, will become available.

  9. Localization of Iron in Arabidopsis Seed Requires the Vacuolar Membrane Transporter VIT1

    SciTech Connect

    Kim,S.; Punshon, T.; Lanzirotti, A.; Li, L.; Alonso, J.; Ecker, J.; Kaplan, J.; Guerinot, M.

    2006-01-01

    Iron deficiency is a major human nutritional problem wherever plant-based diets are common. Using synchrotron x-ray fluorescence microtomography to directly visualize iron in Arabidopsis seeds, we show that iron is localized primarily to the provascular strands of the embryo. This localization is completely abolished when the vacuolar iron uptake transporter VIT1 is disrupted. Vacuolar iron storage is also critical for seedling development because vit1-1 seedlings grow poorly when iron is limiting. We have uncovered a fundamental aspect of seed biology that will ultimately aid the development of nutrient-rich seed, benefiting both human health and agricultural productivity.

  10. Local climate explains degree of seed dormancy in Hypericum elodes L. (Hypericaceae).

    PubMed

    Carta, A; Probert, R; Puglia, G; Peruzzi, L; Bedini, G

    2016-01-01

    Seed dormancy and germination characteristics may vary within species in response to several factors. Knowledge of such variation is crucial to understand plant evolution and adaptation to environmental changes. We examined the correlation of climate and population genetic differentiation (ISSR) with primary seed dormancy and germination behaviour in populations of the Atlantic-European soft-water pool specialist Hypericum elodes. Primary dormancy was measured by analysing seed germination response of fresh seeds and after various periods of cold stratification. Laboratory germination experiments revealed that the single most important factor for promoting germination was cold stratification prior to placing at the germination temperature. However, in agreement with their weaker primary dormancy, the seeds germinated well when fresh, and the benefit of cold stratification was more relaxed for the southern populations. Seeds of all populations demonstrated a near absolute requirement for a light and alternating temperature regime in order to germinate. The promoting effect of alternating temperatures was particularly effective at warm temperatures (mean 20 °C) but not at cool temperatures. Whilst seed germination requirements were similar among populations, the degree of primary dormancy varied considerably and was not associated with population genetic differentiation. Primary dormancy degree was instead associated with local climate: higher temperature in summer and rainfall in winter predicted weak and rapid loss of dormancy. These results suggest that seed maturation environment may play a substantial role in explaining the degree of dormancy in H. elodes, highlighting that physiological dormancy can be modulated by local climate.

  11. Measurement of /sup 125/I-low density lipoprotein uptake in selected tissues of the squirrel monkey by quantitative autoradiography

    SciTech Connect

    Tompkins, R.G.; Schnitzer, J.J.; Yarmush, M.L.; Colton, C.K.; Smith, K.A.

    1988-09-01

    A recently developed technique of absolute quantitative light microscopic autoradiography of /sup 125/I-labeled proteins in biologic specimens was used to measure /sup 125/I-low density lipoprotein (/sup 125/I-LDL) concentration levels in various tissues of the squirrel monkey after 30 minutes of in vivo LDL circulation. Liver and adrenal cortex exhibited high /sup 125/I-LDL concentrations, presumably because of binding to specific cell surface receptors and/or internalization in vascular beds with high permeability to LDL. High tissue concentrations of LDL were associated with the zona fasciculata and reticularis of the adrenal cortex and the interstitial cells of Leydig in the testis; significantly lower levels of /sup 125/I-LDL were observed in the adrenal medulla, the zona glomerulosa, and germinal centers of the testis. Contrary to previous reports, low /sup 125/I-LDL concentrations were observed throughout the gastrointestinal tract and in lymph nodes. In addition, multiple arterial intramural focal areas of high /sup 125/I-LDL concentrations were identified in arteries supplying the adrenal gland, lymph node, small bowel, and liver.

  12. A local dormancy cline is related to the seed maturation environment, population genetic composition and climate

    PubMed Central

    Fernández-Pascual, Eduardo; Jiménez-Alfaro, Borja; Caujapé-Castells, Juli; Jaén-Molina, Ruth; Díaz, Tomás Emilio

    2013-01-01

    Background and Aims Seed dormancy varies within species in response to climate, both in the long term (through ecotypes or clines) and in the short term (through the influence of the seed maturation environment). Disentangling both processes is crucial to understand plant adaptation to environmental changes. In this study, the local patterns of seed dormancy were investigated in a narrow endemic species, Centaurium somedanum, in order to determine the influence of the seed maturation environment, population genetic composition and climate. Methods Laboratory germination experiments were performed to measure dormancy in (1) seeds collected from different wild populations along a local altitudinal gradient and (2) seeds of a subsequent generation produced in a common garden. The genetic composition of the original populations was characterized using intersimple sequence repeat (ISSR) PCR and principal co-ordinate analysis (PCoA), and its correlation with the dormancy patterns of both generations was analysed. The effect of the local climate on dormancy was also modelled. Key Results An altitudinal dormancy cline was found in the wild populations, which was maintained by the plants grown in the common garden. However, seeds from the common garden responded better to stratification, and their release from dormancy was more intense. The patterns of dormancy variation were correlated with genetic composition, whereas lower temperature and summer precipitation at the population sites predicted higher dormancy in the seeds of both generations. Conclusions The dormancy cline in C. somedanum is related to a local climatic gradient and also corresponds to genetic differentiation among populations. This cline is further affected by the weather conditions during seed maturation, which influence the receptiveness to dormancy-breaking factors. These results show that dormancy is influenced by both long-and short-term climatic variation. Such processes at such a reduced spatial

  13. Specific uptake, dissociation, and degradation of /sup 125/I-labeled insulin in isolated turtle (Chrysemys dorbigni) thyroid glands

    SciTech Connect

    Marques, M.; da Silva, R.S.; Turyn, D.; Dellacha, J.M.

    1985-11-01

    Thyroid glands from turtles (Chrysemys dorbigni) pretreated with potassium iodide were incubated with /sup 125/I-insulin in the presence or absence of unlabeled insulin, in order to study its specific uptake. At 24 degrees, the specific uptake reached a plateau at 180 min of incubation. The dose of bovine insulin that inhibited 50% of the /sup 125/I-insulin uptake was 2 micrograms/ml of incubation medium. Most of the radioactive material (71%) extracted from the gland, after 30 min incubation with /sup 125/I-insulin, eluted in the same position as labeled insulin on Sephadex G-50. Only 24% eluted in the salt position. After 240 min incubation, increased amount of radioactivity appeared in the Na/sup 125/I position. When bovine insulin was added together with the labeled hormone, a substantial reduction of radioactivity was observed in the insulin and Na/sup 125/I elution positions. Dissociation studies were performed at 6 degrees in glands preincubated with /sup 125/I-insulin either at 24 or 6 degrees. The percentage of trichloroacetic acid (TCA)-soluble radioactive material in the dissociation medium increased with incubation time at both temperatures. However, the degradation activity was lower at 6 than at 24 degrees. The addition of bovine insulin to the incubation buffer containing /sup 125/I-insulin reduced the radioactive degradation products in the dissociated medium. Chloroquine or bacitracin inhibited the degradation activity. Incubation of thyroid glands with /sup 125/I-hGH or /sup 125/I-BSA showed values of uptake, dissociation, and degradation similar to those experiments in which an excess of bovine insulin was added together with the labeled hormone. Thus, by multiple criteria, such as specific uptake, dissociation, and degradation, the presence of insulin-binding sites in the turtle thyroid gland may be suggested.

  14. Derivatives of cyclosporin compatible with antibody-based assays. I. The generation of (/sup 125/I)-labeled cyclosporin

    SciTech Connect

    Mahoney, W.C.; Orf, J.W.

    1985-03-01

    The immunosuppressive drug cyclosporin A, has been successfully iodinated to a specific activity of 300 Ci per gram. /sup 125/I-labeled cyclosporin and (/sup 3/H)cyclosporin are nearly equivalent as tracers in a radioimmunoassay in producing standard lines (suppression by unlabeled cyclosporin) and in assigning values to clinical samples. In addition, the (/sup 125/I)-labeled cyclosporin has greater than twice the sensitivity, and it is stable to long-term storage. Use of a (/sup 125/I)-labeled cyclosporin tracer is more convenient, more reproducible, more precise, and easier than the tritiated-cyclosporin alternative in radioimmunoassay of this compound.

  15. Preparation and one-step purification of mono-125I-angiotensin II for radioligand binding assays

    SciTech Connect

    Speth, R.C.; Husain, A.

    1984-04-01

    A one-step purification of mono-/sup 125/I-angiotensin II prepared by the chloramine T procedure is described. The purification is effected on a cellulose cation exchange column with isocratic elution by 50 mM sodium acetate, pH 5.0. The purity of the mono-/sup 125/I-angiotensin II was determined by thin layer chromatography, high pressure liquid chromatography, enzymatic digestion, radioreceptor assay, and radioimmunoassay. Preparation and purification of mono-/sup 125/I-angiotensin II by this procedure offers significant advantages over existing methods for its preparation in terms of purity, simplicity, efficiency, and cost.

  16. A rapid means of separating A14-/sup 125/I-insulin from heterogeneously labeled insulin molecules for biologic studies

    SciTech Connect

    Stentz, F.B.; Wright, R.K.; Kitabchi, A.E.

    1982-12-01

    We have used two methods for the preparation of a highly homogeneous insulin with high specific activity. After iodination with chloramine T, the labeled peptides were retained on a disposable Sep Pak cartridge and subsequently eluted. The eluted labeled insulins were further purified by either DEAE cellulose or high performance liquid chromatography (HPLC) to separate A14-/sup 125/I- from A19-/sup 125/I-insulin. Both methods of chromatography were effective, but HPLC offered the advantage of better resolution in less time and higher yields of A14-/sup 125/I-insulin, which is suitable for biologic studies in various target tissues.

  17. Rapid extraction, radioiodination, and in vivo catabolism of 125I-labeled fibrinogen in the horse

    SciTech Connect

    Coyne, C.P.; Hornof, W.J.; Kelly, A.B.; O'Brien, T.R.; DeNardo, S.J.

    1985-12-01

    Two methods were analyzed for the rapid extraction of equine fibrinogen from fresh plasma, using ammonium sulfate-sodium phosphate buffer. Fibrinogen from each of these 2 methods was then radiolabeled with 125I (half-life = 60.2 days, gamma = 35 keV), using monochloroiodine reagent. Mean protein-bound activity was 98.5% and mean clottable radioactivity was 94.1%. Radiolabeled fibrinogen administered IV to 15 horses had an overall mean (+/- SD) plasma half-life of 4.95 +/- 0.44 days.

  18. Scintillation Studies of the Mouse Mammary Tumor Virus with ^125I

    NASA Astrophysics Data System (ADS)

    Yazdi, Amir; Blue, Eric; Bradley, Eric; Majewski, Stan; Mohammed, Shira; Qian, Jianguo; Saha, Margaret; Schworer, Stephen; Sutton, Jonathan; Weisenberger, Andrew; Welsh, Robert

    2007-10-01

    We have applied the techniques of scintillation imaging to studies of the mouse mammary tumor virus (MMTV). In these studies, Sodium Iodide Symporter (NIS) transfers the radioactive ^125I to the mammary glands of lactating mice and in particular to those mammaries with visible tumors. These studies have principally been carried out using pixellated scintillators coupled to position sensitive photomultiplier tubes (PSPMTs). More recently, we have initiated such studies with a monolithic slab of LaBr3 scintillator coupled to an array of PSPMTs. Several techniques of mapping and measuring the development of such tumors have been employed. These will be discussed in detail and preliminary results will be reported.

  19. Ocular penetration of (/sup 125/I)IVDU, a radiolabeled analogue of bromovinyldeoxyuridine

    SciTech Connect

    Maudgal, P.C.; Verbruggen, A.M.; De Clercq, E.; Busson, R.; Bernaerts, R.; de Roo, M.; Ameye, C.; Missotten, L.

    1985-01-01

    Following topical application of (/sup 125/)IVDU, the radiolabeled analogue of bromovinyldeoxyuridine ((E)-5-(2-bromovinyl)-2'-deoxyuridine), as 0.5% or 0.3% eyedrops, to rabbits, (/sup 125/I)IVDU appeared in the anterior chamber fluid at drug levels well above the minimum concentration (0.01 microgram/mL) required for inhibition of herpes simplex virus type 1 replication. These findings are consistent with the efficacy of 0.5% bromovinyldeoxyuridine eyedrops in the topical treatment of herpes simplex uveitis.

  20. Plant regeneration from seeds responds to phylogenetic relatedness and local adaptation in Mediterranean Romulea (Iridaceae) species.

    PubMed

    Carta, Angelino; Hanson, Sarah; Müller, Jonas V

    2016-06-01

    Seed germination is the most important transitional event between early stages in the life cycle of spermatophytes and understanding it is crucial to understand plant adaptation and evolution. However, so far seed germination of phylogenetically closely related species has been poorly investigated. To test the hypothises that phylogenetically related plant species have similar seed ecophysiological traits thereby reflecting certain habitat conditions as a result of local adaptation, we studied seed dormancy and germination in seven Mediterranean species in the genus Romulea (Iridaceae). Both the across-species model and the model accounting for shared evolutionary history showed that cool temperatures (≤ 15°C) were the main factor that promoted seed germination. The absence of embryo growth before radicle emergence is consistent with a prompt germination response at cool temperatures. The range of temperature conditions for germination became wider after a period of warm stratification, denoting a weak primary dormancy. Altogether these results indicate that the studied species exhibit a Mediterranean germination syndrome, but with species-specific germination requirements clustered in a way that follows the phylogenetic relatedness among those species. In addition, species with heavier seeds from humid habitats showed a wider range of conditions for germination at dispersal time than species from dry habitats possessing lighter seeds. We conclude that while phylogenetically related species showed very similar germination requirements, there are subtle ecologically meaningful differences, confirming the onset of adaptation to local ecological factors mediated by species relatedness.

  1. Are local filters blind to provenance? Ant seed predation suppresses exotic plants more than natives.

    PubMed

    Pearson, Dean E; Icasatti, Nadia S; Hierro, Jose L; Bird, Benjamin J

    2014-01-01

    The question of whether species' origins influence invasion outcomes has been a point of substantial debate in invasion ecology. Theoretically, colonization outcomes can be predicted based on how species' traits interact with community filters, a process presumably blind to species' origins. Yet, exotic plant introductions commonly result in monospecific plant densities not commonly seen in native assemblages, suggesting that exotic species may respond to community filters differently than natives. Here, we tested whether exotic and native species differed in their responses to a local community filter by examining how ant seed predation affected recruitment of eighteen native and exotic plant species in central Argentina. Ant seed predation proved to be an important local filter that strongly suppressed plant recruitment, but ants suppressed exotic recruitment far more than natives (89% of exotic species vs. 22% of natives). Seed size predicted ant impacts on recruitment independent of origins, with ant preference for smaller seeds resulting in smaller seeded plant species being heavily suppressed. The disproportionate effects of provenance arose because exotics had generally smaller seeds than natives. Exotics also exhibited greater emergence and earlier peak emergence than natives in the absence of ants. However, when ants had access to seeds, these potential advantages of exotics were negated due to the filtering bias against exotics. The differences in traits we observed between exotics and natives suggest that higher-order introduction filters or regional processes preselected for certain exotic traits that then interacted with the local seed predation filter. Our results suggest that the interactions between local filters and species traits can predict invasion outcomes, but understanding the role of provenance will require quantifying filtering processes at multiple hierarchical scales and evaluating interactions between filters.

  2. Autoradiographic distribution of /sup 125/I-galanin binding sites in the rat central nervous system

    SciTech Connect

    Skofitsch, G.; Sills, M.A.; Jacobowitz, D.M.

    1986-11-01

    Galanin (GAL) binding sites in coronal sections of the rat brain were demonstrated using autoradiographic methods. Scatchard analysis of /sup 125/I-GAL binding to slide-mounted tissue sections revealed saturable binding to a single class of receptors with a Kd of approximately 0.2 nM. /sup 125/I-GAL binding sites were demonstrated throughout the rat central nervous system. Dense binding was observed in the following areas: prefrontal cortex, the anterior nuclei of the olfactory bulb, several nuclei of the amygdaloid complex, the dorsal septal area, dorsal bed nucleus of the stria terminalis, the ventral pallidum, the internal medullary laminae of the thalamus, medial pretectal nucleus, nucleus of the medial optic tract, borderline area of the caudal spinal trigeminal nucleus adjacent to the spinal trigeminal tract, the substantia gelatinosa and the superficial layers of the dorsal spinal cord. Moderate binding was observed in the piriform, periamygdaloid, entorhinal, insular cortex and the subiculum, the nucleus accumbens, medial forebrain bundle, anterior hypothalamic, ventromedial, dorsal premamillary, lateral and periventricular thalamic nuclei, the subzona incerta, Forel's field H1 and H2, periventricular gray matter, medial and superficial gray strata of the superior colliculus, dorsal parts of the central gray, peripeduncular area, the interpeduncular nucleus, substantia nigra zona compacta, ventral tegmental area, the dorsal and ventral parabrachial and parvocellular reticular nuclei. The preponderance of GAL-binding in somatosensory as well as in limbic areas suggests a possible involvement of GAL in a variety of brain functions.

  3. Detection by cationized /sup 125/I-cytochrome C of proteoglycans (PG) transferred to nylon

    SciTech Connect

    Heimer, R.; Sampson, P.M.; Fishman, A.P.

    1986-05-01

    Cytochrome c, labeled with /sup 125/I, has been used by us for staining glycosaminoglycans (GAG) separated by electrophoresis on cellulose acetate strips. As GAG between 1-10 ng could be quantified by autoradiography and densitometry, the reagent is approximately 100-fold more sensitive than currently used non-radiolabeled stains. The authors extend now the use of radiolabeled cytochrome c to the quantification of PG transblotted to solid supports subsequent to separation on polyacrylamine slab gels. Dot blotting used for exploring optimal conditions for detecting PG indicated that because of low background positively charged Nylon 66 was superior to nitrocellulose. Increasing the positive charge of the staining reagent by cationization decreased background radiation even further so that 1 ng PG could be seen readily after 5 hrs of autoradiography. Use of cationized /sup 125/I-cytochrome c has been made in detecting PG of bovine fetal epiphyseal cartilage (> 1 x 10/sup 6/ D) and PG of bovine aorta (0.25 x 10/sup 6/ D) following slab gel electrophoresis and electrophoretic transblotting. With effective electrophoretic transfer of the PG to positively charged Nylon 66, the sensitivity of detection of the two PG was increased at least 100-fold over that observed when the gels were stained with toluidine blue, the method in current use.

  4. Relationship between alveolar bone measured by /sup 125/I absorptiometry with analysis of standardized radiographs: 1. Magiscan

    SciTech Connect

    Hausmann, E.; Ortman, L.F.; McHenry, K.; Fallon, J.

    1982-05-01

    Previous studies have shown that /sup 125/I absorptiometry gives an accurate and sensitive measure of alveolar bone mass. The purpose of this study was to determine the relationship between alveolar bone mass determined by /sup 125/I absorptiometry and bone density obtained by analysis of standardized intraoral radiographs by the Magiscan System. A defect of increasing size was made at one site of the alveolar bone in a human skull. The amount of bone remaining at each step was calculated using /sup 125/I absorptiometry. Standardized radiographs were also taken at each step and the relative density in the area of the defect was determined by the Magiscan System. The Magiscan's System Computer Memory permits analysis of identical areas on a longitudinal series of films of the same alveolar bone location. The results indicate that in estimating amounts of alveolar bone the Magiscan analysis of standardized intraoral radiography is similar in sensitivity and accuracy to /sup 125/I absorptiometry.

  5. Receptor binding and cell-mediated metabolism of (/sup 125/I)monoiodoglucagon by isolated canine hepatocytes

    SciTech Connect

    Hagopian, W.A.; Tager, H.S.

    1984-07-25

    A reverse-phase HPLC method has been developed to purify /sup 125/I-labeled products resulting from the chloramine-T-based iodination of glucagon. In addition the products ((/sup 125/I)iodoTyr/sup 10/ /sup 13/)glucagon, ((/sup 125/I)iodoTyr/sup 13/)glucagon, and ((/sup 125/I)iodoTyr/sup 10/)glucagon) have been used to study the receptor binding of glucagon and the cell-mediated metabolism of the hormone by isolated canine hepatocytes. It was concluded that (a) not withstanding apparent differences in affinities exhibited by the three peptides, the interactions with the glucagon receptor are functionally equivalent, and (b) the cell-mediated metabolism of receptor-bound glucagon involves the formation of hormone-derived peptides in which the biologically important NH/sub 2/-terminal region of the hormone has been modified by limited proteolytic cleavage.

  6. Endocytosis and subsequent processing of 125I-labelled immunoglobulin G by guinea pig yolk sac in vitro.

    PubMed Central

    Douglas, G C; King, B F

    1985-01-01

    We have developed conditions for studying the binding, uptake, degradation and transport of 125I-labelled IgG by yolk sac in vitro. Specific binding to tissue at 4 degrees C and to paraformaldehyde-treated tissue at 37 degrees C was time- and temperature-dependent and showed saturation kinetics (Kd,4 degrees C = 2.9 X 10(-6) M, Kd,37 degrees C = 5.3 X 10(-6) M). Uptake was studied at 37 degrees C using untreated tissue (K uptake = 13.3 X 10(-6) M) and was inhibited by preincubation with metabolic poisons but not with cycloheximide. Tissue that had been incubated with 125I-labelled IgG at 37 degrees C released radiolabelled degradation products and intact 125I-labelled IgG into the medium. Experiments with paraformaldehyde-treated and untreated tissue showed that release of intact 125I-labelled IgG was mostly the result of ligand dissociation from surface binding sites. However, more 125I-labelled IgG was released from untreated tissue than could be accounted for solely by loss of surface-bound ligand and the difference was presumed to reflect uptake, transport and exocytosis of 125I-labelled IgG. Degradation of 125I-labelled IgG was inhibited by leupeptin and lysosomotropic amines. These drugs had no detectable effect on 125I-labelled IgG release. The results suggest that degradation and transport of IgG are not intimately related and are consistent with a previously proposed model for IgG transport via coated vesicles which do not fuse with lysosomes and for non-selective uptake into another class of vesicle which does fuse with lysosomes. PMID:4004783

  7. Heterogeneity in mouse seminal vesicle epithelial cells responding to androgen as evaluated by incorporation of (/sup 125/I)iododeoxyuridine

    SciTech Connect

    Terada, N.; Ogasawara, Y.; Yamane, T.; Matsumoto, K.; Kitamura, Y.

    1985-04-01

    When the uptake of 5-(/sup 125/I)iodo-2'-deoxyuridine ((/sup 125/I)IdUrd) into the seminal vesicle of castrated mice was measured 3 days after starting injections of various doses of testosterone propionate (TP), logarithmic values of (/sup 125/I)IdUrd uptake were proportional to the logarithmic doses of TP in the range of 0.04-2 micrograms/g BW. The (/sup 125/I)IdUrd uptake values correlated well with the labeling and mitotic indices of epithelial cells. Since daily injections of 0.4 microgram TP/g BW did not increase significantly the weight or DNA content or protein content of the seminal vesicle, the (/sup 125/I)IdUrd uptake is a sensitive index of androgen action. Moreover, this suggests that low doses of androgen induce division of epithelial cells without resulting in the increase in cell number. The (/sup 125/I)IdUrd radioactivity in the seminal vesicle was measured 2-15 days after the injection of (/sup 125/I)IdUrd, since the value represented the fraction of surviving cells synthesizing DNA at the time of (/sup 125/I)IdUrd injection. When injections of 4 micrograms TP/g BW were continued, the incorporated radioactivity was retained. In contrast, continuous injections of 0.2 microgram TP/g BW did not maintain the radioactivity, of which incorporation was induced by the same dose of TP. Thus, the present result suggests the presence of heterogeneity in androgen-responsive epithelial cells of the seminal vesicle.

  8. Β-amylase from starchless seeds of Trigonella foenum-graecum and its localization in germinating seeds.

    PubMed

    Srivastava, Garima; Kayastha, Arvind M

    2014-01-01

    Fenugreek (Trigonella foenum-graecum) seeds do not contain starch as carbohydrate reserve. Synthesis of starch is initiated after germination. A β-amylase from ungerminated fenugreek seeds was purified to apparent electrophoretic homogeneity. The enzyme was purified 210 fold with specific activity of 732.59 units/mg. Mr of the denatured enzyme as determined from SDS-PAGE was 58 kD while that of native enzyme calculated from size exclusion chromatography was 56 kD. Furthermore, its identity was confirmed to be β-amylase from MALDI-TOF analysis. The optimum pH and temperature was found to be 5.0 and 50°C, respectively. Starch was hydrolyzed at highest rate and enzyme showed a Km of 1.58 mg/mL with it. Antibodies against purified Fenugreek β-amylase were generated in rabbits. These antibodies were used for localization of enzyme in the cotyledon during different stages of germination using fluorescence and confocal microscopy. Fenugreek β-amylase was found to be the major starch degrading enzyme depending on the high amount of enzyme present as compared to α-amylase and also its localization at the periphery of amyloplasts. A new finding in terms of its association with protophloem was observed. Thus, this enzyme appears to be important for germination of seeds.

  9. The Comparative Effectiveness of Rodents and Dung Beetles as Local Seed Dispersers in Mediterranean Oak Forests

    PubMed Central

    Pérez-Ramos, Ignacio M.; Verdú, José R.; Numa, Catherine; Marañón, Teodoro; Lobo, Jorge M.

    2013-01-01

    The process of seed dispersal of many animal-dispersed plants is frequently mediated by a small set of biotic agents. However, the contribution that each of these dispersers makes to the overall recruitment may differ largely, with important ecological and management implications for the population viability and dynamics of the species implied in these interactions. In this paper, we compared the relative contribution of two local guilds of scatter-hoarding animals with contrasting metabolic requirements and foraging behaviours (rodents and dung beetles) to the overall recruitment of two Quercus species co-occurring in the forests of southern Spain. For this purpose, we considered not only the quantity of dispersed seeds but also the quality of the seed dispersal process. The suitability for recruitment of the microhabitats where the seeds were deposited was evaluated in a multi-stage demographic approach. The highest rates of seed handling and predation occurred in those microhabitats located under shrubs, mostly due to the foraging activity of rodents. However, the probability of a seed being successfully cached was higher in microhabitats located beneath a tree canopy as a result of the feeding behaviour of beetles. Rodents and beetles showed remarkable differences in their effectiveness as local acorn dispersers. Quantitatively, rodents were much more important than beetles because they dispersed the vast majority of acorns. However, they were qualitatively less effective because they consumed a high proportion of them (over 95%), and seeds were mostly dispersed under shrubs, a less suitable microhabitat for short-term recruitment of the two oak species. Our findings demonstrate that certain species of dung beetles (such as Thorectes lusitanicus), despite being quantitatively less important than rodents, can act as effective local seed dispersers of Mediterranean oak species. Changes in the abundance of beetle populations could thus have profound implications

  10. The comparative effectiveness of rodents and dung beetles as local seed dispersers in Mediterranean oak forests.

    PubMed

    Pérez-Ramos, Ignacio M; Verdú, José R; Numa, Catherine; Marañón, Teodoro; Lobo, Jorge M

    2013-01-01

    The process of seed dispersal of many animal-dispersed plants is frequently mediated by a small set of biotic agents. However, the contribution that each of these dispersers makes to the overall recruitment may differ largely, with important ecological and management implications for the population viability and dynamics of the species implied in these interactions. In this paper, we compared the relative contribution of two local guilds of scatter-hoarding animals with contrasting metabolic requirements and foraging behaviours (rodents and dung beetles) to the overall recruitment of two Quercus species co-occurring in the forests of southern Spain. For this purpose, we considered not only the quantity of dispersed seeds but also the quality of the seed dispersal process. The suitability for recruitment of the microhabitats where the seeds were deposited was evaluated in a multi-stage demographic approach. The highest rates of seed handling and predation occurred in those microhabitats located under shrubs, mostly due to the foraging activity of rodents. However, the probability of a seed being successfully cached was higher in microhabitats located beneath a tree canopy as a result of the feeding behaviour of beetles. Rodents and beetles showed remarkable differences in their effectiveness as local acorn dispersers. Quantitatively, rodents were much more important than beetles because they dispersed the vast majority of acorns. However, they were qualitatively less effective because they consumed a high proportion of them (over 95%), and seeds were mostly dispersed under shrubs, a less suitable microhabitat for short-term recruitment of the two oak species. Our findings demonstrate that certain species of dung beetles (such as Thorectes lusitanicus), despite being quantitatively less important than rodents, can act as effective local seed dispersers of Mediterranean oak species. Changes in the abundance of beetle populations could thus have profound implications

  11. Autoradiographic characterization of (+-)-1-(2,5-dimethoxy-4-( sup 125 I) iodophenyl)-2-aminopropane (( sup 125 I)DOI) binding to 5-HT2 and 5-HT1c receptors in rat brain

    SciTech Connect

    Appel, N.M.; Mitchell, W.M.; Garlick, R.K.; Glennon, R.A.; Teitler, M.; De Souza, E.B. )

    1990-11-01

    The 5-HT2 (serotonin) receptor has traditionally been labeled with antagonist radioligands such as (3H)ketanserin and (3H)spiperone, which label both agonist high-affinity (guanyl nucleotide-sensitive) and agonist low-affinity (guanyl nucleotide-insensitive) states of this receptor. The hallucinogen 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) is an agonist which labels the high-affinity guanyl nucleotide-sensitive state of brain 5-HT2 receptors selectively. In the present study, conditions for autoradiographic visualization of (+/-)-(125I)DOI-labeled 5-HT2 receptors were optimized and binding to slide-mounted sections was characterized with respect to pharmacology, guanyl nucleotide sensitivity and anatomical distribution. In slide-mounted rat brain sections (+/-)-(125I)DOI binding was saturable, of high affinity (KD approximately 4 nM) and displayed a pharmacologic profile typical of 5-HT2 receptors. Consistent with coupling of 5-HT2 receptors in the high-affinity state to a guanyl nucleotide regulatory protein, (125I)DOI binding was inhibited by guanyl nucleotides but not by adenosine triphosphate. Patterns of autoradiographic distribution of (125I)DOI binding to 5-HT2 receptors were similar to those seen with (3H)ketanserin- and (125I)-lysergic acid diethylamide-labeled 5-HT2 receptors. However, the density of 5-HT2 receptors labeled by the agonist (125I)DOI was markedly lower (30-50%) than that labeled by the antagonist (3H)ketanserin. High densities of (125I)DOI labeling were present in olfactory bulb, anterior regions of cerebral cortex (layer IV), claustrum, caudate putamen, globus pallidus, ventral pallidum, islands of Calleja, mammillary nuclei and inferior olive. Binding in hippocampus, thalamus and hypothalamus was generally sparse.

  12. 7 CFR 361.2 - Preemption of State and local laws; general restrictions on the importation of seed and screenings.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... restrictions on the importation of seed and screenings. 361.2 Section 361.2 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.2 Preemption of State and local...

  13. 7 CFR 361.2 - Preemption of State and local laws; general restrictions on the importation of seed and screenings.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... restrictions on the importation of seed and screenings. 361.2 Section 361.2 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE IMPORTATION OF SEED AND SCREENINGS UNDER THE FEDERAL SEED ACT § 361.2 Preemption of State and local...

  14. Brain damage from sup 125 I brachytherapy evaluated by MR imaging, a blood-brain barrier tracer, and light and electron microscopy in a rat model

    SciTech Connect

    Bernstein, M.; Marotta, T.; Stewart, P.; Glen, J.; Resch, L.; Henkelman, M. )

    1990-10-01

    Changes in normal rat brain were studied acutely, and at 3, 6, 9, and 12 months following interstitial brachytherapy with high-activity {sup 125}I seeds. An 80-Gy radiation dose was administered to an area with a 5.5-mm radius. Effects were measured with magnetic resonance (MR) imaging (with and without gadolinium enhancement), leakage of horseradish peroxidase (HRP), electron microscopy, and light microscopy. Significant histological damage was seen at radiation doses above 295 Gy, and breakdown of the blood-brain barrier was observed only in tissue receiving a dose of 165 Gy or greater. Blood-brain barrier breakdown increased up to the 6-month time point, and thereafter appeared to stabilize or decrease. The area of blood-brain barrier disruption indicated by gadolinium-enhanced MR imaging was greater than that indicated by leakage of HRP.

  15. Search for a 17 keV neutrino in the internal bremsstrahlung spectrum of 125I

    NASA Astrophysics Data System (ADS)

    Hindi, M. M.; Kozub, R. L.; Robinson, S. J.

    1994-06-01

    We have searched for evidence of the emission of a 17 keV neutrino in the internal bremsstrahlung (IB) spectrum accompanying the electron capture decay of 125I. The IB spectrum, recorded in a planar Ge detector, has 1.2×106 counts per keV at 17 keV below the 2p end point. We set an upper limit of 0.4% for the admixture of a 17 keV neutrino, at the 90% confidence level, and exclude a 0.8% admixture at the 99.6% confidence level. The QEC value is found to be 185.77+/-0.06 keV. We also find that the recent calculations of Surić et al., which employ relativistic self-consistent-field atomic wave functions, reproduce the shape and relative intensity of IB partial spectra within a few percent.

  16. HPLC-purified 2-(/sup 125/I)iodomelatonin labels multiple binding sites in hamster brain

    SciTech Connect

    Niles, L.P.; Pickering, D.S.; Sayer, B.G.

    1987-09-30

    Binding of 2-(/sup 125/I)iodomelatonin in hamster brain synaptosomal membranes at 0 degrees C is rapid, saturable, reversible and sensitive to heat and trypsin treatment. Computer resolution of curvilinear Scatchard plots yielded high- and low-affinity components as follows: Kd1 = 0.32 +/- 0.14 nM, Bmax1 = 5.6 +/- 1.7 fmol/mg protein and Kd2 = 10.5 +/- 3.2 nM, Bmax2 = 123 +/- 33 fmol/mg protein (n = 3). Competition experiments indicated that 2-iodomelatonin and prazosin are the most potent inhibitors of high-affinity binding. Unlike prazosin, several alpha-adrenergic agents and various neurotransmitters were ineffective. These findings suggest that prazosin may be a potent antagonist at a unique, non-alpha-adrenergic, high-affinity binding site for melatonin.

  17. Intramolecular quadruplex conformation of human telomeric DNA assessed with 125I-radioprobing

    PubMed Central

    He, Yujian; Neumann, Ronald D.; Panyutin, Igor G.

    2004-01-01

    A repeated non-coding DNA sequence d(TTAGGG)n is present in the telomeric ends of all human chromosomes. These repeats can adopt multiple inter and intramolecular non-B-DNA conformations that may play an important role in biological processes. Two intramolecular structures of the telomeric oligonucleotide dAGGG(TTAGGG)3, antiparallel and parallel, have been solved by NMR and X-ray crystallography. In both structures, the telomeric sequence adopts an intramolecular quadruplex structure that is stabilized by G-4 quartets, but the ways in which the sequence folds into the quadruplex are different. The folds of the human telomeric DNA were described as an anti-parallel basket-type and a parallel propeller-type. We applied 125I-radioprobing to determine the conformation of the telomeric quadruplex in solution, in the presence of either Na+ or K+ ions. The probability of DNA breaks caused by decay of 125I is inversely related to the distance between the radionuclide and the sugar unit of the DNA backbone; hence, the conformation of the DNA backbone can be deduced from the distribution of breaks. The probability of breaks measured in the presence of Na+ and K+ were compared with the distances in basket-type and propeller-type quadruplexes obtained from the NMR and crystal structures. Our radioprobing data demonstrate that the antiparallel conformation was present in solution in the presence of both K+ and Na+. The preferable conformation in the Na+-containing solution was the basket-type antiparallel quadruplex whereas the presence of K+ favored the chair-type antiparallel quadruplex. Thus, we believe that the two antiparallel and the parallel conformations may coexist in solution, and that their relative proportion is determined by the type and concentration of ions. PMID:15475390

  18. On-line I-/Te- separation for the AMS analysis of 125I

    NASA Astrophysics Data System (ADS)

    Charles, C. R. J.; Cornett, R. J.; Zhao, X.-L.; Litherland, A. E.; Kieser, W. E.

    2015-10-01

    The isobar separator for anions (ISA) was used together with a 3 MV tandem accelerator mass spectrometer (AMS) to demonstrate the real time (on-line) separation of Te- from I-. Following the ion source mass spectrometry and major retardation to tens of eV, the ISA uses a radiofrequency quadrupole (RFQ) ion guide to confine and direct I- and associated Te- isobar anions through a gas-reaction cell, where chemical reactions occur at eV energies with the electronegative gas NO2. Anions are subsequently reaccelerated out of the ISA to near original ion source extraction energies for AMS analysis. At 5 mTorr NO2 in the ISA gas-reaction cell, 125Te- was observed to be attenuated by a factor of ∼107 as compared to 127I- that did not experience significant (<50%) losses. A comparative test using 37Cl- and 32S- (having similar chemical properties to iodine and tellurium) showed a 32S- attenuation of >107 relative to 37Cl- under the same ISA-AMS conditions. The preferential destruction of Te- (and S-) at eV energies in the ISA is likely due to a larger favorable destruction cross-section with NO2. This study is the first demonstration of I-Te anion separation for AMS, and makes possible the use of 125I, free of the contaminant 125Te isobar after suitable sample purification, for future 129I/125I carrier-free analyses of natural samples at ultra-low trace levels.

  19. (/sup 125/I)diiodoinsulins. Binding affinities, biologic potencies, and properties of their decay products

    SciTech Connect

    Perez Maceda, B.; Linde, S.; Sonne, O.; Gliemann, J.

    1982-07-01

    Insulin was iodinated with 0.3-0.4 mol /sup 125/I/mol insulin using the lactoperoxidase method. About one-third of the radioactivity incorporated into insulin was in diiodoinsulins and about 40% of these molecules contained diiodotyrosine in residue 14 of the A chain. Most of the remaining molecules contained one A14-monoiodotyrosine and one monoiodotyrosine in either position A19, B16, or B26. The binding affinity and biologic potency of this heterogeneous diiodoinsulin preparation was not significantly different from that of A14-(/sup 125/I)monoiodoinsulin in rat adipocytes, whereas it was slightly reduced in hepatocytes and IM-9 lymphocytes. From the iodine distribution and previous data on the binding affinity of each of the four monoiodoinsulin isomers it was calculated that A14-diiodotyrosine-insulin possesses full binding affinity and biologic potency in adipocytes. Diiodoinsulins isolated from another iodoinsulin preparation (iodate method) contained 58% A19-diiodotyrosine-insulin, and most remaining molecules contained one A19-monoiodotyrosine. The binding affinity of this mixed diiodoinsulin preparation was approximately one-fourth of that of A14-monoiodoinsulin in adipocytes, IM-9 lymphocytes, and hepatocytes. It was calculated that A19-diiodotyrosine-insulin is nearly devoid of binding affinity. The diiodoinsulins (lactoperoxidase method) decayed to iodide (probably from diiodotyrosine-insulin) or to polymers with little specific but a markedly increased nonspecific binding. In addition, the polymers had a marked tendency to adsorb to cellulose acetate filters. Conclusions: 1. The binding affinities of diiodoinsulins range from very low values to values at least as high as that of insulin depending on the positions of the iodine moieties. 2. The relative binding affinities vary among tissues. 3. Polymeric decay products give high nonspecific binding.

  20. In vivo seeding and cross-seeding of localized amyloidosis: a molecular link between type 2 diabetes and Alzheimer disease.

    PubMed

    Oskarsson, Marie E; Paulsson, Johan F; Schultz, Sebastian W; Ingelsson, Martin; Westermark, Per; Westermark, Gunilla T

    2015-03-01

    Several proteins have been identified as amyloid forming in humans, and independent of protein origin, the fibrils are morphologically similar. Therefore, there is a potential for structures with amyloid seeding ability to induce both homologous and heterologous fibril growth; thus, molecular interaction can constitute a link between different amyloid forms. Intravenous injection with preformed fibrils from islet amyloid polypeptide (IAPP), proIAPP, or amyloid-beta (Aβ) into human IAPP transgenic mice triggered IAPP amyloid formation in pancreas in 5 of 7 mice in each group, demonstrating that IAPP amyloid could be enhanced through homologous and heterologous seeding with higher efficiency for the former mechanism. Proximity ligation assay was used for colocalization studies of IAPP and Aβ in islet amyloid in type 2 diabetic patients and Aβ deposits in brains of patients with Alzheimer disease. Aβ reactivity was not detected in islet amyloid although islet β cells express AβPP and convertases necessary for Aβ production. By contrast, IAPP and proIAPP were detected in cerebral and vascular Aβ deposits, and presence of proximity ligation signal at both locations showed that the peptides were <40 nm apart. It is not clear whether IAPP present in brain originates from pancreas or is locally produced. Heterologous seeding between IAPP and Aβ shown here may represent a molecular link between type 2 diabetes and Alzheimer disease.

  1. Characterization of membrane-bound and soluble D2 receptors in canine caudate using ( sup 125 I)IBZM

    SciTech Connect

    Schonwetter, B.S.; Luedtke, R.R.; Kung, M.P.; Billings, J.; Kung, H.F.; Molinoff, P.B. )

    1989-07-01

    (S)-(-)-3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl) methyl)benzamide (IBZM) was shown to be a high-affinity antagonist selective for the D2 subtype of dopamine receptor. Binding sites for the radioligand (125I)IBZM were characterized with membranes and digitonin-solubilized extracts of canine caudate enriched by chromatography on heparin-agarose. Nonspecific binding, defined using 2 microM (+)-butaclamol, was less than 10% of the total ligand bound at the Kd of the receptor for ({sup 125}I)IBZM. Direct binding, competition and kinetic experiments indicated that ({sup 125}I)IBZM bound to a homogeneous population of binding sites. The rank order of potency for inhibition of the binding of ({sup 125}I)IBZM by antagonists and agonists was found to be consistent with the pharmacological profile expected of a D2 receptor. The affinities of ({sup 125}I)IBZM for membrane-associated and detergent-solubilized binding sites were essentially identical (Kd congruent to 0.4 nM). This result contrasts with findings obtained in studies with ({sup 3}H)spiroperidol, where a marked decrease in the affinity of the receptor for the ligand has been observed during detergent solubilization and purification of the receptor. The high selectivity, nanomolar affinity and high specific activity of ({sup 125}I)IBZM and the results obtained in studies with detergent extracts suggest that ({sup 125}I)IBZM will be a particularly useful ligand for studies of D2 receptors in the presence of detergents.

  2. Bupropion Binds to Two Sites in the Torpedo Nicotinic Acetylcholine Receptor Transmembrane Domain: A Photoaffinity Labeling Study with the Bupropion Analog [125I]-SADU-3-72

    PubMed Central

    Pandhare, Akash; Hamouda, Ayman K.; Staggs, Brandon; Aggarwal, Shaili; Duddempudi, Phaneendra K.; Lever, John R.; Lapinsky, David J.; Jansen, Michaela; Cohen, Jonathan B.; Blanton, Michael P.

    2012-01-01

    Bupropion, a clinically-used antidepressant and smoking-cessation drug, acts as a noncompetitive antagonist of nicotinic acetylcholine receptors (nAChRs). To identify its binding site(s) in nAChRs, we developed a photoreactive bupropion analog, (±)-2-(N-tert-butylamino)-3′-[125I]-iodo-4′-azidopropiophenone (SADU-3-72). Based upon inhibition of [125I]SADU-3-72 binding, SADU-3-72 binds with high affinity (IC50 = 0.8 μM) to the Torpedo nAChR in the resting (closed channel) state and in the agonist-induced desensitized state, and bupropion binds to that site with three-fold higher affinity in the desensitized (IC50 = 1.2 μM) than in the resting state. Photolabeling of Torpedo nAChRs with [125I]SADU-3-72 followed by limited in-gel digestion of nAChR subunits with endoproteinase Glu-C established the presence of [125I]SADU-3-72 photoincorporation within nAChR subunit fragments containing M1-M2-M3 helices (αV8-20K, βV8-22/23K and γV8-24K) or M1-M2 helices (δV8-14). Photolabeling within βV8-22/23K, γV8-24K and δV8-14 was reduced in the desensitized state and inhibited by ion channel blockers selective for the resting (tetracaine) or desensitized (thienycyclohexylpiperidine (TCP)) state, and this pharmacologically specific photolabeling was localized to the M2-9 leucine ring (δLeu265, βLeu257) within the ion channel. In contrast, photolabeling within the αV8-20K was enhanced in the desensitized state and not inhibited by TCP, but was inhibited by bupropion. This agonist-enhanced photolabeling was localized to αTyr213 in αM1. These results establish the presence of two distinct bupropion binding sites within the Torpedo nAChR transmembrane domain: a high affinity site at the middle (M2-9) of the ion channel and a second site near the extracellular end of αM1 within a previously described halothane (general anesthetic) binding pocket. PMID:22394379

  3. Continuous Low-dose-rate Irradiation of Iodine-125 Seeds Inhibiting Perineural Invasion in Pancreatic Cancer

    PubMed Central

    Lu, Zheng; Dong, Teng-Hui; Si, Pei-Ren; Shen, Wei; Bi, Yi-Liang; Min, Min; Chen, Xin; Liu, Yan

    2016-01-01

    Background: Perineural invasion (PNI) is a histopathological characteristic of pancreatic cancer (PanCa). The aim of this study was to observe the treatment effect of continuous low-dose-rate (CLDR) irradiation to PNI and assess the PNI-related pain relief caused by iodine-125 (125I) seed implantation. Methods: The in vitro PNI model established by co-culture with dorsal root ganglion (DRG) and cancer cells was interfered under 2 and 4 Gy of 125I seeds CLDR irradiation. The orthotopic models of PNI were established, and 125I seeds were implanted in tumor. The PNI-related molecules were analyzed. In 30 patients with panCa, the pain relief was assessed using a visual analog scale (VAS). Pain intensity was measured before and 1 week, 2 weeks, and 1, 3, and 6 months after 125I seed implantation. Results: The co-culture of DRG and PanCa cells could promote the growth of PanCa cells and DRG neurites. In co-culture groups, the increased number of DRG neurites and pancreatic cells in radiation group was significantly less. In orthotopic models, the PNI-positive rate in radiation and control group was 3/11 and 7/11; meanwhile, the degrees of PNI between radiation and control groups was significant difference (P < 0.05). At week 2, the mean VAS pain score in patients decreased by 50% and significantly improved than the score at baseline (P < 0.05). The pain scores were lower in all patients, and the pain-relieving effect was retained about 3 months. Conclusions: The CLDR irradiation could inhibit PNI of PanCa with the value of further study. The CLDR irradiation could do great favor in preventing local recurrence and alleviating pain. PMID:27748339

  4. Visualization of the dopamine transporter in the human brain postmortem with the new selective ligand [125I]PE2I.

    PubMed

    Hall, H; Halldin, C; Guilloteau, D; Chalon, S; Emond, P; Besnard, J; Farde, L; Sedvall, G

    1999-01-01

    Using a new, 125I-labeled, selective high affinity dopamine transporter ligand, N-(3-iodoprop-2E-enyl)-2beta-carbomethoxy-3beta-(4'-methy lph enyl)nort ropane (PE2I), the distribution of the dopamine transporter was characterized in the normal postmortem human brain using whole hemisphere autoradiography. PE2I was radioiodinated to high specific radioactivity (2200 Ci/mmol, 81 GBq/micromol). PE2I binds to the dopamine transporter with high potency and, in contrast to beta-CIT, it has very low affinities for the serotonin and noradrenaline transporters. The autoradiograms showed very intense binding in basal ganglia (putamen, nucleus caudatus, nucleus accumbens) and lower binding in substantia nigra. Very low or no binding was found in other brain structures, including the neocortex or cerebellum. The labeling of human dopamine transporters with [125I]PE2I was inhibited by the dopamine transporter inhibitors GBR 12909 and beta-CIT, but not by citalopram (serotonin transporter inhibitor) or maprotiline (noradrenaline transporter inhibitor). Possibly due to the relatively high lipophilicity of the compound (theoretical log p = 4.68), it accumulated slightly in white matter. Thus, in vitro autoradiography using [125I]PE2I provided detailed qualitative and quantitative evidence that the dopamine transporter is almost exclusively localized in the basal ganglia of the human brain. Moreover, the autoradiograms indicate that [11C]PE2I and [123I]PE2I should be suitable for the in vivo visualization of the human dopamine transporter with PET or SPECT, respectively.

  5. Uptake and binding of /sup 125/I-calmodulin by isolated rat renal brush border membrane vesicles

    SciTech Connect

    Meezan, E.; Elgavish, A.; Wallace, R.W.

    1986-05-01

    The authors have investigated the interaction of /sup 125/I-calmodulin with isolated rat renal brush border membrane vesicles (BBV) using an experimental protocol which allows us to distinguish between ligand binding to the outside of the vesicles vs. uptake and possible binding to the vesicle interior. By examining the association of /sup 125/I-calmodulin with BBV as a function of medium osmolarity (300-1100 mosm) to alter intravesicular space, virtually all ligand interaction with BBV was found to represent uptake of intact /sup 125/I-calmodulin into the intravesicular space. Uptake appeared specific by the following criteria: (1) it was largely calcium dependent (2) it was inhibited in a dose dependent fashion by calmodulin and the homologous protein troponin C, but not by unrelated proteins (lysozyme, cytochrome C, insulin) (3) it was inhibited by known calmodulin antagonists (calmidazolium, mellitin, trifluoperazine). Calmodulin uptake may be followed by binding of /sup 125/I-calmodulin to intravesicular BBV proteins; calmodulin-binding proteins in BBV with molecular weights of 143K, 118K, 50K, 47.5K, 46.5K and 35K were identified by Western blotting techniques. The specific association of /sup 125/I-calmodulin with isolated BBV is of interest in regard to the possible role of this calcium regulatory protein in the protein reabsorptive and ion transport functions of this renal tubular membrane fraction.

  6. Binding of /sup 125/I-labeled recombinant beta interferon (IFN-beta Ser17) to human cells

    SciTech Connect

    O'Rourke, E.C.; Drummond, R.J.; Creasey, A.A.

    1984-12-01

    The authors investigated the binding of /sup 125/I-labeled beta interferon (IFN-beta Ser17), a nonglycosylated recombinant human fibroblast interferon in which cysteine at position 17 is replaced by serine by site-specific mutagenesis. An optimized chloramine T radiolabeling method produced a highly labeled, fully active /sup 125/I-IFN suitable for these studies. Unlike the case with the chloramine T method, incorporation of a single mole of Bolton-Hunter reagent into a mole of IFN-beta Ser17 led to nearly complete loss of biological activity. /sup 125/I-IFN-beta Ser17, prepared by the chloramine T method, bound specifically to human lymphoblastoid cells (Daudi) with a dissociation constant of 0.24 nM. The number of binding sites per cell was 4,000. In competition assays, unlabeled beta interferons (native, recombinant IFN-beta Cys17, and various preparations of IFN-beta Ser17) equally displaced labeled IFN-beta Ser17 on Daudi cells. Recombinant IFN-alpha-1 displaced /sup 125/I-IFN-beta binding to Daudi cells less efficiently than did unlabeled native or recombinant beta interferon. However, at the concentrations tested, native gamma interferon showed no competition with /sup 125/I-IFN. The results indicate that IFN-beta Ser17 and native IFN-beta posses similar binding properties.

  7. Critical analysis of (/sup 131/I)- and (/sup 125/I)human thyroglobulin labels for radioimmunoassay use

    SciTech Connect

    Schlumberger, M.; Van Herle, A.J.

    1982-03-01

    (/sup 125/I)- and (/sup 131/I)thyroglobin (Tg) tracer obtained by two different oxidation methods, chloramine-T (ChlT) and lactoperoxidase (LP-ase), were analyzed to assess their suitability in the development of a RIA. Pairs of tracers which were prepared on a single day using these methods with a single source of /sup 131/I and /sup 125/I were compared. The following conclusions were reached. (1) Both /sup 131/I and /sup 125/I isotopes, using Chl-T or LP-ase as oxidants, produce suitable tracers. (2) (/sup 131/I)Tg can be used repeatedly for 2 weeks without repurification. (3) (/sup 125/I)Tg, in contrast, has to be rechromatographed weekly on sephadex G-200 to maintain assay sensitivity and adequate maximal binding. (4) Under these conditions, 2- or 9-day tracers with either isotope using Chl-T or LP-ase give similar Tg determinations in the serum. (5) The LP-ase-chromatographed /sup 125/I tracer seems to lead to higher maximal binding in the assay than the Chl-T-repurified tracer.

  8. Standardization of 125I and 109Cd by the photon-photon coincidence method in PTKMR-BATAN.

    PubMed

    Marsoem, Pujadi; Wurdiyanto, Gatot; Candra, Hermawan

    2012-09-01

    A photon-photon coincidence system was constructed for the standardization of (125)I and (109)Cd in PTKMR-BATAN, Indonesia. Two NaI(Tl) detectors of 76 mm diameter × 6mm thickness with 0.5mm aluminum window were used, which were positioned approximately symmetrically to the source holder. The electronic chain was almost the same as for a 4πβ-γ system. The CANBERRA Multiport II multi channel analyzer was used for energy calibration and a Philips type PM3092 oscilloscope for visualization of the pulses. A polyethylene plastic was used as the source substrate for the (125)I and (109)Cd samples. The activity of a (125)I solution was measured by the photon-photon coincidence and the efficiency extrapolation method (Schrader and Walz, 1987), whereas the activity of a (109)Cd solution was determined by a tracer method using (125)I (Schrader, 2006). The result of the (125)I activity showed good agreement with the result of measurements using a calibrated ionization chamber, and the result of (109)Cd also showed good agreement with the measurements result using a LEGe detector.

  9. Radiobiological effects of /sup 131/I and /sup 125/I on the DNA of the rat thyroid

    SciTech Connect

    Abdel-Nabi, H.; Ortman, J.A.

    1983-03-01

    One of the major disadvantages of the use of /sup 131/I in the treatment of thyrotoxicosis is the development of hypothyroidism. Alternatively, /sup 125/I has been proposed for thyrotoxicosis therapy, and was thought to be preferable to /sup 131/I because of the short range of its emitted soft electrons.Several studies have shown /sup 125/I to be as effective as /sup 131/I in the treatment of thyrotoxicosis, and equally likely to produce hupothyroidism. This work compared the radiobiological effects of /sup 131/I and /sup 125/I given in doses to deliver the same amount of radiation to the rat thyroid gland.These effects were studied by in vivo determination of single-strand DNA breaks by alkaline sucrose gradient sedimentation using the DABA fluorescent technique to detect the DNA. Serum T/sub 4/ and TSH concentrations and percentage T/sub 3/ uptake were determined by RIA. The incidence of hypothyroidism following /sup 131/I and /sup 125/I therapy was found to be the same (10% in each group). The extent of DNA damage following /sup 125/I therapy was greater than the damage induced by a larger dose of /sup 131/I.

  10. Quantification, localization, and speciation of selenium in seeds of canola and two mustard species compared to seed-meals produced by hydraulic press.

    PubMed

    Bañuelos, Gary S; Walse, Spencer S; Yang, Soo In; Pickering, Ingrid J; Fakra, Sirine C; Marcus, Matthew A; Freeman, John L

    2012-07-17

    Brassica plants accumulate selenium (Se) especially in seeds when grown in soils laden with Se. We report a chemical analysis of Se in Brassica seeds (canola, Indian mustard, and white mustard) and in their hydraulically pressed seed meals, which are used as a Se supplement in livestock animal feeds. Complementary techniques were used to measure total Se concentrations, to map the localization of Se, and to quantify different Se forms. Seeds and hydraulically pressed seed meals contained an average of 1.8 and 2.0 μg Se g(-1) DW, respectively. Selenium was primarily located in cotyledons and roots of seed embryos. Microfocused Se K-edge XANES and bulk XANES showed that seeds contained 90% of Se as C-Se-C forms. Hydraulically pressing seeds for oil caused changes in the forms of Se as follows: 40-55% C-Se-C forms, 33-42% selenocystine, 5-12% selenocysteine, and 11-14% trimethylselenonium ion. Aqueous extracts of seed and seed meals were also analyzed by SAX-HPLC/ICPMS and found to contain mainly the C-Se-C form SeMet, but also another C-Se-C form MeSeCys, which is of dietary pharmacological interest for cancer inhibition. In addition, SAX-HPLC/ICPMS also detected selenocystine and selenocysteine, further confirming the results obtained by XANES analyses.

  11. /sup 111/In-platelet and /sup 125/I-fibrinogen deposition in the lungs in experimental acute pancreatitis

    SciTech Connect

    Goulbourne, I.A.; Watson, H.; Davies, G.C.

    1987-12-01

    An experimental model of acute pancreatitis in rats has been used to study intrapulmonary /sup 125/I-fibrinogen and /sup 111/In-platelet deposition. Pancreatitis caused a significant increase in wet lung weight compared to normal, and this could be abolished by heparin or aspirin pretreatment. /sup 125/I-fibrinogen was deposited in the lungs of animals to a significantly greater degree than in controls (P less than 0.01). /sup 125/I-fibrinogen deposition was reduced to control levels by pretreatment with aspirin or heparin (P less than 0.05). The uptake of radiolabeled platelets was greater in pancreatitis than in controls (P less than 0.001). Pancreatitis appears to be responsible for platelet entrapment in the lungs. Platelet uptake was reduced by heparin treatment but unaffected by aspirin therapy.

  12. Binding of /sup 125/I-hCG to rainbow trout (Salmo gairdneri) testis in vitro. [Human Chorionic Gonadotropin

    SciTech Connect

    Schlaghecke, R.

    1983-02-01

    Homogenates of maturing rainbow trout testes show specific binding sites for /sup 125/I-labeled hCG (. /sup 125/I-labeled hCG). The binding is competitively inhibited by unlabeled hCG and by a hypophyseal extract of rainbow trout. It could be demonstrated that the tissue /sup 125/I-hCG binding specificity is restricted to the gonadal preparation. The trout testis was characterized by determining affinity and capacity from Scatchard plot analysis giving a high constant of dissociation Kd 3.65 x 10(-10)/M and a low binding capacity of 0.88 x 10(-15) M/mg tissue. The test system is markedly dependent on temperature, incubation-time, and pH. The maximum binding was found at 37 degrees during 2 hr of incubation in a buffer of pH 7.5.

  13. Isradipine, a calcium-entry blocker, decreases vascular (125-I)low-density lipoprotein entry in hypercholesterolemic rabbits

    SciTech Connect

    Sinzinger, H.; Lupattelli, G.; Virgolini, I.; Gerakakis, A.; Fitscha, P.; Molinari, E.; Angelberger, P. Vienna, Austria)

    1991-04-01

    In 72 male rabbits aged 6 months, the endothelium of the abdominal aorta was abraded by a Fogarthy catheter. The animals were then fed a 1% cholesterol-supplemented diet for 4 weeks. In addition, half of the animals were treated for the entire period with isradipine (0.3 mg/kg daily), a dihydropyridine calcium antagonist; the other 36 animals served as controls. One hour and 3, 6, 12, 24, and 48 hours before the animals were killed, (125-I)low-density lipoprotein (LDL 10 microCi) was administered intravenously (i.v.) to six animals in each group. The (125-I)LDL entry was quantified in the abdominal aorta according to the type and presence of endothelial lining. Isradipine significantly reduced the (125-I)LDL entry at most time intervals. In parallel, an increase in vascular prostaglandin (PGI2) synthesis was noted, which might be the underlying mechanism for the decreased LDL entry.

  14. An ecological genetic delineation of local seed-source provenance for ecological restoration

    PubMed Central

    Krauss, Siegfried L; Sinclair, Elizabeth A; Bussell, John D; Hobbs, Richard J

    2013-01-01

    An increasingly important practical application of the analysis of spatial genetic structure within plant species is to help define the extent of local provenance seed collection zones that minimize negative impacts in ecological restoration programs. Here, we derive seed sourcing guidelines from a novel range-wide assessment of spatial genetic structure of 24 populations of Banksia menziesii (Proteaceae), a widely distributed Western Australian tree of significance in local ecological restoration programs. An analysis of molecular variance (AMOVA) of 100 amplified fragment length polymorphism (AFLP) markers revealed significant genetic differentiation among populations (ΦPT = 0.18). Pairwise population genetic dissimilarity was correlated with geographic distance, but not environmental distance derived from 15 climate variables, suggesting overall neutrality of these markers with regard to these climate variables. Nevertheless, Bayesian outlier analysis identified four markers potentially under selection, although these were not correlated with the climate variables. We calculated a global R-statistic using analysis of similarities (ANOSIM) to test the statistical significance of population differentiation and to infer a threshold seed collection zone distance of ∼60 km (all markers) and 100 km (outlier markers) when genetic distance was regressed against geographic distance. Population pairs separated by >60 km were, on average, twice as likely to be significantly genetically differentiated than population pairs separated by <60 km, suggesting that habitat-matched sites within a 30-km radius around a restoration site genetically defines a local provenance seed collection zone for B. menziesii. Our approach is a novel probability-based practical solution for the delineation of a local seed collection zone to minimize negative genetic impacts in ecological restoration. PMID:23919158

  15. Absorption of enzymatically active sup 125 I-labeled bovine milk xanthine oxidase fed to rabbits

    SciTech Connect

    Rzucidlo, S.J. ); Zikakis, J.P. )

    1990-05-01

    Rabbits fed a regular laboratory diet supplemented with a high-fat milk containing xanthine oxidase (XO) were studied to determine the presence of active XO in the blood. A pilot feeding study, where rabbits consumed a high-fat diet containing xanthine oxidase, showed a correlation between dairy food consumption and XO activity in the blood. Antibody to dietary XO was also found. In a second study, rabbits were fed ad libitum the high-fat milk and blood serum samples were tested weekly for XO activity. No elevation in serum XO activity was found. A third study showed that serum XO activity was increased when rabbits were force fed the high-fat milk. The final study consisted of force feeding {sup 125}I-labeled XO to one rabbit to ascertain whether the observed increase in serum XO was due to dietary or endogenous XO. Isoelectric focusing of sera collected from the test rabbit strongly suggested that at least a portion of the serum XO contained the radioactive label. This is the first direct evidence showing the uptake of dietary active XO from the gut.

  16. Altered (/sup 125/I)epidermal growth factor binding and receptor distribution in psoriasis

    SciTech Connect

    Nanney, L.B.; Stoscheck, C.M.; Magid, M.; King, L.E. Jr.

    1986-03-01

    Stimulation of growth and differentiation of human epidermis by epidermal growth factor (EGF) is mediated by its binding to specific receptors. Whether EGF receptors primarily mediate cell division or differentiation in hyperproliferative disease such as psoriasis vulgaris is unclear. To study the pathogenesis of psoriasis, 4-mm2 punch biopsy specimens of normal, uninvolved, and involved psoriatic skin were assayed for EGF receptors by autoradiographic, immunohistochemical, and biochemical methods. Using autoradiographic and immunohistochemical methods, basal keratinocytes were found to contain the greatest number of EGF binding sites and immunoreactive receptors as compared to the upper layers of the epidermis in both normal epidermis and psoriatic skin. No EGF receptor differences between normal and psoriatic epidermis were observed in this layer. In the upper layers of the epidermis, a 2-fold increase in EGF binding capacity was observed in psoriatic skin as compared with normal thin or thick skin. Biochemical methods indicated that (/sup 125/I)EGF binding was increased in psoriatic epidermis as compared with similar thickness normal epidermis when measured on a protein basis. Epidermal growth factor was shown to increase phosphorylation of the EGF receptor in skin. EGF receptors retained in the nonmitotic stratum spinosum and parakeratotic stratum corneum may reflect the incomplete, abnormal differentiation that occurs in active psoriatic lesions. Alternatively, retained EGF receptors may play a direct role in inhibiting cellular differentiation in the suprabasal layers.

  17. Absence of preferential uptake of ( sup 125 I)iododihydrorhodamine 123 by four human tumor xenografts

    SciTech Connect

    Kinsey, B.M.; Van den Abbeele, A.D.; Adelstein, S.J.; Kassis, A.I. )

    1989-11-01

    The biodistribution of ({sup 125}I)iododihydrorhodamine 123 has been studied over a 96-h period in four human tumor xenograft models: HT-29 colon adenocarcinoma, PC-3 prostate carcinoma, HT-1080 fibrosarcoma, and PaCa-2 pancreatic carcinoma. Elimination of radioactivity in the tumor-bearing nude mice was rapid during the first 24 h and slow thereafter. The lack of uptake in the thyroid indicated there was little, if any, deiodination of the molecule. Activity was found mainly in the liver and spleen. Accumulation of radioactivity was low in all four tumors examined. At 4 h postinjection, as well as at 24 and 48 h, however, the total radioactive content in each of the four tumors was directly proportional to the weight of the tumor sample. This correlation was independent of tumor type, route of injection (i.v./i.p.) or dose (1.2-6 microCi/mouse). This was not true for any of the normal tissues, suggesting that this accumulation may be governed by certain intrinsic characteristics of the cancers tested.

  18. Improved /sup 125/I radioimmunoassay for cotinine by selective removal of bridge antibodies

    SciTech Connect

    Knight, G.J.; Wylie, P.; Holman, M.S.; Haddow, J.E.

    1985-01-01

    We describe an /sup 125/I-based RIA for cotinine, the major metabolite of nicotine. The slope of the dose-response curve was quite shallow (6-8% change in binding per doubling dose), resulting in between-assay CVs of 15 to 20%. This effect occurred because the radioligand formed by linking a cotinine derivative to tyramine manifested greater affinity for the anti-cotinine antibodies than did cotinine itself. We absorbed the serum with a derivative of nicotine coupled to the carrier protein via a chemical bridge similar to that used to form the cotinine/carrier protein immunogen. An RIA in which we used such absorbed serum showed a significantly increased slope of the dose-response curve (11-13% change in binding per doubling dose), and between-assay CVS were only 6 to 8%. We suggest that this improvement results because absorption removes anti-bridge antibodies directed against the chemical-bond common to the cotinine/carrier-protein immunogen and to the cotinine/tyramine radioligand.

  19. Direct method for detection and characterization of cell surface receptors for insulin by means of 125I-labeled autoantibodies against the insulin receptor.

    PubMed Central

    Jarrett, D B; Roth, J; Kahn, C R; Flier, J S

    1976-01-01

    Autoantibodies directed against the cell surface receptors for insulin are found in some patients with extreme insulin resistance. These antibodies specifically inhibit the binding of insulin to its receptor. A purified IgG fraction from one patient's plasma was labeled with 125I. The 125I-labeled antireceptor antibody, which initially represented about 0.3% of the total 125I-IgG, was enriched by selective adsorption and subsequent elution from cells rich in insulin receptors. The 125I-antireceptor antibody bound to cells and the binding was inhibited by whole plasma and purified IgG from this patient, as well as whole plasma from another patient with autoantibodies to the insulin receptor. Insulins that differed 300-fold in biological potency and affinity inhibited binding of 125I-antireceptor antibody in direct proportion to their ability to bind to the insulin receptor. The binding of 125I-antireceptor antibody was closely correlated with the binding of 125I-insulin over a wide range of receptor concentrations on different cell types. Experimentally induced reduction of the insulin receptor concentration was associated with parallel decreases in the binding of 125I-antireceptor antibody and 125I-insulin. The preparation of 125I-antireceptor antibody with a high specific activity by cytoadsorption and elution has provided a sensitive method for the detection of receptors and autoantibodies to cell surface components. PMID:1069300

  20. Binding of an ( sup 125 I) labelled thromboxane A2/prostaglandin H2 receptor agonist to baboon platelets

    SciTech Connect

    Dorn, G.W. II; De Jesus, A. )

    1989-12-01

    To characterize the thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptor on baboon platelets the binding of (125I)BOP was studied. (125I)BOP bound to washed baboon platelets in a saturable manner. Scatchard analysis of binding isotherms revealed a Kd of 1.12 +/- 0.08 nM and a binding capacity of 54 +/- 5 fmoles/10(8) platelets (326 sites/platelet). Several TXA2/PGH2 agonists and antagonists displaced (125I)BOP from its baboon platelet binding site with a rank order of potency similar to human platelets: I-BOP greater than SQ29548 greater than U46619 = I-PTA-OH greater than PTA-OH. I-BOP aggregated washed baboon platelets with an EC50 of 10 +/- 4 nM. The results indicate that (125I)BOP binds to the TXA2/PGH2 receptor on baboon platelets and that this receptor is similar to its human counterpart.

  1. An Optimized Protocol for the Efficient Radiolabeling of Gold Nanoparticles by Using a 125I-labeled Azide Prosthetic Group.

    PubMed

    Jeon, Jongho; Shim, Ha Eun; Mushtaq, Sajid; Choi, Mi Hee; Park, Sang Hyun; Choi, Dae Seong; Jang, Beom-Su

    2016-10-10

    Here, we demonstrate a detailed protocol for the radiosynthesis of a (125)I-labeled azide prosthetic group and its application to the efficient radiolabeling of DBCO-group-functionalized gold nanoparticles using a copper-free click reaction. Radioiodination of the stannylated precursor (2) was carried out by using [(125)I]NaI and chloramine T as an oxidant at room temperature for 15 min. After HPLC purification of the crude product, the purified (125)I-labeled azide (1) was obtained with high radiochemical yield (75 ± 10%, n = 8) and excellent radiochemical purity (>99%). For the synthesis of radiolabeled 13-nm-sized gold nanoparticles, the DBCO-functionalized gold nanoparticles (3) were prepared by using a thiolated polyethylene glycol polymer. A copper-free click reaction between 1 and 3 gave the (125)I-labeled gold nanoparticles (4) with more than 95% of radiochemical yield as determined by radio-thin-layer chromatography (radio-TLC). These results clearly indicate that the present radiolabeling method using a strain-promoted copper-free click reaction will be useful for the efficient and convenient radiolabeling of DBCO-group-containing nanomaterials.

  2. Relationship between alveolar bone measured by /sup 125/I absorptiometry with analysis of standardized radiographs: 2. Bjorn technique

    SciTech Connect

    Ortman, L.F.; McHenry, K.; Hausmann, E.

    1982-05-01

    The Bjorn technique is widely used in periodontal studies as a standardized measure of alveolar bone. Recent studies have demonstrated the feasibility of using /sup 125/I absorptiometry to measure bone mass. The purpose of this study was to compare /sup 125/I absorptiometry with the Bjorn technique in detecting small sequential losses of alveolary bone. Four periodontal-like defects of incrementally increasing size were produced in alveolar bone in the posterior segment of the maxilla of a human skull. An attempt was made to sequentially reduce the amount of bone in 10% increments until no bone remained, a through and through defect. The bone remaining at each step was measured using /sup 125/I absorptiometry. At each site the /sup 125/I absorptiometry measurements were made at the same location by fixing the photon source to a prefabricated precision-made occlusal splint. This site was just beneath the crest and midway between the borders of two adjacent teeth. Bone loss was also determined by the Bjorn technique. Standardized intraoral films were taken using a custom-fitted acrylic clutch, and bone measurements were made from the root apex to coronal height of the lamina dura. A comparison of the data indicates that: (1) in early bone loss, less than 30%, the Bjorn technique underestimates the amount of loss, and (2) in advanced bone loss, more than 60% the Bjorn technique overestimates it.

  3. Autoradiography: (/sup 125/I)SCH 23982 binds with picomolar affinity to D1 sites on striatonigral neurons

    SciTech Connect

    Altar, C.A.; Marien, M.R.

    1986-03-01

    SCH 23390 is selective D1 antagonist. The authors show for the first time, with iodinated SCH 23390, (/sup 125/I)SCH 23982, D1 binding sites on striatonigral neurons. Rat brain sections were covered for 1 hr by a pH 7.6 TRIS buffer containing 2-770 pM (/sup 125/I)SCH 23982, rinsed 2 min at 4 /sup 0/C, dried, and exposed to film for 18 hr. (/sup 125/I)SCH 23982 was displaced by D1 (SCH 23390; IC50= 200 pM; cis-flupenthixol, 10 nM; SKF 38393, 90 nM) but not D2 (sulpiride, LY171555) ligands. Intermediate D1 binding was found in the internal capsule and entopeduncular nucleus. Striatal quinolinate (100 nmol) decreased nigral and striatal D1 binding. Intranigral 6-hydroxydopamine (6 ..mu..g) that destroyed > 90% of nigrostriatal dopamine neurons did not alter nigral or striatal D1 binding. Thus, (/sup 125/I)SCH 23982 labels with pM affinity D1 sites that reside on striatonigral neurons.

  4. Development of a high specific activity radioligand, /sup 125/I-LSD, and its application to the study of serotonin receptors

    SciTech Connect

    Kadan, M.J.

    1987-01-01

    /sup 125/I-Labeled receptor ligands can be synthesized with specific activities exceeding 2000 Ci/mmol, making them nearly 70-fold more sensitive in receptor site assays than (mono) tritiated ligands. We have synthesized and characterized /sup 125/I-lysergic acid diethylamide (/sup 125/I-LSD), the first radioiodinated ligand for serotonin receptor studies. The introduction of /sup 125/I at the 2 position of LSD increased both the affinity and selectivity of this compound for serotonin 5-HT/sub 2/ receptors in rat cortex. The high specific activity of /sup 125/I-LSD and its high ratio of specific to nonspecific binding make this ligand especially useful for autoradiographic studies of serotonin receptor distribution. We have found that /sup 125/I-LSD binds with high affinity to a class of serotonin receptors in the CNS of the marine mollusk Aplysia californica.

  5. Reduction of transmural sup 125 I-albumin concentration in rat aortic media by chronic hypertension

    SciTech Connect

    Belmin, J.; Michel, J.B.; Curmi, P.A.; Salzmann, J.L.; Juan, L.; Tedgui, A. )

    1991-03-01

    Relative 125I-albumin concentration was measured in vivo in the aortic media of sham-operated (n = 10) and hypertensive (two-kidney, one clip) rats, untreated (n = 8) or treated (n = 10) by an angiotensin converting enzyme inhibitor (CEI, Trandolapril). Blood pressure was acutely lowered to a normal level at the time of the experiment in hypertensive rats (n = 7) to separate the direct effect of increased pressure from the effect of pressure-induced structural changes. Relative tissue concentration profiles of labeled albumin across the media were obtained using a serial frozen-sectioning technique. In hypertensive rats, the mean medial albumin concentration decreased by 35% in the ascending arch and 32% in the descending arch (p less than 0.01). When blood pressure was acutely lowered in hypertensive animals, this value decreased further by 56% in the ascending arch, 48% in the descending arch (p less than 0.01), and 22% in the thoracic aorta (p less than 0.05) as compared with controls. The medial thickness in hypertensive rats was significantly increased (more in the ascending arch than in the rest of the aorta). Four-week CEI treatment reversed hypertension and medial thickening, but the mean medial albumin concentration remained significantly lower in the arch (by 36% in the ascending part and 40% in the descending part, p less than 0.01). The collagen content in the thoracic aorta was significantly increased in hypertensive rats (by 40%, p less than 0.01) and remained increased (by 29%, p less than 0.01) after CEI treatment. These results suggested that the hypertension-induced structural changes might reduce the medial distribution volume for albumin, whereas elevated blood pressure per se tended to enhance albumin concentration within the media.

  6. 2-(/sup 125/I)iodomelatonin binding sites in hamster brain membranes: pharmacological characteristics and regional distribution

    SciTech Connect

    Duncan, M.J.; Takahashi, J.S.; Dubocovich, M.L.

    1988-05-01

    Studies in a variety of seasonally breeding mammals have shown that melatonin mediates photoperiodic effects on reproduction. Relatively little is known, however, about the site(s) or mechanisms of action of this hormone for inducing reproductive effects. Although binding sites for (3H)melatonin have been reported previously in bovine, rat, and hamster brain, the pharmacological selectivity of these sites was never demonstrated. In the present study, we have characterized binding sites for a new radioligand, 2-(125I)iodomelatonin, in brains from a photoperiodic species, the Syrian hamster. 2-(125I)Iodomelatonin labels a high affinity binding site in hamster brain membranes. Specific binding of 2-(125I)iodomelatonin is rapid, stable, saturable, and reversible. Saturation studies demonstrated that 2-(125I)iodomelatonin binds to a single class of sites with an affinity constant (Kd) of 3.3 +/- 0.5 nM and a total binding capacity (Bmax) of 110.2 +/- 13.4 fmol/mg protein (n = 4). The Kd value determined from kinetic analysis (3.1 +/- 0.9 nM; n = 5) was very similar to that obtained from saturation experiments. Competition experiments showed that the relative order of potency of a variety of indoles for inhibition of 2-(125I)iodomelatonin binding site to hamster brain membranes was as follows: 6-chloromelatonin greater than or equal to 2-iodomelatonin greater than N-acetylserotonin greater than or equal to 6-methoxymelatonin greater than or equal to melatonin greater than 6-hydroxymelatonin greater than or equal to 6,7-dichloro-2-methylmelatonin greater than 5-methoxytryptophol greater than 5-methoxytryptamine greater than or equal to 5-methoxy-N,N-dimethyltryptamine greater than N-acetyltryptamine greater than serotonin greater than 5-methoxyindole (inactive).

  7. Biological Effects of Irradiating Hepatocellular Carcinoma Cells by Internal Exposure with 125I-Labeled 5-Iodo-2′-Deoxyuridine-Chitosan Drug Loading Nanoparticles

    PubMed Central

    Zhu, Ran; Wan, Jianmei; Jiang, Bo; Zhou, Dayong; Song, Miaoli

    2014-01-01

    Abstract In this study, the authors evaluate the biological effects of irradiation of hepatocellular carcinoma cells by internal exposure with 125I-labeled 5-iodo-2′-deoxyuridine (125I-UdR)-chitosan drug loading nanoparticles (125I-UdR-CS-DLN). The authors observed that accumulation of nanoparticles was significantly (p<0.05) higher in hepatocellular carcinoma cells HepG2 than normal liver cells HL-7702 after treated with 125I-UdR-CS-DLN for 30 minutes. Survival of HepG2 cells was significantly lower at 125I-UdR-CS-DLN doses higher than 37 kBq/mL (more significant in the G1 phase and G2/M phase) than the HL-7702 cells. In addition, 125I-UdR-CS-DLN induced a higher level of DNA double-strand breaks than 125I-UdR, and HepG2 cells exhibited a lower level of DNA repair when compared with HL-7702 cells. In vivo animal experiments, TUNEL staining, after targeted treatment, showed that 125I-UdR-CS-DLN induced significant cell apoptosis in rabbit hepatocellular tumors in situ than 125I-UdR infusion at the same dose. In conclusion, hepatocellular carcinoma cells were significantly irradiated with 125I-UdR-CS-DLN compared with 125I-UdR, and 125I-UdR-CS-DLN irradiation enhanced DNA damage, induced liver cancer cell apoptosis, and prevented DNA damage repair. However, evaluating the extent of damage and organ sparing in vivo should also be considered. PMID:25379613

  8. Transfer across mucosal epithelium, tissue content and metabolic fate of 125I-(ipodate-sodium) on isolated everted segments of rat small intestine.

    PubMed

    Komp, B; Forth, W

    1980-04-01

    1. Transfer and tissue content of 125I-radioactivity was measured after administration of 125I-(ipodate-sodium) to everted rat jejunal segments. 2. After having administered 10(-5) M 125I-(ipodate-sodium) on both sides of the everted sacs the S/M ratio of the concentration of 125I-radioactivity was 1.5 in jejunal segments and 2.3 in ileal segments. The tissue content was nearly equal for both segments. According to the apparent partition coefficient for ipodate-sodium at pH 7, the 125I-radioactivity is accumulated in the tissue about 10-fold. 3. Lowering of the temperature of the incubation medium from 37 degrees C to 15 degrees C prevents the building up of a concentration gradient between the serosal and the mucosal side on either jejunal and ileal segments whereas the tissue content of 125I-radioactivity was nearly unchanged. 4. With increasing concentrations (1.6--10(-6)--9.6-10(-4) M) of 125I-(ipodate-sodium) administered on the mucosal side the transfer and the tissue content of 125I-radioactivity were decreased. This appears to be a toxic effect since in jejunal segments also the S/M ratio for the concentration of glucose decreases. 5. The analysis of the 125I-radioactivity in the serosal fluid of jejunal segments showed that the bulk of the 125I-radioactivity was present in the aqueous phase and only 33% as the unchanged ipodate-sodium in the organic phase. 10% of the 125I-radioactivity must be attributed to inorganic iodine. The concentration of 125I-(ipodate-sodium) administered in the mucosal fluid only was 3.2-10(-6) M. At lower temperature (7 degrees C) the bulk of the 125I-radioactivity in the serosal fluid was found in the organic phase, i.e. as unchanged ipodate-sodium. 6. After the incubation of the aqueous phase with beta-glucuronidase or NaOH about 97% of the 125I-radioactivity could be extracted into the organic phase. This means that the bulk of the 125I-radioactivity in the aqueous phase is present as a conjugate, e.g. ester glucuronide of the

  9. Internalization and lysosomal association of (/sup 125/I)angiotensin II in norepinephrine-containing cells of the rat adrenal medulla

    SciTech Connect

    Bianchi, C.; Gutkowska, J.; Charbonneau, C.; Ballak, M.; Anand-Srivastava, M.B.; De Lean, A.; Genest, J.; Cantin, M.

    1986-10-01

    The morphological localization of (/sup 125/I)angiotensin II (AII) in the rat adrenal medulla (AM) was studied by light- and electron-microscopic radioautography in vivo. With light microscopy the presence of binding sites for AII in both norepinephrine-containing (NE) and epinephrine-containing (E) cells was confirmed. With electron microscopy, it was found that AII binds to the cell surface of NE cells, is progressively internalized, and is associated with lysosomes and Golgi complex within 20 min, whereas in E cells AII seems to be internalized earlier and recycled back to the cell surface within 5 min without any appreciable association with intracellular organelles. These results suggest different intracellular pathways for AII in NE and E cells of the rat AM.

  10. Dosimetry of (125)I and (103)Pd COMS eye plaques for intraocular tumors: report of Task Group 129 by the AAPM and ABS.

    PubMed

    Chiu-Tsao, Sou-Tung; Astrahan, Melvin A; Finger, Paul T; Followill, David S; Meigooni, Ali S; Melhus, Christopher S; Mourtada, Firas; Napolitano, Mary E; Nath, Ravinder; Rivard, Mark J; Rogers, D W O; Thomson, Rowan M

    2012-10-01

    Dosimetry of eye plaques for ocular tumors presents unique challenges in brachytherapy. The challenges in accurate dosimetry are in part related to the steep dose gradient in the tumor and critical structures that are within millimeters of radioactive sources. In most clinical applications, calculations of dose distributions around eye plaques assume a homogenous water medium and full scatter conditions. Recent Monte Carlo (MC)-based eye-plaque dosimetry simulations have demonstrated that the perturbation effects of heterogeneous materials in eye plaques, including the gold-alloy backing and Silastic insert, can be calculated with reasonable accuracy. Even additional levels of complexity introduced through the use of gold foil "seed-guides" and custom-designed plaques can be calculated accurately using modern MC techniques. Simulations accounting for the aforementioned complexities indicate dose discrepancies exceeding a factor of ten to selected critical structures compared to conventional dose calculations. Task Group 129 was formed to review the literature; re-examine the current dosimetry calculation formalism; and make recommendations for eye-plaque dosimetry, including evaluation of brachytherapy source dosimetry parameters and heterogeneity correction factors. A literature review identified modern assessments of dose calculations for Collaborative Ocular Melanoma Study (COMS) design plaques, including MC analyses and an intercomparison of treatment planning systems (TPS) detailing differences between homogeneous and heterogeneous plaque calculations using the American Association of Physicists in Medicine (AAPM) TG-43U1 brachytherapy dosimetry formalism and MC techniques. This review identified that a commonly used prescription dose of 85 Gy at 5 mm depth in homogeneous medium delivers about 75 Gy and 69 Gy at the same 5 mm depth for specific (125)I and (103)Pd sources, respectively, when accounting for COMS plaque heterogeneities. Thus, the adoption of

  11. Seeding Method Influences Warm-Season Grass Abundance and Distribution but not Local Diversity in Grassland Restoration

    USGS Publications Warehouse

    Yurkonis, K.A.; Wilsey, B.J.; Moloney, K.A.; Drobney, P.; Larson, D.L.

    2010-01-01

    Ecological theory predicts that the arrangement of seedlings in newly restored communities may influence future species diversity and composition. We test the prediction that smaller distances between neighboring seeds in drill seeded grassland plantings would result in lower species diversity, greater weed abundance, and larger conspecific patch sizes than otherwise similar broadcast seeded plantings. A diverse grassland seed mix was either drill seeded, which places seeds in equally spaced rows, or broadcast seeded, which spreads seeds across the ground surface, into 24 plots in each of three sites in 2005. In summer 2007, we measured species abundance in a 1 m2 quadrat in each plot and mapped common species within the quadrat by recording the most abundant species in each of 64 cells. Quadrat-scale diversity and weed abundance were similar between drilled and broadcast plots, suggesting that processes that limited establishment and controlled invasion were not affected by such fine-scale seed distribution. However, native warm-season (C4) grasses were more abundant and occurred in less compact patches in drilled plots. This difference in C4 grass abundance and distribution may result from increased germination or vegetative propagation of C4 grasses in drilled plots. Our findings suggest that local plant density may control fine-scale heterogeneity and species composition in restored grasslands, processes that need to be further investigated to determine whether seed distributions can be manipulated to increase diversity in restored grasslands. ?? 2010 Society for Ecological Restoration International.

  12. Seeding method influences warm-season grass abundance and distribution but not local diversity in grassland restoration

    USGS Publications Warehouse

    Yurkonis, Kathryn A.; Wilsey, Brian J.; Moloney, Kirk A.; Drobney, Pauline; Larson, Diane L.

    2010-01-01

    Ecological theory predicts that the arrangement of seedlings in newly restored communities may influence future species diversity and composition. We test the prediction that smaller distances between neighboring seeds in drill seeded grassland plantings would result in lower species diversity, greater weed abundance, and larger conspecific patch sizes than otherwise similar broadcast seeded plantings. A diverse grassland seed mix was either drill seeded, which places seeds in equally spaced rows, or broadcast seeded, which spreads seeds across the ground surface, into 24 plots in each of three sites in 2005. In summer 2007, we measured species abundance in a 1 m2 quadrat in each plot and mapped common species within the quadrat by recording the most abundant species in each of 64 cells. Quadrat-scale diversity and weed abundance were similar between drilled and broadcast plots, suggesting that processes that limited establishment and controlled invasion were not affected by such fine-scale seed distribution. However, native warm-season (C4) grasses were more abundant and occurred in less compact patches in drilled plots. This difference in C4 grass abundance and distribution may result from increased germination or vegetative propagation of C4 grasses in drilled plots. Our findings suggest that local plant density may control fine-scale heterogeneity and species composition in restored grasslands, processes that need to be further investigated to determine whether seed distributions can be manipulated to increase diversity in restored grasslands.

  13. Use of 125I-labeled human serum albumin for quantitation of microvascular permeability in rat skin: reevaluation of an old method for studies on substances with an enhancing effect on microvascular permeability

    SciTech Connect

    Gerdin, B.

    1981-11-01

    A method of determining the leakage of 125I-labeled human serum albumin in the plasma into a standardized area of rat skin to study the effects of intracutaneous application of vasoactive substances on microvascular permeability, was reevaluated. The effect is expressed as a quotient (Q) between the amount of labeled albumin in the test area and that in an area injected with buffer. This calculation is simple and as reliable as more complicated expressions of activity. Within a limited dose range, linear/log dose-response curves can be obtained after application of histamine or bradykinin. Locally injected 125I-labeled human serum albumin is eliminated very slowly from rat skin and determination of the amount of radiolabeled albumin in skin after an intravenous injection therefore represents leakage from the vascular compartments. The potentialities and advantages of this method in pharmacological studies are stressed.

  14. (S)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-5-[125I]iodo- 2-methoxybenzamide hydrochloride, a new selective radioligand for dopamine D-2 receptors.

    PubMed

    de Paulis, T; Janowsky, A; Kessler, R M; Clanton, J A; Smith, H E

    1988-10-01

    From salicyclic acid, the two enantiomers of N-[(1-ethyl-2-pyrrolidinyl)methyl]-5-iodo-2-methoxybenzamide (6b) were prepared in a five-step synthesis. With use of Heindel's triazene method for introduction of the radionuclide, the iodine-125-labeled substituted benzamide was obtained with a calculated specific activity of 136 Ci/mmol and 14% radiochemical yield. For the preparation of the iodine-125-labeled benzamide with higher specific activity, this method was unsuccessful and utilization of the corresponding tri-n-butyltin derivative was required. Treatment of the latter in dilute hydrochloric acid with sodium iodide-125 and chloramine-T gave [125I](S)-6b in 56% radiochemical yield and at least 97% radiochemical purity. The displacement of [125I](S)-6b and [3H](S)-sulpiride from their respective binding sites in striatal rat brain homogenates using various neuroleptic agents showed that (S)-6b has the same binding profile but more potent binding for dopamine D-2 receptors than has sulpiride. These experiments also indicate that the S enantiomer of 6b is a specific ligand (KD = 1.2 nM) for the D-2 receptor. Further, the octanol-water partition coefficient of (S)-6b as determined by reverse-phase high-performance liquid chromatography was found to be 40 times greater than that for sulpiride. Thus (S)-6b has a lipophilicity that will allow a relatively higher uptake into the brain compared to sulpiride. In vivo experiments with rats show that [125I](S)-6b penetrates readily into the brain and is preferentially localized in the striatum as compared to the cerebellum, the ratio of uptake being 7.2 to 1, 60 min after injection. These observations of good brain penetration and high affinity and selectivity for D-2 receptors indicate that the corresponding iodine-123-labeled benzamide may be a useful ligand for the noninvasive visualization study of dopamine D-2 receptor sites in vivo by single photon emission computed tomography.

  15. /sup 3/H and /sup 125/I radioimmunoassays of haloperidol compared with fluoroimmunoassay involving antibody coupled to magnetizable solid phase

    SciTech Connect

    Rowell, F.J.; Hui, S.M.; Kamel, S.R.

    1981-07-01

    Radioimmunoassays for haloperidol are described, involving use of tritium- or 125I-labeled drug or tritium-labeled spiroperidol, and a rabbit antiserum to a drug/bovine serum albumin conjugate. The 125I-labeled drug was prepared by the Chloramine T iodination technique. A fluoroimmunoassay for haloperidol is also described in which the antiserum is coupled to magnetizable solid-phase medium, and fluorescein-labeled haloperidol is used. The assays have acceptable accuracy, precision, and reproducibility, and are specific for haloperidol and similar butyrophenones, with no significant interference from known metabolites and other drugs. Only the radioimmunoassays have sufficient sensitivity to cover the whole range of haloperidol concentrations in serum. The fluoroimmunoassay can be used to monitor high concentrations of haloperidol in 150-microL samples or the complete concentration range of 1-mL serum samples that are extracted and concentrated before assay.

  16. /sup 3/H and /sup 125/I radioimmunoassays of haloperidol compared with fluoroimmunoassay involving antibody coupled to magnetizable solid phase

    SciTech Connect

    Rowell, F.J.; Hui, S.M.; Kamel, S.R.

    1981-07-01

    Radioimmunoassays for haloperidol are described, involving use of tritium-or /sup 125/I-labeled drug or tritium-labeled spiroperidol, and a rabbit antiserum to a drug/bovine serum albumin conjugate. The /sup 125/I-labeled drug was prepared by the Chloramine T iodination technique. A fluoroimmunoassay for haloperidol is also described in which the antiserum is coupled to magnetizable solid-phase medium, and fluorescein-labeled haloperidol is used. The assays have acceptable accuracy, precision, and reproducibility, and are specific for haloperidol and similar butyrophenones, with no significant interference from known metabolites and other drugs. Only the radioimmunoassays have sufficient sensitivity to cover the whole range of haloperidol concentrations in serum. The fluoroimmunoassay can be used to monitor high concentrations of haloperidol in 150 ..mu..L samples or the complete concentration range of 1-mL serum samples that are extracted and concentrated before assay.

  17. Dual-head gamma camera system for intraoperative localization of radioactive seeds

    NASA Astrophysics Data System (ADS)

    Arsenali, B.; de Jong, H. W. A. M.; Viergever, M. A.; Dickerscheid, D. B. M.; Beijst, C.; Gilhuijs, K. G. A.

    2015-10-01

    Breast-conserving surgery is a standard option for the treatment of patients with early-stage breast cancer. This form of surgery may result in incomplete excision of the tumor. Iodine-125 labeled titanium seeds are currently used in clinical practice to reduce the number of incomplete excisions. It seems likely that the number of incomplete excisions can be reduced even further if intraoperative information about the location of the radioactive seed is combined with preoperative information about the extent of the tumor. This can be combined if the location of the radioactive seed is established in a world coordinate system that can be linked to the (preoperative) image coordinate system. With this in mind, we propose a radioactive seed localization system which is composed of two static ceiling-suspended gamma camera heads and two parallel-hole collimators. Physical experiments and computer simulations which mimic realistic clinical situations were performed to estimate the localization accuracy (defined as trueness and precision) of the proposed system with respect to collimator-source distance (ranging between 50 cm and 100 cm) and imaging time (ranging between 1 s and 10 s). The goal of the study was to determine whether or not a trueness of 5 mm can be achieved if a collimator-source distance of 50 cm and imaging time of 5 s are used (these specifications were defined by a group of dedicated breast cancer surgeons). The results from the experiments indicate that the location of the radioactive seed can be established with an accuracy of 1.6 mm  ±  0.6 mm if a collimator-source distance of 50 cm and imaging time of 5 s are used (these experiments were performed with a 4.5 cm thick block phantom). Furthermore, the results from the simulations indicate that a trueness of 3.2 mm or less can be achieved if a collimator-source distance of 50 cm and imaging time of 5 s are used (this trueness was achieved for all 14 breast phantoms which

  18. Acetylation of chromosome squashes of Drosophila melanogaster decreases the background in autoradiographs from hybridization with [125I]-labeled RNA.

    PubMed

    Hayashi, S; Gillam, I C; Delaney, A D; Tener, G M

    1978-08-01

    DNA in prepared chromosomes from the larval salivary glands of Drosophila melanogaster was hybridized with [125I]-labeled 5S and tRNA from the same organism. Autoradiography revealed that radioactivity was frequently bound to all regions of the slides, masking labeling of the chromosomes. Acetylation of the preparations before hybridization prevented the formation of this background and revealed the specific chromosomal sites.

  19. Binding and internalization in vivo of (/sup 125/I)hCG in Leydig cells of the rat

    SciTech Connect

    Hermo, L.; Lalli, M.

    1988-01-01

    The present study was performed to demonstrate the binding, mode of uptake, pathway and fate of iodinated human chorionic gonadotropin ((/sup 125/I)hCG) by Leydig cells in vivo using electron microscope radioautography. Following a single injection of (/sup 125/I)hCG into the interstitial space of the testis, the animals were fixed by perfusion with glutaraldehyde at 20 minutes, 1, 3, 6 and 24 hours. The electron microscope radioautographs demonstrated a prominent and qualitatively similar binding of the labeled hCG on the microvillar processes of the Leydig cells at 20 minutes, 1, 3, and 6 hours. The specificity of the (/sup 125/I)hCG binding was determined by injecting a 100-fold excess of unlabeled hormone concurrently with the labeled hormone. Under these conditions, the surface, including the microvillar processes of Leydig cells, was virtually unlabeled, indicating that the binding was specific and receptor-mediated. In animals injected with labeled hCG and sacrificed 20 minutes later, silver grains were also seen overlying the limiting membrane of large, uncoated surface invaginations and large subsurface vacuoles with an electron-lucent content referred to as endosomes. A radioautographic reaction was also seen within multivesicular bodies with a pale stained matrix. At 1 hour, silver grains appeared over dense multivesicular bodies and occasionally over secondary lysosomes, in addition to the structures mentioned above, while at 3 and 6 hours, an increasing number of secondary lysosomes became labeled. At 24 hours, binding of (/sup 125/I)hCG to the microvillar processes of Leydig cells persisted but was diminished, although a few endosomes, multivesicular bodies and secondary lysosomes still showed a radioautographic reaction. No membranous tubules that were seen in close proximity to, or in continuity with, endosomes and multivesicular bodies were observed to be labeled at any time interval.

  20. /sup 125/I-labeled crosslinking reagent that is hydrophilic, photoactivatable, and cleavable through an azo linkage

    SciTech Connect

    Denny, J.B.; Blobel, G.

    1984-09-01

    A radioactive crosslinking reagent, N-(4-(p-azido-m-(/sup 125/I)iodophenylazo)benzoyl)-3-aminopropyl-N'-oxysulfosuccinimide ester, has been synthesized. The reagent is photoactivatable, water-soluble, cleavable through an azo linkage, and labeled with /sup 125/I at the carrier-free specific activity of 2000 Ci/mmol. Any protein derivatized with the reagent is thus converted into an /sup 125/I-labeled photoaffinity probe. Crosslinks are formed following photolysis with 366-nm light, and cleavage by sodium dithionite results in the donation of radioactivity to the distal partner in crosslinked complexes. The newly labeled proteins are then analyzed by gel electrophoresis and autoradiography. The compound was prepared by iodination of N-(4-(p-aminophenylazo)benzoyl)-3-aminopropionic acid using carrier-free Na/sup 125/I and chloramine-T, followed by azide formation and conversion to the water-soluble sulfosuccinimide ester. As a model system, protein A-Sepharose was derivatized with the reagent under subdued light. Each derivatized protein A molecule contained only one crosslinker. The derivatized protein A-Sepharose was then photolyzed in the presence of human serum and subsequently treated with sodium dithionite. Analysis of the serum by gel electrophoresis revealed that 1.1% of the radioactive label originally present on the protein A-Sepharose was transferred to the heavy chain of IgG, which was the most intensely labeled protein in the gel. The next most intensely labeled protein was IgG light chain, which incorporated radioactivity that was lower by a factor of 3.6 than that of the heavy chain. 36 references, 3 figures.

  1. Enhanced EJ Cell Killing of 125I Radiation by Combining with Cytosine Deaminase Gene Therapy Regulated by Synthetic Radio-Responsive Promoter

    PubMed Central

    Li, Ling; Kang, Lei; Wang, Rong-Fu; Yan, Ping; Zhao, Qian; Yin, Lei; Guo, Feng-qin

    2015-01-01

    Abstract Aim: To investigate the enhancing effect of radionuclide therapy by the therapeutic gene placed under the control of radio-responsive promoter. Methods: The recombinant lentivirus E8-codA-GFP, including a synthetic radiation-sensitive promoter E8, cytosine deaminase (CD) gene, and green fluorescent protein gene, was constructed. The gene expression activated by 125I radiation was assessed by observation of green fluorescence. The ability of converting 5-fluorocytosine (5-FC) to 5-fluorourial (5-FU) by CD enzyme was assessed by high-performance liquid chromatography. The viability of the infected cells exposed to 125I in the presence of 5-FC was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the infected cells exposed to 125I alone served as negative control and 5-FU as positive control. Results: The recombinant lentiviral vector was constructed successfully. On exposure of infected cells to 125I, green fluorescence can be observed and 5-FU can be detected. MTT assay showed that the survival rate for infected cells treated with 125I was lower compared with the 125I control group, but higher than the positive control group. Conclusion: The synthetic promoter E8 can induce the expression of downstream CD gene under 125I radiation, and the tumor killing effect of 125I can be enhanced by combining CD gene therapy with radiosensitive promoter. PMID:26382009

  2. Studies on gonococcus infection. XVIII. 125I-labeled peptide mapping of the major protein of the gonococcal cell wall outer membrane.

    PubMed Central

    Swanson, J

    1979-01-01

    The major outer membrane proteins from 10 gonococcal strains were examined after 125I-labeling of the proteins as single bands resolved by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. These 125I-proteins were then treated with either trypsin or alpha-chymotrypsin, and the resultant 125I-peptides were visualized by autoradiography after two-dimensional electrophoretic and chromatographic separation on thin-layer cellulose sheets. Several 125I-peptides were present in all the major outer membrane proteins examined. The presence and absence of additional 125I-peptides segregated the major proteins into two pattern groups. One group consisted of major outer membranes with molecular weights of 34,000 or 33,000; major proteins with molecular weights of 32,000 constituted the other group. Two beta-lactamase-producing gonococcal isolates were examined. Their major outer membrane proteins were identical in apparent molecular weights and alpha-chymotryptic 125I-peptide fingerprints; these proteins contained 125I-peptides not found in other gonococcal major proteins. No 125I-peptide differences were found among the major outer membrane proteins of strain F62 gonococci that exhibited differences in piliation and/or colony opacity characteristics. Images PMID:110681

  3. Comparative sensitivity of /sup 125/I-protein A and enzyme-conjugated antibodies for detection of immunoblotted proteins

    SciTech Connect

    Bernstein, J.M.; Stokes, C.E.; Fernie, B.

    1987-01-01

    Immunoblotting is a powerful technique for the detection of small amounts of immunologically interesting proteins in unpurified preparations. Iodinated protein A (PA) has been widely used as a second antibody for detection of proteins; however, it does not bind equally well to immunoglobulins from different species nor does it bind to all subclasses of immunoglobulin G (IgG). We compared the sensitivity of (/sup 125/I)PA with those of both horseradish peroxidase-conjugated second antibodies (HRP) and glucose oxidase-anti-glucose oxidase (GAG) soluble complexes for visualizing bovine serum albumin, human IgG, or human C3 which was either dot blotted or electroblotted to nitrocellulose. (/sup 125/I)PA was uniformly 10- to 100-fold less sensitive than either HRP or GAG. GAG was more sensitive than HRP except for C3 (electroblotting) and bovine serum albumin and IgG (dot blotting), in which they were equivalent. In general, dot blotting was 10- to 1000-fold more sensitive than electroblotting. Although relative sensitivities varied depending on the proteins analyzed and the antisera used, GAG appeared to be superior to (/sup 125/I)PA and HRP for detection of immunoblotted proteins.

  4. Reoxygenation, but neither hypoxia nor intermittent ischemia, increases ( sup 125 I)endothelin-1 binding to rat cardiac membranes

    SciTech Connect

    Liu, J.J.; Gu, X.H.; Casley, D.J.; Nayler, W.G. )

    1990-03-01

    Standard binding techniques were used to establish whether either hypoxia, reoxygenation, perfusion under acidotic conditions, or stunning of the myocardium resembles ischemia and postischemic reperfusion in increasing cardiac membrane ({sup 125}I)endothelin-1 (ET-1) binding site density (Bmax). Membranes from aerobically perfused rat hearts bound ({sup 125}I)ET-1 to a single population of sites, with an affinity (KD) of 0.093 +/- 0.004 nM and a Bmax of 98.8 +/- 5.2 fmol/mg of protein. Bmax was increased (p less than 0.01) after 30 min of global ischemia, and further increased upon reperfusion, without changes in KD or selectivity. Neither three 10 min episodes of ischemia separated by 15 min of perfusion, nor perfusion at pH 6.8 instead of 7.4, nor 60 min of hypoxia altered Bmax, KD, or selectivity. Reoxygenation after 60 min of hypoxia increased Bmax (p less than 0.01) and KD (p less than 0.01) without changing selectivity. These results are interpreted to mean that the ischemia-induced increase in Bmax for ({sup 125}I)ET-1 cannot be explained simply in terms of the ischemia-induced acidosis, or the accompanying reduction in tissue adenosine triphosphate and creatine phosphate.

  5. Increased ocular blood flow and /sup 125/I-albumin permeation in galactose-fed rats: inhibition by sorbinil

    SciTech Connect

    Tilton, R.G.; Chang, K.; Weigel, C.; Eades, D.; Sherman, W.R.; Kilo, C.; Williamson, J.R.

    1988-06-01

    125I-Albumin permeation and blood flow (assessed with 15 micron, 85Sr-labelled microspheres) were determined in the retina, choroid, anterior uvea, and brain of male Sprague-Dawley rats fed diets containing 50% dextrin (control) or 50% galactose. Blood flow was increased in the retina, choroid, and anterior uvea but not in the brain of rats fed galactose for 3 weeks and 3 months versus controls, and was normalized by sorbinil (an inhibitor of aldose reductase) in the 3-week group. After 8 months of galactose feeding, blood flow was reduced to normal levels in the retina and was slightly below normal in the choroid; blood flow remained elevated in the anterior uvea but was significantly lower than that observed at 3 weeks and at 3 months. In rats fed galactose for 8 months, sorbinil completely normalized blood flow in the choroid, and decreased, but did not normalize, blood flow in the anterior uvea. 125I-Albumin permeation was increased in the retina, choroid, and anterior uvea of rats fed 50% galactose for 3 weeks, 3 months, and 8 months versus controls, but was unchanged in the brain. Sorbinil normalized 125I-albumin permeation in all three ocular tissues in 8-month galactose-fed rats. Polyol levels were increased significantly in all three ocular tissues of 3-week galactose-fed rats; sorbinil markedly decreased, but did not normalize, polyol levels in all three tissues.

  6. 125I-labeled gonadoliberin and high specific activity and immunoreactivity: method of iodination and rapid separation.

    PubMed

    Sarda, A K; Barnes, M A; Nair, R M

    1980-04-01

    We describe optimum conditions for iodinating gonadoliberin with use of relatively large proportions of Na 125I. Products of the iodination are separated on an anion-exchange resin (Amberlite IRA-400). The 125I-labeled gonadoliberin thus obtained has a high specific activity (1400 to 1590 Ci/g); because of the conditions of iodination, we believe that the predominant species of the labeled decapeptide is the mono-iodinated one. Our separation and purification of the labeled substance on ion-exchange resin is rapid, economical, and less cumbersome than the use of a Biogel P-2 column. There is no adsorption of the labeled hormone onto the resin, as evidenced by analytical recovery studies with tritium-labeled gonadoliberin. Paper-strip chromatoelectrophoresis showed no free Na 125I or radiolabeled damaged peptide fragments after purification on the resin. When antiserum was used at a concentration 32-fold that used in the regular assay procedure, only 4% of the radioactivity remained in the free form, indicating the high immunoreactivity of the labeled hormone.

  7. Sarafotoxin S6c is a relatively weak displacer of specifically bound /sup 125/I-endothelin

    SciTech Connect

    Nayler, W.G.; Gu, X.H.; Casley, D.J.

    1989-05-30

    Sarafotoxin S6a, S6b and S6c are chemically related vasoconstrictor polypeptides obtained from the venom of the snake, Atractaspis engaddensis. Each contains twenty one amino acid residues, two intrachain cysteine linkages and a long hydrophobic tail. Structurally these polypeptides resemble endothelin. Binding studies with /sup 125/I-endothelin showed that /sup 125/I-endothelin bound to rat ventricular membranes is totally displaceable by sarafotoxin S6b and endothelin, with IC50 values of 0.21 and 0.16 nM, respectively. Sarafotoxin S6c, which differs from sarafotoxin S6b in containing threonine instead of serine at residue 2, arginine instead of lysine at residue 4, and glutamic acid instead of lysine at residue 9, only weakly displaced bound /sup 125/I-endothelin (IC50, 854 nM). These results indicate that the ability of the sarafotoxins to interact with the endothelin binding site is not solely dependent on the long hydrophobic tail or the cysteine linkages.

  8. Immunoassay of 5-methyltetrahydrofolate: use of /sup 125/I-labeled protein A as the tracer molecule for specific antibody

    SciTech Connect

    Langone, J.J.

    1980-05-15

    A sensitive and specific solid-phase radioimmunoassay for 5-methyltetrahydrofolate (5-MTHFA) has been developed. /sup 125/I-Labeled staphylococcal Protein A (/sup 125/I-PA) was used as the tracer molecule for rabbit IgG antibodies bound to 5-MTHFA immobilized on polyacrylamide beads. The dose-dependent inhibition of antibody binding by fluid-phase drug was reflected in decreased binding of /sup 125/I-PA. This inhibition, determined in the presence of known amounts of 5-MTHFA, served as the basis for quantification of 5-MTHFA in test samples. An early bleeding was relatively specific; 4.5 ng 5-MTHFA inhibited immune binding by 50% compared to 7700 ng folinic acid or 1200 ng tetrahydrofolate. Other folic acid analogs, including methotrexate, failed to inhibit significantly. The assay using a later bleeding was more sensitive since 1.6 ng 5-MTHFA gave 50% inhibition (detection limit 0.2 ng), but folinic acid cross-reacted significantly. Absorption with immobilized folinic acid markedly enhanced the specificity of this antiserum and resulted in a 15 to 20% increase in maximum inhibition by 5-MTHFA. The assay could be carried out in the presence of 0.025 ml human serum or urine without affecting the standard curve, and was used to determine levels of 5-MTHFA in serum of drug-treated rabbits.

  9. Binding of ( sup 125 I)iodipine to parathyroid cell membranes: Evidence of a dihydropyridine-sensitive calcium channel

    SciTech Connect

    Jones, J.I.; Fitzpatrick, L.A. )

    1990-04-01

    The parathyroid cell is unusual, in that an increase in extracellular calcium concentrations inhibits PTH release. Calcium channels are glycoproteins that span cell membranes and allow entry of extracellular calcium into cells. We have demonstrated that the calcium channel agonist (+)202-791, which opens calcium channels, inhibits PTH release and that the antagonist (-)202-791, which closes calcium channels, stimulates PTH release. To identify the calcium channels responsible for these effects, we used a radioligand that specifically binds to calcium channels. Bovine parathyroid cell membranes were prepared and incubated under reduced lighting with (125I) iodipine (SA, 2000 Ci/mmol), which recognizes 1,4-dihydropyridine-sensitive calcium channels. Bound ligand was separated from free ligand by rapid filtration through Whatman GF/B filters. Nonspecific binding was measured by the inclusion of nifedipine at 10 microM. Specific binding represented approximately 40% of the total binding. The optimal temperature for (125I) iodipine binding was 4 C, and binding reached equilibrium by 30 min. The equilibrium dissociation constant (Kd) was approximately 550 pM, and the maximum number of binding sites was 780 fmol/mg protein. Both the calcium channel agonist (+)202-791 and antagonist (-)202-791 competitively inhibited (125I) iodipine binding, with 50% inhibition concentrations of 20 and 300 nM, respectively. These data indicate the presence of dihydropyridine-sensitive calcium channels on parathyroid cell membranes.

  10. Seeds of Locally Aligned Motion and Stress Coordinate a Collective Cell Migration

    PubMed Central

    Zaritsky, Assaf; Welf, Erik S.; Tseng, Yun-Yu; Angeles Rabadán, M.; Serra-Picamal, Xavier; Trepat, Xavier; Danuser, Gaudenz

    2015-01-01

    We find how collective migration emerges from mechanical information transfer between cells. Local alignment of cell velocity and mechanical stress orientation—a phenomenon dubbed “plithotaxis”—plays a crucial role in inducing coordinated migration. Leader cells at the monolayer edge better align velocity and stress to migrate faster toward the open space. Local seeds of enhanced motion then generate stress on neighboring cells to guide their migration. Stress-induced motion propagates into the monolayer as well as along the monolayer boundary to generate increasingly larger clusters of coordinately migrating cells that move faster with enhanced alignment of velocity and stress. Together, our analysis provides a model of long-range mechanical communication between cells, in which plithotaxis translates local mechanical fluctuations into globally collective migration of entire tissues. PMID:26682808

  11. A Randomized Prospective Comparison of Patient-Assessed Satisfaction and Clinical Outcomes with Radioactive Seed Localization versus Wire Localization.

    PubMed

    Bloomquist, Erica V; Ajkay, Nicolas; Patil, Sujata; Collett, Abigail E; Frazier, Thomas G; Barrio, Andrea V

    2016-01-01

    Radioactive seed localization (RSL) has emerged as an alternative to wire localization (WL) in patients with nonpalpable breast cancer. Few studies have prospectively evaluated patient satisfaction and outcomes with RSL. We report the results of a randomized trial comparing RSL to WL in our community hospital. We prospectively enrolled 135 patients with nonpalpable breast cancer between 2011 and 2014. Patients were randomized to RSL or WL. Patients rated the pain and the convenience of the localization on a 5-point Likert scale. Characteristics and outcomes were compared between groups. Of 135 patients enrolled, 10 were excluded (benign pathology, palpable cancer, mastectomy, and previous ipsilateral cancer) resulting in 125 patients. Seventy patients (56%) were randomized to RSL and 55 (44%) to WL. Fewer patients in the RSL group reported moderate to severe pain during the localization procedure compared to the WL group (12% versus 26%, respectively, p = 0.058). The overall convenience of the procedure was rated as very good to excellent in 85% of RSL patients compared to 44% of WL patients (p < 0.0001). There was no difference between the volume of the main specimen (p = 0.67), volume of the first surgery (p = 0.67), or rate of positive margins (p = 0.53) between groups. RSL resulted in less severe pain and higher convenience compared to WL, with comparable excision volume and positive margin rates. High patient satisfaction with RSL provides another incentive for surgeons to strongly consider RSL as an alternative to WL.

  12. Subcellular localization and vacuolar targeting of sorbitol dehydrogenase in apple seed.

    PubMed

    Wang, Xiu-Ling; Hu, Zi-Ying; You, Chun-Xiang; Kong, Xiu-Zhen; Shi, Xiao-Pu

    2013-09-01

    Sorbitol is the primary photosynthate and translocated carbohydrate in fruit trees of the Rosaceae family. NAD(+)-dependent sorbitol dehydrogenase (NAD-SDH, EC 1.1.1.14), which mainly catalyzes the oxidation of sorbitol to fructose, plays a key role in regulating sink strength in apple. In this study, we found that apple NAD-SDH was ubiquitously distributed in epidermis, parenchyma, and vascular bundle in developing cotyledon. NAD-SDH was localized in the cytosol, the membranes of endoplasmic reticulum and vesicles, and the vacuolar lumen in the cotyledon at the middle stage of seed development. In contrast, NAD-SDH was mainly distributed in the protein storage vacuoles in cotyledon at the late stage of seed development. Sequence analysis revealed there is a putative signal peptide (SP), also being predicated to be a transmembrane domain, in the middle of proteins of apple NAD-SDH isoforms. To investigate whether the putative internal SP functions in the vacuolar targeting of NAD-SDH, we analyzed the localization of the SP-deletion mutants of MdSDH5 and MdSDH6 (two NAD-SDH isoforms in apple) by the transient expression system in Arabidopsis protoplasts. MdSDH5 and MdSDH6 were not localized in the vacuoles after their SPs were deleted, suggesting the internal SP functions in the vacuolar targeting of apple NAD-SDH.

  13. What's the meaning of local? Using molecular markers to define seed transfer zones for ecological restoration in Norway.

    PubMed

    Jørgensen, Marte Holten; Elameen, Abdelhameed; Hofman, Nadine; Klemsdal, Sonja; Malaval, Sandra; Fjellheim, Siri

    2016-06-01

    According to the Norwegian Diversity Act, practitioners of restoration in Norway are instructed to use seed mixtures of local provenance. However, there are no guidelines for how local seed should be selected. In this study, we use genetic variation in a set of alpine species (Agrostis mertensii, Avenella flexuosa, Carex bigelowii, Festuca ovina, Poa alpina and Scorzoneroides autumnalis) to define seed transfer zones to reduce confusion about the definition of 'local seeds'. The species selected for the study are common in all parts of Norway and suitable for commercial seed production. The sampling covered the entire alpine region (7-20 populations per species, 3-15 individuals per population). We characterised genetic diversity using amplified fragment length polymorphisms. We identified different spatial genetic diversity structures in the species, most likely related to differences in reproductive strategies, phylogeographic factors and geographic distribution. Based on results from all species, we suggest four general seed transfer zones for alpine Norway. This is likely more conservative than needed for all species, given that no species show more than two genetic groups. Even so, the approach is practical as four seed mixtures will serve the need for restoration of vegetation in alpine regions in Norway.

  14. Synthesis and evaluation of (17 alpha,20E)-21-(/sup 125/I)iodo-19-norpregna-1,3,5(10),20-tetraene-3,17 -diol and (17 alpha,20E)-21-(/sup 125/I)iodo-11 beta-methoxy-19-norpregna-1,3,5(10),20-tetraene-3,17-diol (17 alpha-(iodovinyl)estradiol derivatives) as high specific activity potential radiopharmaceuticals

    SciTech Connect

    Nakatsuka, I.; Ferreira, N.L.; Eckelman, W.C.; Francis, B.E.; Rzeszotarski, W.J.; Gibson, R.E.; Jagoda, E.M.; Reba, R.C.

    1984-10-01

    Two 17 alpha-(/sup 125/I)iodovinyl estradiol derivatives 4b,d possessing high specific activity have been prepared and tested as potential radiopharmaceuticals. The use of the 3-acetyl derivatives 2c,e and the replacement of iodine monochloride with sodium iodide and Chloramine-T in THF/phosphate buffer (pH 7.0) permitted us to synthesize no-carrier-added (17 alpha,20E)-21-(/sup 125/I)iodo-19-norpregna-1,3,5(10),20-tetraene-3,17-d iol (4b) and (17 alpha,20E)-21-(/sup 125/I)iodo-11 beta-methoxy-19-norpregna-1,3,5(10),20-tetraene-3,17-diol (4d) with 50% radiochemical yield and high purity. Although the specific activity represents only half of the theoretical value in some cases, this modified approach is a substantial improvement over the previously published method. Our preliminary distribution studies indicate that although both 4b and 4d localize in the tissues known to have a large concentration of estrogen receptors, 4d accumulates in higher amounts in target tissues and provides a high target to nontarget ratio.

  15. Effects of different batches of /sup 125/iodine on properties of /sup 125/I-hFSH and characteristics of radioligand-receptor assays

    SciTech Connect

    Melson, B.E.; Sluss, P.M.; Reichert, L.E. Jr.

    1987-02-01

    Radioiodination of highly purified human follicle-stimulating hormone (hFSH) (4000 IU/mg) was performed every other week for 23 weeks using 2 mCI carrier free Na/sup 125/I (Amersham Corp., 15 mCi/micrograms I2) in the presence of lactoperoxidase. Incorporation of /sup 125/I into hFSH was determined by the method of R. C. Greenwood, W. M. Hunter, and J. S. Grover (1963) Biochem. J. 89, 114). Hormone binding was studied in vitro under steady-state conditions (16 h, 20 degrees C) using different calf testis membrane preparations having similar receptor characteristics. Each /sup 125/I-hFSH preparation was characterized for maximum bindability, specific activity of bindable radioligand as determined by self-displacement analysis, and by determination of Ka and Rt. Incorporation of /sup 125/I into FSH was relatively constant over the large number of experiments (62.4 +/- 6.4 microCi/micrograms; n = 23). By comparison, however, specific radioactivity of the receptor bindable fraction of /sup 125/I-hFSH was related to the lot of /sup 125/I utilized, and was significantly (P less than or equal to 0.01) lower and more variable (28.7 +/- 10.5 microCi/micrograms). Maximum bindability of /sup 125/I-hFSH was not correlated to specific activity (r = 0.06) but was negatively correlated to hFSH /sup 125/I incorporation (r = -0.47; P less than or equal to 0.05). These observations demonstrate the need to assess the quality of each batch of radioligand before undertaking radioligand-receptor assays and suggest that differences in Na/sup 125/I lots affect specific radioactivity of the radioligand and its receptor binding characteristics.

  16. (-)(125I)-iodopindolol, a new highly selective radioiodinated beta-adrenergic receptor antagonist: measurement of beta-receptors on intact rat astrocytoma cells

    SciTech Connect

    Barovsky, K.; Brooker, G.

    1980-01-01

    (-)-Pindolol, one of the most potent beta-adrenergic receptor antagonists, was radioiodinated using chloramine-T oxidation of carrier-free Na 125I and separated from unreacted pindolol to yield 2200 Ci/mmole (-)-(125I)-iodopindolol ((-)-(125I)-IPin). Mass and ultraviolet spectra confirmed that the iodination occurred on the indole ring, presumably at the 3 position. The binding of radiolabeled (-)-(125I)-IPin to beta-adrenergic receptors has been studied using intact C6 rat astrocytoma cells (2B subclone) grown in monolayer cultures. Binding of (-)(125IPin was saturable with time and concentration. Using 13 pM (-)-(125I)IPin, binding equilibrium was reached in 90 min at 21-22 degrees C. The reverse rate constant was 0.026 min-1 at 21/sup 0/C. Specific binding (expressed as 1 microM(-)-propranolol displaceable counts) of (-)-(125I)-IPin was 95% of total binding. Scatchard analysis of (-)-(125I)-I)Pin binding revealed approximately 4300 receptors/cell and a dissociation constant of 30 pM. This was in excellent agreement with the kinetically determined dissociation constant of 35 pM. Displacement by propranolol and isoproterenol showed that (-)-(125I)-IPin binding sites were pharmacologically and stereospecifically selective. These results indicate that (-)-(125I)-IPin, a pure (-)-stereoisomer, high specific activity radioligand, selectively binds to beta-adrenergic receptors in whole cells with a high percentage of specific binding and should therefore be useful in the study and measurement of cellular beta-adrenergic receptors.

  17. A Randomized Prospective Comparison of Patient-Assessed Satisfaction and Clinical Outcomes with Radioactive Seed Localization Versus Wire Localization

    PubMed Central

    Bloomquist, Erica V.; Ajkay, Nicolas; Patil, Sujata; Collett, Abigail E.; Frazier, Thomas G.; Barrio, Andrea V.

    2015-01-01

    Background Radioactive seed localization (RSL) has emerged as an alternative to wire localization (WL) in patients with non-palpable breast cancer. Few studies have prospectively evaluated patient satisfaction and outcomes with RSL. We report the results of a randomized trial comparing RSL to WL in our community hospital. Materials and Methods We prospectively enrolled 135 patients with non-palpable breast cancer between 2011 and 2014. Patients were randomized to RSL or WL. Patients rated the pain and the convenience of the localization on a 5-point Likert scale. Characteristics and outcomes were compared between groups. Results Of 135 patients enrolled, 10 were excluded (benign pathology, palpable cancer, mastectomy and previous ipsilateral cancer) resulting in 125 patients. Seventy patients (56%) were randomized to RSL and 55 (44%) to WL. Fewer patients in the RSL group reported moderate to severe pain during the localization procedure compared to the WL group (12% versus 26%, respectively, p=0.058). The overall convenience of the procedure was rated as very good to excellent in 85% of RSL patients compared to 44% of WL patients (p<0.0001). There was no difference between the volume of the main specimen (p=0.67), volume of the first surgery (p=0.67), or rate of positive margins (p=0.53) between groups. Conclusions RSL resulted in less severe pain and higher convenience compared to WL, with comparable excision volume and positive margin rates. High patient satisfaction with RSL provides another incentive for surgeons to strongly consider RSL as an alternative to WL. PMID:26696461

  18. Characterization of [125I]ZM 241385 binding to adenosine A2A receptors in the pineal of sheep brain.

    PubMed

    Yan, X; Koos, B J; Kruger, L; Linden, J; Murray, T F

    2006-06-22

    Adenosine is a ubiquitous neuromodulator and homeostatic regulator that exerts its physiologic actions through activation of A(1), A(2A), A(2B) and A(3) adenosine receptor subtypes. In the central nervous system, adenosine's action in neurons is manifested in its modulation of tonic inhibitory control. Adenosine released in the brain during hypoxia has critical depressant effects on breathing in fetal and newborn mammals, an action suggested to be mediated by A(2A) receptors in the posteromedial thalamus. In an effort to more accurately define the spatial distribution of adenosine A(2A) receptors in fetal sheep diencephalon, we have used a receptor autoradiographic technique utilizing an iodinated radioligand [(125)I]ZM 241385, which has greater sensitivity and resolution than the tritiated compound. The distribution of ligand binding sites in the fetal sheep diencephalon indicated that the highest levels of binding were in select thalamic nuclei, including those implicated in hypoxic depression of fetal breathing, and the pineal. Given the high density of labeled A(2A) receptors in the pineal, these sites were characterized more fully in homogenate radioligand binding assays. These data indicate that [(125)I]ZM 241385 binding sites display a pharmacological signature consistent with that of adenosine A(2A) receptors and are expressed at similar levels in fetal, lamb and adult ovine brain. The adenosine A(2A) receptor pharmacologic signature of the [(125)I]ZM 241385 binding site in pineal cell membranes generalized to the site characterized in membranes derived from other portions of the lamb thalamus, including the sector involved in hypoxic inhibition of fetal breathing. These results have important implications for the functional roles of adenosine A(2A) receptors in the thalamus and pineal of sheep brain.

  19. Angiotensin II receptors labelled with 125I-[Sar1, Ile8]-AII in albino rabbit ocular tissues.

    PubMed

    Mallorga, P; Babilon, R W; Sugrue, M F

    1989-08-01

    High affinity binding sites for the angiotensin II antagonist 125I-[Sar1,Ile8]-AII have been identified and characterized in membrane suspensions of ocular tissues of albino rabbits. Scatchard analysis of the binding indicated a single class of sites with Kd values of 186, 92, 152, 50, 102 pM for the iris + ciliary body, choroid, ciliary process, retina and cornea, respectively. The corresponding concentrations of binding sites were 22, 68, 35, 22 and 4 fmole/mg of protein. The order of potency for several AII analogs to compete with 125I-[Sar1,Ile8]-AII at its binding sites in iris + ciliary body membranes ([Sar1,Leu8]-AII = [Sar1,Ile8]-AII greater than AII = [Sar1, Ala8]-AII greater than AIII greater than AI) resembled the order of potency found for AII receptors in other tissues. The competition curves for this tissue using AII and AIII were best explained by the existence of two populations of binding sites. The addition of the guanine nucleotide, GppNHp, to the assay resulted in a 6.7-fold and 2.3-fold decrease in the respective affinities of AII and AIII for 125I-[Sar1,Ile8]-AII binding sites without a change in the slope of the competition curves. The GppNHp-induced effect was also observed in ciliary process membranes but not in retinal or choroidal membranes. These results indicate the presence of AII receptors regulated by a GTP-binding protein in both the ciliary process and the iris + ciliary body of the rabbit. They also suggest a difference in the guanine nucleotide regulation of AII receptors in different ocular tissues.

  20. Determination of 125I impurities in [ 123I]labelled radiopharmaceuticals, by liquid scintillation counting: sensitivity of the method

    NASA Astrophysics Data System (ADS)

    Bonardi, M. L.; Birattari, C.; Groppi, F.; Gini, L.; Mainardi, C. H. S.; Menapace, E.

    2004-01-01

    Iodine-125 is a radioisotopic impurity "always" present in iodine-123, produced by nuclear reactions induced either on natural or "highly" enriched targets. Liquid scintillation counting is a very sensitive tool to determine low level impurities of both low energy electrons and photons in aqueous and organic solutions of radiopharmaceutical compounds. With this technique it was possible to determine, on commercial samples, that the content of 125I was of the order of not less than 0.1% for 123I produced via 127I(p,5n) reactions and not less than 0.01% for 123I produced via "highly" enriched 124Xe(p,X) nuclear reactions.

  1. Macrophage clearance of 125I-labelled polyvinyl pyrrolidone in the horse: effect of ovarian steroids and persistent endometritis.

    PubMed

    Watson, E D; Stokes, C R

    1988-11-01

    The rate of clearance of 125I-labelled polyvinyl pyrrolidone (PVP) from blood was measured in mares as an indicator of macrophage function. In three out of four cycling mares, PVP clearance was slower during oestrus than dioestrus. Similarly, administration of oestrogen to four ovariectomised mares tended to depress PVP clearance compared with clearance from the same mares before they received oestrogen. However, the effect of oestrogen was not statistically significant. Mares susceptible to persistent endometritis had rates of PVP clearance which were similar to those of genitally normal mares.

  2. Genetic delineation of local provenance defines seed collection zones along a climate gradient

    PubMed Central

    Hufford, Kristina M.; Veneklaas, Erik J.; Lambers, Hans; Krauss, Siegfried L.

    2016-01-01

    Efforts to re-establish native plant species should consider intraspecific variation if we are to restore genetic diversity and evolutionary potential. Data describing spatial genetic structure and the scale of adaptive differentiation are needed for restoration seed sourcing. Genetically defined provenance zones provide species-specific guidelines for the distance within which seed transfer likely maintains levels of genetic diversity and conserves locally adapted traits. While a growing number of studies incorporate genetic marker data in delineation of local provenance, they often fail to distinguish the impacts of neutral and non-neutral variation. We analysed population genetic structure for 134 amplified fragment length polymorphism (AFLP) markers in Stylidium hispidum (Stylidiaceae) along a north–south transect of the species' range with the goal to estimate the distance at which significant genetic differences occur among source and recipient populations in restoration. In addition, we tested AFLP markers for signatures of selection, and examined the relationship of neutral and putatively selected markers with climate variables. Estimates of population genetic structure revealed significant levels of differentiation (ΦPT = 0.23) and suggested a global provenance distance of 45 km for pairwise comparisons of 16 populations. Of the 134 markers, 13 exhibited evidence of diversifying selection (ΦPT = 0.52). Using data for precipitation and thermal gradients, we compared genetic, geographic and environmental distance for subsets of neutral and selected markers. Strong isolation by distance was detected in all cases, but positive correlations with climate variables were present only for markers with signatures of selection. We address findings in light of defining local provenance in ecological restoration. PMID:26755503

  3. CT-simulator based brachytherapy planner: seed localization and incorporation of biological considerations.

    PubMed

    Mayer, R; Fong, W; Frankel, T; Simons, S; Kleinberg, L; Lee, D J

    1998-01-01

    Radiation dose prescription, interpretation, and planning can be problematic for brachytherapy due to high spatial heterogeneity, varying and various dose rates, absence of superimposed calculated isodose distributions onto affected tissues, and lack of dose volume histograms. A new treatment planner has been developed to reduce these limitations in brachytherapy planning. The PC-based planning system uses a CT-simulator to sequentially scan the patient to generate orthogonal images (to localize seed positions) and subsequently axially scan the patient. This sequential scanning procedure avoids using multiple independent patient scans, templates, external frames, or fiducial markers to register the reconstructed seed positions with patient contours. Dose is computed after assigning activity to (low dose rate) Ir192, linear Cs137, or I125 seeds or dwell times (high dose rate) to the Ir192 source. The planar isodose distribution is superimposed onto axial, coronal, or sagittal views of the tissues following image reconstruction. The treatment plan computes (1) direct and cumulative volume dose histograms for individual tissues, (2) the average, standard deviation, and coefficient of skewness of the dose distribution within individual tissues, (3) an average (over all tissue pixels) survival probability (S) and average survival dose DASD for a given radiation treatment, (4) normal tissue complication probability (NTCP) delivered to a given tissue. All four computed quantities account for dose heterogeneity. These estimates of the biological response to radiation from laboratory-based studies may help guide the evaluation of the prescribed low- or high-dose rate therapy in retrospective and prospective clinical studies at a number of treatment sites.

  4. Comparison of [82Br]4-bromoantipyrine and [125I]4-iodoantipyrine: the kinetics of exchange reaction and biodistribution in rats.

    PubMed

    Liu, B L; Kung, H F; Billings, J; Blau, M

    1987-01-01

    Kinetics and mechanism of isotope exchange reaction between [82Br]bromide anion and 4-bromoantipyrine (BrAP), and the iodine-bromine exchange reaction between [125I]iodide anion and BrAP were studied. The preparation of [82Br]BrAP followed by exponential exchange law, the kinetics of the exchange reaction is a second-order reaction with an activation energy of 23.3 kcal/mol. The optimal exchange condition for halogen exchange between [125I]iodide and BrAP was by a hydrothermal melt method at 110 degrees C and 5 min reaction time. The partition coefficient at pH 7.0 for IAP and BrAP was 20.9 and 13.5, respectively. However, BrAP, which displayed the lower partition coefficient, showed higher brain uptake in rats than that for IAP (2.0% dose/organ vs 1.74% dose/organ), at 2 min after an i.v. injection.

  5. Biodistribution and fate of core-labeled (125)I polymeric nanocarriers prepared by Flash NanoPrecipitation (FNP).

    PubMed

    Tang, Christina; Edelstein, Jasmine; Mikitsh, John L; Xiao, Edward; Hemphill, Aaron H; Pagels, Robert; Chacko, Ann-Marie; Prud'homme, Robert

    2016-04-14

    Non-invasive medical imaging techniques such as positron emission tomography (PET) imaging are powerful platforms to track the fate of radiolabeled materials for diagnostic or drug delivery applications. Polymer-based nanocarriers tagged with non-standard PET radionuclides with relatively long half-lives (e.g. (64)Cu: t1/2 = 12.7 h, (76)Br: t1/2 = 16.2h, (89)Zr: t1/2 = 3.3 d, (124)I: t1/2 = 4.2 d) may greatly expand applications of nanomedicines in molecular imaging and therapy. However, radiolabeling strategies that ensure stable in vivo association of the radiolabel with the nanocarrier remain a significant challenge. In this study, we covalently attach radioiodine to the core of pre-fabricated nanocarriers. First, we encapsulated polyvinyl phenol within a poly(ethylene glycol) coating using Flash NanoPrecipitation (FNP) to produce stable 75 nm and 120 nm nanocarriers. Following FNP, we radiolabeled the encapsulated polyvinyl phenol with (125)I via electrophilic aromatic substitution in high radiochemical yields (> 90%). Biodistribution studies reveal low radioactivity in the thyroid, indicating minimal leaching of the radiolabel in vivo. Further, PEGylated [(125)I]PVPh nanocarriers exhibited relatively long circulation half-lives (t1/2 α = 2.9 h, t1/2 β = 34.9 h) and gradual reticuloendothelial clearance, with 31% of injected dose in blood retained at 24 h post-injection.

  6. Topical disposition of two strengths of a 125I-rhEGF jelly in rat skin wounds.

    PubMed

    Duconge, J; Prats, P A; Valenzuela, C; Aguilera, A; Rojas, I; Becquer, M A; Alvarez, D; Estrada, L; Alfonso-Ortíz, S; Hardy-Rando, E; García-Pulpeiro, O; Fernández-Sánchez, E

    2004-07-01

    Growth factors have proved to be an effective therapeutic strategy. However, some controversies have arisen concerning their efficacy in topical wound treatments. Stabilization of epidermal growth factors at the wound site and long-lasting receptor occupancy are important factors for wound repair. This study evaluated the cumulative profiles of two jellies containing 10 or 20 microg of 125I-rhEGF per gram of jelly, in a rat full-thickness skin lesion model. The prolonged time-courses at the wound sites for both strengths compared with saline solutions previously evaluated using a similar skin lesion model are reported. It seems that these two topical formulations that provide more sustained amounts of 125I-rhEGF over the period of sampling, would probably achieve the required wound healing response in terms of cell proliferation, collagen deposition and protein synthesis. Further studies need to be developed in order to elucidate whether such an in vivo disposition pattern is consistent with an earlier and stronger promotion of wound healing events.

  7. Radioimmunoanalysis of delta-9-THC in blood by means of an /sup 125/I tracer. [Delta-9-Tetrahydrocannabinol

    SciTech Connect

    Owens, S.M.; McBay, A.J.; Reisner, H.M.

    1982-01-01

    A radioimmunoassay for delta-9-THC in plasma, whole blood, or hemolyzed blood specimens has been presented. Samples and standards were diluted with methanol and centrifuged. An aliquot of the supernatant fluid was incubated with RIA buffer, /sup 125/I-labeled delta-8-THC and rabbit anti-THC serum. Solid phase goat anti-rabbit immunoglobulins were added to separate bound from free THC. After centrifugation the supernatant fluid was aspirated and the radioactivity of the precipitate was counted in a gamma counter. The concentration of THC was calculated from a standard curve using the logit-log transformation of the average counts of duplicate tubes. The assay had several advantages. Methanol dilution gave better results than direct analysis. The /sup 125/I-labeled THC had high specific activity and could be counted in a gamma counter. The immunological separation of antibody-bound THC from free THC was better than separation techniques using ammonium sulfate and activated charcoal. THC was determined in 0.1 ml of sample with a sensitivity of 1.5 ng/ml in plasma and 3.0 ng/ml in hemolyzed blood.

  8. Root hard-tissue demineralization rate measured by sup 125 I absorptiometry: Comparison with lesion-depth measurements

    SciTech Connect

    Almqvist, H.; Wefel, J.S.; Lagerloef, F. )

    1990-08-01

    The aim of the present study was to compare demineralization of root hard tissue, monitored by {sup 125}I absorptiometry, with lesion-depth measurements under polarized light microscopy. The intact roots of ten human molars, which had not been exposed to the oral environment, were divided into 39 cementum/dentin blocks and exposed to a buffer solution of pH 4.5 containing 2.2 mmol/L calcium and inorganic phosphate. After demineralization for 3.5, 7, 14, and 21 days, transmission measurements by {sup 125}I absorptiometry were performed, and one block from each tooth was taken out of the solution for lesion-depth measurement. The results showed a high degree of correlation (r = 0.952) between lesion depth and change in transmission, with a more rapid increase initially in both variables. A linear relationship with the square root of time was found. Conversion of transmission data to lesion-depth data was possible when this caries model system was used on cementum dentin blocks.

  9. Human circulating monocytes internalize 125I-insulin in a similar fashion to rat hepatocytes: relevance to receptor regulation in target and nontarget tissues.

    PubMed

    Grunberger, G; Robert, A; Carpentier, J L; Dayer, J M; Roth, A; Stevenson, H C; Orci, L; Gorden, P

    1985-08-01

    Circulating monocytes bind 125I-insulin in a specific fashion and have been used to analyze the ambient receptor status in humans. When freshly isolated circulating monocytes are incubated with 125I-insulin and examined by electron microscopic autoradiography, approximately 18% of the labeled material is internalized after 15 minutes at 37 degrees C. By 2 hours at 37 degrees C, approximately one half of the 125I-insulin is internalized. Internalization occurs also at 15 degrees C but at a slower rate. Furthermore, the monocytes bind and internalize 125I-insulin in a manner that mirrors that of major target tissues, such as rat hepatocytes. These data suggest that the insulin receptor of the circulating monocyte might be regulated by adsorptive endocytosis in a manner analogous to that of target tissue, such as the liver.

  10. Radiotherapy of unresectable pancreatic carcinoma: a six year experience with 104 patients. [/sup 125/I; Betatron

    SciTech Connect

    Whittington, R.; Dobelbower, R.R.; Mohiuddin, M.; Rosato, F.E.; Weiss, S.M.

    1981-12-01

    From 1974 to 1980, 104 patients with unresectable carcinoma of the pancreas were seen in the Department of Radiation Therapy at Thomas Jefferson University Hospital. Sixty-six patients were accepted for definitive therapy. Of these, 48 patients received precision high dose radiotherapy to a dose of 6800 rad on the 45 MeV Betatron, using either photons alone or mixed photon and high energy electron beams. Eighty-nine percent of the patients completed treatment as per the protocol. Relief of symptoms was obtained in 65% of patients. Median survival was 10 months. In spite of the high doses employed, 67% of the patients had evidence of recurrent tumor in the treatment volume at the time of death. In view of the high incidence of local failure with precision high dose therapy alone, a protocol using Iodine-125 implantation to supplement the external beam therapy was developed in 1978. Since then, 18 patients with disease confined to the region of the pancreas were treated with the combination of Iodine-125 implantation and precision high dose therapy. Eighty-five percent of the patients completed treatment. Follow-up ranges from eight to 22 months. None of the patients completing the treatment protocol have developed local recurrence of tumor. These results are presented together with details of the treatment technique, normal tissue reactions and implications for future approaches to the treatment of localized unresectable cancer of the pancreas.

  11. Binding and degradation of /sup 125/I-insulin by isolated rat renal brush border membranes: evidence for low affinity, high capacity insulin recognition sites

    SciTech Connect

    Meezan, E.; Pillion, D.J.; Elgavish, A.

    1988-10-01

    The kidney plays a major role in the handling of circulating insulin in the blood, primarily via reuptake of filtered insulin at the luminal brush border membrane. 125I-insulin associated with rat renal brush border membrane vesicles (BBV) in a time- and temperature-dependent manner accompanied by degradation of the hormone to trichloroacetic acid (TCA)-soluble fragments. Both association and degradation of 125I-insulin were linearly proportional to membrane protein concentration with virtually all of the degradative activity being membrane associated. Insulin, proinsulin and desoctapeptide insulin all inhibited the association and degradation of 125I-insulin by BBV, but these processes were not appreciably affected by the insulin-like growth factors IGF-I and IGF-II or by cytochrome c and lysozyme, low molecular weight, filterable, proteins, which are known to be reabsorbed in the renal tubules by luminal endocytosis. When the interaction of 125I-insulin with BBV was studied at various medium osmolarities (300-1100 mosM) to alter intravesicular space, association of the ligand with the vesicles was unaffected, but degradation of the ligand by the vesicles decreased progressively with increasing medium osmolarity. Therefore, association of 125I-insulin to BBV represented binding of the ligand to the membrane surface and not uptake of the hormone or its degradation products into the vesicles. Attempts to crosslink 125I-insulin to a high-affinity insulin receptor using the bifunctional reagent disuccinimidyl suberate revealed only trace amounts of an 125I-insulin-receptor complex in brush border membrane vesicles in contrast to intact renal tubules where this complex was readily observed. Both binding and degradation of 125I-insulin by brush border membranes did not reach saturation even at concentrations of insulin approaching 10(-5) M.

  12. Inhibitory Effects of PEI-RGD/125I-(αV) ASODN on Growth and Invasion of HepG2 Cells

    PubMed Central

    Cai, Haidong; Qiao, Yu; Sun, Ming; Yuan, Xueyu; Luo, Qiong; Yang, Yuehua; Yuan, Shidong; Lv, Zhongwei

    2015-01-01

    Background To investigate the in vitro inhibitory effects of PEI-RGD/125I-(αV)ASODN (PEI, polyethylenimine; RGD, Arg-Gly-Asp; ASODN, antisense oligodeoxynucleotide) on the growth and invasion of HepG2 cells. Material/Methods ASODN of the integrin αV-subunit was marked with 125I and underwent complexation with PEI-RGD, a PEI derivative. Next, PEI-RGD/125I-(αV) ASODN was introduced into HepG2 cells via receptor-mediated transfection, and its inhibition rate on HepG2 cell growth was tested using the methyl thiazolyl tetrazolium (MTT) method. The effects of PEI-RGD/125I-(αV) ASODN on HepG2 cell invasion ability were evaluated using the Boyden chamber assay. Results 1) The 125I marking rate of (αV) ASODN was 73.78±4.09%, and the radiochemical purity was 96.68±1.38% (greater than 90% even after a 48-h incubation period at 37°C), indicating high stability. 2) The cytotoxicity assays showed that the cell inhibition rates did not differ significantly between the PEI-RGD/125I-(αV)ASODN group and the PEI-RGD/(αV) ASODN group, but they were both significantly higher than in the other groups and were positively correlated (r=0.879) with the dosage within a certain range. 3) The invasion assays showed that the inhibition rate was significantly greater in the PEI-RGD/125I-(αV) ASODN group compared to the other groups. Conclusions PEI-RGD/125I-(αV) ASODN can efficiently inhibit the growth and proliferation of HepG2 cells and can also weaken their invasive ability. PMID:26258995

  13. Local host adaptation and use of a novel host in the seed beetle Megacerus eulophus.

    PubMed

    Stotz, Gisela C; Suárez, Lorena H; Gonzáles, Wilfredo L; Gianoli, Ernesto

    2013-01-01

    Spatial variation in host plant availability may lead to specialization in host use and local host adaptation in herbivorous insects, which may involve a cost in performance on other hosts. We studied two geographically separated populations of the seed beetle Megacerus eulophus (Coleoptera: Bruchidae) in central Chile: a population from the host Convolvulus chilensis (in Aucó) and a population from C. bonariensis (in Algarrobo). In Aucó C. chilensis is the only host plant, while in Algarrobo both C. bonariensis and C. chilensis are available. We tested local adaptation to these native host plants and its influence on the use of another, exotic host plant. We hypothesized that local adaptation would be verified, particularly for the one-host population (Aucó), and that the Aucó population would be less able to use an alternative, high-quality host. We found evidence of local adaptation in the population from C. chilensis. Thus, when reared on C. chilensis, adults from the C. chilensis population were larger and lived longer than individuals from the C. bonariensis population, while bruchids from the two populations had the same body size and longevity when reared on C. bonariensis. Overall, bruchids from the C. chilensis population showed greater performance traits than those from the C. bonariensis population. There were no differences between the bruchid populations in their ability to use the alternative, exotic host Calystegia sepium, as shown by body size and longevity patterns. Results suggest that differences in local adaptation might be explained by differential host availability in the study populations.

  14. Local Host Adaptation and Use of a Novel Host in the Seed Beetle Megacerus eulophus

    PubMed Central

    Stotz, Gisela C.; Suárez, Lorena H.; Gonzáles, Wilfredo L.; Gianoli, Ernesto

    2013-01-01

    Spatial variation in host plant availability may lead to specialization in host use and local host adaptation in herbivorous insects, which may involve a cost in performance on other hosts. We studied two geographically separated populations of the seed beetle Megacerus eulophus (Coleoptera: Bruchidae) in central Chile: a population from the host Convolvulus chilensis (in Aucó) and a population from C. bonariensis (in Algarrobo). In Aucó C. chilensis is the only host plant, while in Algarrobo both C. bonariensis and C. chilensis are available. We tested local adaptation to these native host plants and its influence on the use of another, exotic host plant. We hypothesized that local adaptation would be verified, particularly for the one-host population (Aucó), and that the Aucó population would be less able to use an alternative, high-quality host. We found evidence of local adaptation in the population from C. chilensis. Thus, when reared on C. chilensis, adults from the C. chilensis population were larger and lived longer than individuals from the C. bonariensis population, while bruchids from the two populations had the same body size and longevity when reared on C. bonariensis. Overall, bruchids from the C. chilensis population showed greater performance traits than those from the C. bonariensis population. There were no differences between the bruchid populations in their ability to use the alternative, exotic host Calystegia sepium, as shown by body size and longevity patterns. Results suggest that differences in local adaptation might be explained by differential host availability in the study populations. PMID:23326528

  15. Comparison of cyclosporine determinations in whole blood by three different methods. HPLC, /sup 125/I RIA and /sup 3/H RIA

    SciTech Connect

    Huang, W.Y.; Lipsey, A.I.; Cheng, M.H.

    1987-04-01

    The authors have analyzed and compared the cyclosporine concentrations in whole blood specimens from pediatric renal transplant patients using three different methods: high-performance liquid chromatography (HPLC) (5u C18 reverse-phase column), /sup 3/H radioimmunoassay (RIA), and /sup 125/I RIA (substituted /sup 3/H-tracer in Sandoz Kit with /sup 125/I tracer. Results obtained by the /sup 125/I RIA correlated well with results obtained by the /sup 3/H RIA. Both RIA methods had similar correlation with the HPLC method. The /sup 125/I RIA method showed higher sensitivity and greater precision than the /sup 3/H RIA method. The authors conclude that the /sup 125/I RIA method can be used for cyclosporine determination in whole blood specimens. The use of the /sup 125/I RIA provides a simple and rapid method with higher counting efficiency and less background quenching than the /sup 3/H RIA method, which requires cumbersome liquid scintillation counting procedures.

  16. Direct interaction between the catalytic subunit of the calmodulin-sensitive adenylate cyclase from bovine brain with /sup 125/I-labeled wheat germ agglutinin and /sup 125/I-labeled calmodulin

    SciTech Connect

    Minocherhomjee, A.M.; Selfe, S.; Flowers, N.J.; Storm, D.R.

    1987-07-14

    A calmodulin-sensitive adenylate cyclase has been purified to apparent homogeneity from bovine cerebral cortex using calmodulin-Sepharose followed by forskolin-Sepharose and wheat germ agglutinin-Sepharose. The final product appeared as one major polypeptide of approximately 135,000 daltons on sodium dodecyl sulfate-polyacrylamide gels. This polypeptide was a major component of the protein purified through calmodulin-Sepharose. The catalytic subunit was stimulated 3-4-fold by calmodulin (CaM) with a turnover number greater than 1000 min/sup -1/ and was directly inhibited by adenosine. The catalytic subunit of the enzyme interacted directly with /sup 125/I-CaM on a sodium dodecyl sulfate-polyacrylamide gel overlay system, and this interaction was Ca/sup 2 +/ concentration dependent. In addition, the catalytic subunit was shown to directly bind /sup 125/I-labeled wheat germ agglutinin using a sodium dodecyl sulfate-polyacrylamide gel overlay technique, and N-acetylglucosamine inhibited binding of the lectin to the catalytic subunit. Calmodulin did not inhibit binding of wheat germ agglutinin to the catalytic subunit, and the binding of calmodulin was unaffected by wheat germ agglutinin. These data illustrate that the catalytic subunit of the calmodulin-sensitive adenylate cyclase is a glycoprotein which interacts directly with calmodulin and that adenosine can inhibit the enzyme without intervening receptors or G coupling proteins. It is concluded that the catalytic subunit of adenylate cyclase is a transmembrane protein with a domain accessible from the outer surface of the cell.

  17. 125I implantation for carcinoma of prostate. Further follow-up of first 100 cases.

    PubMed

    Grossman, H B; Batata, M; Hilaris, B; Whitmore, W F

    1982-12-01

    Analysis of the first 100 patients at the Memorial Sloan-Kettering Cancer Center with Stage B or C prostatic cancer treated by pelvic lymph node dissection and Iodine-125 implantation and endocrine therapy when specifically indicated revealed five-year survival rates of 87 and 77 per cent, respectively. Tumor stage, tumor grade, and lymph node metastasis each correlated with survival, but the latter was the most significant factor. Although routine follow-up biopsies were not performed, local tumor control as judged by serial digital rectal examination defined a prognostically favored group of patients. In the absence of controls, however, whether the latter response indicates a salutary effect of the treatment which produces an improved survival or merely identifies a group of patients who were predetermined to have a more favorable survival is undetermined.

  18. With or without a Script? Comparing Two Styles of Participatory Video on Enhancing Local Seed Innovation System in Bangladesh

    ERIC Educational Resources Information Center

    Chowdhury, Ataharul Huq; Odame, Helen Hambly; Hauser, Michael

    2010-01-01

    Recent experiences in participatory video-making raise the question of how best to use this medium for enhancing local seed innovation systems. Embedded in a mini-process of participatory action research, two styles of participatory video--scripted and scriptless--were tested and assessed together with farmers and facilitators in Bogra District,…

  19. delta 9-(16 alpha-/sup 125/I)iodo-19-nortestosterone: a gamma-emitting photoaffinity label for the progesterone receptor

    SciTech Connect

    Lamb, D.J.; Bullock, D.W.; Hoyte, R.M.; Hochberg, R.B.

    1988-05-01

    We have synthesized 16 alpha-iodo-4,9-estradien-17 beta-ol-3-one (delta 9-16 alpha-iodo-19-nortestosterone (delta 9-INT)) labeled with 125I (delta 9-(16 alpha-125I)INT) to provide a new gamma-emitting photoaffinity ligand for the progesterone receptor that has many advantages over the currently available (3H)R5020. We have characterized the interaction of delta 9-(16 alpha-125I)INT with the rabbit uterine progesterone receptor and have demonstrated the usefulness of this compound for studies of receptor structure. The binding of 2 nM (3H)progesterone to receptor in rabbit uterine cytosol was specifically competed for by 19-nortestosterone, 16 alpha-iodo-19-nortestosterone, and delta 9-INT. Scatchard analysis demonstrated that delta 9-(16 alpha-125I)INT and (3H)progesterone estimated the same number of binding sites in rabbit uterine cytosol, with a Kd for delta 9-(16 alpha-125I)INT of about 2.7 nM. The binding of delta 9-(16 alpha-125I)INT was inhibited by both progesterone and R5020, whereas testosterone, estradiol, and 5 alpha-dihydrotestosterone were ineffective. In cytosol, delta 9-(16 alpha-125I)INT covalently labeled the same mol wt receptor forms as (3H)R5020. Although the efficiency of cross-linking was similar for (3H)R5020 (3%) and delta 9-(16 alpha-125I)INT (4%), the radioactivity was 10-fold greater due to the higher specific activity of delta 9-(16 alpha-125I)INT and the lack of sample quench. The use of delta 9-(16 alpha-125I)INT greatly increases the sensitivity and efficiency of the photoaffinity labeling technique; it will provide a valuable tool for further studies of the progesterone receptor, allowing the detection of receptor in dilute cytosol after gel electrophoresis under denaturing conditions.

  20. Inhibitory Action of Ethanolic Extract of Seeds of Moringa oleifera Lam. On Systemic and Local Anaphylaxis.

    PubMed

    Mahajan, Shailaja G; Mehta, Anita A

    2007-10-01

    The current study characterizes the mechanism by which the seed extract of Moringa oleifera Lam (Moringaceae) decreases the mast cell-mediated immediate type hypersensitivity reaction. The immediate type hypersensitivity reaction is involved in many allergic diseases such as asthma and allergic rhinitis. Moringa oleifera, a shrub widely used in the traditional medicine in India, has been reported to possess anti-cancer, hypotensive, anti-arthritic, and anti-inflammatory activities. In the present study, the effects of the ethanolic extract of seeds of Moringa oleifera (MOEE-herbal remedy) on systemic and local anaphylaxis were investigated. The potential anti-anaphylactic effect of MOEE was studied in a mouse model of Compound 48/80-induced systemic anaphylactic shock. Passive cutaneous anaphylaxis activated by anti IgE-antibody was also used to assess the effect of MOEE. In addition, rat peritoneal mast cells (RPMC) were used to investigate the effect of MOEE on histamine release induced by compound 48/80. When administered 1 hr before 48/80 injection, MOEE at doses of 0.001-1.000 g/kg completely inhibited the inducible induced anaphylactic shock. MOEE significantly inhibited passive cutaneous anaphylaxis activated by anti-IgE antibody at a dose of 1 g/kg. When MOEE extract was given as pretreatment at concentrations ranging 0.1-100 mg/ml, the histamine release from the mast cells that was induced by the 48/80 was reduced in a dose-dependent manner. These results suggest a potential role for MOEE as a source of anti-anaphylactic agents for use in allergic disorders.

  1. In Vivo and In Vitro Binding of Vip3Aa to Spodoptera frugiperda Midgut and Characterization of Binding Sites by 125I Radiolabeling

    PubMed Central

    Chakroun, Maissa

    2014-01-01

    Bacillus thuringiensis vegetative insecticidal proteins (Vip3A) have been recently introduced in important crops as a strategy to delay the emerging resistance to the existing Cry toxins. The mode of action of Vip3A proteins has been studied in Spodoptera frugiperda with the aim of characterizing their binding to the insect midgut. Immunofluorescence histological localization of Vip3Aa in the midgut of intoxicated larvae showed that Vip3Aa bound to the brush border membrane along the entire apical surface. The presence of fluorescence in the cytoplasm of epithelial cells seems to suggest internalization of Vip3Aa or a fragment of it. Successful radiolabeling and optimization of the binding protocol for the 125I-Vip3Aa to S. frugiperda brush border membrane vesicles (BBMV) allowed the determination of binding parameters of Vip3A proteins for the first time. Heterologous competition using Vip3Ad, Vip3Ae, and Vip3Af as competitor proteins showed that they share the same binding site with Vip3Aa. In contrast, when using Cry1Ab and Cry1Ac as competitors, no competitive binding was observed, which makes them appropriate candidates to be used in combination with Vip3A proteins in transgenic crops. PMID:25002420

  2. In vivo and in vitro binding of Vip3Aa to Spodoptera frugiperda midgut and characterization of binding sites by (125)I radiolabeling.

    PubMed

    Chakroun, Maissa; Ferré, Juan

    2014-10-01

    Bacillus thuringiensis vegetative insecticidal proteins (Vip3A) have been recently introduced in important crops as a strategy to delay the emerging resistance to the existing Cry toxins. The mode of action of Vip3A proteins has been studied in Spodoptera frugiperda with the aim of characterizing their binding to the insect midgut. Immunofluorescence histological localization of Vip3Aa in the midgut of intoxicated larvae showed that Vip3Aa bound to the brush border membrane along the entire apical surface. The presence of fluorescence in the cytoplasm of epithelial cells seems to suggest internalization of Vip3Aa or a fragment of it. Successful radiolabeling and optimization of the binding protocol for the (125)I-Vip3Aa to S. frugiperda brush border membrane vesicles (BBMV) allowed the determination of binding parameters of Vip3A proteins for the first time. Heterologous competition using Vip3Ad, Vip3Ae, and Vip3Af as competitor proteins showed that they share the same binding site with Vip3Aa. In contrast, when using Cry1Ab and Cry1Ac as competitors, no competitive binding was observed, which makes them appropriate candidates to be used in combination with Vip3A proteins in transgenic crops.

  3. The use of a high-purity germanium detector for routine measurements of {sup 125}I in radiation workers

    SciTech Connect

    Kopp, P.; Bergmann, H.; Havlik, E.; Aiginger, H.; Unfried, E.; Riedlmayer, L.

    1994-12-01

    A high-purity germanium detector was calibrated for the assessment of {sup 125}I uptake in the thyroid gland of radiation workers. A cylindrical water phantom (perspex walls) with high flexibility for position and size of the thyroid was constructed. Within a massive shielding chamber built for a whole-body counter, an activity of 2.2 Bq was detectable (MDA). This is well below the very restrictive limiting value of 20 Bq for inhalation specified by Austrian law. An activity of 128 Bq was measured with a statistical uncertainty of 5% in a counting period of 10 min. Various parameters influencing the result are investigated as well as the performance of two other measurement geometries outside the shielding chamber. 13 refs., 4 figs., 2 tabs.

  4. [Radioactivity for 137Cs, 125I, 131I, 59Fe, y 57Co windows from foods included in the basic alimentary basket and in the water, consumed in the state of Carabobo, Venezuela].

    PubMed

    Torres, Annabell; Tovar, María; Malpica, Oscar; Eblen-Zajjur, Antonio

    2002-01-01

    One of the input ways of radionucleids into the organism is through food intake. The aim of the present study is to measure the radioactivity levels in food and water samples within energy windows corresponding to 137Cs, 125I, 131I, 59Fe, and 57Co. Samples were taken from local and imported food belonging to the venezuelan basic alimentary basket and included: beef meat, hen egg, chicken bone, tomato, black bean, rice, powder milk from local dealers or imported from Italy and New Zeeland, potable water from the Valencia city aqueduct and bottled water from local sources or imported from Portugal. Radioactivity was measured with a well type Nal (TI) scintillation counter. Analyzed foods and water presented levels lower than the minimal detectable activity for 137Cs, 131I, 59Fe, 57Co, but it was detected in the Valencia city aqueduct water and in bottled water imported from Portugal, levels greater than the minimal detectable activity for the 125I energy window. These results strongly suggest the need of repeated multienergy windows monitoring of radioactivity of basic alimentary basket foods and potable water.

  5. p-( sup 125 I)iodoclonidine, a novel radiolabeled agonist for studying central alpha 2-adrenergic receptors

    SciTech Connect

    Baron, B.M.; Siegel, B.W. )

    1990-09-01

    Unlabeled p-iodoclonidine was efficacious in attenuating forskolin-stimulated cAMP accumulation in SK-N-SH neuroblastoma cells. Maximal attenuation was 76 +/- 3%, with an EC50 of 347 +/- 60 nM. Comparable values of epinephrine were 72 +/- 3% and 122 +/- 22 nM. Responses to both agonists were abolished by 10 microM phentolamine. Therefore, p-iodoclonidine is an agonist in a cell culture model system of the neuronal alpha 2-adrenergic receptor. p-(125I)Iodoclonidine binding to membranes were measured using various regions of the rat brain. The agonist labeled a single population of sites present on cerebral cortical membranes, which was saturable (Bmax = 230 fmol/mg of protein) and possessed high affinity for the ligand (Kd = 0.6 nM). Binding was largely specific (93% at 0.6 nM). A variety of alpha 2-adrenergic agonists and antagonists were shown to compete for the binding of the radioligand. The binding of p-(125I)iodoclonidine was much less sensitive to agents that interact with alpha 1-adrenergic, serotonergic, and dopaminergic receptors. Approximately 65% of the binding was sensitive to guanine nucleotides. Association kinetics using 0.4 nM radioligand were biphasic (37% associate rapidly, with kobs = 0.96 min-1, with the remainder binding more slowly, with kobs = 0.031 min-1) and reached a plateau by 90 min at 25 degrees. Dissociation kinetics were also biphasic, with 30% of the binding dissociating rapidly (k1 = 0.32 min-1) and the remainder dissociating 50-fold more slowly (k2 = 0.006 min-1). Agonist binding is, therefore, uniquely complex and probably reflects the conformational changes that accompany receptor activation.

  6. Kinetics and isotherm of fibronectin adsorption to three-dimensional porous chitosan scaffolds explored by 125I-radiolabelling

    PubMed Central

    Amaral, Isabel F.; Sousa, Susana R.; Neiva, Ismael; Marcos-Silva, Lara; Kirkpatrick, Charles J.; Barbosa, Mário A.; Pêgo, Ana P.

    2013-01-01

    In this study, 125I-radiolabelling was explored to follow the kinetics and isotherm of fibronectin (FN) adsorption to porous polymeric scaffolds, as well as to assess the elution and exchangeability of pre-adsorbed FN following incubation in serum-containing culture medium. Chitosan (CH) porous scaffolds with two different degrees of acetylation (DA 4% and 15%) were incubated in FN solutions with concentrations ranging from 5 to 50 µg/mL. The kinetic and isotherm of FN adsorption to CH were successfully followed using 125I-FN as a tracer molecule. While on DA 4% the levels of adsorbed FN increased linearly with FN solution concentration, on DA 15% a saturation plateau was attained, and FN adsorbed amounts were significantly lower. These findings were supported by immunofluorescent studies that revealed, for the same FN solution concentration, higher levels of exposed cell-binding domains on DA 4% as compared with DA 15%. Following incubation in serum containing medium, DA 4% also revealed higher ability to exchange pre-adsorbed FN by new FN molecules from serum than DA 15%. In accordance, when assessing the efficacy of passively adsorbed FN to promote endothelial cell (EC) adhesion to CH, ECs were found to adhere at higher levels to DA 4% as compared with DA 15%, 5 µg/mL of FN being already efficient in promoting cell adhesion and cytoskeletal organization on CH with DA 4%. Taken together the results show that protein radiolabelling can be used as an effective tool to study protein adsorption to porous polymeric scaffolds, both from single and complex protein solutions. PMID:23635535

  7. Preliminary Characterization and In Vivo Studies of Structurally Identical 18F- and 125I-Labeled Benzyloxybenzenes for PET/SPECT Imaging of β-Amyloid Plaques

    PubMed Central

    Yang, Yanping; Zhang, Xiaoyang; Cui, Mengchao; Zhang, Jinming; Guo, Zhide; Li, Yesen; Zhang, Xianzhong; Dai, Jiapei; Liu, Boli

    2015-01-01

    With the assistance of molecular docking and 3D-QSAR models established previously, structurally identical 18F- and 125I-labeled benzyloxybenzene derivatives were designed to achieve the early detection of Aβ plaques by PET/SPECT imaging. In competition binding assay, ligands 7a and 12a displayed high binding affinities to Aβ42 aggregates with Ki values of 19.5 nM and 23.9 nM, respectively. Specific plaque labeling was observed on the in vitro autoradiography of brain sections from AD patients and Tg mice. In biodistribution, [125I]7a, [18F]7a, [125I]12a and [18F]12a all exhibited high initial brain uptakes (>5% ID/g at 2 min). [125I]7a and [125I]12a cleared fast from the normal brain regions, while corresponding [18F]7a and [18F]12a showed slow washout rates. Dynamic microPET/CT and microSPECT/CT imaging data in normal ICR mice were in accordance with in vivo biodistribution results. In vivo metabolism results indicated that the different clearance profiles between the structurally identical 18F- and 125I-labeled tracers could be attributed to different biochemical characteristics of the radiometabolites. Radioiodinated benzyloxybenzene derivatives exhibited good in vivo biostability in brain. Ex vivo autoradiography further confirmed the strong in vivo Aβ labeling ability of [125I]7a. These new fluorinated and iodinated benzyloxybenzenes can develop into PET/SPECT dual imaging agents targeting Aβ plaques. PMID:26170205

  8. Inhibition of sup 125 I organification and thyroid hormone release by interleukin-1, tumor necrosis factor-alpha, and interferon-gamma in human thyrocytes in suspension culture

    SciTech Connect

    Sato, K.; Satoh, T.; Shizume, K.; Ozawa, M.; Han, D.C.; Imamura, H.; Tsushima, T.; Demura, H.; Kanaji, Y.; Ito, Y. )

    1990-06-01

    To elucidate the mechanism of decreased 131I uptake by the thyroid gland in patients with subacute thyroiditis and painless thyroiditis, human thyroid follicles were cultured with interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF alpha), and/or interferon-gamma (IFN gamma), and the effects of these cytokines on thyroid function were studied in vitro. When human thyrocytes were cultured in RPMI-1640 medium containing 0.5% fetal calf serum and TSH for 5-8 days, the cells incorporated 125I, synthesized de novo (125I)iodotyrosines and (125I)iodothyronines, and secreted (125I)T4 and (125I)T3 into the medium. IL-1 alpha and IL-1 beta inhibited 125I incorporation and (125I)iodothyronine release in a concentration-dependent manner. The minimal inhibitory effect was detected at 10 pg/ml. Electron microscopic examination revealed a marked decrease in lysosome formation in IL-1-treated thyrocytes. TNF alpha and IFN gamma also inhibited thyroid function in a concentration-dependent manner. Furthermore, when thyrocytes were cultured with IL-1, TNF alpha and IFN gamma, these cytokines more than additively inhibited thyroid function. Although the main mechanism of 131I uptake suppression in the thyroid gland in subacute thyroiditis is due to cellular damage and suppression of TSH release, our present findings suggest that IL-1, TNF alpha, and IFN gamma produced in the inflammatory process within the thyroid gland further inhibit iodine incorporation and at least partly account for the decreased 131I uptake by the thyroid gland in destruction-induced hyperthyroidism.

  9. [125I]2-(2-chloro-4-iodo-phenylamino)-5-methyl-pyrroline (LNP 911), a high-affinity radioligand selective for I1 imidazoline receptors.

    PubMed

    Greney, Hugues; Urosevic, Dragan; Schann, Stephan; Dupuy, Laurence; Bruban, Véronique; Ehrhardt, Jean-Daniel; Bousquet, Pascal; Dontenwill, Monique

    2002-07-01

    The I1 subtype of imidazoline receptors (I1R) is a plasma membrane protein that is involved in diverse physiological functions. Available radioligands used so far to characterize the I(1)R were able to bind with similar affinities to alpha2-adrenergic receptors (alpha2-ARs) and to I1R. This feature was a major drawback for an adequate characterization of this receptor subtype. New imidazoline analogs were therefore synthesized and the present study describes one of these compounds, 2-(2-chloro-4-iodo-phenylamino)-5-methyl-pyrroline (LNP 911), which was of high affinity and selectivity for the I1R. LNP 911 was radioiodinated and its binding properties characterized in different membrane preparations. Saturation experiments with [125I]LNP 911 revealed a single high affinity binding site in PC-12 cell membranes (K(D) = 1.4 nM; B(max) = 398 fmol/mg protein) with low nonspecific binding. [125I]LNP 911 specific binding was inhibited by various imidazolines and analogs but was insensitive to guanosine-5'-O-(3-thio)triphosphate. The rank order of potency of some competing ligands [LNP 911, PIC, rilmenidine, 4-chloro-2-(imidazolin-2-ylamino)-isoindoline (BDF 6143), lofexidine, and clonidine] was consistent with the definition of [125I]LNP 911 binding sites as I1R. However, other high-affinity I1R ligands (moxonidine, efaroxan, and benazoline) exhibited low affinities for these binding sites in standard binding assays. In contrast, when [125I]LNP 911 was preincubated at 4 degrees C, competition curves of moxonidine became biphasic. In this case, moxonidine exhibited similar high affinities on [125I]LNP 911 binding sites as on I1R defined with [125I]PIC. Moxonidine proved also able to accelerate the dissociation of [125I]LNP 911 from its binding sites. These results suggest the existence of an allosteric modulation at the level of the I1R, which seems to be corroborated by the dose-dependent enhancement by LNP 911 of the agonist effects on the adenylate cyclase pathway

  10. ET-22CONVECTION-ENHANCED DELIVERY OF THE AUGER-ELECTRON-EMITTER 125I-UdR: A HIGHLY EFFICIENT THERAPY IN AN ORTHOTOPIC GLIOBLASTOMA XENOGRAFT MODEL

    PubMed Central

    Halle, Bo; Thisgaard, Helge; Aaberg-Jessen, Charlotte; Olsen, Birgitte; Dam, Johan; Langkjær, Niels; Munthe, Sune; Någren, Kjell; Høilund-Carlsen, Poul Flemming; Kristensen, Bjarne

    2014-01-01

    BACKGROUND: Glioblastomas (GBMs), the most common and malignant primary brain tumors, always recur after standard treatment. In order to develop more efficient therapies, we tested a novel therapeutic approach using the radioactive Auger-electron-emitter (AEE) [125I]5-Iodo-2'-deoxyuridine (125I-UdR). This drug incorporates into DNA of dividing cells and upon decay emission of Auger-electrons causes clusters of double strand breaks leading to cell death. METHODS: In vitro, cells from two GBM spheroid cultures (T78 & T87) were exposed to either 125I-UdR or 127I-UdR (non-radioactive analogue) and tumor cell viability and migration were measured. In vivo, nude rats were implanted orthotopically with T87 cells and after tumor formation micro infusion pumps were implanted enabling direct intratumoral convection-enhanced delivery (CED). Animals were divided into three groups (I-III). Group I (n = 8) was treated with 127I-UdR by CED, group II (n = 7) with neoadjuvant methotrexate (MTX) + 125I-UdR by CED and group III with neoadjuvant MTX + 125I-UdR by CED and concomitant systemic temozolomide (TMZ). Rats were followed for 180 days post-treatment with repeated [11C]methylaminoisobutyric acid ([11C]MeAIB) positron emission tomography scans and blood sampling. Single photon emission computed tomography/computed tomography (SPECT/CT) scans were performed to evaluate 125I-UdR distribution. Additionally, post-mortem histological examination of brain, liver, kidneys and thyroid gland was performed. RESULTS: In vitro, 125I-UdR significantly decreased GBM cell viability and migration. In group I, no animals (8/8) survived longer than 23 days after treatment start. In group II, 4/7 animals survived the entire observation period of 180 days. In group III, all animals (8/8) survived the entire observation period. SPECT/CT showed a widespread intracerebral distribution of 125I-UdR, while blood samples and post-mortem histology revealed no signs of dose-limiting adverse effects

  11. Measurement of cyclosporine concentrations in whole blood: HPLC and radioimmunoassay with a specific monoclonal antibody and /sup 3/H- or /sup 125/I-labeled ligand compared

    SciTech Connect

    Wolf, B.A.; Daft, M.C.; Koenig, J.W.; Flye, M.W.; Turk, J.W.; Scott, M.G.

    1989-01-01

    We compared cyclosporine concentrations in whole blood as measured by HPLC and by RIA with a monoclonal antibody specific for cyclosporine with /sup 3/H- or /sup 125/I-labeled cyclosporine ligand. The /sup 3/H-RIA kit slightly underestimated cyclosporine concentrations (greater than 600 micrograms/L) in comparison with HPLC. Over a wide range of concentrations, cyclosporine measured with the /sup 125/I-RIA kit correlated well with HPLC (slope = 0.99, n = 301, r = 0.98), observed for samples from recipients of kidney, heart, or liver allografts (respective slopes: 1.01, 0.93, and 1.00). The /sup 125/I-RIA standard curve was linear to 1000 micrograms of cyclosporine per liter. Inter- and intra-assay CVs for /sup 125/I-RIA measurements of cyclosporine were less than or equal to 7%. Evidently, the /sup 125/I-RIA kit involving a monoclonal antibody specific for cyclosporine is equivalent to the HPLC assay and can replace it for therapeutic drug monitoring of cyclosporine therapy.

  12. Selective chromosomal damage and cytotoxicity of sup 125 I-labeled monoclonal antibody 17-1a in human cancer cells

    SciTech Connect

    Woo, D.V.; Li, D.; Mattis, J.A.; Steplewski, Z. )

    1989-06-01

    A monoclonal antibody, 17-1a, which reacts with antigen expressed in human colon cancers was radiolabeled in high specific activity with {sup 125}I. The combination of the antibody and this radionuclide was observed to elicit specific cellular damage after being internalized into cells of the SW1116 human colon cancer cell line. The degree of internalization was quantitatively measured and found to increase over time to 49% after a 48-h incubation period. During this period, significant chromosome aberrations were observed in the SW1116 cell line due to the Auger electrons of {sup 125}I. This damage was not observed using Na{sup 125}I, a nonimmunoreactive radiolabeled antibody, or cells which did not contain the requisite antigen. The number of chromosomal aberrations increased with increasing radioactive concentration of {sup 125}I-17-1a. The nuclear damage resulted in specific cellular cytotoxicity and decreased cell survival of SW1116 cells exposed to various concentrations of {sup 125}I-17-1a.

  13. Implication of the visual system in the regulation of activity cycles in the absence of solar light: 2-[125I]iodomelatonin binding sites and melatonin receptor gene expression in the brains of demersal deep-sea gadiform fish

    PubMed Central

    Priede, I. G.; Williams, L. M.; Wagner, H.-J.; Thom, A.; Brierley, I.; Collins, M. A.; Collin, S. P.; Merrett, N. R.; Yau, C.

    1999-01-01

    Relative eye size, gross brain morphology and central localization of 2-[125I]iodomelatonin binding sites and melatonin receptor gene expression were compared in six gadiform fish living at different depths in the north-east Atlantic Ocean: Phycis blennoides (capture depth range 265 to 1260 m), Nezumia aequalis (445 to 1512 m), Coryphaenoides rupestris (706 to 1932 m), Trachyrincus murrayi (1010 to 1884 m), Coryphaenoides guentheri (1030 m) and Coryphaenoides (Nematonurus) armatus (2172 to 4787 m). Amongst these, the eye size range was 0.15 to 0.35 of head length with a value of 0.19 for C. (N.) armatus, the deepest species. Brain morphology reflected behavioural differences with well-developed olfactory regions in P. blennoides, T. murrayi and C. (N.) armatus and evidence of olfactory deficit in N. aequalis, C. rupestris and C. guentheri. All species had a clearly defined optic tectum with 2-[125I]iodomelatonin binding and melatonin receptor gene expression localized to specific brain regions in a similar pattern to that found in shallow-water fish. Melatonin receptors were found throughout the visual structures of the brains of all species. Despite living beyond the depth of penetration of solar light these fish have retained central features associated with the coupling of cycles of growth, behaviour and reproduction to the diel light–dark cycle. How this functions in the deep sea remains enigmatic.

  14. Cytochemical localization of reserves during seed development in Arabidopsis thaliana under spaceflight conditions.

    PubMed

    Kuang, A; Xiao, Y; Musgrave, M E

    1996-01-01

    Successful development of seeds under spaceflight conditions has been an elusive goal of numerous long-duration experiments with plants on orbital spacecraft. Because carbohydrate metabolism undergoes changes when plants are grown in microgravity, developing seed storage reserves might be detrimentally affected during spaceflight. Seed development in Arabidopsis thaliana plants that flowered during 11 d in space on shuttle mission STS-68 has been investigated in this study. Plants were grown to the rosette stage (13 d) on a nutrient agar medium on the ground and loaded into the Plant Growth Unit flight hardware 18 h prior to lift-off. Plants were retrieved 3 h after landing and siliques were immediately removed from plants. Young seeds were fixed and processed for microscopic observation. Seeds in both the ground control and flight plants are similar in their morphology and size. The oldest seeds from these plants contain completely developed embryos and seed coats. These embryos developed radicle, hypocotyl, meristematic apical tissue, and differentiated cotyledons. Protoderm, procambium, and primary ground tissue had differentiated. Reserves such as starch and protein were deposited in the embryos during tissue differentiation. The aleurone layer contains a large quantity of storage protein and starch grains. A seed coat developed from integuments of the ovule with gradual change in cell composition and cell material deposition. Carbohydrates were deposited in outer integument cells especially in the outside cell walls. Starch grains decreased in number per cell in the integument during seed coat development. All these characteristics during seed development represent normal features in the ground control plants and show that the spaceflight environment does not prevent normal development of seeds in Arabidopsis.

  15. Cytochemical localization of reserves during seed development in Arabidopsis thaliana under spaceflight conditions

    NASA Technical Reports Server (NTRS)

    Kuang, A.; Xiao, Y.; Musgrave, M. E.

    1996-01-01

    Successful development of seeds under spaceflight conditions has been an elusive goal of numerous long-duration experiments with plants on orbital spacecraft. Because carbohydrate metabolism undergoes changes when plants are grown in microgravity, developing seed storage reserves might be detrimentally affected during spaceflight. Seed development in Arabidopsis thaliana plants that flowered during 11 d in space on shuttle mission STS-68 has been investigated in this study. Plants were grown to the rosette stage (13 d) on a nutrient agar medium on the ground and loaded into the Plant Growth Unit flight hardware 18 h prior to lift-off. Plants were retrieved 3 h after landing and siliques were immediately removed from plants. Young seeds were fixed and processed for microscopic observation. Seeds in both the ground control and flight plants are similar in their morphology and size. The oldest seeds from these plants contain completely developed embryos and seed coats. These embryos developed radicle, hypocotyl, meristematic apical tissue, and differentiated cotyledons. Protoderm, procambium, and primary ground tissue had differentiated. Reserves such as starch and protein were deposited in the embryos during tissue differentiation. The aleurone layer contains a large quantity of storage protein and starch grains. A seed coat developed from integuments of the ovule with gradual change in cell composition and cell material deposition. Carbohydrates were deposited in outer integument cells especially in the outside cell walls. Starch grains decreased in number per cell in the integument during seed coat development. All these characteristics during seed development represent normal features in the ground control plants and show that the spaceflight environment does not prevent normal development of seeds in Arabidopsis.

  16. SU-D-201-06: Random Walk Algorithm Seed Localization Parameters in Lung Positron Emission Tomography (PET) Images

    SciTech Connect

    Soufi, M; Asl, A Kamali; Geramifar, P

    2015-06-15

    Purpose: The objective of this study was to find the best seed localization parameters in random walk algorithm application to lung tumor delineation in Positron Emission Tomography (PET) images. Methods: PET images suffer from statistical noise and therefore tumor delineation in these images is a challenging task. Random walk algorithm, a graph based image segmentation technique, has reliable image noise robustness. Also its fast computation and fast editing characteristics make it powerful for clinical purposes. We implemented the random walk algorithm using MATLAB codes. The validation and verification of the algorithm have been done by 4D-NCAT phantom with spherical lung lesions in different diameters from 20 to 90 mm (with incremental steps of 10 mm) and different tumor to background ratios of 4:1 and 8:1. STIR (Software for Tomographic Image Reconstruction) has been applied to reconstruct the phantom PET images with different pixel sizes of 2×2×2 and 4×4×4 mm{sup 3}. For seed localization, we selected pixels with different maximum Standardized Uptake Value (SUVmax) percentages, at least (70%, 80%, 90% and 100%) SUVmax for foreground seeds and up to (20% to 55%, 5% increment) SUVmax for background seeds. Also, for investigation of algorithm performance on clinical data, 19 patients with lung tumor were studied. The resulted contours from algorithm have been compared with nuclear medicine expert manual contouring as ground truth. Results: Phantom and clinical lesion segmentation have shown that the best segmentation results obtained by selecting the pixels with at least 70% SUVmax as foreground seeds and pixels up to 30% SUVmax as background seeds respectively. The mean Dice Similarity Coefficient of 94% ± 5% (83% ± 6%) and mean Hausdorff Distance of 1 (2) pixels have been obtained for phantom (clinical) study. Conclusion: The accurate results of random walk algorithm in PET image segmentation assure its application for radiation treatment planning and

  17. Synthesis and evaluation of an (125)I-labeled azide prosthetic group for efficient and bioorthogonal radiolabeling of cyclooctyne-group containing molecules using copper-free click reaction.

    PubMed

    Choi, Mi Hee; Shim, Ha Eun; Nam, You Ree; Kim, Hye Rim; Kang, Jung Ae; Lee, Dong-Eun; Park, Sang Hyun; Choi, Dae Seong; Jang, Beom-Su; Jeon, Jongho

    2016-02-01

    Herein we report the radiosynthesis of a pyridine derived azide prosthetic group for iodine radioisotope labeling of dibenzocyclooctyne (DBCO) conjugated molecules. The radiolabeling of the stannylated precursor 2 was conducted using [(125)I]NaI and chloramine-T to give (125)I-labeled azide ([(125)I]1) with high radiochemical yield (72±8%, n=4) and radiochemical purity (>99%). Using (125)I-labeled azide ([(125)I]1), cyclic RGD peptide and near infrared fluorescent molecule were efficiently labeled with modest to good radiochemical yields. The biodistribution study and SPECT/CT images showed that [(125)I]1 underwent rapid renal clearance. These results clearly demonstrated that [(125)I]1 could be used as an useful radiotracer for in vivo pre-targeted imaging as well as efficient in vitro radiolabeling of DBCO containing molecules.

  18. Detection by /sup 125/I-cationized cytochrome c of proteoglycans and glycosaminoglycans immobilized on unmodified and on positively charged nylon 66

    SciTech Connect

    Heimer, R.; Molinaro, L. Jr.; Sampson, P.M.

    1987-09-01

    We have examined the detection by a /sup 125/I-labeled basic protein, cationized cytochrome c, of selected proteoglycans (PGs) and standard preparations of glycosaminoglycans (GAGs) immobilized on Nylon 66 and also on positively charged Nylon 66. Immobilization on Nylon 66 appears to allow a relative freedom of interaction between PGs or GAGs and /sup 125/I-cationized cytochrome c, but a more restricted reaction was observed when PGs and GAGs were immobilized to positively charged Nylon 66. On this support PGs with large numbers of GAG side chains reacted well with /sup 125/I-cationized cytochrome c, but GAGs were minimally reactive. By taking advantage of some of the properties of large-pore agarose-acrylamide gels, rapid partial characterization of some PGs can be accomplished in the 10-ng range, and therefore at a sensitivity equal to PGs with internal biosynthetic labels.

  19. Translocation of 125I, 75Se and 36Cl to wheat edible parts following wet foliar contamination under field conditions.

    PubMed

    Hurtevent, P; Thiry, Y; Levchuk, S; Yoschenko, V; Henner, P; Madoz-Escande, C; Leclerc, E; Colle, C; Kashparov, V

    2013-07-01

    Apart from radiocaesium and radiostrontium, there have been few studies on the foliar transfer of radionuclides in plants. Consequently, specific translocation factor (ftr) values for (129)I, (79)Se and (36)Cl are still missing from the IAEA reference databases. The translocation of short - lived isotopes, (125)I and (75)Se, and of (36)Cl to wheat grain were measured under field conditions following acute and chronic wet foliar contamination at various plant growth stages in the absence of leaching caused by rain. The translocation factors ranged from 0.02% to 1.1% for (125)I (a value similar to Sr), from 0.1% to 16.5% for (75)Se, and from 1% to 14.9% for (36)Cl. Both (36)Cl and (75)Se were as mobile as Cs. The phenomenological analysis showed that each element displayed a specific behavior. Iodide showed the lowest apparent mobility because of its preferential fixation in or on the leaves and a significant amount probably volatilized. Selenite internal transfer was significant and possibly utilized the sulphur metabolic pathway. However bio - methylation of selenite may have led to increased volatilization. Chloride was very mobile and quickly diffused throughout the plant. In addition, the analysis underlined the importance of plant growth responses to annual variations in weather conditions that can affect open field experiments because plant growth stage played a major role in ftr values dispersion. The chronic contamination results suggested that a series of acute contamination events had an additive effect on translocated elements. The highest translocation value obtained for an acute contamination event was shown to be a good conservative assessment of chronic contamination if data on chronic contamination translocation are lacking. The absence of rain leaching during the experiment meant that this investigation avoided potential radionuclide transfer by the roots, which also meant that radionuclide retention on or in the leaves was maximized. This study was

  20. Mono(125I)iodo-Tyr10,MetO17)-vasoactive intestinal polypeptide. Preparation, characterization, and use for radioimmunoassay and receptor binding

    SciTech Connect

    Martin, J.L.; Rose, K.; Hughes, G.J.; Magistretti, P.J.

    1986-04-25

    Vasoactive intestinal polypeptide (VIP) was labeled with sodium (125I)iodide using the chloramine-T method and subsequently purified by reverse-phase high performance liquid chromatography.Three main 125I-labeled peaks designated A, B, and C resulted from the radioiodination and purification procedures. They were characterized by electrophoresis of tryptic fragments; Edman degradation (for Peaks A and C); enzymatic digestion to amino acids by leucine aminopeptidase, carboxypeptidase Y and Pronase; and treatment with cyanogen bromide. Peak A corresponds to VIP monoiodinated on Tyr10 and with the Met17 residue oxidized to methionine sulfoxide. This (mono(125I)iodo-Tyr10,MetO17)VIP displays the following characteristics. 1) It constitutes quantitatively the major product of the iodination procedure (62.5%); 2) it is well resolved from other labeled and unlabeled products; 3) it is stable (2 months at -20 degrees C); 4) it possesses a high specific activity (2050 Ci/mmol); 5) it maintains the biological activity of native VIP; and 6) it binds to antibody and membrane recognition sites in a specific, saturable, and reversible manner. Reduction of (mono(125I)iodo-Tyr10, Met-O17)VIP to (mono(125I)iodo-Tyr10)VIP does not improve the performance of the tracer in a radioimmunoassay. The method described in this article is simple and rapid and yields a molecular form of 125I-labeled VIP that has been fully characterized and is suitable for use in biological studies.

  1. Nicotinic binding in rat brain: autoradiographic comparison of (/sup 3/H)acetylcholine, (/sup 3/H)nicotine, and (/sup 125/I)-alpha-bungarotoxin

    SciTech Connect

    Clarke, P.B.; Schwartz, R.D.; Paul, S.M.; Pert, C.B.; Pert, A.

    1985-05-01

    Three radioligands have been commonly used to label putative nicotinic cholinoceptors in the mammalian central nervous system: the agonists (/sup 3/H)nicotine and (/sup 3/H)acetylcholine ((/sup 3/H)ACh--in the presence of atropine to block muscarinic receptors), and the snake venom extract, (/sup 125/I)-alpha-bungarotoxin((/sup 125/I)BTX), which acts as a nicotinic antagonist at the neuromuscular junction. Binding studies employing brain homogenates indicate that the regional distributions of both (/sup 3/H)nicotine and (/sup 3/H)ACh differ from that of (/sup 125/I)BTX. The possible relationship between brain sites bound by (/sup 3/H)nicotine and (/sup 3/H)ACh has not been examined directly. The authors have used the technique of autoradiography to produce detailed maps of (/sup 3/H)nicotine, (/sup 3/H)ACh, and (/sup 125/I)BTX labeling; near-adjacent tissue sections were compared at many levels of the rat brain. The maps of high affinity agonist labeling are strikingly concordant, with highest densities in the interpeduncular nucleus, most thalamic nuclei, superior colliculus, medial habenula, presubiculum, cerebral cortex (layers I and III/IV), and the substantia nigra pars compacta/ventral tegmental area. The pattern of (/sup 125/I)BTX binding is strikingly different, the only notable overlap with agonist binding being the cerebral cortex (layer I) and superior colliculus. (/sup 125/I)BTX binding is also dense in the inferior colliculus, cerebral cortex (layer VI), hypothalamus, and hippocampus, but is virtually absent in thalamus. Various lines of evidence suggest that the high affinity agonist-binding sites in brain correspond to nicotinic cholinergic receptors similar to those found at autonomic ganglia; BTX-binding sites may also serve as receptors for nicotine and are possibly related to neuromuscular nicotinic cholinoceptors.

  2. The thyroid hormone transporters MCT8 and MCT10 transport the affinity-label N-bromoacetyl-[(125)I]T3 but are not modified by it.

    PubMed

    Visser, W Edward; van Mullem, Alies A A; Jansen, Jurgen; Visser, Theo J

    2011-04-30

    Thyroid hormone (TH) transporter proteins mediate transport of TH across the plasma membrane, thereby facilitating its intracellular bioavailability. As only a few transporters have been identified which are relatively specific for TH, including monocarboxylate transporter (MCT) 8 and MCT10, the need for identification of novel specific TH transporters is obvious. A possible strategy to identify TH transporters is their modification with a ligand-derived affinity-label and subsequent identification by mass spectrometry. Previously, N-bromoacetyl (BrAc)-iodothyronines have been reported as useful affinity-labels for human (h) MCT8. In the present study we reinvestigated possible BrAc[(125)I]T3-labeling of hMCT8 and hMCT10. The present study demonstrates that hMCT8 and hMCT10 both facilitate BrAc[(125)I]T3 transport, but are not labeled by BrAc[(125)I]T3. We provide evidence that human protein disulfide isomerase, which molecular mass is similar to hMCT8, is labeled by BrAc[(125)I]T3. In addition, differential inhibitory effects were observed of iodothyronines derivatives with different side chains on T3 transport by hMCT8 and hMCT10. In conclusion, we demonstrated that not hMCT8 and hMCT10, but human protein disulfide isomerase, is labeled by BrAc[(125)I]T3. The usefulness of BrAc[(125)I]T3 as a tool for the identification of novel TH transporters remains to be explored.

  3. Updated Solid Water trade mark sign to water conversion factors for {sup 125}I and {sup 103}Pd brachytherapy sources

    SciTech Connect

    Meigooni, Ali S.; Awan, Shahid B.; Thompson, Nathan S.; Dini, Sharifeh A.

    2006-11-15

    Dosimetric characteristics of brachytherapy sources are normally determined in water using a Monte Carlo simulation technique and in water equivalent phantom material using both experimental and Monte Carlo simulation techniques. The consensuses of these results are then calculated for clinical applications by converting experimental data obtained in water equivalent material to water using a conversion factor. These conversion factors are normally determined as a ratio of the Monte Carlo-simulated dose rate constant in liquid water to the dose rate constant in a water-equivalent phantom material. However, it has been noted that conversion factors utilized by some investigators have been derived using incorrect phantom material composition and incorrect cross-sectional data information. The impact of errors associated with the cross-sectional data and chemical composition of the phantom material used in dosimetric evaluation of brachytherapy sources has been investigated in this project. Results of these investigations have shown that the use of Solid Water trade mark sign with 1.7% calcium content, as compared to the 2.3% value stated by the manufacturer, may lead to 5% and 9% differences in conversion factors for {sup 125}I and {sup 103}Pd, respectively.

  4. A rapid radioimmunoassay using /sup 125/I-labeled staphylococcal protein A for antibody to varicella-zoster virus

    SciTech Connect

    Richman, D.D.; Cleveland, P.H.; Oxman, M.N.; Zaia, J.A.

    1981-05-01

    A sensitive radioimmunoassay for serum antibody to varicella-zoster virus is described; it uses 125I-labeled staphylococcal protein A and a specially designed immunofiltration apparatus. The assay accurately distinguishes between individuals who are susceptible and those who are immune to infection with varicella-zoster virus. In addition, it can detect passive antibody in recipients of varicella-zoster immune globulin. This radioimmunoassay also detects the heterologous antibody responses that occasionally occur in patients infected with herpes simplex virus, which also have been detected by other antibody assays. The particular advantages of this assay are the use of noninfectious reagents, the speed of execution (less than 3 hr), the requirement for only small quantities of serum (30 microliters), the objectivity of end-point determination, and the capability of screening large numbers of sera. Consequently, this radioimmunoassay is especially useful for the rapid identification of susceptible individuals, which is essential for the appropriate management of patients and hospital personnel after exposure to varicella.

  5. (125)I-spectramide: A novel benzamide displaying potent and selective effects at the D sub 2 dopamine receptor

    SciTech Connect

    Sanchez-Roa, P.M.; Grigoriadis, D.E.; Wilson, A.A.; Sharkey, J.; Dannals, R.F.; Villemagne, Victor, L.; Wong, D.F.; Wagner, H.N. Jr.; Kuhar, M.J. )

    1989-01-01

    The new substituted benzamide Spectramide, (N-(2-(4-iodobenzyl-N-methylamino)-2-methoxy-4-ethyl)-5-chloro-methylamine benzamide) labelled with {sup 125}I was used as a potent and highly selective dopamine-D{sub 2} receptor antagonist in rat striatal homogenates for in vitro receptor binding. Kinetic experiments demonstrated the reversibility of the binding and the estimated Kd from saturation analysis was 25 pM, with a Bmax of 20 pmol/g of tissue. Competition studies showed that spectramide did not interact potently with the D{sub 1} or dopamine-uptake site. Drugs known to interact with other receptor system were weak competitors of the binding, while binding was potently inhibited by other D{sub 2} antagonists, such as spiperone and eticlopride. These data indicate that Spectramide binds selectively and with high affinity to the dopamine D{sub 2} receptors, and may prove to be a useful tool for the study of these receptors in vivo using PET or SPECT.

  6. Erythropoietin messenger RNA levels in developing mice and transfer of /sup 125/I-erythropoietin by the placenta

    SciTech Connect

    Koury, M.J.; Bondurant, M.C.; Graber, S.E.; Sawyer, S.T.

    1988-07-01

    Erythropoietin (EP) mRNA was measured in normal and anemic mice during fetal and postnatal development. Normal fetal livers at 14 d of gestation contained a low level of EP mRNA. By day 19 of gestation, no EP mRNA was detected in normal or anemic fetal livers or normal fetal kidneys, but anemic fetal kidneys had low levels of EP mRNA. Newborn through adult stage mice responded to anemia by accumulating renal and hepatic EP mRNA. However, total liver EP mRNA was considerably less than that of the kidneys. Juvenile animals, 1-4 wk old, were hyperresponsive to anemia in that they produced more EP mRNA than adults. Moreover, nonanemic juveniles had readily measured renal EP mRNA, whereas the adult level was at the lower limit of detection. Because of the very low level of fetal EP mRNA, placental transfer of EP was evaluated. When administered to the pregnant mouse, /sup 125/I-EP was transferred in significant amounts to the fetuses. These results indicate that in mice the kidney is the main organ of EP production at all stages of postnatal development and that adult kidney may also play some role in providing EP for fetal erythropoiesis via placental transfer of maternal hormone.

  7. Venous function in the leg after postoperative thrombosis diagnosed with /sup 125/I-fibrinogen uptake test

    SciTech Connect

    Lindhagen, A.; Bergqvist, D.; Hallboeoek, T.; Efsing, H.O.

    1983-02-01

    The /sup 125/I-fibrinogen uptake test (FUT) has been widely used in the past decade to detect postoperative thrombosis. FUT has been shown to correlate well with phlebography, and positive FUT is associated with a high frequency of pulmonary embolism. The long-term venous function of the leg after FUT-detected postoperative thrombosis, however, is inadequately documented. In 179 patients who had been studied after operation with FUT, a follow-up evaluation of FUT as an indicator of risk for development of deep venous insufficiency was made four to five years later. The patients replied to a questionnaire, were clinically examined, and underwent venous strain-gauge plethysmography, venous pressure measurement, and, in some cases, phlebography. No statistically significant differences were found in any of the parameters between legs that had been FUT-positive and those that were FUT-negative at the time of the operation. The frequency of deep venous insufficiency thus was equal in FUT-positive and FUT-negative legs. It was also independent of the site of FUT-detected thrombus in the leg.

  8. /sup 125/I-Clq-binding and specific antibodies as indicators of pulmonary disease activity in cystic fibrosis

    SciTech Connect

    Moss, R.B.; Hsu, Y.P.; Lewiston, N.J.

    1981-08-01

    We studied the incidence and levels of circulating immune complexes by the /sup 125/I-Clq-binding assay in patients with cystic fibrosis in relation to clinical respiratory status and specific IgG and IgE antibodies to Pseudomonas aeruginosa. Staphylococcus aureus, Aspergillus fumigatus, and Candida albicans. Overall prevalence of CIC was 43%, but 86% of serially studied patients had evidence of CIC at some time. Patients with acute respiratory exacerbations and deteriorating pulmonary function had a higher incidence of CIC (76%) as compared to stable patients (36%, P less than 0.01), as well as significantly higher levels of CIC. Acute exacerbations were also associated with significant increases in IgG antibody to Pseudomonas (P less than 0.005) but not in other antibodies. CIC did not correlate with Pseudomonas-specific IgG nor with any other specific antibody studied. A variety of age-related differences in specific antibody levels were seen. The episodic appearance of CIC is common in CF and is usually associated with exacerbation of lung disease.

  9. Direct /sup 125/I-radioligand assays for serum progesterone compared with assays involving extraction of serum

    SciTech Connect

    Ratcliffe, W.A.; Corrie, J.E.; Dalziel, A.H.; Macpherson, J.S.

    1982-06-01

    Researchers compared two direct radioimmunoassays for progesterone in 50 microL of unextracted serum or plasma with assays involving extraction of serum. The direct assays include the use of either danazol at pH 7.4 or 8-anilino-1-naphthalenesulfonic acid at pH 4.0 to displace progesterone from serum binding-proteins. Progesterone is then assayed by using an antiserum to a progesterone 11 alpha hemisuccinyl conjugate and the radioligand /sup 125/I-labeled progesterone 11 alpha-glucuronyl tyramine, with separation by double-antibody techniques. Direct assays with either displacing agent gave good analytical recovery of progesterone added to human serum, and progesterone values for patients' specimens correlated well (r greater than 0.96) with results of assays involving extraction of serum. Precision was similar with each displacing agent over the working range 2.5-100 nmol/L and superior to that of extraction assays. Researchers conclude that these direct assays of progesterone are analytically valid and more robust, precise, and technically convenient than many conventional methods involving extraction of serum.

  10. Direct /sup 125/I-radioligand assays for serum progesterone compared with assays involving extraction of serum

    SciTech Connect

    Ratcliffe, W.A.; Corrie, J.E.T.; Dalziel, A.H.; Macpherson, J.S.

    1982-06-01

    Two direct radioimmunoassays for progesterone in 50 ..mu..L of unextracted serum or plasma with assays involving extraction of serum were compared. The direct assays include the use of either danazol at pH 7.4 or 8-anilino-1-naphthalenesulfonic acid at pH 4.0 to displace progesterone from serum binding-proteins. Progesterone is then assayed by using an antiserum to a progesterone 11..cap alpha..-hemisuccinyl conjugate and the radioligand /sup 125/I-labeled progesterone 11..cap alpha..-glucuronyl tyramine, with separation by double-antibody techniques. Direct assays with either displacing agent gave good analytical recovery of progesterone added to human serum, and progesterone values for patients' specimens correlated well (r > 0.96) with results of assays involving extraction of serum. Precision was similar with each displacing agent over the working range 2.5-100 nmol/L and superior to that of extraction assays. We conclude that these direct assays of progesterone are analytically valid and more robust, precise, and technically convenient than many conventional methods involving extraction of serum.

  11. High correlation between prolactinemia, 125-I hLH binding and progesterone secretion by an experimental luteoma

    SciTech Connect

    Lux, V.A.R.; Tesone, M.; Larrea, G.A.; Libertun, C.

    1984-12-03

    Autoimplantation of an ovary, containing fresh corpora lutea, into the spleen of an ovariectomized rat is followed by strong luteinization and size increase of the grafted gonad. Thus, large amounts of luteal tissue for biochemical studies, and their histological controls are available. Furthermore, progesterone secretion can be easily determined in samples collected from the portal vein. Since prolactin has been implicated in the control of luteal tissue, the role of this hormone on hLH binding and progesterone secretion was determined. Different levels of endogenous serum prolactin were achieved by pharmacological treatments with neurotropic agents. Scatchard plots of 125-I hLH binding data derived from luteoma particulate fractions revealed the presence of one type of binding site with high affinity. At the same time as binding increased, prolactinemia augmented, with a high correlation (R:0.99) between prolactinemia and LH binding. Moreover, progesterone secreted by the luteoma increased as LH binding sites augmented (R:0.97). It is conclude that a high correlation between prolactinemia and LH binding, as well as between this last parameter and progesterone output exists in the experimental luteoma. 40 references, 2 figures, 1 table.

  12. /sup 125/I-labeled radioimmunoassay kits for progesterone evaluated for use in an in vitro fertilization program

    SciTech Connect

    Blight, L.F.; White, G.H.

    1983-06-01

    We have evaluated two commercially available /sup 125/I radioimmunoassay kits (Diagnostic Products Corp., DPC; and Radioassay Systems Laboratories, RSL) for measurement of serum or plasma progesterone, to determine their suitability for use in in vitro fertilization programs. Both kits were suitably rapid for program requirements. Results by both were linear with concentration up to 60 nmol/L, and both had acceptable lower detection limits of 0.3 nmol/L. Kit-determined progesterone concentrations (y) for 100 patients' samples correlated well with results by our existing 3H radioimmunoassay method (y . 1.11x + 0.2, r . 0.965 for the DPC kit; y . 1.01x + 1.4, r . 0.974 for the RSL kit). Mean analytical recovery for the RSL kit was 116%, that for the DPC kit, 202%. Within-batch precision, expressed as the mean CV for three concentrations of progesterone, was 6.5% for the RSL kit, and 16.4% for the DPC kit; between-day CV was 8.1% for the RSL kit, 17.7% for the DPC kit. We conclude that the RSL kit provides a rapid, precise, and accurate assay for serum progesterone, suitable for use in a fertilization program, but do not recommend the DPC kit for either this purpose or the more general purpose of tracking menstrual cycles.

  13. In vitro and in vivo properties of (/sup 125/I) (R,S) 4IQNB: A lower affinity diastereomeric muscarinic receptor radiotracer

    SciTech Connect

    Gibson, R.E.; Schneidau, T.A.; Rzeszotarski, W.J.; Cohen, V.I.; Eckelman, W.C.; Reba, R.C.

    1985-05-01

    The (R,R) diastereomer of 3-Quinuclidinyl 4-Iodobenzilate (4IQNB) is a high affinity muscarinic acetylcholine receptor radiotracer which has provided images of receptor distribution in the CNS of man. The radiotracer is of such high affinity that dissociation in vivo is not evident in man after 6-half-lives I-123. Since the dissociation kinetics of radiotracer may be helpful for receptor quantitation, the authors have prepared (/sup 125/I) (R,S) 4IQNB: a diastereomer of 4IQNB which as a lower affinity for the m-AChR than the (R,R) isomer. The equilibrium association constant for the (R,S) diastereomer is 1.10 x 10/sup 9/ M/sup -1/, which is 4-fold lower in affinity than (/sup 3/H) (R) QNB and 2-fold lower than that of the (R,R) 4IQNB. Of more interest, the dissociation rate constant of (R,S) 4IQNB is 0.099 (+0.01)/min., 15-fold more rapid than that of the (R,R) isomer. The systemic distribution of (R,S) 4IQNB is similar to that of (R,R) 4IQNB except localization in the myocardium is 2-fold lower, reflecting the lower affinity. Nonreceptor interactions are the same since the compounds differ only as optical isomers around the carbinol chiral center. In the CNS peak activities are obtained in the corpus striatum (and other M/sub 1/-receptor rich structures) which are the same as obtained with (R,R) 4IQNB. However, no washout of (R,R) 4IQNB is observed after 4 hrs and only 60% in 24 hrs. By contrast, 65% of (R,S) 4IQNB washes out in 4 hrs and no significant activity is detected after 24 hrs. The increased washout kinetics should provide a better radiotracer for determining muscarinic receptor concentrations in the CNS of man.

  14. Autoradiographical detection of cholecystokinin-A receptors in primate brain using sup 125 I-Bolton Hunter CCK-8 and 3H-MK-329

    SciTech Connect

    Hill, D.R.; Shaw, T.M.; Graham, W.; Woodruff, G.N. )

    1990-04-01

    In vitro autoradiography was performed in order to visualize cholecystokinin-A (CCK-A) receptors in sections of Cynomolgus monkey brain. CCK-A receptors were defined as those which displayed high affinity for the selective non-peptide antagonist MK-329 (L-364,718) and were detected in several regions by selective inhibition of 125I-Bolton Hunter CCK using MK-329 or direct labeling with 3H-MK-329. In the caudal medulla, high densities of CCK-A sites were present in the nucleus tractus solitarius, especially the caudal and medial aspects, and also the dorsal motor nucleus of the vagus. CCK-A sites were localized to a number of hypothalamic nuclei such as the supraoptic and paraventricular nuclei, the dorsomedial and infundibular nuclei as well as the neurohypophysis. The mammillary bodies and supramammillary nuclei also contained CCK-A receptor sites. High concentrations of CCK-A receptors were present in the substantia nigra zona compacta and also the ventral tegmental area and may be associated with dopamine cell bodies. Binding of 3H-MK-329 was also detected in parts of the caudate nucleus and ventral putamen. The detection, by autoradiographical means, of CCK-A receptors throughout the Cynomolgus monkey brain contrasts with similar studies performed using rodents and suggests differences in the density and, perhaps, the importance of CCK-A receptors in the primate as opposed to the rodent. The data suggest the possibility that CCK-A receptors may be involved in a number of important brain functions as diverse as the processing of sensory information from the gut, the regulation of hormone secretion, and the activity of dopamine cell activity.

  15. Progestin receptors in brain and pituitary of 20-day-old fetal mice: an autoradiographic study using (/sup 125/I)progestin

    SciTech Connect

    Shughrue, P.J.; Stumpf, W.E.; Sar, M.; Elger, W.; Schulze, P.E.

    1989-01-01

    The distribution of progestin target sites in the brain and pituitary of estrogen-primed 20-day-old fetal mice was investigated by thaw-mount autoradiography. Three pregnant mice were each implanted sc with a Silastic tube containing estrogen on day 17 and ovariectomized on day 19 of gestation. Twenty-four hours after ovariectomy 10 fetuses (5 males and 5 females) were collected and each injected sc with 0.33 microgram/100 g BW (/sup 125/I)progestin (SA, 2200 Ci/mM). For competition, two additional fetuses were injected with 20 micrograms R5020 1 h before (Z)-17 beta-hydroxy-17 alpha-(2(/sup 125/I)iodovinyl)4-estren-3-one ((/sup 125/I)Progestin) to demonstrate that nuclear uptake and retention of radioactivity were specific for progestin. Two hours after injection of (/sup 125/I)Progestin all fetuses were mounted, frozen, and sectioned in a cryostat. After 1-37 days of exposure, sections were developed and scanned for labeled cells. Cells with nuclear concentration were found in the male and female preoptic area, within certain nuclear groups in the basal hypothalamus, in the central gray of the midbrain, and in the pituitary. No labeling was detected in the cortex or amygdala. The results indicate that cells in certain regions of the brain and pituitary express progestin receptors at the end of gestation and suggest that progesterone is important for the normal development of these cells.

  16. /sup 125/I-FK 33-824: a selective probe for radioautographic labeling of mu opioid receptors in the brain

    SciTech Connect

    Moyse, E.; Pasquini, F.; Quirion, R.; Beaudet, A.

    1986-03-01

    The selectivity of the Met-enkephalin analog FK 33-824 (FK) for mu opioid receptors has been, over the years, a matter of controversy. We report here pharmacological and radioautographic data demonstrating that at nanomolar concentrations. /sup 125/I-FK interacts exclusively with mu sites. (1) Specific binding of /sup 125/I-FK to rat striatal membranes is totally inhibited by mu- and/or delta-preferring ligands according to monovalent, Michaelian kinetics, with a potency proportional to the affinity of competing drugs for mu receptors. (2) Unlabeled FK competes only at high concentration with the delta-selective ligand 3H-DPLPE and according to the same kinetics as the mu-selective agonist DAGO. (3) /sup 125/I-FK generates the same regional radioautographic labeling pattern as 3H-DAGO. We conclude that when used at nanomolar concentrations /sup 125/I-FK constitutes a selective probe for the radioautographic detection of mu opioid receptors at both light and electron microscopic levels.

  17. In vitro covalent binding of new brain tracer, para-125I-amphetamine, to rat liver and lung microsomes

    SciTech Connect

    Joulin, Y.; Delaforge, M.; Hoellinger, H.; Moretti, J.L.; Sonnier, M.; Cesaro, P. )

    1990-01-01

    p-125I-amphetamine (I-Amp) is retained significantly in liver and lung during brain tomoscintigraphy. To attempt to explain this clinical observation, we have investigated the interaction of I-Amp with rat liver and lung microsomal proteins. Studies using spectral shift technique indicate that low concentration of I-Amp gives a type I complex and high concentration appears very stable type II complex with cytochrome P-450 Fe III. In the presence of NADPH, I-Amp gives rise to a 455 nm absorbing complex with similar properties to the Fe-RNO complexes. This complex formation was greatly enhanced with phenobarbital treated liver microsomes. The in vitro binding study shows that I-Amp and/or its metabolites was covalently bound to macromolecules in the presence of the molecular oxygen and NADPH-generating system. Incubation in the presence of glutathione, cystein and radical scavengers decreases binding. Mixed function oxydase (MFO) inhibitors diminish the amount of covalent binding and alter the extent of metabolite formation. The total covalent binding level increased with liver microsomes from PB pretreated rats as it was observed with the 455nm complex formation. The radioactivity distribution on microsomal proteins was examinated with SDS polyacrylamide gel electrophoresis and autoradiography. This experiment proves that the radiolabelled compounds are bound on the cytochrome P-450. The radioactivity bound increased when the PB induced rat liver microsomes were used. All these results indicate that I-Amp was activated by an oxydative process dependent on the MFO system which suggests a N-oxydation of I-Amp and the formation of reactive entities which covalently bind to proteins.

  18. Feasibility and impact of the measurement of extracellular fluid volume simultaneous with GFR by 125I-iothalamate.

    PubMed

    Visser, Folkert W; Muntinga, Jaap H J; Dierckx, Rudi A; Navis, Gerjan

    2008-09-01

    The feasibility, validity, and possible applications of the assessment of extracellular fluid volume (ECFV) simultaneous with glomerular filtration rate (GFR) were assessed in a series of validation studies using the constant infusion method of (125)I-iothalamate (IOT). In 48 subjects with a broad range of GFR, distribution volume (V(d)) of IOT corresponded well with V(d) bromide (16.71 +/- 3.0 and 16.73 +/- 3.2 l, respectively, not significant), with a strong correlation (r = 0.933, P < 0.01) and without systematic deviations. Reproducibility assessment in 25 healthy male subjects showed coefficients of variation of 8.6% of duplicate measurement of V(d) IOT during strictly standardized (50 mmol Na(+)/d) sodium intake. An increase in dietary sodium intake (200 mmol Na(+)/d) induced a corresponding rise in V(d) IOT of 1.11 +/- 1.5 l (P < 0.01). In 158 healthy prospective kidney donors, the impact of indexing of GFR to ECFV was analyzed. Age, gender, height, and body surface area (BSA) were determinants of GFR. Whereas GFR, GFR/BSA, and GFR/height were gender-dependent, GFR/ECFV was gender-independent and not related to height or BSA. This supports the potential of normalizing GFR by ECFV. Thus, ECFV can be simultaneously assessed with GFR by the constant infusion method using IOT. After appropriate validation, also other GFR tracers could be used for such a simultaneous estimation, providing a valuable resource of data on ECFV in renal studies and, moreover, allowing GFR to be indexed to the body fluid compartment it clears: the ECFV.

  19. Leaving home ain't easy: non-local seed dispersal is only evolutionarily stable in highly unpredictable environments

    PubMed Central

    Snyder, Robin E.

    2011-01-01

    It is widely understood that in the presence of asynchronous environmental variation, seeds disperse to escape disturbances, avoid crowding or colonize newly favourable habitat before a superior competitor can arrive. If seeds are dispersing for any of these reasons, it seems intuitive that they should travel far enough to reach conditions uncorrelated with their natal environment: why ‘escape in space’ only to land somewhere more or less like where they started? However, in this paper, I present a series of mathematical experiments which show that the evolutionarily stable mean dispersal distance remains well short of the spatial correlation length of the environmental variation, regardless of disturbance severity, coevolution with a superior competitor or the presence of a small fraction of seeds which travel well beyond the mean distance. Non-local dispersal arises only as part of a polymorphism that evolves when favourable conditions are fleeting. To the degree that non-local dispersal is a response to environmental variation, it appears to be a response to environmental unpredictability. PMID:20843844

  20. /sup 125/I-Fibrin deposition in contact sensitivity reactions in the mouse. Sensitivity of the assay for quantitating reactions after active or passive sensitization

    SciTech Connect

    Mekori, Y.A.; Dvorak, H.F.; Galli, S.J.

    1986-03-15

    The clotting associated with delayed hypersensitivity (DH) responses in the mouse by sensitizing the animals to the contactant oxazolone (Ox), and then administering /sup 125/I-guinea pig fibrinogen i.v. 10 to 30 min before antigen challenge 5 days later. Early (4 to 8 hr) contact sensitivity (CS) responses in immunized mice were barely detectable by three conventional measures of CS, but the total /sup 125/I-cpm in ears challenged with hapten was 3.6 to 4.5 x that in control ears challenged with vehicle alone; moreover, the amount of urea-insoluble cpm (cross-linked /sup 125/I-fibrin-associated cpm) in the reactions to Ox was 6.5-fold to 8.2-fold that present in the control reactions. In 24 hr reactions that were near peak intensity by measurements of ear swelling, ear weight ratios, and ratios of /sup 125/I-5-iodo-2-deoxyuridine-labeled leukocyte infiltration, the cpm in antigen-challenged ears exceeded that in control ears by 13-fold to 53-fold. In addition, antigen-challenged ears contained 27 to 300 x the urea-insoluble cpm present in control ears. /sup 125/I-Fibrin deposition was not a specific characteristic of CS reactions, because a small amount of urea-insoluble reactivity was also detected in some reactions to Ox in native mice. Nevertheless, the assay was exquisitely sensitive and readily detected quantitative differences between the immunologically specific and nonspecific reactions at very early intervals after challenge or with suboptimal doses of antigen.

  1. Pilot clinical trial of 5-[{sup 125}I] iodo-2{prime}-deoxyuridine in the treatment of colorectal cancer metastic to the liver

    SciTech Connect

    Macapinlac, H.A.; Kemeny, N.; Daghighian, F.

    1996-04-01

    The thymidine analog, 5-iodo-2{prime}-deoxyuridine (IUdR), is incorporated in the DNA of cell sin the S phase. When incorporated in the DNA, short-range Auger electrons emitted by {sup 125}I-labeled IUdR can cause double-strand breaks, delivering a lethal radiation dose to the cell. We conducted therapeutic trial to evaluate [{sup 125}I/{sup 131}I]IUdR pharmacokinetics in liver metastases from colorectal cancer. Dosimetry, safety, and therapeutic potential were assessed. Four patients were each infused with 5 mCi [{sup 125}I]IUdR and 10 mCi [{sup 131}I]IUdR through the sideport of a hepatic artery pump. Iodine-131 images were quantitated and used for pharmacokinetic studies. The radioactivity in the DNA of biopsy samples of tumor, normal liver and bone marrow, obtained 24 or 48 hr after injection, was counted. All patients had [{sup 125}I]IUdR and [{sup 131}I]IUdR uptake in tumor, with a biexponential clearance. Repeat injections in individual patients showed little variation in tumor uptake, especially in the slow clearance component. On planar images, no long-term retention was seen in bone marrow or other activity dividing normal tissues. Radioactivity in the DNA of one marrow sample taken at 24 hr was above background, but in another taken at 48 hr it was equal to background levels. No side effects were noted, no hematologic toxicity was observed in any patients and no tumor responses were seen. There is persisten uptake of [{sup 125}I]IUdR in hepatic tumors, thereby making hepatic artery infusion a suitable mode of delivery for therapy. Repeat injections will be needed because only 15%-50% of tumor cells are in the S phase. Based on results from this pilot study, a therapeutic regimen is being planned. 43 refs. 2 figs.

  2. Tritiated-nicotine- and /sup 125/I-alpha-bungarotoxin-labeled nicotinic receptors in the interpeduncular nucleus of rats. II. Effects of habenular destruction

    SciTech Connect

    Clarke, P.B.; Hamill, G.S.; Nadi, N.S.; Jacobowitz, D.M.; Pert, A.

    1986-09-15

    The cholinergic innervation of the interpeduncular nucleus (IPN) is wholly extrinsic and is greatly attenuated by bilateral habenular destruction. We describe changes in the labeling of putative nicotinic receptors within this nucleus at 3, 5, or 11 days after bilateral habenular lesions. Adjacent tissue sections of the rat IPN were utilized for /sup 3/H-nicotine and /sup 125/I-alpha-bungarotoxin (/sup 125/I-BTX) receptor autoradiography. Compared to sham-operated controls, habenular destruction significantly reduced autoradiographic /sup 3/H-nicotine labeling in rostral (-25%), intermediate (-13%), and lateral subnuclei (-36%). Labeling in the central subnucleus was unchanged. Loss of labeling was maximal at the shortest survival time (3 days) and did not change thereafter. In order to establish whether this loss was due to a reduction in the number or the affinity of /sup 3/H-nicotine-binding sites, a membrane assay was performed on microdissected IPN tissue from rats that had received surgery 3 days previously. Bilateral habenular lesions produced a 35% reduction of high-affinity /sup 3/H-nicotine-binding sites, with no change in binding affinity. Bilateral habenular lesions reduced /sup 125/I-BTX labeling in the intermediate subnuclei, and a slight increase occurred in the rostral subnucleus. In the lateral subnuclei, /sup 125/I-BTX labeling was significantly reduced (27%) at 3 days but not at later survival times. In view of the known synaptic morphology of the habenulointerpeduncular tract, it is concluded that a subpopulation of /sup 3/H-nicotine binding sites within the IPN is located on afferent axons and/or terminals. This subpopulation, located within rostral, intermediate, and lateral subnuclei, may correspond to presynaptic nicotinic cholinergic receptors. Sites that bind /sup 125/I-BTX may include a presynaptic subpopulation located in the lateral and possibly the intermediate subnuclei.

  3. Health-Related Quality of Life up to Six Years After {sup 125}I Brachytherapy for Early-Stage Prostate Cancer

    SciTech Connect

    Roeloffzen, Ellen M.A.; Lips, Irene M.; Gellekom, Marion P.R. van; Roermund, Joep van; Frank, Steven J.; Battermann, Jan J.; Vulpen, Marco van

    2010-03-15

    Purpose: Health-related quality of life (HRQOL) after prostate brachytherapy has been extensively described in published reports but hardly any long-term data are available. The aim of the present study was to prospectively assess long-term HRQOL 6 years after {sup 125}I prostate brachytherapy. Methods and Materials: A total of 127 patients treated with {sup 125}I brachytherapy for early-stage prostate cancer between December 2000 and June 2003 completed a HRQOL questionnaire at five time-points: before treatment and 1 month, 6 months, 1 year, and 6 years after treatment. The questionnaire included the RAND-36 generic health survey, the cancer-specific European Organization for Research and Treatment of Cancer core questionnaire (EORTCQLQ-C30), and the tumor-specific EORTC prostate cancer module (EORTC-PR25). A change in a score of >=10 points was considered clinically relevant. Results: Overall, the HRQOL at 6 years after {sup 125}I prostate brachytherapy did not significantly differ from baseline. Although a statistically significant deterioration in HRQOL at 6 years was seen for urinary symptoms, bowel symptoms, pain, physical functioning, and sexual activity (p <.01), most changes were not clinically relevant. A statistically significant improvement at 6 years was seen for mental health, emotional functioning, and insomnia (p <.01). The only clinically relevant changes were seen for emotional functioning and sexual activity. Conclusion: This is the first study presenting prospective HRQOL data up to 6 years after {sup 125}I prostate brachytherapy. HRQOL scores returned to approximately baseline values at 1 year and remained stable up to 6 years after treatment. {sup 125}I prostate brachytherapy did not adversely affect patients' long-term HRQOL.

  4. Universal Length Dependence of Rod-to-Seed Exciton Localization Efficiency in Type I and Quasi-Type II CdSe@CdS Nanorods.

    PubMed

    Wu, Kaifeng; Hill, Lawrence J; Chen, Jinquan; McBride, James R; Pavlopolous, Nicholas G; Richey, Nathaniel E; Pyun, Jeffrey; Lian, Tianquan

    2015-04-28

    A critical step involved in many applications of one-dimensional seeded CdSe@CdS nanorods, such as luminescent solar concentrators, optical gains, and photocatalysis, is the localization of excitons from the light-harvesting CdS nanorod antenna into the light-emitting CdSe quantum dot seed. We report that the rod-to-seed exciton localization efficiency decreases with the rod length but is independent of band alignment between the CdSe seed and CdS rod. This universal dependence can be well modeled by the competition between exciton one-dimensional diffusion to the CdSe seed and trapping on the CdS rod. This finding provides a rational approach for optimizing these materials for their various device applications.

  5. Reagents for astatination of biomolecules. 5. Evaluation of hydrazone linkers in (211)At- and (125)I-labeled closo-decaborate(2-) conjugates of Fab' as a means of decreasing kidney retention.

    PubMed

    Wilbur, D Scott; Chyan, Ming-Kuan; Hamlin, Donald K; Nguyen, Holly; Vessella, Robert L

    2011-06-15

    Evaluation of monoclonal antibody (mAb) fragments (e.g., Fab', Fab, or engineered fragments) as cancer-targeting reagents for therapy with the α-particle emitting radionuclide astatine-211 ((211)At) has been hampered by low in vivo stability of the label and a propensity of these proteins localize to kidneys. Fortunately, our group has shown that the low stability of the (211)At label, generally a meta- or para-[(211)At]astatobenzoyl conjugate, on mAb Fab' fragments can be dramatically improved by the use of closo-decaborate(2-) conjugates. However, the higher stability of radiolabeled mAb Fab' conjugates appears to result in retention of radioactivity in the kidneys. This investigation was conducted to evaluate whether the retention of radioactivity in kidney might be decreased by the use of an acid-cleavable hydrazone between the Fab' and the radiolabeled closo-decaborate(2-) moiety. Five conjugation reagents containing sulfhydryl-reactive maleimide groups, a hydrazone functionality, and a closo-decaborate(2-) moiety were prepared. In four of the five conjugation reagents, a discrete poly(ethylene glycol) (PEG) linker was used, and one substituent adjacent to the hydrazone was varied (phenyl, benzoate, anisole, or methyl) to provide varying acid sensitivity. In the initial studies, the five maleimido-closo-decaborate(2-) conjugation reagents were radioiodinated ((125)I or (131)I), then conjugated with an anti-PSMA Fab' (107-1A4 Fab'). Biodistributions of the five radioiodinated Fab' conjugates were obtained in nude mice at 1, 4, and 24 h post injection (pi). In contrast to closo-decaborate(2-) conjugated to 107-1A4 Fab' through a noncleavable linker, two conjugates containing either a benzoate or a methyl substituent on the hydrazone functionality displayed clearance rates from kidney, liver, and spleen that were similar to those obtained with directly radioiodinated Fab' (i.e., no conjugate). The maleimido-closo-decaborate(2-) conjugation reagent containing a

  6. Uptake of injected 125I-ricin by rat liver in vivo. Subcellular distribution and characterization of the internalized ligand.

    PubMed Central

    Frénoy, J P; Turpin, E; Janicot, M; Gehin-Fouque, F; Desbuquois, B

    1992-01-01

    Subcellular-fractionation techniques were used to characterize the endocytic pathway followed by ricin in rat liver in vivo and tentatively identify the site(s) at which the ricin interchain disulphide bridge is split. After injection of 125I-ricin, hepatic uptake of radioactivity was maximum at 30 min (40% of injected dose). At 5 min, about 80% of the radioactivity in the homogenate was recovered in the microsomal (P) fraction, but later on the recovery of the radioactivity in the mitochondrial-lysosomal (ML) fractions progressively increased (50% at 30 min) at the expense of that in the P fraction. Subfractionation of the P and ML fractions on analytical sucrose-density gradients revealed a time-dependent translocation of the radioactivity from low- to high-density endocytic structures, with median relative densities at 5 and 60 min of about 1.15 and 1.16 (P fraction) and 1.19 and 1.22 (ML fraction) respectively. The late distribution of the radioactivity in the ML fraction was similar to that of the lysosomal marker acid phosphatase. Studies with co-injected lactose and mannan showed that ricin was internalized mainly via the mannose receptor. In the presence of mannan, the late recovery of radioactivity in the ML fraction was decreased, and the distribution of the radioactivity associated with the P fraction was shifted toward lower densities (median relative density 1.13), indicating a different pathway of endocytosis. Analysis of the radioactivity associated with the ML and S fractions by SDS/PAGE revealed a time-dependent increase in the amount of intact A- and B-chains and low-molecular-mass products. When ML fractions containing partially processed ricin were incubated at 37 degrees C at pH 5 or at pH 7.2 in the presence of ATP, only low-molecular-mass products were generated. We conclude that internalized ricin associates with endocytic structures whose size and density of equilibration increase with time, and that, although detectable in these structures

  7. Comparison of Dosimetric and Biologic Effective Dose Parameters for Prostate and Urethra Using {sup 131}Cs and {sup 125}I for Prostate Permanent Implant Brachytherapy

    SciTech Connect

    Sahgal, Arjun; Jabbari, Siavash; Chen, Josephine; Pickett, Barbie; Roach, Mack; Weinberg, Vivian; Hsu, I-C.; Pouliot, Jean

    2008-09-01

    Purpose: To compare the urethral and prostate absolute and biologic effective doses (BEDs) for {sup 131}Cs and {sup 125}I prostate permanent implant brachytherapy (PPI). Methods and Materials: Eight previously implanted manually planned {sup 125}I PPI patients were replanned manually with {sup 131}Cs, and re-planned using Inverse Planning Simulated Annealing. {sup 131}Cs activity and the prescribed dose (115 Gy) were determined from that recommended by IsoRay. The BED was calculated for the prostate and urethra using an {alpha}/{beta} ratio of 2 and was also calculated for the prostate using an {alpha}/{beta} ratio of 6 and a urethral {alpha}/{beta} ratio of 2. The primary endpoints of this study were the prostate D{sub 90} BED (pD{sub 90}BED) and urethral D{sub 30} BED normalized to the maximal potential prostate D{sub 90} BED (nuD{sub 30}BED). Results: The manual plan comparison ({alpha}/{beta} = 2) yielded no significant difference in the prostate D{sub 90} BED (median, 192 Gy{sub 2} for both isotopes). No significant difference was observed for the nuD{sub 30}BED (median, 199 Gy{sub 2} and 202 Gy{sub 2} for {sup 125}I and {sup 131}Cs, respectively). For the inverse planning simulated annealing plan comparisons ({alpha}/{beta} 2), the prostate D{sub 90} BED was significantly lower with {sup 131}Cs than with {sup 125}I (median, 177 Gy{sub 2} vs. 187 Gy{sub 2}, respectively; p = 0.01). However, the nuD{sub 30}BED was significantly greater with {sup 131}Cs than with {sup 125}I (median, 192 Gy{sub 2} vs. 189 Gy{sub 2}, respectively; p = 0.01). Both the manual and the inverse planning simulated annealing plans resulted in a significantly lower prostate D{sub 90} BED (p = 0.01) and significantly greater nuD{sub 30}BED for {sup 131}Cs (p = 0.01), compared with {sup 125}I, when the prostate {alpha}/{beta} ratio was 6 and the urethral {alpha}/{beta} ratio was 2. Conclusion: This report highlights the controversy in comparing the dose to both the prostate and the organs

  8. In Vivo Magnetic Particle Targeting by Local Gradient Field of Interstitial Seeds Magnetized in an Ex Vivo Uniform Field

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Qiang; Zheng, Lu; Wang, Xu-Fei

    2014-02-01

    The possibility of in vivo magnetic particle targeting by the locally induced gradient field of interstitial ferromagnetic implants, magnetized in an ex vivo uniform field, is evaluated by a modelling analysis. A simplified 3D model analogous to a torso size, with a continuous laminar flow through the volume with the typical velocity and viscosity values of in vivo blood flow and a ferromagnetic seed inserted in the volume center vertical to the flow, is used to evaluate the magnetic particle capturing efficiency by the seed, which is magnetized in a uniform field. The initial modelling results indicate that for 1-10 μm iron oxide particles transporting with a blood flow of 0.5-5 mm/s, the seeds of tungsten steel, magnet steel and cast cobalt all present an effective particle capturing efficiency, which shows a fast initial increase and a slow saturation with the increasing magnetic field, a quasilinear increase with the increasing particle size, and a nonlinear decrease with the increasing blood velocity.

  9. Microfocus X-ray imaging of the internal geometry of brachytherapy seeds.

    PubMed

    Hasegawa, Tomoyuki; Hanada, Takashi; Yorozu, Atsunori; Ito, Hidetaka; Masuda, Shinji; Kawahara, Maki; Yogo, Katsunori; Hayakawa, Kazushige

    2014-04-01

    Precise and reliable geometrical data on the internal structure of seeds are indispensable for dosimetric calculation in brachytherapy. We used a novel microfocus X-ray imaging technique for observing the internal structure of brachytherapy seeds. Two popular (125)I seed models were evaluated. Obtained high precision images enabled us to observe the internal structure of seeds qualitatively. Geometrical size parameters were evaluated quantitatively with uncertainty of 0.01-0.04 mm (k=2).

  10. Population differences in host use by a seed-beetle: local adaptation, phenotypic plasticity and maternal effects.

    PubMed

    Amarillo-Suárez, Angela R; Fox, Charles W

    2006-11-01

    For insects that develop inside discrete hosts, both host size and host quality constrain offspring growth, influencing the evolution of body size and life history traits. Using a two-generation common garden experiment, we quantified the contribution of maternal and rearing hosts to differences in growth and life history traits between populations of the seed-feeding beetle Stator limbatus that use a large-seeded host, Acacia greggii, and a small-seeded host, Pseudosamanea guachapele. Populations differed genetically for all traits when beetles were raised in a common garden. Contrary to expectations from the local adaptation hypothesis, beetles from all populations were larger, developed faster and had higher survivorship when reared on seeds of A. greggii (the larger host), irrespective of their native host. We observed two host plant-mediated maternal effects: offspring matured sooner, regardless of their rearing host, when their mothers were reared on P. guachapele (this was not caused by an effect of rearing host on egg size), and females laid larger eggs on P. guachapele. This is the first study to document plasticity by S. limbatus in response to P. guachapele, suggesting that plasticity is an ancestral trait in S. limbatus that likely plays an important role in diet expansion. Although differences between populations in growth and life history traits are likely adaptations to their host plants, host-associated maternal effects, partly mediated by maternal egg size plasticity, influence growth and life history traits and likely play an important role in the evolution of the breadth of S. limbatus' diet. More generally, phenotypic plasticity mediates the fitness consequences of using novel hosts, likely facilitating colonization of new hosts, but also buffering herbivores from selection post-colonization. Plasticity in response to novel versus normal hosts varied among our study populations such that disentangling the historical role of plasticity in

  11. 3-((3-/sup 125/I)Iodo-4-hydroxyphenyl)propionyl Carbohydrazide, a new radioiodination reagent for ultrasensitive detection and determination of periodate-oxidized nucleoside derivatives

    SciTech Connect

    Randerath, K.

    1981-08-01

    A new radioiodination reagent for the identification and quantitation of periodate-oxidized ribonucleosides was developed. The reagent, 3-((3-/sup 125/I)iodo-4-hydroxyphenyl)propionyl carbohydrazide, was prepared by radioiodination of 3-(4-hydroxyphenyl)propionic acid N-hydroxysuccinimide ester in the presence of chloramine T, followed by reduction of the latter with sodium arsenite and treatment of the radioiodinated ester with an excess of carbohydrazide. The reagent reacted quantitatively with periodate-oxidized nucleosides to form /sup 125/I-labeled morpholine derivatives which were separated by thin-layer chromatography and quantitated by liquid scintillation counting. The reagent was found to react also with other carbonyl compounds and thus may find more general application in the qualitative and quantitative ultramicroanalysis of aldehydes and ketones.

  12. Rapid method for the preparation of 125I-labelled human growth hormone for receptor studies, using reverse-phase high performance liquid chromatography

    SciTech Connect

    Ilondo, M.M.; Dehart, I.; De Meyts, P.

    1986-01-29

    Human growth hormone was labelled with 125 Iodine by the stoichiometric modification of the chloramine-T method to a specific activity of 50-80 microCi/microgram, and the iodinated mixture was purified by reverse-phase high performance liquid chromatography using a C18 column (SynChropak RP-P) and a linear gradient. Compared with the usual Sephadex G-100 chromatography, HPLC gave a much better separation, with a higher yield and a considerably reduced analysis time (30 min vs 5 h). The (125I)-labelled preparation had normal binding to IM-9 lymphocyte receptors. The maximum bindability of the HPLC-purified preparation approximated 90%, which is the best value so far reported for human growth hormone. It is concluded that HPLC is a fast, convenient and reproducible method for obtaining an improved (125I)-labelled human growth hormone for receptor studies.

  13. Presence of plasma proteins facilitates the uptake of /sup 125/I-thrombin by the rabbit thoracic aorta endothelium in vitro

    SciTech Connect

    Hatton, M.W.; Moar, S.L.

    1986-07-01

    Various purified proteins, protein derivatives and two polysaccharides were added individually to a physiological medium in order to effect uptake of /sup 125/I-thrombin by the rabbit aorta endothelium. Over a wide range of concentration (0.004-40 mg/ml), the presence of either purified rabbit or bovine albumin during thrombin uptake encouraged an increase (70-110%) in /sup 125/I-thrombin binding by the endothelium and subendothelium compared to uptake by aorta segments in the absence of added protein. Pretreatment of aorta segments with albumin before incubation with /sup 125/I-thrombin in the absence of albumin did not encourage thrombin uptake to the same extent as having /sup 125/I-thrombin and albumin together. Purified human transferrin, rabbit IgG, chicken ovalbumin or denatured bovine casein could replace albumin to produce a similar enhancement of thrombin uptake. Replacing active concentrations of albumin by either reduced-carboxymethylated albumin, defatted albumin, plasmin-treated or thermolysin-treated albumin also caused an increase (50-130%) in thrombin binding, whereas replacement by acid-hydrolysed albumin or with polyglutamic acid was either ineffective or even inhibitory. Lysine-modified or arginine-modified albumins caused a small enhancement (14-32%) and no enhancement of thrombin uptake, respectively. Dextran, at low concentration (0.04-0.4 mg/ml) did not influence thrombin uptake, and at higher concentration (4-40 mg/ml) caused a decrease in uptake by both the endothelium and subendothelial layers. Low concentration of dextran sulphate inhibited thrombin uptake to 20-30% of control values. These data express the importance of accompanying protein in the response of the vascular endothelium during binding of thrombin. The possibility that other protein-cell interactions may be similarly influenced by macromolecular solutes is also discussed.

  14. Comparison of whole body and tissue blood volumes in rainbow trout (Salmo gairdneri) with 125I bovine serum albumin and 51Cr-erythrocyte tracers

    USGS Publications Warehouse

    Gingerich, W.H.; Pityer, R.A.

    1989-01-01

    Total, packed cell and, plasma volume estimates were made for the whole body and selected tissues of rainbow trout by the simultaneous injection of radiolabelled trout erythrocyte (51Cr-RBC) and radioiodinated bovine serum albumin (125I-BSA) tracers. Blood volumes were estimated with both markers separately by the tracer-hematocrit method and as the combination of the 51Cr-RBC packed cell and 125I-BSA plasma volumes. Mean whole body blood volume was significantly less when calculated from the 51Cr-RBC tracer data (3.52±0.78 ml/100 g; ±SD) than when calculated with the 125I-BSA tracer (5.06±0.86 ml/100 g) or as the sum of the two volumes combined (4.49±0.60 ml/100 g). The whole body hematocrit (28±5%), estimated as the quotient of the 51Cr-RBC volume divided by the sum of the 125I-BSA and the 51Cr-RBC volumes, also was significantly less than the dorsal aortic microhematocrit (36±4%). Estimates of total blood volumes in most tissues were significantly smaller when calculated from the51Cr-RBC data than when calculated by the other two methods. Tissue blood volumes were greatest in highly vascularized and well perfused tissues and least in poorly vascularized tissues. The relative degree of vascularization among tissues generally remained the same regardless of whether the red cell or the plasma tracer was used to calculated blood volume. It is not clear whether the expanded plasma volume is the result of the distribution of erythrocyte-poor blood into the secondary circulation or the result of extravascular exchange of plasma proteins.

  15. Effects of oral contraceptives, or lanosterol, on ADP-induced aggregation and binding of /sup 125/I-fibrinogen to rat platelets

    SciTech Connect

    McGregor, L.; Toor, B.; McGregor, J.L.; Renaud, S.; Clemetson, K.J.

    1984-03-01

    The aggregation to ADP and the binding of /sup 125/I-fibrinogen to platelets from rats treated with oral contraceptives or normal platelets treated in vitro with lanosterol were compared to their respective controls. Both types of platelets showed a significant increase in ADP-induced aggregation and in binding of fibrinogen, indicating that the effect of oral contraceptives could be partly due to increased levels of lanosterol in platelet membrane.

  16. Biochemical and ultrastructural processing of (/sup 125/I)epidermal growth factor in rat epidermis and hair follicles: accumulation of nuclear label

    SciTech Connect

    Green, M.R.; Mycock, C.; Smith, C.G.; Couchman, J.R.

    1987-03-01

    Although the intracellular ultrastructural processing of epidermal growth factor (EGF) and its receptor have been described in cell culture systems, very few studies have examined this phenomenon in intact tissues. We have examined the ultrastructural and biochemical handling of (/sup 125/I)EGF in the epidermis and hair follicle bulb of intact, viable, 3- to 5-day-old rat skin the EGF receptor distribution of which has already been documented and in which EGF has been shown to be biologically active. After incubation of explants with 10 nM (/sup 125/I)EGF for 2.5 h at 25 degrees or 37 degrees C, radiolabel was detected over the basal cells of the epidermis and hair follicle outer root sheath, confirming previous light microscope observations. More specifically, silver grains were observed near coated and uncoated plasma membrane and coated membrane invaginations, Golgi apparatus, lysosomal structures, and nuclei. Sodium azide inhibited internalization of label, whereas a series of lysosomal inhibitors (chloroquine, monensin, and iodoacetamide) caused a slight increase in silver grains associated with lysosomal vesicles and a decrease in nuclear label. Biochemical analysis indicated that greater than 35% of radioactivity following incubation at 37 degrees C was in the form of degraded (/sup 125/I)EGF fragments and that inclusion of chloroquine, monensin, and iodoacetamide reduced this value to 20.8%, 8.6%, and 4.0%, respectively. In addition, chloramine T-prepared (/sup 125/I)EGF was found to be covalently cross-linked with low efficiency to a protein having the molecular weight of the EGF receptor. These data are discussed in the light of the effects of EGF on epithelial cell proliferation in skin.

  17. Low-LET and high-LET radiation action of {sup 125}I decays in DNA: Effect of cysteamine on micronucleus formation and cell killing

    SciTech Connect

    Hofer, K.G.; Bao, S.P.

    1995-02-01

    Chinese hamster ovary cells were pulse-labeled with {sup 125}I-iododeoxyuridine during early S phase, and cell samples were harvested 30 min or 5 h after labeling. The samples were frozen (with or without 25 mM cysteamine) and stored at -196{degrees}C for accumulation of {sup 125}I decays. X-ray control experiments were performed at 37{degrees}C and -196{degrees}C. Aliquots of cells were plated for evaluating micronucleus formation and cell survival. The results demonstrated a striking shift in micronucleus formation and cell death with time after labeling. Cells frozen 30 min after labeling exhibited effects typical of low-LET radiation, but cells frozen 5 h after labeling showed a response characteristic of high-LET radiation. Cysteamine provided protection against the effects of {sup 125}I during the initial phase of effects characteristic of low-LET radiation, but no protection was seen during the phase characteristic of high-LET radiation. When cell survival was evaluated as a function of micronucleus frequency rather than dose in decays/cell, the survival curves for all treatment groups became superimposed. Previous work using the same experimental system had failed to show a direct link between {sup 125}I-induced DNA double-strand breaks and cell death. These findings are consistent with the hypothesis that DNA damage may not be the sole mechanism for cell killing and that damage to higher-order structures in the cell nucleus may contribute to (or modify) radiation-induced cell death. 50 refs., 7 figs.

  18. Binding of (/sup 125/I)-N-(p-aminophenethyl)spiroperidol to the D-2 dopamine receptor in the neurointermediate lobe of the rat pituitary gland: a thermodynamic study

    SciTech Connect

    Agui, T.; Amlaiky, N.; Caron, M.G.; Kebabian, J.W.

    1988-02-01

    The novel iodinated ligand (/sup 125/I)-N-(p-aminophenethyl)spiroperidol ((/sup 125/I)NAPS) was used to identify the D-2 dopamine receptor in the intermediate lobe of the rat pituitary gland. The binding of (/sup 125/I)NAPS was of high affinity and saturable, given that the dissociation constant and the maximal binding were 34.7 +/- 4.8 pM and 21.1 +/- 2.5 fmol/mg of protein, respectively. The ability of dopaminergic agonists and antagonists to compete with (/sup 125/I)NAPS varied markedly with incubation temperature. The marked decrease of the molar potency associated with increasing incubation temperature in the competitive displacement curve suggested that the binding of five agonists, dopamine, (-)-apomorphine, (-)-n-propylnorapomorphine, N-0434, and LY-171555, to the D-2 dopamine receptor was enthalpy-driven, with a negative change in entropy. In contrast, the binding of three antagonists, fluphenazine, (+)-butaclamol, and domperidone, was entropy-driven, with positive change in entropy, suggesting less temperature-sensitive change in the molar potency. Several molecules gave unanticipated results; the molar potency of two dopamine agonists, bromocriptine and lisuride, was much less temperature-sensitive than the other agonists used in this study. The thermodynamic parameters for the atypical agonists indicated entropy-driven binding. Conversely, the molar potency of (+)-apomorphine, a dopamine receptor antagonist, was markedly affected by incubation temperature, indicating enthalpy-driven binding. Another antagonist, YM-09151-2, was affected by the inclusion of sodium chloride in the assay system: in the absence of sodium chloride, the drug was relatively weak and displayed enthalpy-driven binding; in the presence of sodium chloride, its molar potency was increased and its binding manner turned into entropy-driven.

  19. Simple, rapid /sup 125/I-labeled cyclosporine double antibody/polyethylene glycol radioimmunoassay used in a pediatric cardiac transplant program

    SciTech Connect

    Berk, L.S.; Webb, G.; Imperio, N.C.; Nehlsen-Cannarella, S.L.; Eby, W.C.

    1986-01-01

    We modified the Sandoz cyclosporine radioimmunoassay because of our need for frequent clinical monitoring of cyclosporine drug levels in allo- and xenograft pediatric cardiac transplant patients. With application of a commercially available (/sup 125/I)cyclosporine label in place of (/sup 3/H)cyclosporine and a second antibody/polyethylene glycol (PEG) method of separation in place of charcoal separation, we simplified and enhanced the speed and precision of assay performance. Studies of 140 whole blood samples comparing this new method to the (/sup 3/H)cyclosporine radioimmunoassay (RIA) method of Berk and colleagues yielded a coefficient of correlation of 0.96 (p less than 0.00001) with means of 626 and 667 ng/ml for (/sup 3/H)RIA and (/sup 125/I)RIA, respectively, and a regression equation of y = 28 + 1.02x. The major advantages are that total assay time is reduced to approximately 1 h; (/sup 125/I)cyclosporine label is used, avoiding the problems associated with liquid scintillation counting; and precision is enhanced by separating bound and free fractions with second antibody/PEG. These modifications should provide for greater ease of assay performance and improved clinical utility of cyclosporine monitoring not only in the pediatric but also in the adult transplant patient.

  20. Uptake and therapeutic effectiveness of /sup 125/I- and /sup 211/At-methylene blue for pigmented melanoma in an animal model system

    SciTech Connect

    Link, E.M.; Brown, I.; Carpenter, R.N.; Mitchell, J.S.

    1989-08-01

    The investigations concerning a targeted radiotherapy for pigmented melanoma with a radiolabeled phenothiazine derivative, 3,7-(dimethylamino)phenazathionium chloride (methylene blue (MTB)), were continued using melanotic and amelanotic sublines of B16 melanoma. Two radionuclides, 125I and 211At, emitting Auger electrons and alpha particles, respectively, replaced 35S previously studied since their biological effectiveness is significantly higher. In vitro autoradiography revealed a selective accumulation of methylene blue labeled with either of the radioisotopes in pigmented melanoma cells but its absence in nonpigmented cells. Treatments with (125I)MTB and (211At)MTB were performed both in vitro and in vivo, with their effectiveness determined by lung clonogenic assay. (125I)MTB proved to be relatively ineffective when incorporated into melanosomes distributed in the cytoplasm, i.e., too far away from the genome. Conspicuous therapeutic effects were achieved with (211At)MTB for pigmented melanoma only. 211At itself did not affect either of the investigated sublines of B16 melanoma confirming once again the high affinity of methylene blue to melanin. Calculations of cumulative radiation doses from (211At)MTB deposited in melanotic melanoma tumors and pigmented normal organs which would be at a particular risk led to the conclusion that (211At)MTB could be used for a highly selective and very efficient targeted radiotherapy of pigmented melanomas without damaging normal tissues.

  1. 125I-DPDYN, monoiodo(D-Pro10)dynorphin(1-11): a highly radioactive and selective probe for the study of kappa opioid receptors

    SciTech Connect

    Gairin, J.E.; Jomary, C.; Pradayrol, L.; Cros, J.; Meunier, J.C.

    1986-02-13

    The mono- and diiodinated derivatives of the kappa-selective ligand (D-Pro10)dynorphin(1-11), DPDYN, were prepared. Their binding properties at the three opioid receptor types (mu, delta and kappa) were examined and compared to those of the parent peptide. The monoiodo derivative shows a general although moderate decrease in affinity and retains high kappa selectivity (KI mu/KI kappa = 48 and KI delta/KI kappa = 140). The binding properties of the diiodo derivative are found to be dramatically decreased. Radioiodination of DPDYN leads to the monoiodinated peptide with high specific activity (700-800 Ci/mmol). In guinea-pig cerebellum membranes, a kappa-specific tissue, (125I)-labelled monoiodo(D-Pro10)dynorphin(1-11), 125I-DPDYN, interacts specifically and reversibly with a single class of binding sites (Bmax = 118 fmol/mg protein) with a high affinity (KD = 0.12 nM from equilibrium experiments, 0.18 nM from kinetics studies). Therefore, because of its high specific radioactivity, high affinity and reasonably good selectivity, 125I-DPDYN designates itself as the probe of the k-opioid receptor type.

  2. Receptor binding characterization of the benzodiazepine radioligand sup 125 I-Ro16-0154: Potential probe for SPECT (Single Photon Emission Computed Tomography) brain imaging

    SciTech Connect

    Johnson, E.W.; Woods, S.W.; Zoghbi, S.; Baldwin, R.M.; Innis, R.B. ); McBride, B.J. )

    1990-01-01

    The binding of an iodinated benzodiazepine (BZ) radioligand has been characterized, particularly in regard to its potential use as a neuroreceptor brain imaging agent with SPECT (Single Photon Emission Computed Tomography). Ro16-0154 is an iodine-containing BZ antagonist and a close analog of Ro15-1788. In tissue homogenates prepared from human and monkey brain, the binding of {sup 125}I-labeled Ro16-0154 was saturable, of high affinity, and had high ratios of specific to non-specific binding. Physiological concentrations of NaCl enhanced specific binding approximately 15% compared to buffer without this salt. Kinetic studies of association and dissociation demonstrated a temperature dependent decrease in affinity with increasing temperature. Drug displacement studies confirmed that {sup 125}I-Ro16-0154 binds to the central type BZ receptor: binding is virtually identical to that of {sup 3}H-Ro15-1788 except that {sup 125}I-Ro16-0154 shows an almost 10 fold higher affinity at 37{degree}C. These in vitro results suggest that {sup 123}I-labeled Ro16-0154 shows promise as a selective, high affinity SPECT probe of the brain's BZ receptor.

  3. Relationship of changing delta 4-steroid 5 alpha-reductase activity to (125I)iododeoxyuridine uptake during regeneration of involuted rat prostates

    SciTech Connect

    Kitahara, S.; Higashi, Y.; Takeuchi, S.; Oshima, H. )

    1989-04-01

    To elucidate the phenotypic expression of proliferating prostatic cells, rats were castrated, and the regenerating process of involuted ventral prostates during testosterone propionate (TP) administration was investigated by examining morphology, (5-{sup 125}I)iododeoxyuridine ({sup 125}I-UdR) uptake, DNA content, weight, acid phosphatase, and delta 4-steroid 5 alpha-reductase (5 alpha-reductase) activities. Morphologically, TP treatment initially increased the number of epithelial cells lining glandular lobules and subsequently restored the shape of epithelial cells. {sup 125}I-UdR uptake peaked on Day 3 of TP treatment and stayed at higher levels than for uncastrated controls until Day 14 of treatment. Prostatic weight, protein content, acid phosphatase, and DNA content returned to uncastrated control levels by Day 14 of TP treatment. TP administration markedly stimulated prostatic 5 alpha-reductase activity, which peaked on the Day 5 of treatment and decreased to uncastrated control levels by Day 14 of treatment. It is concluded that TP administration to castrated rats initially induced active mitotic division of the remaining stem cells, followed by formation of differentiated functional epithelial cells. Prostatic 5 alpha-reductase was highly active at the initial phase of active mitotic cell division. The major portion of the increased enzyme activity can be regarded as a phenotypic expression of stem or transient cells of prostatic epithelium.

  4. Survival of patients with advanced pancreatic cancer after iodine125 seeds implantation brachytherapy

    PubMed Central

    Han, Quanli; Deng, Muhong; Lv, Yao; Dai, Guanghai

    2017-01-01

    Abstract Background: Brachytherapy with iodine125-labeled seeds (125I-seeds) implantation is increasingly being used to treat tumors because of its positional precision, minimal invasion, least damage to noncancerous tissue due to slow and continuous release of radioactivity and facilitation with modern medical imaging technologies. This study evaluates the survival and pain relief outcomes of the 125I-seeds implantation brachytherapy in advanced pancreatic cancer patients. Methods: Literature search was carried out in multiple electronic databases (Google Scholar, Embase, Medline/PubMed, and Ovid SP) and studies reporting I125 seeds implantation brachytherapy in pancreatic cancer patients with unresectable tumor were selected by following predetermined eligibility criteria. Random effects meta-analysis was performed to achieve inverse variance weighted effect size of the overall survival rate after the intervention. Sensitivity and subgroups analyses were also carried out. Results: Twenty-three studies (824 patients’ data) were included in the meta-analysis. 125I-seeds implantation brachytherapy alone was associated with 8.98 [95% confidence interval (CI): 6.94, 11.03] months (P < 0.00001) overall survival with 1-year survival of 25.7 ± 9.3% (mean ± standard deviation; SD) and 2-year survival was 17.9 ± 8.6% (mean ± SD). In stage IV pancreatic cancer patients, overall survival was 7.13 [95% CI: 4.75, 9.51] months (P < 0.00001). In patients treated with 125I-seeds implantation along with 1 or more therapies, overall survival was 11.75 [95% CI: 9.84, 13.65] months (P < 0.00001) with 1-year survival of 47.4 ± 22.75% (mean ± SD) and 2-year survival was 16.97 ± 3.1% (mean ± SD). 125I-seeds brachytherapy was associated with relief of pain in 79.7 ± 9.9% (mean ± SD) of the patients. Conclusions: Survival of pancreatic cancer patients after 125I-seeds implantation brachytherapy is found to be 9 months

  5. Observational Signatures of High-Redshift Quasars and Local Relics of Black Hole Seeds

    NASA Astrophysics Data System (ADS)

    Reines, Amy E.; Comastri, Andrea

    2016-10-01

    Observational constraints on the birth and early evolution of massive black holes come from two extreme regimes. At high redshift, quasars signal the rapid growth of billion-solar-mass black holes and indicate that these objects began remarkably heavy and/or accreted mass at rates above the Eddington limit. At low redshift, the smallest nuclear black holes known are found in dwarf galaxies and provide the most concrete limits on the mass of black hole seeds. Here, we review current observational work in these fields that together are critical for our understanding of the origin of massive black holes in the Universe.

  6. Distribution of Non-AT1, Non-AT2 Binding of 125I-Sarcosine1, Isoleucine8 Angiotensin II in Neurolysin Knockout Mouse Brains

    PubMed Central

    Speth, Robert C.; Carrera, Eduardo J.; Bretón, Catalina; Linares, Andrea; Gonzalez-Reiley, Luz; Swindle, Jamala D.; Santos, Kira L.; Schadock, Ines; Bader, Michael; Karamyan, Vardan T.

    2014-01-01

    The recent identification of a novel binding site for angiotensin (Ang) II as the peptidase neurolysin (E.C. 3.4.24.16) has implications for the renin-angiotensin system (RAS). This report describes the distribution of specific binding of 125I-Sarcosine1, Isoleucine8 Ang II (125I-SI Ang II) in neurolysin knockout mouse brains compared to wild-type mouse brains using quantitative receptor autoradiography. In the presence of p-chloromercuribenzoic acid (PCMB), which unmasks the novel binding site, widespread distribution of specific (3 µM Ang II displaceable) 125I-SI Ang II binding in 32 mouse brain regions was observed. Highest levels of binding >700 fmol/g initial wet weight were seen in hypothalamic, thalamic and septal regions, while the lowest level of binding <300 fmol/g initial wet weight was in the mediolateral medulla. 125I-SI Ang II binding was substantially higher by an average of 85% in wild-type mouse brains compared to neurolysin knockout brains, suggesting the presence of an additional non-AT1, non-AT2, non-neurolysin Ang II binding site in the mouse brain. Binding of 125I-SI Ang II to neurolysin in the presence of PCMB was highest in hypothalamic and ventral cortical brain regions, but broadly distributed across all regions surveyed. Non-AT1, non-AT2, non-neurolysin binding was also highest in the hypothalamus but had a different distribution than neurolysin. There was a significant reduction in AT2 receptor binding in the neurolysin knockout brain and a trend towards decreased AT1 receptor binding. In the neurolysin knockout brains, the size of the lateral ventricles was increased by 56% and the size of the mid forebrain (−2.72 to +1.48 relative to Bregma) was increased by 12%. These results confirm the identity of neurolysin as a novel Ang II binding site, suggesting that neurolysin may play a significant role in opposing the pathophysiological actions of the brain RAS and influencing brain morphology. PMID:25147932

  7. Distribution of non-AT1, non-AT2 binding of 125I-sarcosine1, isoleucine8 angiotensin II in neurolysin knockout mouse brains.

    PubMed

    Speth, Robert C; Carrera, Eduardo J; Bretón, Catalina; Linares, Andrea; Gonzalez-Reiley, Luz; Swindle, Jamala D; Santos, Kira L; Schadock, Ines; Bader, Michael; Karamyan, Vardan T

    2014-01-01

    The recent identification of a novel binding site for angiotensin (Ang) II as the peptidase neurolysin (E.C. 3.4.24.16) has implications for the renin-angiotensin system (RAS). This report describes the distribution of specific binding of 125I-Sarcosine1, Isoleucine8 Ang II (125I-SI Ang II) in neurolysin knockout mouse brains compared to wild-type mouse brains using quantitative receptor autoradiography. In the presence of p-chloromercuribenzoic acid (PCMB), which unmasks the novel binding site, widespread distribution of specific (3 µM Ang II displaceable) 125I-SI Ang II binding in 32 mouse brain regions was observed. Highest levels of binding >700 fmol/g initial wet weight were seen in hypothalamic, thalamic and septal regions, while the lowest level of binding <300 fmol/g initial wet weight was in the mediolateral medulla. 125I-SI Ang II binding was substantially higher by an average of 85% in wild-type mouse brains compared to neurolysin knockout brains, suggesting the presence of an additional non-AT1, non-AT2, non-neurolysin Ang II binding site in the mouse brain. Binding of 125I-SI Ang II to neurolysin in the presence of PCMB was highest in hypothalamic and ventral cortical brain regions, but broadly distributed across all regions surveyed. Non-AT1, non-AT2, non-neurolysin binding was also highest in the hypothalamus but had a different distribution than neurolysin. There was a significant reduction in AT2 receptor binding in the neurolysin knockout brain and a trend towards decreased AT1 receptor binding. In the neurolysin knockout brains, the size of the lateral ventricles was increased by 56% and the size of the mid forebrain (-2.72 to +1.48 relative to Bregma) was increased by 12%. These results confirm the identity of neurolysin as a novel Ang II binding site, suggesting that neurolysin may play a significant role in opposing the pathophysiological actions of the brain RAS and influencing brain morphology.

  8. Feasibility of vibro-acoustography with a quasi-2D ultrasound array transducer for detection and localizing of permanent prostate brachytherapy seeds: A pilot ex vivo study

    SciTech Connect

    Mehrmohammadi, Mohammad; Kinnick, Randall R.; Fatemi, Mostafa; Alizad, Azra; Davis, Brian J.

    2014-09-15

    Purpose: Effective permanent prostate brachytherapy (PPB) requires precise placement of radioactive seeds in and around the prostate. The impetus for this research is to examine a new ultrasound-based imaging modality, vibro-acoustography (VA), which may serve to provide a high rate of PPB seed detection while also effecting enhanced prostate imaging. The authors investigate the ability of VA, implemented on a clinical ultrasound (US) scanner and equipped with a quasi-2D (Q2D) array US transducer, to detect and localize PPB seeds in excised prostate specimens. Methods: Nonradioactive brachytherapy seeds were implanted into four excised cadaver prostates. A clinical US scanner equipped with a Q2D array US transducer was customized to acquire both US and C-scan VA images at various depths. The VA images were then used to detect and localize the implanted seeds in prostate tissue. To validate the VA results, computed tomography (CT) images of the same tissue samples were obtained to serve as the reference by which to evaluate the performance of VA in PPB seed detection. Results: The results indicate that VA is capable of accurately identifying the presence and distribution of PPB seeds with a high imaging contrast. Moreover, a large ratio of the PPB seeds implanted into prostate tissue samples could be detected through acquired VA images. Using CT-based seed identification as the standard, VA was capable of detecting 74%–92% of the implanted seeds. Additionally, the angular independency of VA in detecting PPB seeds was demonstrated through a well-controlled phantom experiment. Conclusions: Q2DVA detected a substantial portion of the seeds by using a 2D array US transducer in excised prostate tissue specimens. While VA has inherent advantages associated with conventional US imaging, it has the additional advantage of permitting detection of PPB seeds independent of their orientation. These results suggest the potential of VA as a method for PPB imaging that

  9. The production, localization and spreading of reactive oxygen species contributes to the low vitality of long-term stored common beech (Fagus sylvatica L.) seeds.

    PubMed

    Ratajczak, Ewelina; Małecka, Arleta; Bagniewska-Zadworna, Agnieszka; Kalemba, Ewa Marzena

    2015-02-01

    The common beech (Fagus sylvatica L.) is propagated by seeds, but the seed set is irregular with five to ten years in between crops. It is therefore necessary to store the seeds. However, beech seeds lose germinability during long-term storage. In this study, beech seeds were stored at -10°C under controlled conditions for 2, 5, 8, 11 and 13 years. Our results show that beech seeds lose germinability during storage in proportion to the duration of storage. The decrease in germinability correlated with increased electrolyte leakage and accumulation of superoxide anion radicals, hydrogen peroxide and hydroxyl radicals. Furthermore, a strong positive correlation was observed among the releases of superoxide anion radicals, hydrogen peroxide and hydroxyl radicals. In situ localization showed that superoxide anion radicals and hydrogen peroxide were first detectable in root cap cells. When the seed storage time was extended, the reactive oxygen species fluorescence expanded to more areas of the radicle, reaching the root apical meristem. A storage time-dependent decrease in catalase activity, observed in both embryonic axes and cotyledons, was also positively correlated with germinability. DNA fragmentation was observed in beech seeds during storage and occurred predominantly in embryonic axes stored for 5 years and more. Altogether, these results suggest that the loss of germinability in beech seeds during long-term storage depends on several factors, including strong of reactive oxygen species accumulation accompanied by reduced catalase activity as well as membrane injury and DNA alternations, which may be aging-related and ROS-derived. We suggest that the accumulating reactive oxygen species that spread to the root apical meristem are key factors that affect seed germinability after long-term storage.

  10. Ethnolinguistic structuring of sorghum genetic diversity in Africa and the role of local seed systems.

    PubMed

    Westengen, Ola T; Okongo, Mark Atam; Onek, Leo; Berg, Trygve; Upadhyaya, Hari; Birkeland, Siri; Kaur Khalsa, Siri Dharma; Ring, Kristoffer H; Stenseth, Nils C; Brysting, Anne K

    2014-09-30

    Sorghum is a drought-tolerant crop with a vital role in the livelihoods of millions of people in marginal areas. We examined genetic structure in this diverse crop in Africa. On the continent-wide scale, we identified three major sorghum populations (Central, Southern, and Northern) that are associated with the distribution of ethnolinguistic groups on the continent. The codistribution of the Central sorghum population and the Nilo-Saharan language family supports a proposed hypothesis about a close and causal relationship between the distribution of sorghum and languages in the region between the Chari and the Nile rivers. The Southern sorghum population is associated with the Bantu languages of the Niger-Congo language family, in agreement with the farming-language codispersal hypothesis as it has been related to the Bantu expansion. The Northern sorghum population is distributed across early Niger-Congo and Afro-Asiatic language family areas with dry agroclimatic conditions. At a finer geographic scale, the genetic substructure within the Central sorghum population is associated with language-group expansions within the Nilo-Saharan language family. A case study of the seed system of the Pari people, a Western-Nilotic ethnolinguistic group, provides a window into the social and cultural factors involved in generating and maintaining the continent-wide diversity patterns. The age-grade system, a cultural institution important for the expansive success of this ethnolinguistic group in the past, plays a central role in the management of sorghum landraces and continues to underpin the resilience of their traditional seed system.

  11. Differential photoaffinity labeling of catalytic subunits of NaK-ATPase with carrier-free /sup 125/I-cardiac glycosides

    SciTech Connect

    Lowndes, J.; Hokin-Neaverson, M.; Ruoho, A.

    1986-05-01

    The authors have obtained evidence for structural differences in the cardiac glycoside binding site between the ..cap alpha.. and ..cap alpha..(+) forms of the catalytic subunit of NaK-ATPase, using three closely related photoaffinity derivatives of the cardiotonic steroid, digitoxigenin. (/sup 125/I)N-(p-azido-m-iodo-o-hydroxybenzoyl)-4-amino-4,6-dideoxy-galactosyl digitoxigenin (IA-GaD), (/sup 125/I)N-(3-(p-azido-m-iodophenyl)-propionyl)-4-amino-4,6-dideoxy-ga-lactosyl digitoxigenin (AIPP-GaD) and (/sup 125/I)N-(3-(p-azido-m-iodophenyl)-propionyl)-4-amino-4,6-dideoxy-glucosyl digitoxi-genin (AIPP-GluD) were synthesized. AIPP-GaD and AIPP-GluD are stereoisomers. Eel electroplax and dog kidney NaK-ATPase (..cap alpha.. form) and rat brain synaptosomes (rich in ..cap alpha..(+) form) were photolabelled and then analyzed by SDS-PAGE and autoradiography. Photolysis with either carrier-free IA-GaD or AIPP-GluD gave ouabain-protectable labelling of NaK-ATPase catalytic subunit from all three tissues. However, photolysis with AIPP-GaD showed protectable labelling of the enzyme from eel and kidney but not from brain. This suggests a structural difference in the ..cap alpha..(+) form which results in either an inability to bind AIPP-GaD, or, perhaps more likely, an absence of a photoinsertion site in the correct location in the ..cap alpha..(+) form, as compared with the ..cap alpha.. form. It is of interest that the labelling pattern of the enzyme in the human erythrocyte resembles that of the brain enzyme.

  12. The inhibition of PB125I formation in calf thyroid caused by 14-iodo-15-hydroxy-eicosatrienoic acid is due to decreased H2O2 availability.

    PubMed

    Krawiec, L; Chazenbalk, G D; Puntarulo, S A; Burton, G; Boveris, A; Valsecchi, R M; Pisarev, M A

    1988-02-01

    Previous work from our laboratory has shown that 14-iodo-15-hydroxy-5,8,11-eicosatrienoic acid (I-HO-A) is a potent inhibitor of iodine organification in calf thyroid slices. The present studies were performed in order to clarify the mechanism of this action. Incubation of thyroid slices with 10(-4)M I-HO-A caused a 47 and 53% decrease in PB125I formation after 30 and 60 min incubation, respectively. In a series of experiments an inverse relationship between the degree of inhibition caused by I-HO-A and total iodine content and basal iodoprotein formation was observed. Chromatographic analysis of the labeled compounds showed a significant decrease in 125I incorporation into MIT, DIT, T3 and total iodolipid. The site of the inhibitory effect of I-HO-A was then sought. TPO was measured by three different methods. When TPO was solubilized from I-HO-A treated slices, no change in enzymatic activity was observed. Moreover, the same lack of action was found when solubilized TPO was incubated with I-HO-A. The production and release of H2O2 into the incubation medium was measured by chemiluminiscence technique. In control slices the values increased during the first 10 min and reached a plateau. Pretreatment of the slices with 10(-4)M KI caused a 51% inhibition, while the same concentration of I-HO-A produced a 59% inhibition. The possibility that I-HO-A might exert its action through a putative protein inhibitor was also explored. Incubation of slices with 10(-5)M I-HO-A caused a 46% decrease in PB125I formation and addition of actinomycin D or puromycin failed to alter this effect.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Characterization and distribution of (125I)epidepride binding to dopamine D2 receptors in basal ganglia and cortex of human brain

    SciTech Connect

    Joyce, J.N.; Janowsky, A.; Neve, K.A. )

    1991-06-01

    The distribution and pharmacology of the binding of {sup 125}I-epidepride, a substituted benzamide with high affinity and selectivity for dopamine (DA) D2 receptors in rat brain is described in human brain. Saturation analysis of the binding of {sup 125}I-epidepride to membranes derived from striatum and regions of cortex demonstrated similar Kd values (34 and 28-33 pM, respectively) but differing maximum density of binding site values (152 and 3-8 fmol/mg of protein, respectively). The pharmacological profile of binding in cortex was also similar to striatum (epidepride greater than spiperone greater than butaclamol = flupenthixol greater than clozapine) except that an additional low-affinity site, blocked by the alpha-2 adrenergic antagonist idazoxan, was present in cortex. Quantification by autoradiography also demonstrated the greatest binding in the basal ganglia, with the striatum exhibiting greater binding than the pallidal complex or midbrain regions. For the pallidum, binding in the external segment was higher than the internal segment. Within the midbrain the binding of {sup 125}I-epidepride correlated well with the known distribution of DA-containing cell bodies, with the substantia nigra (pars compacta and pars lateralis) and ventral tegmental area (A10) higher than area A8 and central gray. Binding in frontal and parietal cortex was highest in the internal layers (layers V and VI). Temporal cortex showed a 2-fold higher density of binding than other cortical regions and a trilaminar pattern; binding was greater in the external (layers I and II) and internal layers than in the middle layers (III and IV). This pattern changed in the parahippocampal complex. Within the lateral occipitotemporal cortex, binding was densest in layers I to III and very low in layers IV to VI, but binding was almost nonexistent in the adjacent entorhinal cortex.

  14. Ultrasonically guided percutaneous implantation of iodine-125 seeds in pancreatic carcinoma

    SciTech Connect

    Joyce, F.; Burcharth, F.; Holm, H.H.; Stroyer, I. )

    1990-10-01

    Cancer of the pancreas is most often not diagnosed before it has reached unresectable stages. The development of effective palliative treatment for these patients and for those with recurrence after resection is clearly needed. The present study reports the results of ultrasonically guided percutaneous implantation of {sup 125}I seeds in 19 patients with cancer of the pancreas. Twelve patients had further adjuvant external radiation. Despite satisfactory seed placement and delivery of the planned radiation dose in most cases, clinical improvement was lacking or only slight and short-lived. No difference in survival or palliation was observed between patients treated with seeds alone compared with patients treated with seeds and external radiation. Survival after seed implantation was short (median 140 days, range 7-401 days). Ultrasonically guided percutaneous implantation of {sup 125}I seeds cannot be recommended in the treatment of unresectable carcinoma of the pancreas.

  15. ATP-dependent degradation of /sup 125/I-bovine serum albumin by rabbit reticulocytes does not need repression of an endogenous inhibitor

    SciTech Connect

    Saus, J.; Timoneda, J.

    1987-01-01

    The ubiquitin-dependent proteolysis of /sup 125/I-bovine serum albumin in rabbit reticulocytes has been investigated. Using various reticulocyte fractions (reticulocyte protease, inhibitor-free protease, ubiquitin and inhibitor) in the presence or absence of ATP, we found that the repression of an endogenous inhibitor, as suggested by others for alpha-casein proteolysis, is unlikely for bovine serum albumin. Therefore, differences exist in the ATP-dependent proteolytic pathway of rabbit reticulocytes depending on the substrate. Fractionation of the reticulocyte ATP-dependent proteolytic system revealed at least two proteolytic and two inhibitory fractions involved in the proteolysis of bovine serum albumin.

  16. Preparation of stable sup 125 I cyclic GMP tyrosine methyl ester suitable for 3',5' cyclic GMP radioimmunoassay by HPLC

    SciTech Connect

    Thompson, M.R.; Luttrell, M.; Giannella, R.A. )

    1990-01-01

    Determination of the concentration of cyclic guanosine monophosphate (cGMP) by radioimmunoassay (RIA) depends upon the availability of suitable radiolabeled tracers and antibody to detect the product. Reverse phase chromatographic techniques can easily separate the reaction products of chloramine-T iodination of succinyl cGMP tyrosine methyl ester. The binding characteristics of the iodination reaction products to anti-cGMP antibody have been determined. Purified succinyl cyclic nucleotide 125I-tyrosine methyl ester binds to cGMP antisera identically as commercially available tracer. The tracer is stable for greater than three months.

  17. Studies of the biogenic amine transporters. IV. Demonstration of a multiplicity of binding sites in rat caudate membranes for the cocaine analog [125I]RTI-55.

    PubMed

    Rothman, R B; Cadet, J L; Akunne, H C; Silverthorn, M L; Baumann, M H; Carroll, F I; Rice, K C; de Costa, B R; Partilla, J S; Wang, J B

    1994-07-01

    The drug 3 beta-[4'-iodophenyl]tropan-2 beta-carboxylic acid methyl ester (RTI-55) is a cocaine congener with high affinity for the dopamine transporter (Kd < 1 nM). The present study characterized [125I]RTI-55 binding to membranes prepared from rat, monkey and human caudates and COS cells transiently expressing the cloned rat dopamine (DA) transporter. Using the method of binding surface analysis, two binding sites were resolved in rat caudate: a high-capacity binding site (site 1, Bmax = 11,900 fmol/mg of protein) and a low-capacity site (site 2, Bmax = 846 fmol/mg of protein). The Kd (or Ki) values of selected drugs at the two sites were as follows: (Ki for high-capacity site and Ki for low-capacity site, respectively): RTI-55 (0.76 and 0.21 nM), 1-[2-diphenyl-methoxy)ethyl]-4-(3-phenylpropyl)piperazine (0.79 and 358 nM), mazindol (37.6 and 631 nM), 2 beta-carbomethoxy-3 beta-(4-fluorophenyl)tropane (45.0 and 540 nM) and cocaine (341 and 129 nM). Nisoxetine, a selective noradrenergic uptake blocker, had low affinity for both sites. Serotonergic uptake blockers had a high degree of selectivity and high affinity for the low-capacity binding site (Ki of citalopram = 0.38 nM; Ki of paroxetine = 0.033 nM). The i.c.v. administration of 5,7-dihydroxytryptamine to rats pretreated with nomifensine (to protect dopaminergic and noradrenergic nerve terminals) selectively decreased the Bmax of site 2, strongly supporting the idea that site 2 is a binding site on the serotonin (5-HT) transporter. This serotonergic lesion also increased the affinity of [125I]RTI-55 for the DA transporter by 10-fold. The ligand selectivity of the caudate 5-HT transporter was different from the [I125]RTI-55 binding site on the 5-HT transporter present in membranes prepared from whole rat brain minus caudate. The [125I]RTI-55 binding to the DA transporter was further resolved into two components, termed sites 1a and 1b, by using human and monkey (Macaca mulatta) caudate membranes but not the

  18. Incidence and specificity of antibodies to types I, II, III, IV, and V collagen in rheumatoid arthritis and other rheumatic diseases as measured by 125I-radioimmunoassay

    SciTech Connect

    Stuart, J.M.; Huffstutter, E.H.; Townes, A.S.; Kang, A.H.

    1983-07-01

    Antibodies to human native and denatured types I, II, III, IV, and V collagens were measured using 125I-radioimmunoassay. Mean levels of binding by sera from 30 rheumatoid arthritis patients were significantly higher than those from 20 normal subjects against all of the collagens tested. The relative antibody concentration was higher in synovial fluid than in simultaneously obtained serum. Many patients with gout or various other rheumatic diseases also had detectable anticollagen antibodies. With a few notable exceptions, the majority of the reactivity detected in all patient groups was directed against covalent structural determinants present on all of the denatured collagens, suggesting a secondary reaction to tissue injury.

  19. No effect of seed source on multiple aspects of ecosystem functioning during ecological restoration: cultivars compared to local ecotypes of dominant grasses

    PubMed Central

    Baer, Sara G; Gibson, David J; Gustafson, Danny J; Benscoter, Allison M; Reed, Lewis K; Campbell, Ryan E; Klopf, Ryan P; Willand, Jason E; Wodika, Ben R

    2014-01-01

    Genetic principles underlie recommendations to use local seed, but a paucity of information exists on the genetic distinction and ecological consequences of using different seed sources in restorations. We established a field experiment to test whether cultivars and local ecotypes of dominant prairie grasses were genetically distinct and differentially influenced ecosystem functioning. Whole plots were assigned to cultivar and local ecotype grass sources. Three subplots within each whole plot were seeded to unique pools of subordinate species. The cultivar of the increasingly dominant grass, Sorghastrum nutans, was genetically different than the local ecotype, but genetic diversity was similar between the two sources. There were no differences in aboveground net primary production, soil carbon accrual, and net nitrogen mineralization rate in soil between the grass sources. Comparable productivity of the grass sources among the species pools for four years shows functional equivalence in terms of biomass production. Subordinate species comprised over half the aboveground productivity, which may have diluted the potential for documented trait differences between the grass sources to influence ecosystem processes. Regionally developed cultivars may be a suitable alternative to local ecotypes for restoration in fragmented landscapes with limited gene flow between natural and restored prairie and negligible recruitment by seed. PMID:24567751

  20. A comparative study of seed localization and dose calculation on pre- and post-implantation ultrasound and CT images for low-dose-rate prostate brachytherapy

    NASA Astrophysics Data System (ADS)

    Ali, Imad; Algan, Ozer; Thompson, Spencer; Sindhwani, Puneet; Herman, Terence; Cheng, Chih-Yao; Ahmad, Salahuddin

    2009-09-01

    This work investigates variation in the volume of the prostate measured at different stages through the prostate brachytherapy procedure for 30 patients treated with I-125 radioactive seeds. The implanted seeds were localized on post-implantation ultrasound (US) images and the effect of prostate enlargement due to edema on dose coverage for 15 patients was studied. The volume of the prostate was measured at four stages as follows: (a) 2-3 weeks prior to implantation using US imaging, (b) then at the start of the intra-operative prostate brachytherapy procedure on the day of the implant, (c) immediately post-implantation using US imaging in the operating room and (d) finally by CT imaging at nearly 4 weeks post-implantation. Comparative prostate volume studies were performed using US imaging stepper and twister modes. For the purpose of this study, the implanted seeds were localized successfully on post-implant ultrasound twister images, retrospectively. The plans using post-implant US imaging were compared with intra-operative plans on US and plans created on CT images. The prostate volume increases about 10 cm3 on average due to edema induced by needle insertion and seed loading during implantation. The visibility of the implanted seeds on US twister images acquired post-implantation is as good as those on CT images and can be localized and used for dose calculation. The dose coverage represented by parameters such as D90 (dose covering 90% of the volume) and V100 (volume covered by 100% dose) is poorer on plans performed on post-implantation twister US studies than on the intra-operative live plan or the CT scan performed 4 weeks post-operatively. For example, the mean D90 difference on post-implantation US is lower by more than 15% than that on pre-implantation US. The volume enlargement of the prostate due to edema induced by needle insertion and seed placement has a significant effect on the quality of dosimetric coverage in brachytherapy prostate seed

  1. Nanodosimetry of Auger electrons: A case study from the decay of 125I and 0-18-eV electron stopping cross sections of cytosine

    NASA Astrophysics Data System (ADS)

    Michaud, M.; Bazin, M.; Sanche, L.

    2013-03-01

    Radiopharmaceuticals emitting Auger electrons are often injected into patients undergoing cancer treatment with targeted radionuclide therapy (TRT). In this type of radiotherapy, the radiation source is radial and most of the emitted primary particles are low-energy electrons (LEEs) having kinetic energies distributed mostly from zero to a few hundred electron volts with very short ranges in biological media. These LEEs generate a high density of energy deposits and clustered damage, thus offering a relative biological effectiveness comparable to that of alpha particles. In this paper, we present a simple model and corresponding measurements to assess the energy deposited near the site of the radiopharmaceuticals in TRT. As an example, a calculation is performed for the decay of a single 125I radionuclide surrounded by a 1-nm-radius spherical shell of cytosine molecules using the energy spectrum of LEEs emitted by 125I along with their stopping cross sections between 0 and 18 eV. The dose absorbed by the cytosine shell, which occupies a volume of 4 nm3, is extremely high. It amounts to 79 kGy per decay of which 3%, 39%, and 58% is attributed to vibrational excitations, electronic excitations, and ionization processes, respectively.

  2. Monoclonal antibodies to human plasma low-density lipoproteins. I. Enhanced binding of 125I-labeled low-density lipoproteins by combined use of two monoclonal antibodies.

    PubMed

    Mao, S J; Patton, J G; Badimon, J J; Kottke, B A; Alley, M C; Cardin, A D

    1983-11-01

    Four monoclonal antibodies (IgG2b) to human plasma low-density lipoproteins (LDL) have been characterized. The binding affinities of each monoclonal antibody to 125I-labeled LDL were moderately high, ranging from 10(8) to 10(10) L/mol at 4 degrees C, but were reduced by at least 50-70% at 37 degrees C. The maximum binding of each monoclonal antibody was unique, ranging from 20 to 95% of total 125I-labeled LDL, suggesting that LDL particles were immunochemically heterogeneous. One antibody, LP-34, had both high and low binding affinities to LDL. Another, LP-47, exhibited high affinity for isolated LDL, yet reacted poorly with native LDL in plasma, indicating that the conformation of isolated LDL differs from that of native LDL in plasma. Unlike polyclonal serum antibodies, a mixture of four monoclonal antibodies failed to precipitate LDL, but did show a drastic increase in binding to LDL. We found that only two of our monoclonal antibodies were necessary for such synergistic enhancement. We propose that one of the monoclonal antibodies may serve as a catalytic reagent, and discuss the clinical significance of this finding.

  3. Development of beta 1 and beta 2 adrenergic receptors in baboon brain: an autoradiographic study using (/sup 125/I)iodocyanopindolol

    SciTech Connect

    Slesinger, P.A.; Lowenstein, P.R.; Singer, H.S.; Walker, L.C.; Casanova, M.F.; Price, D.L.; Coyle, J.T.

    1988-07-15

    (125I)iodocyanopindolol (ICYP) autoradiography was used to investigate the temporal development and distribution of beta 1 and beta 2 receptors in brains of baboons at ages embryonic day 100 (E100), full-term gestation (El80), and 3 years. In all brain regions examined, with the exception of the hippocampus, binding to beta 1 receptors exceeded that to beta 2 receptors. The highest densities of beta 1 receptors were found in the caudate nucleus, putamen, globus pallidus, substantia nigra, and cerebral cortex; intermediate receptor densities were observed in most nuclei of thalamus, and the lowest concentrations were in the hippocampus. At E100, beta receptors were identified in the striatum, globus pallidus, and thalamus. During maturation, the number of beta 1 receptors declined in cortical areas but increased in the head of the caudate and putamen. Significant differences in the developmental distribution of beta receptors during development were also detected: at E100 and E180 beta 1 receptors appeared as patches in the caudate and putamen, but by 3 years of age they were more homogeneously distributed in both regions; changes also occurred in the distribution of binding within cortical layers. Autoradiograms of (125I)ICYP and (3H)mazindol binding show overlapping patches of labeling in the E180 striatum, suggesting a possible developmental association between beta receptors and dopamine high-affinity uptake carrier sites. This study demonstrates that noradrenergic receptors in the primate forebrain undergo significant developmental reorganization with regional variations.

  4. Preparation of /sup 125/I-labeled human growth hormone of high quality binding properties endowed with long-term stability

    SciTech Connect

    Biscayart, P.L.; Paladini, A.C.; Vita, N.; Roguin, L.P.

    1989-01-01

    /sup 125/I-labeled human growth hormone (/sup 125/I-labeled.hGH) was prepared by using two variants of the chloramine T labelling procedure and purified by polyacrylamide gel electrophoresis (PAGE) of the reaction mixture. Variant A produced a tracer with high specific activity (100 +/- 10 microCi/microgram), high maximal binding capacity to antibodies (93%) and long-term stability (at least 150 days at -20/degree/C). No diiodinated tyrosil residues could be detected in this tracer. Variant B was devised to obtain higher yields of labeled hormone. The electrophoresis of the iodination mixture revealed two radioactive components with Rm values of 0.49 and 0.55 which result from the iodination of hGH variants preexisting in the starting material. Both tracers had similar specific activities (70 +/- 10 microCi/microgram), high maximal binding capacity to antibodies or receptors (80-100%, after 80 days of their obtention) and high stability (at least 100 days at -20/degree/C). It is concluded that the iododerivatives of hGH obtained by either method are adequate to perform radioimmunoassay and receptor studies and have long-term stability.

  5. Lymphatic flow in humans as indicated by the clearance of /sup 125/I-labeled albumin from the subcutaneous tissue of the leg

    SciTech Connect

    Fernandez, M.J.; Davies, W.T.; Owen, G.M.; Tyler, A.

    1983-08-01

    Since the removal of albumin from the extracellular space and its return to the vascular compartment is the essential function of the lymphatic system, the rate at which it is removed from the interstitial tissue may be regarded as a means of estimating lymphatic efficiency. An objective measure of lymphatic function can be obtained by monitoring the rate of clearance following injection of /sup 125/I-labeled albumin (RIHSA) from the subcutaneous tissue of a limb. The clearance of /sup 125/I-RIHSA from lower limb was monitored in a group of patients with normal limbs, patients with unilateral edema due to deep vein thrombosis, and patients with bilateral edema due to hypoproteinemia. The mean T1/2 in normal legs was 32.7 hr, compared to 23.7 hr in edematous limbs due to deep vein thrombosis and 19.4 in edematous limbs due to hypoproteinemia. There is a clear-cut difference in clearance rate between edematous and nonedematous limbs. This suggests that lymphatic flow is increased in edema due to venous obstruction and hypoproteinemia.

  6. Monte Carlo calculated microdosimetric spread for cell nucleus-sized targets exposed to brachytherapy 125I and 192Ir sources and 60Co cell irradiation.

    PubMed

    Villegas, Fernanda; Tilly, Nina; Ahnesjö, Anders

    2013-09-07

    The stochastic nature of ionizing radiation interactions causes a microdosimetric spread in energy depositions for cell or cell nucleus-sized volumes. The magnitude of the spread may be a confounding factor in dose response analysis. The aim of this work is to give values for the microdosimetric spread for a range of doses imparted by (125)I and (192)Ir brachytherapy radionuclides, and for a (60)Co source. An upgraded version of the Monte Carlo code PENELOPE was used to obtain frequency distributions of specific energy for each of these radiation qualities and for four different cell nucleus-sized volumes. The results demonstrate that the magnitude of the microdosimetric spread increases when the target size decreases or when the energy of the radiation quality is reduced. Frequency distributions calculated according to the formalism of Kellerer and Chmelevsky using full convolution of the Monte Carlo calculated single track frequency distributions confirm that at doses exceeding 0.08 Gy for (125)I, 0.1 Gy for (192)Ir, and 0.2 Gy for (60)Co, the resulting distribution can be accurately approximated with a normal distribution. A parameterization of the width of the distribution as a function of dose and target volume of interest is presented as a convenient form for the use in response modelling or similar contexts.

  7. Characterization of (/sup 125/I)omega-conotoxin binding to brain N calcium channels and (-)(/sup 3/H) desmethoxyverapamil binding to novel calcium channels in osteoblast-like osteosarcoma cells

    SciTech Connect

    Wagner, J.A.

    1987-01-01

    This dissertation provides molecular evidence for a diversity of Ca/sup 2 +/ channels in neuronal and non-neuronal tissues. First, I demonstrated specific, reversible, saturable binding sites for omega (/sup 125/I)conotoxin GVIA (omega(/sup 125/I)CTX) in rat brain and rabbit sympathetic ganglion. Omega (/sup 125/I)CTX binding has a unique pharmacology, ion selectivity, and anatomical distribution in rat brain. Omega (/sup 125/I)CTX binding was solubilized, retaining an appropriate pharmacology and ion selectivity. Omega(/sup 125/I)CTX binding may be associated with a Ca/sup 2 +/ channel because the K/sub D/ of omega (/sup 125/I)CTX is similar to the IC/sub 50/ of inhibition of depolarization-induced /sup 45/Ca/sup 2 +/ flux into rat brain synaptosomes. Specific (-)(/sup 3/H)desmethoxyverapamil ((-)(/sup 3/H)DMV) binding sites were demonstrated on osteoblast-like osteosarcoma cell membranes.

  8. Quantification, localization and identification of selenium in seeds of canola and two mustard species compared to seed meals produced by hydraulic press

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brassica plants accumulate selenium (Se), especially in seeds, when grown in soils laden with Se in the westside of the San Joaquin Valley. In this study, we attempt to accurately determine the forms of Se present in the Se-enriched products produced from plants grown for the phytomanagement of Se. ...

  9. Prescription dose in permanent {sup 131}Cs seed prostate implants

    SciTech Connect

    Yue Ning; Heron, Dwight E.; Komanduri, Krishna; Huq, M. Saiful

    2005-08-15

    Recently, {sup 131}Cs seeds have been introduced for prostate permanent seed implants. This type of seed has a relatively short half-life of 9.7 days and has its most prominent emitted photon energy peaks in the 29-34 keV region. Traditionally, 145 and 125 Gy have been prescribed for {sup 125}I and {sup 103}Pd seed prostate implants, respectively. Since both the half-life and dosimetry characteristics of {sup 131}Cs seed are quite different from those of {sup 125}I and {sup 103}Pd, the appropriate prescription dose for {sup 131}Cs seed prostate implant may well be different. This study was designed to use a linear quadratic radiobiological model to determine an appropriate dose prescription scheme for permanent {sup 131}Cs seed prostate implants. In this model, prostate edema was taken into consideration. Calculations were also performed for tumors of different doubling times and for other related radiobiological parameters of different values. As expected, the derived prescription dose values were dependent on type of tumors and types of edema. However, for prostate cancers in which tumor cells are relatively slow growing and are reported to have a mean potential doubling time of around 40 days, the appropriate prescription dose for permanent {sup 131}Cs seed prostate implants was determined to be: 127{sub -12}{sup +5}Gy if the experiences of {sup 125}I seed implants were followed and 121{sub -3}{sup +0}Gy if the experiences of {sup 103}Pd seed implants were followed.

  10. /sup 125/Iodine implants as an adjuvant to surgery and external beam radiotherapy in the management of locally advanced head and neck cancer

    SciTech Connect

    Martinez, A.; Goffinet, D.R.; Fee, W.; Goode, R.; Cox, R.S.

    1983-03-15

    /sup 125/Iodine seeds either individually placed or inserted into absorbable Vicryl suture carriers were utilized in conjunction with surgery and external beam radiotherapy in an attempt to increase local control rates in patients with (1) advanced oropharyngeal and laryngopharyngeal cancers (T3-T4, N2-N3), (2) massive cervical lymphadenopathy (N3) and an unknown primary site and (3) locally recurrent head and neck cancers. Forty-eight patients were treated with 55 implants. The carotid artery was implanted in 15 patients, while seven patients had seeds inserted into the base of the skull region, and another three patients had implants near cranial nerves. Eighteen of the 48 patients were treated for cure. The actuarial survival at five years in this subgroup was 50%. The overall local control in the head and neck area was 58%. In this group no patients to date have had a local failure in the implanted volume. Seventeen patients with comparable stage of disease treated prior to 1974 with curative intent without /sup 125/I implants were analyzed retrospectively for comparison with the implanted patients. The actuarial survival of these patients was 18% and the overall head and neck control was 21%. These differences are statistically significant at a P value of 0.01 and 0.007, respectively. Seventeen patients received implants for local recurrence. The local control in the head and neck area was 50%; however, the 2.5 year actuarial survival was only 17%. The complication rate was 11% (six of 55 implants). The improved survival, the high local control, and the minimal complication rates in this series makes the intraoperative implantation of /sup 125/I seeds and effective adjunctive treatment to surgery and external beam irradiation.

  11. Planting local seed for growth to nationwide E/PO efforts

    NASA Astrophysics Data System (ADS)

    Fox, N.; Beisser, K.; Mendez, F.; Cockrell, D.; Wilhide, B.

    The Johns Hopkins University Applied Physics Laboratory (JHU/APL) is the home to hundreds of scientists and engineers, all involved in research, design and implementation of space missions. Many of these people actively seek out ways to raise awareness and interest in the local community by visiting schools, giving public lectures and supporting events held at the laboratory. During the past few years, APL has begun to foster a number of firm partnerships with organizations to further these community opportunities and provide a test bed for both formal and informal education activities through the Space Department E/PO office One of our ongoing partnerships is with the Maryland Science Center in Baltimore. A continual challenge faced by museums is how to stay current and allow visitors to experience the immediacy and excitement of scientific discovery. To help meet these challenges, the Maryland Science Center houses "SpaceLink", the Nation's first space, science and astronomy update center. Part media center, part discovery room, and part newsroom, the exhibit is a multi-purpose Professional Development Site for educators and a "classroom of the future" for K 12 students. APL scientists and- engineers regularly support SpaceLink's flexible programming, including scientist in residence, monthly credited seminars for educators (Teachers' Thursdays), a menu of Classroom Programs on request, Distance Learning Teacher Presentations, and special Live Events to highlight mission milestones and space-related anniversaries. This allows the guest scientists and engineers to interact directly with the public. These events also compliment the APL exhibits housed at the Science Center. JHU/APL offers an exciting environment for the study of applications in space by hosting the annual Maryland Summer Center for Space Science sponsored by the Maryland State Department of Education. Rising 6t h and 7t h grade students learn to harness the power of technology and keep pace with

  12. Approaches to calculating AAPM TG-43 brachytherapy dosimetry parameters for {sup 137}Cs, {sup 125}I, {sup 192}Ir, {sup 103}Pd, and {sup 169}Yb sources

    SciTech Connect

    Melhus, Christopher S.; Rivard, Mark J.

    2006-06-15

    Underlying characteristics in brachytherapy dosimetry parameters for medical radionuclides {sup 137}Cs, {sup 125}I, {sup 192}Ir, {sup 103}Pd, and {sup 169}Yb were examined using Monte Carlo methods. Sources were modeled as unencapsulated point or line sources in liquid water to negate variations due to materials and construction. Importance of phantom size, mode of radiation transport physics--i.e., photon transport only or coupled photon:electron transport, phantom material, volume averaging, and Monte Carlo tally type were studied. For noninfinite media, g(r) was found to degrade as r approached R, the phantom radius. MCNP5 results were in agreement with those published using GEANT4. Brachytherapy dosimetry parameters calculated using coupled photon:electron radiation transport simulations did not differ significantly from those using photon transport only. Dose distributions from low-energy photon-emitting radionuclides {sup 125}I and {sup 103}Pd were sensitive to phantom material by upto a factor of 1.4 and 2.0, respectively, between tissue-equivalent materials and water at r=9 cm. In comparison, high-energy photons from {sup 137}Cs, {sup 192}Ir, and {sup 169}Yb demonstrated {+-}5% differences in dose distributions between water and tissue substitutes at r=20 cm. Similarly, volume-averaging effects were found to be more significant for low-energy radionuclides. When modeling line sources with L{<=}0.5 cm, the two-dimensional anisotropy function was largely within {+-}0.5% of unity for {sup 137}Cs, {sup 125}I, and {sup 192}Ir. However, an energy and geometry effect was noted for {sup 103}Pd and {sup 169}Yb, with {sub Pd-103}F(0.5,0 deg.)=1.05 and {sub Yb-169}F(0.5,0 deg.)=0.98 for L=0.5 cm. Simulations of monoenergetic photons for L=0.5 cm produced energy-dependent variations in F(r,{theta}) having a maximum value at 10 keV, minimum at 50 keV, and {approx}1.0 for higher-energy photons up to 750 keV. Both the F6 cell heating and track-length estimators were

  13. Characterization of epoxyeicosatrienoic acid binding site in U937 membranes using a novel radiolabeled agonist, 20-125i-14,15-epoxyeicosa-8(Z)-enoic acid.

    PubMed

    Yang, Wenqi; Tuniki, Venugopal Raju; Anjaiah, Siddam; Falck, J R; Hillard, Cecilia J; Campbell, William B

    2008-03-01

    Epoxyeicosatrienoic acids (EETs) are important regulators of vascular tone and homeostasis. Whether they initiate signaling through membrane receptors is unclear. We developed 20-iodo-14,15-epoxyeicosa-8(Z)-enoic acid (20-I-14,15-EE8ZE), a radiolabeled EET agonist, to characterize EET binding to membranes of U937 cells. 20-I-14,15-EE8ZE stimulated cAMP production in U937 cells with similar potency, but it decreased efficacy compared with 11,12-EET. Maximum cAMP production increased 4.2-fold, with an EC(50) value of 9 muM. Like 14,15-EET, 20-I-14,15-EE8ZE relaxed bovine coronary arteries, with a similar EC(50) value. Both 20-I-14,15-EE8ZE agonist activities were blocked by the EET antagonist 14,15-epoxyeicosa-5(Z)enoic acid (14,15-EE5ZE). Specific 20-(125)I-14,15-EE8ZE binding to U937 membranes reached equilibrium within 10 min and remained unchanged for 30 min at 4 degrees C. The binding was saturable, reversible, and exhibited K(D) and B(max) values of 11.8 +/- 1.1 nM and 5.8 +/- 0.2 pmol/mg protein, respectively. Pretreatment of the membranes with guanosine 5'-O-(3-thio)triphosphate reduced the B(max) in a concentration-related manner. 20-(125)I-14,15-EE8ZE binding was inhibited by eicosanoids with potency order of 11,12-EET >14,15-EE5ZE approximately 14,15-EET > 15-hydroxyeicosatetraenoic acid > 14,15-EET-thiirane >14,15-dihydroxyeicosatrienoic acid. This order is in agreement with the efficacy and potency of cAMP production. In summary, 20-(125)I-14,15-EE8ZE is a radiolabeled EET agonist that is useful to study binding and metabolism. Using this radioligand, we have identified a specific high-affinity and high-abundance EET binding site in U937 cell membranes. This binding site could represent a specific EET receptor, which is probably a G protein-coupled receptor.

  14. Expression of messenger ribonucleic acid and presence of immunoreactive proteins for epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha) and EGF/TGF alpha receptors and 125I-EGF binding sites in human fallopian tube.

    PubMed

    Chegini, N; Zhao, Y; McLean, F W

    1994-05-01

    Reverse transcription polymerase chain reaction (RT-PCR) revealed that the Fallopian tubes express epidermal growth factor (EGF), transforming growth factor (TGF alpha), and EGF receptor (EGF-R) mRNA. The RT-PCR product was verified by restriction enzyme digestion analysis. Immunohistochemically, EGF, TGF alpha, and EGF-R were localized in Fallopian tubes by use of specific antibodies to human EGF, mature fragments of human TGF alpha, and monoclonal antibodies to the extracellular binding domain of EGF-R. The tubal epithelial cells were the primary site of immunoreactive EGF, TGF alpha, and EGF-R, which were present to a lesser extent in the stromal cells, smooth muscle cell layers, fibroblasts of serosal tissue, and arterial endothelial and smooth muscle cells. Using antibodies generated against the amino and carboxy termini of TGF alpha precursor produced a similar cellular distribution to that observed for mature TGF alpha. The intensity of immunoreactive TGF alpha with these antibodies was similar to that seen with EGF. The ciliated and nonciliated epithelial cells in the ampullary and isthmus regions immunostained with similar intensity for EGF, TGF alpha, and EGF-R. The immunostaining for EGF, TGF alpha, and EGF-R was cycle-dependent, was considerably higher during late proliferative and early-to-mid-secretory phases than during early proliferative and late secretory phases of the menstrual cycle, and was reduced during the postmenopausal period. Specimens obtained 5-12 yr after tubal ligation immunostained for EGF, TGF alpha, and EGF-R similarly to sections from unligated tubes taken during the same phase of the cycle. Quantitative autoradiography of 125I-EGF binding generated a pattern similar to that of immunostaining for EGF-R binding. Net grain density/100 microns 2 calculated for different cell types indicated that the epithelial cells had a significantly higher grain density than did other tubal cell types (p < 0.05) without the cycle dependency seen

  15. Studies of the biogenic amine transporters. V. Demonstration of two binding sites for the cocaine analog [125I]RTI-55 associated with the 5-HT transporter in rat brain membranes.

    PubMed

    Silverthorn, M L; Dersch, C M; Baumann, M H; Cadet, J L; Partilla, J S; Rice, K C; Carroll, F I; Becketts, K M; Brockington, A; Rothman, R B

    1995-04-01

    Earlier work characterized the binding of the high-affinity cocaine analog 3 beta-(4-125iodophenyl)-tropane-2-carboxylic acid methyl ester ([125I]RTI-55) to membranes prepared from rat caudate. That investigation demonstrated that [125I]RTI-55-labeled serotonin (5-HT) transporters in addition to dopamine (DA) transporters and resolved [125I]RTI-55 binding to 5-HT transporters into two distinct components. In the present study, we characterized [125I]RTI-55 binding to membranes prepared from whole rat brain minus caudate. The first series of experiments established that [125I]RTI-55 labels both DA and 5-HT transporters and that 50 nM paroxetine and either 1000 nM 1-[2-(diphenylmethoxy)ethyl]-4-(3-phenylpropyl)homopiperazine (LR1111) or 500 nM (RTI-120) could be used to block [125I]RTI-55 binding to the 5-HT and DA transporters, thereby generating selective assay conditions for the DA and 5-HT transporters, respectively. Selective lesioning of dopaminergic and serotonergic neurons with intracerebroventricular 6-hydroxydopamine and 5,7-dihydroxytryptamine selectively decreased [125I]RTI-55 binding to DA and 5-HT transporters, respectively, thereby confirming the selectivity of the assay conditions. The ligand-selectivity pattern of the whole brain minus caudate 5-HT transporter correlated significantly with that of the caudate 5-HT transporter, although there were some striking differences for selected test agents. Additional experiments resolved [125I]RTI-55 binding to the 5-HT transporter into two components. A ligand-selectivity analysis of the two components failed to identify a highly selective test agent. In summary, the major findings of the present study are that [125I]RTI-55 labels both DA and 5-HT transporters in membranes prepared from whole brain minus caudate, that 50 nM paroxetine and either 1000 nM LR1111 or 500 nM RTI-120 can be used as a blocking agent to generate selective assay conditions for the DA and 5-HT transporters, respectively, and that [125

  16. Rapid agonist-induced loss of sup 125 I-. beta. -endorphin opioid receptor sites in NG108-15, but not SK-N-SH neuroblastoma cells

    SciTech Connect

    Cone, R.I.; Lameh, J.; Sadee, W. )

    1991-01-01

    The authors have measured {mu} and {delta} opioid receptor sites on intact SK-N-SH and NG108-15 neuroblastoma cells, respectively, in culture. Use of {sup 125}I-{beta}-endorphin ({beta}E) as a tracer, together with {beta}E(6-31) to block high-affinity non-opioid binding in both cell lines, permitted the measurement of cell surface {mu} and {delta} opioid receptor sites. Labeling was at {delta} sites in NG108-15 cells and predominantly at {mu} sites in SK-N-SH cells. Pretreatment with the {mu} and {delta} agonist, DADLE, caused a rapid loss of cell surface {delta} receptor sites in NG108-15 cells, but failed to reduce significantly {mu} receptor density in SK-N-SH cells.

  17. Preparation of biologically intact radioiodinated hyaluronan of high specific radioactivity: coupling of /sup 125/I-tyramine-cellobiose to amino groups after partial N-deacetylation

    SciTech Connect

    Dahl, L.B.; Laurent, T.C.; Smedsrod, B.

    1988-12-01

    Hyaluronan was substituted with tyramine-cellobiose on amino residues exposed after hydrazinolytic N-deacetylation of the polysaccharide. Nonsubstituted amino groups were reacetylated, and the carboxylic hydrazides were removed by treatment with HIO/sub 3/. The adduct was labeled with /sup 125/I before or after coupling to hyaluronan. N-deacetylation increased with prolonged pretreatment with hydrazine, which also reduced the chain length of hyaluronan. Hydrazinolysis for 30 min produced hyaluronan with Mr 2.2-2.9 x 10(5). This material was substituted with varying amounts of tyramine-cellobiose (from 1 per 20 to 1 per 130 disaccharides). Hyaluronan labeled in this way was recognized by Streptomyces hyaluronidase, hyaluronan affinity protein of cartilage proteoglycan, and receptors for specific endocytosis of hyaluronan in liver endothelial cells. Since tyramine-cellobiose is nondegradable and therefore is arrested intralysosomally at the site of uptake, turnover studies of hyaluronan can be easily carried out with this ligand.

  18. Inhibition of /sup 125/I-labeled ristocetin binding to Micrococcus luteus cells by the peptides related to bacterial cell wall mucopeptide precursors: quantitative structure-activity relationships

    SciTech Connect

    Kim, K.H.; Martin, Y.; Otis, E.; Mao, J.

    1989-01-01

    Quantitative structure-activity relationships (QSAR) of N-Ac amino acids, N-Ac dipeptides, and N-Ac tripeptides in inhibition of /sup 125/I-labeled ristocetin binding to Micrococcus luteus cell wall have been developed to probe the details of the binding between ristocetin and N-acetylated peptides. The correlation equations indicate that (1) the binding is stronger for peptides in which the side chain of the C-terminal amino acid has a large molar refractivity (MR) value, (2) the binding is weaker for peptides with polar than for those with nonpolar C-terminal side chains, (3) the N-terminal amino acid in N-Ac dipeptides contributes 12 times that of the C-terminal amino acid to binding affinity, and (4) the interactions between ristocetin and the N-terminal amino acid of N-acetyl tripeptides appear to be much weaker than those with the first two amino acids.

  19. Growth of Silver Nanowires from Controlled Silver Chloride Seeds and Their Application for Fluorescence Enhancement Based on Localized Surface Plasmon Resonance.

    PubMed

    Bae, Sunwoong; Han, Hyeji; Bae, Jin Gook; Lee, Eun Yeol; Im, Sang Hyuk; Kim, Do Hyun; Seo, Tae Seok

    2017-04-07

    A "Polyol" method has granted low-cost and facile process-controllability for silver-nanowire (Ag-NW) synthesis. Although homogenous and heterogeneous nucleation and growth during Ag-NW synthesis are possible using polyol methods, heterogeneous nucleation and growth of Ag NW guarantees highly selective growth of nanostructures using silver chloride (AgCl) seeds, which provides a stable source of chloride ions (Cl-) and thermodynamic reversibility. In this paper, a microdroplet has been adopted to synthesize uniform AgCl seeds with different diameter that are used for seed-mediated Ag-NW synthesis. The concentration of two precursors (AgNO3 and NaCl) in the droplets is modulated to produce different sizes of AgCl seeds, which determines the diameter and length of Ag NWs. The process of the seed-mediated growth of Ag NWs has been monitored by observing the peak shift in the time-resolved UV-vis extinction spectrum. Furthermore, the distinct plasmonic property of Ag NWs for transverse and longitudinal localized-surface-plasmon-resonance (LSPR)-mediated fluorescence enhancement is utilized. The high aspect ratio and sharp tips work as simple antennas that induce the enhanced fluorescence emission intensity of a fluorophore, which can be applied in the fields of biological tissue imaging and therapy.

  20. Cluster pattern analysis of energy deposition sites for the brachytherapy sources 103Pd, 125I, 192Ir, 137Cs, and 60Co

    NASA Astrophysics Data System (ADS)

    Villegas, Fernanda; Tilly, Nina; Bäckström, Gloria; Ahnesjö, Anders

    2014-09-01

    Analysing the pattern of energy depositions may help elucidate differences in the severity of radiation-induced DNA strand breakage for different radiation qualities. It is often claimed that energy deposition (ED) sites from photon radiation form a uniform random pattern, but there is indication of differences in RBE values among different photon sources used in brachytherapy. The aim of this work is to analyse the spatial patterns of EDs from 103Pd, 125I, 192Ir, 137Cs sources commonly used in brachytherapy and a 60Co source as a reference radiation. The results suggest that there is both a non-uniform and a uniform random component to the frequency distribution of distances to the nearest neighbour ED. The closest neighbouring EDs show high spatial correlation for all investigated radiation qualities, whilst the uniform random component dominates for neighbours with longer distances for the three higher mean photon energy sources (192Ir, 137Cs, and 60Co). The two lower energy photon emitters (103Pd and 125I) present a very small uniform random component. The ratio of frequencies of clusters with respect to 60Co differs up to 15% for the lower energy sources and less than 2% for the higher energy sources when the maximum distance between each pair of EDs is 2 nm. At distances relevant to DNA damage, cluster patterns can be differentiated between the lower and higher energy sources. This may be part of the explanation to the reported difference in RBE values with initial DSB yields as an endpoint for these brachytherapy sources.

  1. A Dose–Response Analysis of Biochemical Control Outcomes After {sup 125}I Monotherapy for Patients With Favorable-Risk Prostate Cancer

    SciTech Connect

    Shiraishi, Yutaka; Yorozu, Atsunori; Ohashi, Toshio; Toya, Kazuhito; Saito, Shiro; Nishiyama, Toru; Yagi, Yasuto; Shigematsu, Naoyuki

    2014-12-01

    Purpose: To define the optimal dose for {sup 125}I prostate implants by correlating postimplantation dosimetry findings with biochemical failure and toxicity. Methods and Materials: Between 2003 and 2009, 683 patients with prostate cancer were treated with {sup 125}I prostate brachytherapy without supplemental external beam radiation therapy and were followed up for a median time of 80 months. Implant dose was defined as the D90 (the minimal dose received by 90% of the prostate) on postoperative day 1 and 1 month after implantation. Therefore, 2 dosimetric variables (day 1 D90 and day 30 D90) were analyzed for each patient. We investigated the dose effects on biochemical control and toxicity. Results: The 7-year biochemical failure-free survival (BFFS) rate for the group overall was 96.4% according to the Phoenix definition. A multivariate analysis found day 1 D90 and day 30 D90 to be the most significant factors affecting BFFS. The cutoff points for day 1 D90 and day 30 D90, calculated from ROC curves, were 163 Gy and 175 Gy, respectively. By use of univariate analysis, various dosimetric cutoff points for day 30 D90 were tested. We found that day 30 D90 cutoff points from 130 to 180 Gy appeared to be good for the entire cohort. Greater D90s were associated with an increase in late genitourinary or gastrointestinal toxicity ≥ grade 2, but the increase was not statistically significant. Conclusions: Improvements in BFFS rates were seen with increasing D90 levels. Day 30 D90 doses of 130 to 180 Gy were found to serve as cutoff levels. For low-risk and low-tier intermediate-risk prostate cancer patients, high prostate D90s, even with doses exceeding 180 Gy, achieve better treatment results and are feasible.

  2. Cluster pattern analysis of energy deposition sites for the brachytherapy sources 103Pd, 125I, 192Ir, 137Cs, and 60Co.

    PubMed

    Villegas, Fernanda; Tilly, Nina; Bäckström, Gloria; Ahnesjö, Anders

    2014-09-21

    Analysing the pattern of energy depositions may help elucidate differences in the severity of radiation-induced DNA strand breakage for different radiation qualities. It is often claimed that energy deposition (ED) sites from photon radiation form a uniform random pattern, but there is indication of differences in RBE values among different photon sources used in brachytherapy. The aim of this work is to analyse the spatial patterns of EDs from 103Pd, 125I, 192Ir, 137Cs sources commonly used in brachytherapy and a 60Co source as a reference radiation. The results suggest that there is both a non-uniform and a uniform random component to the frequency distribution of distances to the nearest neighbour ED. The closest neighbouring EDs show high spatial correlation for all investigated radiation qualities, whilst the uniform random component dominates for neighbours with longer distances for the three higher mean photon energy sources (192Ir, 137Cs, and 60Co). The two lower energy photon emitters (103Pd and 125I) present a very small uniform random component. The ratio of frequencies of clusters with respect to 60Co differs up to 15% for the lower energy sources and less than 2% for the higher energy sources when the maximum distance between each pair of EDs is 2 nm. At distances relevant to DNA damage, cluster patterns can be differentiated between the lower and higher energy sources. This may be part of the explanation to the reported difference in RBE values with initial DSB yields as an endpoint for these brachytherapy sources.

  3. Regulation of the distribution and function of [(125)I]epibatidine binding sites by chronic nicotine in mouse embryonic neuronal cultures.

    PubMed

    Zambrano, Cristian A; Salamander, Rakel M; Collins, Allan C; Grady, Sharon R; Marks, Michael J

    2012-08-01

    Chronic nicotine produces up-regulation of α4β2* nicotinic acetylcholine receptors (nAChRs) (* denotes that an additional subunit may be part of the receptor). However, the extent of up-regulation to persistent ligand exposure varies across brain regions. The aim of this work was to study the cellular distribution and function of nAChRs after chronic nicotine treatment in primary cultures of mouse brain neurons. Initially, high-affinity [(125)I]epibatidine binding to cell membrane homogenates from primary neuronal cultures obtained from diencephalon and hippocampus of C57BL/6J mouse embryos (embryonic days 16-18) was measured. An increase in α4β2*-nAChR binding sites was observed in hippocampus, but not in diencephalon, after 24 h of treatment with 1 μM nicotine. However, a nicotine dose-dependent up-regulation of approximately 3.5- and 0.4-fold in hippocampus and diencephalon, respectively, was found after 96 h of nicotine treatment. A significant fraction of total [(125)I]epibatidine binding sites in both hippocampus (45%) and diencephalon (65%) was located on the cell surface. Chronic nicotine (96 h) up-regulated both intracellular and surface binding in both brain regions without changing the proportion of those binding sites compared with control neurons. The increase in surface binding was not accompanied by an increase in nicotine-stimulated Ca(2+) influx, suggesting persistent desensitization or inactivation of receptors at the plasma membrane occurred. Given the differences observed between hippocampus and diencephalon neurons exposed to nicotine, multiple mechanisms may play a role in the regulation of nAChR expression and function.

  4. Analysis of Recombinant Proteins in Transgenic Rice Seeds: Identity, Localization, Tolerance to Digestion, and Plant Stress Response.

    PubMed

    Wakasa, Yuhya; Takaiwa, Fumio

    2016-01-01

    Rice seeds are an ideal production platform for high-value recombinant proteins in terms of economy, scalability, safety, and stability. Strategies for the expression of large amounts of recombinant proteins in rice seeds have been established in the past decade and transgenic rice seeds that accumulate recombinant products such as bioactive peptides and proteins, which promote the health and quality of life of humans, have been generated in many laboratories worldwide. One of the most important advantages is the potential for direct oral delivery of transgenic rice seeds without the need for recombinant protein purification (downstream processing), which has been attributed to the high expression levels of recombinant products. Transgenic rice will be beneficial as a delivery system for pharmaceuticals and nutraceuticals in the future. This chapter introduces the strategy for producing recombinant protein in the edible part (endosperm) of the rice grain and describes methods for the analysis of transgenic rice seeds in detail.

  5. UUAT1 Is a Golgi-Localized UDP-Uronic Acid Transporter That Modulates the Polysaccharide Composition of Arabidopsis Seed Mucilage.

    PubMed

    Saez-Aguayo, Susana; Rautengarten, Carsten; Temple, Henry; Sanhueza, Dayan; Ejsmentewicz, Troy; Sandoval-Ibañez, Omar; Doñas, Daniela; Parra-Rojas, Juan Pablo; Ebert, Berit; Lehner, Arnaud; Mollet, Jean-Claude; Dupree, Paul; Scheller, Henrik V; Heazlewood, Joshua L; Reyes, Francisca C; Orellana, Ariel

    2017-01-01

    UDP-glucuronic acid (UDP-GlcA) is the precursor of many plant cell wall polysaccharides and is required for production of seed mucilage. Following synthesis in the cytosol, it is transported into the lumen of the Golgi apparatus, where it is converted to UDP-galacturonic acid (UDP-GalA), UDP-arabinose, and UDP-xylose. To identify the Golgi-localized UDP-GlcA transporter, we screened Arabidopsis thaliana mutants in genes coding for putative nucleotide sugar transporters for altered seed mucilage, a structure rich in the GalA-containing polysaccharide rhamnogalacturonan I. As a result, we identified UUAT1, which encodes a Golgi-localized protein that transports UDP-GlcA and UDP-GalA in vitro. The seed coat of uuat1 mutants had less GalA, rhamnose, and xylose in the soluble mucilage, and the distal cell walls had decreased arabinan content. Cell walls of other organs and cells had lower arabinose levels in roots and pollen tubes, but no differences were observed in GalA or xylose contents. Furthermore, the GlcA content of glucuronoxylan in the stem was not affected in the mutant. Interestingly, the degree of homogalacturonan methylation increased in uuat1 These results suggest that this UDP-GlcA transporter plays a key role defining the seed mucilage sugar composition and that its absence produces pleiotropic effects in this component of the plant extracellular matrix.

  6. UUAT1 Is a Golgi-Localized UDP-Uronic Acid Transporter That Modulates the Polysaccharide Composition of Arabidopsis Seed Mucilage[OPEN

    PubMed Central

    Saez-Aguayo, Susana; Rautengarten, Carsten; Temple, Henry; Sanhueza, Dayan; Ejsmentewicz, Troy; Sandoval-Ibañez, Omar; Parra-Rojas, Juan Pablo; Ebert, Berit; Reyes, Francisca C.

    2017-01-01

    UDP-glucuronic acid (UDP-GlcA) is the precursor of many plant cell wall polysaccharides and is required for production of seed mucilage. Following synthesis in the cytosol, it is transported into the lumen of the Golgi apparatus, where it is converted to UDP-galacturonic acid (UDP-GalA), UDP-arabinose, and UDP-xylose. To identify the Golgi-localized UDP-GlcA transporter, we screened Arabidopsis thaliana mutants in genes coding for putative nucleotide sugar transporters for altered seed mucilage, a structure rich in the GalA-containing polysaccharide rhamnogalacturonan I. As a result, we identified UUAT1, which encodes a Golgi-localized protein that transports UDP-GlcA and UDP-GalA in vitro. The seed coat of uuat1 mutants had less GalA, rhamnose, and xylose in the soluble mucilage, and the distal cell walls had decreased arabinan content. Cell walls of other organs and cells had lower arabinose levels in roots and pollen tubes, but no differences were observed in GalA or xylose contents. Furthermore, the GlcA content of glucuronoxylan in the stem was not affected in the mutant. Interestingly, the degree of homogalacturonan methylation increased in uuat1. These results suggest that this UDP-GlcA transporter plays a key role defining the seed mucilage sugar composition and that its absence produces pleiotropic effects in this component of the plant extracellular matrix. PMID:28062750

  7. Monte Carlo study of LDR seed dosimetry with an application in a clinical brachytherapy breast implant

    SciTech Connect

    Furstoss, C.; Reniers, B.; Bertrand, M. J.; Poon, E.; Carrier, J.-F.; Keller, B. M.; Pignol, J. P.; Beaulieu, L.; Verhaegen, F.

    2009-05-15

    A Monte Carlo (MC) study was carried out to evaluate the effects of the interseed attenuation and the tissue composition for two models of {sup 125}I low dose rate (LDR) brachytherapy seeds (Medi-Physics 6711, IBt InterSource) in a permanent breast implant. The effect of the tissue composition was investigated because the breast localization presents heterogeneities such as glandular and adipose tissue surrounded by air, lungs, and ribs. The absolute MC dose calculations were benchmarked by comparison to the absolute dose obtained from experimental results. Before modeling a clinical case of an implant in heterogeneous breast, the effects of the tissue composition and the interseed attenuation were studied in homogeneous phantoms. To investigate the tissue composition effect, the dose along the transverse axis of the two seed models were calculated and compared in different materials. For each seed model, three seeds sharing the same transverse axis were simulated to evaluate the interseed effect in water as a function of the distance from the seed. A clinical study of a permanent breast {sup 125}I implant for a single patient was carried out using four dose calculation techniques: (1) A TG-43 based calculation, (2) a full MC simulation with realistic tissues and seed models, (3) a MC simulation in water and modeled seeds, and (4) a MC simulation without modeling the seed geometry but with realistic tissues. In the latter, a phase space file corresponding to the particles emitted from the external surface of the seed is used at each seed location. The results were compared by calculating the relevant clinical metrics V{sub 85}, V{sub 100}, and V{sub 200} for this kind of treatment in the target. D{sub 90} and D{sub 50} were also determined to evaluate the differences in dose and compare the results to the studies published for permanent prostate seed implants in literature. The experimental results are in agreement with the MC absolute doses (within 5% for EBT

  8. Interleukin-1 receptors in mouse brain: Characterization and neuronal localization

    SciTech Connect

    Takao, T.; Tracey, D.E.; Mitchell, W.M.; De Souza, E.B. )

    1990-12-01

    The cytokine interleukin-1 (IL-1) has a variety of effects in brain, including induction of fever, alteration of slow wave sleep, and alteration of neuroendocrine activity. To examine the potential sites of action of IL-1 in brain, we used iodine-125-labeled recombinant human interleukin-1 (( 125I)IL-1) to identify and characterize IL-1 receptors in crude membrane preparations of mouse (C57BL/6) hippocampus and to study the distribution of IL-1-binding sites in brain using autoradiography. In preliminary homogenate binding and autoradiographic studies, (125I)IL-1 alpha showed significantly higher specific binding than (125I)IL-1 beta. Thus, (125I)IL-1 alpha was used in all subsequent assays. The binding of (125I)IL-1 alpha was linear over a broad range of membrane protein concentrations, saturable, reversible, and of high affinity, with an equilibrium dissociation constant value of 114 +/- 35 pM and a maximum number of binding sites of 2.5 +/- 0.4 fmol/mg protein. In competition studies, recombinant human IL-1 alpha, recombinant human IL-1 beta, and a weak IL-1 beta analog. IL-1 beta +, inhibited (125I)IL-1 alpha binding to mouse hippocampus in parallel with their relative bioactivities in the T-cell comitogenesis assay, with inhibitory binding affinity constants of 55 +/- 18, 76 +/- 20, and 2940 +/- 742 pM, respectively; rat/human CRF and human tumor necrosis factor showed no effect on (125I)IL-1 alpha binding. Autoradiographic localization studies revealed very low densities of (125I)IL-1 alpha-binding sites throughout the brain, with highest densities present in the molecular and granular layers of the dentate gyrus of the hippocampus and in the choroid plexus. Quinolinic acid lesion studies demonstrated that the (125I)IL-1 alpha-binding sites in the hippocampus were localized to intrinsic neurons.

  9. Implanting iodine-125 seeds into rat dorsal root ganglion for neuropathic pain: neuronal microdamage without impacting hind limb motion.

    PubMed

    Jiao, Ling; Zhang, Tengda; Wang, Huixing; Zhang, Wenyi; Fan, Saijun; Huo, Xiaodong; Zheng, Baosen; Ma, Wenting

    2014-06-15

    The use of iodine-125 ((125)I) in cancer treatment has been shown to relieve patients' pain. Considering dorsal root ganglia are critical for neural transmission between the peripheral and central nervous systems, we assumed that (125)I could be implanted into rat dorsal root ganglia to provide relief for neuropathic pain. (125)I seeds with different radioactivity (0, 14.8, 29.6 MBq) were implanted separately through L4-5 and L5-6 intervertebral foramen into the vicinity of the L5 dorsal root ganglion. von Frey hair results demonstrated the mechanical pain threshold was elevated after implanting (125)I seeds from the high radioactivity group. Transmission electron microscopy revealed that nuclear membrane shrinkage, nucleolar margination, widespread mitochondrial swelling, partial vacuolization, lysosome increase, and partial endoplasmic reticulum dilation were visible at 1,440 hours in the low radioactivity group and at 336 hours in the high radioactivity group. Abundant nuclear membrane shrinkage, partial fuzzy nuclear membrane and endoplasmic reticulum necrosis were observed at 1,440 hours in the high radioactivity group. No significant difference in combined behavioral scores was detected between preoperation and postoperation in the low and high radioactivity groups. These results suggested that the mechanical pain threshold was elevated after implanting (125)I seeds without influencing motor functions of the hind limb, although cell injury was present.

  10. Methodology for characterizing seeds under development for brachytherapy by means of radiochromic and photographic films.

    PubMed

    Meira-Belo, L C; Rodrigues, E J T; Grynberg, S E

    2013-04-01

    The development of new medical devices possess a number of challenges, including designing, constructing, and assaying prototypes. In the case of new brachytherapy seeds, this is also true. In this paper, a methodology for rapid dosimetric characterization of (125)I brachytherapy seeds during the early stages of their development is introduced. The characterization methodology is based on the joint use of radiochromic and personal monitoring photographic films in order to determine the planar anisotropy due to the radiation field produced by the seed under development, by means of isodose curves. To evaluate and validate the process, isodose curves were obtained with both types of films after irradiation with a commercial (125)I brachytherapy seed.

  11. The families of papain- and legumain-like cysteine proteinases from embryonic axes and cotyledons of Vicia seeds: developmental patterns, intracellular localization and functions in globulin proteolysis.

    PubMed

    Fischer, J; Becker, C; Hillmer, S; Horstmann, C; Neubohn, B; Schlereth, A; Senyuk, V; Shutov, A; Müntz, K

    2000-05-01

    Families of papain- and legumain-like cysteine proteinases (CPR) were found in Vicia seeds. cDNAs and antibodies were used to follow organ specificity and the developmental course of CPR-specific mRNAs and polypeptides. Four papain-like cysteine proteinases (CPR1, CPR2, proteinase A and CPR4) from vetch seeds (Vicia sativa L.) were analysed. CPR2 and its mRNA were already found in dry embryonic axes. CPR1 was only detected there during early germination. Both CPR1 and CPR2 strongly increased later during germination. In cotyledons, both CPR1 and CPR2 were only observed one to two days later than in the axis. Proteinase A was not found in axes. In cotyledons it could only be detected several days after seeds had germinated. CPR4 mRNA and polypeptide were already present in embryonic axes and cotyledons during seed maturation and decreased in both organs during germination. Purified CPR1, CPR2 and proteinase A exhibited partially different patterns of globulin degradation products in vitro. Although the cDNA-deduced amino acid sequence of the precursor of proteinase A has an N-terminal signal peptide, the enzyme was not found in vacuoles whereas the other papain-like CPRs showed vacuolar localization. Four different legumain-like cysteine proteinases (VsPB2, proteinase B, VnPB1 and VnPB2) of Vicia species were analysed. Proteinase B and VnPB1 mRNAs were detected in cotyledons and seedling organs after seeds had germinated. Proteinase B degraded globulins isolated from mature vetch seeds in vitro. VsPB2 and proteinase B are localized to protein bodies of maturing seeds and seedlings, respectively, of V. sativa. Like VsPB2 from V sativa, also VnPB2 of V. narbonensis corresponds to vacuolar processing enzymes (betaVPE). Based on these results different functions in molecular maturation and mobilization of storage proteins could be attributed to the various members of the CPR families.

  12. Translocation of (125)I, (75)Se and (36)Cl to edible parts of radish, potato and green bean following wet foliar contamination under field conditions.

    PubMed

    Henner, P; Hurtevent, P; Thiry, Y; Levchuk, S; Yoschenko, V; Kashparov, V

    2013-10-01

    Specific translocation factor values (ftr) for (129)I, (79)Se and (36)Cl following foliar transfer are still missing from the IAEA reference databases. The translocation of the short-lived isotopes, (125)I, (75)Se, and (36)Cl, to radish, potato and green bean edible parts was measured under field conditions following acute and chronic wet foliar contamination at various plant growth stages in the absence of leaching caused by rain. The translocation factors obtained for (125)I ranged from 0.8 to 2.6% for radish, from 0.1 to 2.3% for potato and from 0.1 to 2.6% for bean. The translocation factors obtained for (75)Se ranged from 6.3 to 21% for radish, from 1.6 to 32.6% for potato and from 7.7 to 22.8% for bean (values similar to Cs or even higher). The translocation factors obtained for (36)Cl were close to those for (75)Se and ranged from 4.3 to 28.8% for radish, from 0.5 to 31.5% for potato and from 4.3 to 16.3% for bean. Iodide showed the lowest apparent mobility because of its preferential fixation in or on the leaves and a significant amount was probably volatilized. Selenite internal transfer was significant and possibly followed the sulfur metabolic pathway. Chloride was very mobile and quickly diffused throughout the plant. The translocation factors varied with the growth stage and depended on the development state of the edible tissue and its associated sink strength for nutrients and assimilates. For radish, translocation was high during the early vegetative stages. For potato, wheat and bean, a major peak in translocation was seen during the flowering growth stage and the concomitant growth of potato tubers. An additive effect of successive contamination events on translocated elements was shown in radish but not in bean and potato. The highest translocation value obtained for an acute contamination event was shown to be an adequate, conservative indicator of chronic contamination in absence of specific values. Due to the absence of rain leaching during

  13. L-lysine effectively blocks renal uptake of 125I- or 99mTc-labeled anti-Tac disulfide-stabilized Fv fragment.

    PubMed

    Kobayashi, H; Yoo, T M; Kim, I S; Kim, M K; Le, N; Webber, K O; Pastan, I; Paik, C H; Eckelman, W C; Carrasquillo, J A

    1996-08-15

    In this study, we investigated the ability of L-lysine to block renal uptake of 125I- or 99mTc- labeled Fv fragments. Anti-Tac disulfide-stabilized Fv fragment (dsFv) was derived from a murine monoclonal antibody that recognizes the alpha subunit of the interleukin-2 receptor (IL-2R alpha). The 125I- or 99mTc-labeled dsFv was injected i.v. into non-tumor-bearing nude mice or into nude mice bearing SP2/Tac (IL-2R alpha positive) and SP2/0 (IL-2R alpha negative) tumor. We then evaluated the pharmacokinetics of L-[3H]lysine and the effect of L-lysine dose, timing of administration, and route of delivery on catabolism and biodistribution of i.v. dsFv. Peak renal uptake of i.v. or i.p. injected L-[3H]lysine occurred within 5 and 15 min, respectively. The kidney uptake of L-lysine exhibited a dose-response effect. When L-lysine was coinfused or injected shortly before dsFv, renal uptake of dsFv was blocked to < 5% of the control, but longer intervals were less effective. Aminosyn II and Travasol 10% (parenteral amino acid solutions) also blocked renal uptake of radiolabeled dsFv. Administration of L-lysine did not alter the blood kinetics and slightly increased the tumor uptake of dsFv, but it did prevent catabolism in the kidney and resulted in lower amounts of catabolites in the serum and urine. In conclusion, we have shown that a blocking dose of lysine, injected with or immediately before the injection of radiolabeled dsFv, is most effective in blocking the renal uptake of dsFv. This is consistent with the rapid uptake of L-[3H]lysine by the kidney and is further substantiated by the relative ineffectiveness of lysine injected immediately after the radiolabeled dsFv injection.

  14. Studies of the biogenic amine transporters. VI. Characterization of a novel cocaine binding site, identified with [125I]RTI-55, in membranes prepared from whole rat brain minus caudate.

    PubMed

    Rothman, R B; Silverthorn, M L; Baumann, M H; Goodman, C B; Cadet, J L; Matecka, D; Rice, K C; Carroll, F I; Wang, J B; Uhl, G R

    1995-07-01

    Previous studies showed that the cocaine analog [125I]RTI-55 labels dopamine and serotonergic (5-HT) biogenic amine transporters (BATs) with high affinity. Here we characterized [125I]RTI-55 binding to membranes prepared from whole rat brain minus the caudate nuclei. Paroxetine (50 nM) was used to block [125I]RTI-55 binding to 5-HT transporter sites. Initial experiments identified drugs that displaced [125I]RTI-55 binding with moderately low slope factors. Binding surface analysis of the interaction of 3 beta-(4-chlorophenyl)tropan-2 beta-carboxylic acid phenyl ester hydrochloride (RTI-113) and 3 beta-(4-iodophenyl)tropan-2 beta-carboxylic acid phenyl ester hydrochloride (RTI-122) with [125I]RTI-55 binding sites readily resolved two binding sites for [125I]RTI-55 with Kd values of 0.44 nM and 17 nM and Bmax values of 31 and 245 fmol/mg protein. Potent 5-HT and noradrenergic uptake inhibitors had low affinity for both sites. Whereas cocaine, CFT and WIN35,065-2 were 6.0-, 25- and 14-fold selective for the first site, benztropine, PCP and the novel pyrrole, (+-)-(2RS,3aSR,8bRS)-1,2,3,3a,4,8b-hexahydro- 2-benzyl-1-methylindeno-[1,2-b]pyrrole resorcylate [(+-)-HBMP, formerly called (+-)-RTI-4793-14], were moderately selective for the second site. A single binding site with the characteristics of site 1 was resolved using COS cells transiently expressing the cloned rat dopamine transporter. Lesion studies with 6-hydroxydopamine and 5,7-dihydroxytryptamine were conducted to test the hypothesis that site 1 and site 2 are physically distinct. The data showed that these neurotoxins differentially decreased [125I]RTI-55 binding to sites 1 and 2. The differential distribution of sites 1 and 2 in rat brain provides further support for this hypothesis. Viewed collectively, these data show that [125I]RTI-55 labels a novel binding site in rat brain membranes, termed DATsite2, which is not associated with the classic dopamine, serotonin or norepinephrine transporters.

  15. Altered binding of /sup 125/I-labeled calmodulin to a 46. 5-kilodalton protein in skin fibroblasts cultured from patients with cystic fibrosis

    SciTech Connect

    Tallant, E.A.; Wallace, R.W.

    1987-02-01

    The levels of calmodulin and calmodulin-binding proteins have been determined in cultured skin fibroblasts from patients with cystic fibrosis (CF) and age- and sex-matched controls. Calmodulin ranged from 0.20 to 0.76 microgram/mg protein; there was no difference between calmodulin concentration in fibroblasts from CF patients and controls. Calmodulin-binding proteins of 230, 212, 204, 164, 139, 70, 59, 46.5, and 41 kD were identified. A protein with a mobility identical to the 59-kD calmodulin-binding protein was labeled by antiserum against calmodulin-dependent phosphatase. Although Ca/sup 2 +//calmodulin-dependent phosphatase activity was detected, there was no different in activity between control and CF fibroblasts or in the level of phosphatase protein as determined by radioimmunoassay. Lower amounts of /sup 125/I-calmodulin were bound to the 46.5-kD calmodulin-binding protein in CF fibroblasts as compared with controls. The 46.5-kD calmodulin-binding protein may be reduced in CF fibroblasts or its structure may be altered resulting in a reduced binding capacity and/or affinity for calmodulin and perhaps reflecting, either directly or indirectly, the genetic defect responsible for cystic fibrosis.

  16. Binding of /sup 125/I-labeled endotoxin to bovine, canine, and equine platelets and endotoxin-induced agglutination of canine platelets

    SciTech Connect

    Meyers, K.M.; Boehme, M.; Inbar, O.

    1982-10-01

    Endotoxin from Escherichia coli O127:B8, Salmonella abortus-equi and S minnesota induced clumping of some canine platelets (PLT) at a final endotoxin concentration of 1 microgram/ml. Endotoxin-induced clumping of canine PLT was independent of PLT energy-requiring processes, because clumping was observed with canine PLT incubated with 2-deoxy-D-glucose and antimycin A. The PLT responded to adenosine diphosphate before, but not after, incubation with the metabolic inhibitors. Endotoxin induced a slight and inconsistant clumping of bovine and equine PLT at high (mg/ml) endotoxin concentration. High-affinity binding sites could not be demonstrated on canine, bovine, and equine PLT, using /sup 125/I-labeled E coli O127:B8 endotoxin. Nonspecific binding was observed and appeared to be due primarily to an extraneous coat on the PLT surface that was removed by gel filtration. The endotoxin that was bound to PLT did not appear to modify PLT function. An attempt to identify plasma proteins that bound physiologically relevant amounts of endotoxin was not successful. The significance of the endotoxin-induced clumping or lack of it on the pathophysiology of endotoxemia is discussed.

  17. Macrophage function as studied by the clearance of /sup 125/I-labeled polyvinylpyrrolidone in iron-deficient and iron-replete mice

    SciTech Connect

    Kuvibidila, S.; Wade, S.

    1987-01-01

    This study evaluated the effects of iron deficiency and iron repletion on in vivo macrophage function determined by the clearance of /sup 125/I-labeled polyvinylpyrrolidone (PVP). Two experiments were done. There were four groups of C57BL/6 female mice in experiment 1: the iron-deficient (ID), pair-fed (PF), control (C) and the high iron (HI) groups. In experiment 2, there were three ID groups (severe to moderate anemia), three PF, one C and four ID groups that were fed adequate iron for 14 (R-14), 7 (R-7), 3 (R-3) days before or on the day of PVP injection (R-0). The overall rate of PVP clearance from blood was lower in ID than in C or PF groups. This clearance is expressed by a constant, K, calculated from natural log (ln) of the cpm and the time postadministration of PVP that blood was drawn. The theoretical individual macrophages function (alpha PVP), derived from K and the weights of body, spleen and liver, was also lower in ID than in C or PF groups. The impairment was most severe with the most severe iron deficiency. Repletion for 7 to 15 d before PVP administration resulted in a partial correction of the clearance. Moderate undernutrition in the PF group had no effect.

  18. Heterologous expression of chloroplast-localized geranylgeranyl pyrophosphate synthase confers fast plant growth, early flowering and increased seed yield.

    PubMed

    Tata, Sandeep Kumar; Jung, Jihye; Kim, Yoon-Ha; Choi, Jun Young; Jung, Ji-Yul; Lee, In-Jung; Shin, Jeong Sheop; Ryu, Stephen Beungtae

    2016-01-01

    Geranylgeranyl pyrophosphate synthase (GGPS) is a key enzyme for a structurally diverse class of isoprenoid biosynthetic metabolites including gibberellins, carotenoids, chlorophylls and rubber. We expressed a chloroplast-targeted GGPS isolated from sunflower (Helianthus annuus) under control of the cauliflower mosaic virus 35S promoter in tobacco (Nicotiana tabacum). The resulting transgenic tobacco plants expressing heterologous GGPS showed remarkably enhanced growth (an increase in shoot and root biomass and height), early flowering, increased number of seed pods and greater seed yield compared with that of GUS-transgenic lines (control) or wild-type plants. The gibberellin levels in HaGGPS-transgenic plants were higher than those in control plants, indicating that the observed phenotype may result from increased gibberellin content. However, in HaGGPS-transformant tobacco plants, we did not observe the phenotypic defects such as reduced chlorophyll content and greater petiole and stalk length, which were previously reported for transgenic plants expressing gibberellin biosynthetic genes. Fast plant growth was also observed in HaGGPS-expressing Arabidopsis and dandelion plants. The results of this study suggest that GGPS expression in crop plants may yield desirable agronomic traits, including enhanced growth of shoots and roots, early flowering, greater numbers of seed pods and/or higher seed yield. This research has potential applications for fast production of plant biomass that provides commercially valuable biomaterials or bioenergy.

  19. Colonization of spinach by Verticillium dahliae and effects of pathogen localization on the efficacy of seed treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt is caused by the soilborne fungus V. dahliae on spinach (Spinacia oleracea L.) but the disease is a serious problem only in seed production fields. Spinach crops are harvested well before symptom expression, and thus, Verticillium wilt is not a significant threat in fresh and proc...

  20. Characterization of histamine H/sub 1/-receptor binding peptides in guinea pig brain using (/sup 125/I)iodoazidophenpyramine, an irreversible specific photoaffinity probe

    SciTech Connect

    Ruat, M.; Koerner, M.; Garbarg, M.; Gros, C.; Schwartz, J.C.; Tertiuk, W.; Ganellin, C.R.

    1988-04-01

    Aminophenpyramine, a derivative of mepyramine (pyrilamine), a typical antagonists of histamine at its H/sub 1/ receptor was synthesized and converted into (/sup 125/I)iodoazidophenpyramine, a potential photoaffinity probe for the H/sub 1/ receptor. In the dark, reversible binding of this probe to cerebellar membranes occurred with a K/sub d/ of 1.2 x 10/sup -11/ M and a B/sub max/ of 240 fmol/mg of protein and was inhibited by various H/sub 1/-receptor antagonists with the expected potencies. These features establish the compound as one of the most potent H/sub 1/-receptor antagonists known so far. Upon IV irradiation, 5% of the bound radioactivity was covalently incorporated into cerebellar membrane polypeptides as shown by standard NaDodSO/sub 4//PAGE. Two bands of 47 and 56 kDa were consistently labeled, labeling being prevented by various H/sub 1/-receptor antagonists with the expected potencies and stereoselectivity. In the presence of protease inhibitors, labeling of the 56-kDa peptide increased at the expense of the 47-kDa peptide, suggesting that the latter was produced by hydrolysis of the former under the action of membrane proteases. In the absence of 2-mercaptoethanol, a band of 350-400 kDa appeared, apparently at the expense of the lighter bands, suggesting that the latter might be linked by one or more disulfide bridges to a higher molecular mass complex. The authors propose that at least part of the ligand binding domain of the histamine H/sub 1/ receptor resides within a subunit of apparent molecular mass 56,000.

  1. Prophylactic tamsulosin (Flomax) in patients undergoing prostate {sup 125}I brachytherapy for prostate carcinoma: Final report of a double-blind placebo-controlled randomized study

    SciTech Connect

    Elshaikh, Mohamed A.; Ulchaker, James C.; Reddy, Chandana A.; Angermeier, Kenneth W.; Klein, Eric A.; Chehade, Nabil; Altman, Andrew; Ciezki, Jay P. . E-mail: ciezkj@ccf.org

    2005-05-01

    Purpose: To evaluate the effectiveness of prophylactic tamsulosin (Flomax) in reducing the urinary symptoms in patients undergoing {sup 125}I prostate implantation (PI) for prostate adenocarcinoma. Methods and materials: This is a single-institution, double-blind, placebo-controlled, randomized trial for patients undergoing PI for prostate adenocarcinoma comparing prophylactic tamsulosin versus placebo. Eligibility criteria included patients not taking tamsulosin or other {alpha}-blockers treated with PI. The patients were randomly assigned to either tamsulosin (0.8 mg, orally once a day) or matched placebo. All patients started the medication 4 days before PI and continued for 60 days. The American Urologic Association (AUA) symptom index questionnaire was used to assess urinary symptoms. The AUA questionnaire was administered before PI for a baseline score and weekly for 8 weeks after PI. Patients were taken off the study if they developed urinary retention, had intolerable urinary symptoms, or wished to discontinue with the trial. Results: One hundred twenty-six patients were enrolled in this study from November 2001 to January 2003 (118 were evaluable: 58 in the tamsulosin arm and 60 in the placebo group). Pretreatment and treatment characteristics were comparably matched between the two groups. The urinary retention rate was 17% (10 patients) in the placebo group compared with 10% (6 patients) in the tamsulosin group (p = 0.3161). Eighty-eight percent (14 patients) of those who developed urinary retention experienced it within 2 weeks after the PI. Intolerable urinary symptoms were reported equally (10 patients in each group) with 70% occurring in the first 2 weeks after PI. There was a significant difference in mean AUA score in favor of tamsulosin at Week 5 after PI (p = 0.03). Conclusions: Prophylactic tamsulosin (0.8 mg/day) before prostate brachytherapy did not significantly affect urinary retention rates, but had a positive effect on urinary morbidity at

  2. Excitation functions of 124Te(d,xn)124,125I reactions from threshold up to 14 MeV: comparative evaluation of nuclear routes for the production of 124I.

    PubMed

    Bastian, T H; Coenen, H H; Qaim, S M

    2001-09-01

    Excitation functions of the nuclear reactions 124Te(d,xn)124-125I were measured from their respective thresholds up to 14.0 MeV via the stacked-foil technique. Thin samples were prepared by electrolytic deposition of 99.8% enriched 124Te on Ti-backing. The excitation function of the 124Te(d,n)125I reaction was measured for the first time. The present data for the 124Te(d,2n)124I reaction are by an order of magnitude higher than the literature experimental data but are in good agreement with the results of a hybrid model calculation. From the measured cross sections, integral yields of 124,125I were calculated. The energy range Ed = 14 --> 10 MeV appears to be the best compromise between 124I-yield and 1251-impurity. The calculated 124I-yield amounts to 17.5 MBq/microA h and the 125I-impurity to 1.7%. A critical evaluation of the three nuclear routes for the production of 124I, viz. 124Te(d,2n)-, 124Te(p,n)- and 125Te(p,2n)-processes, is given. The reaction studied in this work proved to be least suitable. The 124Te(p,n)-reaction gives 124I of the highest radionuclidic purity, and a small-sized cyclotron is adequate for production purposes. The 125Te(p,2n)-reaction is more suitable at a medium-sized cyclotron: the yield of 124I is four times higher than in the other two reactions but the level of 0.9% 125I-impurity is relatively high.

  3. Pharmacokinetics of internally labeled monoclonal antibodies as a gold standard: comparison of biodistribution of /sup 75/Se-, /sup 111/In-, and /sup 125/I-labeled monoclonal antibodies in osteogenic sarcoma xenografts in nude mice

    SciTech Connect

    Koizumi, M.; Endo, K.; Watanabe, Y.; Saga, T.; Sakahara, H.; Konishi, J.; Yamamuro, T.; Toyama, S.

    1989-04-01

    In order to know the true biodistribution of anti-tumor monoclonal antibodies, three monoclonal antibodies (OST6, OST7, and OST15) against human osteosarcoma and control antibody were internally labeled with 75Se by incubating (75Se)methionine and hybridoma cells. 75Se-labeled monoclonal antibodies were evaluated both in vitro and in vivo using the human osteogenic sarcoma cell line KT005, and the results were compared with those of 125I- and 111In-labeled antibodies. 75Se-, 125I- and 111In-labeled monoclonal antibodies had identical binding activities to KT005 cells, and the immunoreactivity was in the decreasing order of OST6, OST7, and OST15. On the contrary, in vivo tumor uptake (% injected dose/g) of 75Se- and 125I-labeled antibodies assessed using nude mice bearing human osteosarcoma KT005 was in the order of OST7, OST6, and OST15. In the case of 111In, the order was OST6, OST7, and OST15. High liver uptake was similarly seen with 75Se- and 111In-labeled antibodies, whereas 125I-labeled antibodies showed the lowest tumor and liver uptake. These data indicate that tumor targeting of antibody conjugates are not always predictable from cell binding studies due to the difference of blood clearance of labeled antibodies. Furthermore, biodistribution of both 111In- and 125I-labeled antibodies are not identical with internally labeled antibody. Admitting that internally labeled antibody is a ''gold standard'' of biodistribution of monoclonal antibody, high liver uptake of 111In-radiolabeled antibodies may be inherent to antibodies. Little, if any, increase in tumor-to-normal tissue ratios of antibody conjugates will be expected compared to those of 111In-labeled antibodies if stably coupled conjugates are administered i.v.

  4. Comparative histochemical localization of secondary metabolites in seed-raised and in vitro propagated plants of Excoecaria agallocha Linn. (Euphorbiaceae), the milky mangrove tree of historical significance.

    PubMed

    Satyan, R S; Aveek, N; Eganathan, P; Parida, A

    2010-10-01

    Mangroves synthesize novel secondary chemicals that are poorly understood. Among the euphorbiaceous mangrove species, Excoecaria agallocha Linn. produces novel terpenoids and alkaloids of medicinal importance. We conducted a comparative tissue level histochemical study of E. agallocha L. to determine whether in vitro propagation alters the content of phytochemicals within the plant parts. Transverse sections of the root, stem and leaves of seed-raised saplings and in vitro propagated plants stained with 10% vanillin-perchloric acid revealed accumulation of terpenoids in the cork cambium. Alkaloids were localized using Dragendorf's reagent in the cortex of the root sections as brown layers. Methylene blue staining revealed that seed-raised plants possessed more lignified cells, distinct latex ducts and ellipsoidal guard cells compared to the plants propagated in vitro, which revealed abnormal, circular guard cells. The phytochemical content of E. agallocha propagated by the in vitro method was comparable to the seed-raised plants. Phytochemical studies of the species of E. agallocha propagated in vitro would confirm whether the species could be used for its medicinal compounds.

  5. Long-Term Efficacy and Toxicity of Low-Dose-Rate {sup 125}I Prostate Brachytherapy as Monotherapy in Low-, Intermediate-, and High-Risk Prostate Cancer

    SciTech Connect

    Kittel, Jeffrey A.; Reddy, Chandana A.; Smith, Kristin L.; Stephans, Kevin L.; Tendulkar, Rahul D.; Ulchaker, James; Angermeier, Kenneth; Campbell, Steven; Stephenson, Andrew; Klein, Eric A.; Wilkinson, D. Allan; Ciezki, Jay P.

    2015-07-15

    Purpose/Objectives: To report long-term efficacy and toxicity for a single-institution cohort of patients treated with low-dose-rate prostate brachytherapy permanent implant (PI) monotherapy. Methods and Materials: From 1996 to 2007, 1989 patients with low-risk (61.3%), intermediate-risk (29.8%), high-intermediate-risk (4.5%), and high-risk prostate cancer (4.4%) were treated with PI and followed up prospectively in a registry. All patients were treated with {sup 125}I monotherapy to 144 Gy. Late toxicity was coded retrospectively according to a modified Common Terminology Criteria for Adverse Events 4.0 scale. The rates of biochemical relapse-free survival (bRFS), distant metastasis-free survival (DMFS), overall survival (OS), and prostate cancer–specific mortality (PCSM) were calculated. We identified factors associated with late grade ≥3 genitourinary (GU) and gastrointestinal (GI) toxicity, bRFS, DMFS, OS, PCSM, and incontinence. Results: The median age of the patients was 67 years, and the median overall and prostate-specific antigen follow-up times were 6.8 years and 5.8 years, respectively. The overall 5-year rates for bRFS, DMFS, OS, and PCSM were 91.9%, 97.8%, 93.7%, and 0.71%, respectively. The 10-year rates were 81.5%, 91.5%, 76.1%, and 2.5%, respectively. The overall rates of late grade ≥3 GU and GI toxicity were 7.6% and 0.8%, respectively. On multivariable analysis, age and prostate length were significantly associated with increased risk of late grade ≥3 GU toxicity. The risk of incontinence was highly correlated with both pre-PI and post-PI transurethral resection of the prostate. Conclusions: Prostate brachytherapy as monotherapy is an effective treatment for low-risk and low-intermediate-risk prostate cancer and appears promising as a treatment for high-intermediate-risk and high-risk prostate cancer. Significant long-term toxicities are rare when brachytherapy is performed as monotherapy.

  6. Photoresponsive Fischer 344 Rats are reproductively inhibited by melatonin and differ in 2-[125I] lodomelatonin binding from nonphotoresponsive Sprague-Dawley rats.

    PubMed

    Heideman, P D; Bierl, C K; Sylvester, C J

    2001-03-01

    Many temperate-zone species use photoperiod as an environmental cue to regulate reproductive timing. Strains of laboratory rats differ in their responsiveness to photoperiod, with the Fischer 344 (F344) strain being the most responsive known. F344 rats and closely related strains that differ in photoresponsiveness may be useful models to study the mechanisms and genetic basis for photoresponsiveness. We tested two hypotheses: (i) that melatonin mediates photoresponsiveness in F344 rats, as is the case in all other mammals tested, and (ii) that the location, abundance, or affinity of melatonin receptors, as estimated by the amount and location of binding of the radioligand 2-[125I]-iodomelatonin (IMEL) in the brain, might cause variation in photoresponsiveness among rat strains. Melatonin injections 1 h before lights off in a stimulatory photoperiod (L14 : D10) induced reproductive inhibition and reduced weight gain in a manner similar to short days of L8 : D16, while injections of ethanolic saline vehicle did not. Interestingly, melatonin injections administered during an inhibitory photoperiod (L10 : D14) caused greater inhibition of both reproduction and weight gain than short photoperiod alone. Pinealectomized F344 rats implanted subcutaneously with melatonin in a silastic capsule did not differ in testis size or body weight from controls with blank implants. The brains and pars tuberalis of the pituitary from photoresponsive F344 rats and nonphotoresponsive Harlan Sprague-Dawley (HSD) rats were processed for autoradiography using IMEL. We found significantly higher specific IMEL binding in the anterior and posterior regions of the paraventricular nucleus of the thalamus (PVNt) and reuniens nucleus of the thalamus of F344 rats than in the same areas in HSD rats. There were no differences between strains in specific IMEL binding in the medial PVNt, anteroventral and anterodorsal nucleus of the thalamus, suprachiasmatic nucleus, or the pars tuberalis. These

  7. Seed coat color and seed weight contribute differential responses of targeted metabolites in soybean seeds.

    PubMed

    Lee, Jinwook; Hwang, Young-Sun; Kim, Sun Tae; Yoon, Won-Byong; Han, Won Young; Kang, In-Kyu; Choung, Myoung-Gun

    2017-01-01

    The distribution and variation of targeted metabolites in soybean seeds are affected by genetic and environmental factors. In this study, we used 192 soybean germplasm accessions collected from two provinces of Korea to elucidate the effects of seed coat color and seeds dry weight on the metabolic variation and responses of targeted metabolites. The effects of seed coat color and seeds dry weight were present in sucrose, total oligosaccharides, total carbohydrates and all measured fatty acids. The targeted metabolites were clustered within three groups. These metabolites were not only differently related to seeds dry weight, but also responded differentially to seed coat color. The inter-relationship between the targeted metabolites was highly present in the result of correlation analysis. Overall, results revealed that the targeted metabolites were diverged in relation to seed coat color and seeds dry weight within locally collected soybean seed germplasm accessions.

  8. Local tissue destruction and procoagulation properties of Echis carinatus venom: inhibition by Vitis vinifera seed methanol extract.

    PubMed

    Mahadeswaraswamy, Y H; Nagaraju, S; Girish, K S; Kemparaju, K

    2008-07-01

    Plant extracts are extensively used against snakebites in Indian folk medicine. In this study, one such traditionally used plant, Vitis vinifera L. (Vitaceae) seed methanol extract has been studied for its ability to neutralize Indian Echis carinatus (saw-scaled viper) venom. The extract effectively inhibited toxic effects, such as oedema, haemorrhage, myonecrosis and coagulation of citrated human plasma. Further, the extract inhibited the caseinolytic, hyaluronolytic and fibrinogenolytic activities of the venom. The extract caused dose dependent inhibition of the toxic activities studied, suggesting venom inhibition. Thus, the anti-snake venom property of the extract appears to be highly promising for further investigation in order to achieve better neutralization of Indian E. carinatus venom poisoning.

  9. Local temperature effects in the helical scrape-off layer of startup plasmas at Wendelstein 7-X due to N seeding

    NASA Astrophysics Data System (ADS)

    Barbui, Tullio

    2016-10-01

    N seeding discharges have been performed at Wendelstein 7-X during its startup limiter campaign. In this study, the cooling effects on the local electron temperature Te measured by three diagnostic systems are discussed, which have a defined alignment in the helical SOL topology during the W7-X limiter phase. Radial Te profiles obtained from a thermal helium beam and Te measurements from a reciprocating Langmuir probe system, both located inside the same flux tube as the N injection system, are compared to Te from Langmuir probes installed on a limiter tile, which is not directly connected magnetically to the injection flux channel. This setup enables to study the N cooling effect in the flux tube geometry as an important test which impacts the 3-D topology in a low shear stellarator and the edge cooling symmetry. A clear reduction of Te in the entire SOL has been measured as a reaction to the N seeding and the relative variation in the temperature, however, depends on the actual placing of the diagnostic in the flux tube geometry and on the distances from the N injection point. A direct comparison of the measurements to EMC3-EIRENE modeling will be presented. This work has been funded by the Department of Energy under Grant DE-SC0014210 and by EUROfusion under Grant No 633053.

  10. Binding characteristics of 125I-labelled human FSH to granulosa cells from Booroola ewes which were homozygous, heterozygous or non-carriers of a major gene(s) influencing their ovulation rate.

    PubMed

    McNatty, K P; Lun, S; Heath, D A; Hudson, N L; O'Keeffe, L E; Henderson, K M

    1989-05-01

    At 37 degrees C 125I-labelled human (h) FSH (NIAMDD-hFSH-I-3) bound rapidly to granulosa cells from Booroola and Romney ewes with 50% maximum binding achieved after 3 min and equilibrium being reached within 45 min, irrespective of whether the cells were obtained from the FF, F+ or ++ Booroola genotypes or from Romney ewes. Binding of 125I-labelled FSH followed second order kinetics and there was no effect of follicle diameter (1-2.5 mm vs greater than or equal to 3 mm). Irrespective of breed, genotype or follicle size, the mean (+/- s.e.m.) calculated association rate constant, (ka) was 7.3 (+/- 0.8) x 10(5) litres mol-1 sec-1 (n = 12). Dissociation of receptor bound 125I-labelled hFSH was less than 5% after 30 min and low but variable (i.e. between 0 and 30%) after 2-6 h irrespective of breed, genotype or follicle size. No gene-specific differences were noted in binding specificity between F+ and ++ genotypes: studies were not performed with cells from FF ewes because of insufficient cells. The binding of 125I-labelled hFSH could be displaced with sheep FSH (NIH-FSH-S16; 10% cross-reaction) and FSH-P (2.5% cross-reaction) but other sheep pituitary hormones and hCG showed little or no cross-reaction (less than or equal to 0.1%). The calculated binding capacities (Bmax) and equilibrium dissociation constants (Kd) for 125I-labelled hFSH binding to granulosa cells did not differ between the Booroola genotypes or between Booroola or Romney follicles of different diameter (i.e. 1-2.5 mm; or greater than or equal to 3 mm). The overall mean +/- s.e.m. (n = 24) Bmax and Kd values were 16.7 +/- 0.8 fm/mg protein (i.e. approximately 800 available receptor binding sites/cell) and 1.1 +/- 0.1 nM respectively. Collectively, these findings suggest that the earlier maturation of follicles in FF or F+ ewes compared to ++ ewes is unlikely to be due to gene-specific differences in the FSH binding characteristics of the granulosa cells.

  11. Influence of local floral density and sex ratio on pollen receipt and seed output: empirical and experimental results in dichogamous Alstroemeria aurea (Alstroemeriaceae).

    PubMed

    Aizen, Marcelo A

    1997-07-01

    Local density and sexual composition are two aspects of floral neighborhoods thought to influence pollination and seed output of recipient plants. I characterized the floral neighborhood of 436 flowering ramets of Alstroemeria aurea, a southern Andean perennial, distributed among three sites. On each ramet, I measured total pollen receipt and seed output. The long-lived, bumblebee-pollinated flowers of A. aurea are synchronously protandrous with a given ramet being either all male or all female and thus incapable of self or geitonogamous pollination at the ramet level. Even though each ramet changes sex over time, A. aurea forms floral neighborhoods that remain stable with respect to density and sex ratio during the span of a focal ramet female phase. Contrary to expectation, under field conditions neither local density nor sexual identity explained significant amounts of variation in pollen receipt. Density of neighboring flowering ramets marginally affected pollen receipt in two of the three populations but in opposite directions. Despite the absence of strong effects of neighborhood sexual composition on pollen receipt, the sexual identity of neighbors affected seed output which suggests effects on the quality of pollination due to changes in patterns of pollen flow. I also compared pollen loads on the stigmas of artificially isolated ramets (6 m) with those on experimental focal ramets surrounded by six close neighbors (20 cm) that were either all male or all female. Here, pollen receipt by focal ramets in all-male neighborhoods was 1.3 times greater than in isolated ramets, and 3.8 times greater than in ramets in all-female neighborhoods. In these artificial neighborhoods, stigmatic pollen deposition increased significantly over time. In nature, rates of bumblebee visits were higher in female-biased (early-flowering) than in male-biased (late-flowering) co-occurring floral patches. Thus, spatio-temporal shifts in visitation frequencies associated with the

  12. Chemical Composition, Antibacterial and Phytotoxic Activities of Peganum harmala Seed Essential Oils from Five Different Localities in Northern Africa.

    PubMed

    Apostolico, Ida; Aliberti, Luigi; Caputo, Lucia; De Feo, Vincenzo; Fratianni, Florinda; Nazzaro, Filomena; Souza, Lucèia Fàtima; Khadhr, Maroua

    2016-09-15

    Peganum harmala L., also known as Syrian rue or Pègano, is a herbaceous plant belonging to the Zygohpyllaceae family, and is widely used in traditional medicine. The chemical composition of essential oils of P. harmala seeds from five different regions of Northern Africa (Algeria, Egypt, Libya, Morocco and Tunisia) was studied by GC and GC-MS analyses. A total of 105 compounds were identified, the main components being oxygenated monoterpenes and oxygenated sesquiterpenes. Eugenol is the main component in all oils. The antimicrobial activity of the essential oils was assayed against some bacterial strains: Staphylococcus aureus (DSM 25693), Bacillus cereus (DSM 4313), Bacillus cereus (DSM4384), Escherichia coli (DMS 857) and Pseudomonas aeruginosa (ATCC 50071). All the oils showed different inhibitory activity. In the twentieth century this is an important result; we need possible new botanical drugs because the problem of resistance to antimicrobial drugs has become apparent. Moreover, the essential oils were evaluated for their possible in vitro phytotoxic activity against germination and initial radicle growth of Raphanus sativus L., Lepidium sativum L., and Ruta graveolens L. The results showed that both germination and radical elongation were sensitive to the oils.

  13. Autoradiographic localization of peptide YY and neuropeptide Y binding sites in the medulla oblongata

    SciTech Connect

    Leslie, R.A.; McDonald, T.J.; Robertson, H.A.

    1988-09-01

    Peptide YY is a highly potent emetic when given intravenously in dogs. We hypothesized that the area postrema, a small brain stem nucleus that acts as a chemoreceptive trigger zone for vomiting and lies outside the blood-brain barrier, might have receptors that PYY would bind to, in order to mediate the emetic response. We prepared (/sup 125/I)PYY and used autoradiography to show that high affinity binding sites for this ligand were highly localized in the area postrema and related nuclei of the dog medulla oblongata. Furthermore, the distribution of (/sup 125/I)PYY binding sites in the rat medulla oblongata was very similar to that in the dog; the distribution of (/sup 125/I)PYY binding sites throughout the rat brain was seen to be similar to the distribution of (/sup 125/I)NPY binding sites.

  14. Seed Germination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Initiation of seed germination is a critical decision for plants. It is important for seed populations under natural conditions to spread the timing of germination of individual seeds to maximize the probability of species survival. Therefore, seeds have evolved the multiple layers of mechanisms tha...

  15. Studies of the biogenic amine transporters. VII. Characterization of a novel cocaine binding site identified with [125I]RTI-55 in membranes prepared from human, monkey and guinea pig caudate.

    PubMed

    Rothman, R B; Silverthorn, M L; Glowa, J R; Matecka, D; Rice, K C; Carroll, F I; Partilla, J S; Uhl, G R; Vandenbergh, D J; Dersch, C M

    1998-04-01

    [125I]RTI-55 is a cocaine analog with high affinity for dopamine (DA) and serotonin (5-HT) transporters. Quantitative ligand binding studies revealed a novel high affinity [125I]RTI-55 binding site assayed under 5-HT transporter (SERT) conditions which has low affinity for almost all classic biogenic amine transporter ligands, including high affinity 5-HT transporter inhibitors such as paroxetine, but which retains high affinity for cocaine analogs. This site, termed SERT(site2) for its detection under 5-HT transporter conditions (not for an association with the SERT) occurs in monkey caudate, human caudate, and guinea pig caudate membranes, but not in rat caudate membranes. SERT(site2) is distinguished from the DA transporter (DAT) and SERT by several criteria, including a distinct ligand-selectivity profile, the inability to detect SERT(site2) in cells stably expressing the cloned human DAT, and insensitivity to irreversible ligands which inhibit [125I]RTI-55 binding to the DAT and SERT. Perhaps the most striking finding about SERT(site2) is that a wide range of representative antidepressant agents have very low affinity for SERT(site2). The affinity of cocaine for this site is not very different from the concentration cocaine achieves in the brain at pharmacological doses. Viewed collectively with the observation that ligands with high affinity for SERT(site2) are mostly cocaine analogs, these data lead us to speculate that actions of cocaine which differ from those of classic biogenic amine uptake inhibitors may be mediated in part via SERT(site2).

  16. Specific binding of /sup 125/I-labeled human chorionic gonadotropin to gonadal tissue: comparison of limited-point saturation analyses to Scatchard analyses for determining binding capacities and factors affecting estimates of binding capacity

    SciTech Connect

    Spicer, L.J.; Ireland, J.J.

    1986-07-01

    Experiments were conducted to compare gonadotropin binding capacity calculated from limited-point saturation analyses to those obtained from Scatchard analyses, and to test the effects of membrane purity and source of gonadotropin receptors on determining the maximum percentage of radioiodinated hormone bound to receptors (maximum bindability). One- to four-point saturation analyses gave results comparable to results by Scatchard analyses when examining relative binding capacities of receptors. Crude testicular homogenates had lower estimates of maximum bindability of /sup 125/I-labeled human chorionic gonadotropin than more purified gonadotropin receptor preparations. Under similar preparation techniques, some gonadotropin receptor sources exhibited low maximum bindability.

  17. Detection of metabolic activity by [125I]-Iododeoxyuridine incorporation into DNA in Colwellia psychrerythraea over a temperature range from 8 °C to -40 °C

    NASA Astrophysics Data System (ADS)

    Summers, David; Diaz-Maldonado, Hector; Duart-Garcia, Carolina; Karouia, Fathi; Santos, Orlando; Trent, Jonathan

    A central issue of interest for microbial ecology as well as Astrobiology is; "what are the environmental limits of microbial metabolic activity"? This question is crucial to such issues as where life might be found in the solar system, where life might found in extreme environments on the Earth, and how life may have survived and evolved through difficult periods. For example, the last refuges of life on the surface of Mars may well have been environments where temperatures were such that organisms had metabolisms too low to allow them to repair damage caused by background radiation. Understanding how long organisms can persist in state of near-senescence, imposed either by depressed temperatures or starvation, is necessary to comprehend how a biosphere can survive climate cycles. One of the limiting factors in the survival of "dormant" organisms is difficulty in repairing damage to various large molecules such as DNA. Recent work has shown that microbes are not metabolically inactive below the freezing point of water. This raises the questions of what damage can be repaired in these "dormant" states. We present results where we use the incorporation of 125 I-deoxyuridine into the DNA to measure microbial metabolic activity at low temperature. Since an organic iodo group is close to the same as a methyl group, the compound 125 I-deoxyuridine can act as analog for thymidine, becoming incorporated into DNA during repair and/or synthesis. Furthermore, the high activity of 125 I, and the ability of multiphoton detection (MPD) to detect levels below background levels, allow higher sensitivity than is normally possible. Therefore, we present work where the incorporation 125 I-deoxyuridine into the DNA of Colwellia psychrerythraea has been studied over a temperature range from 8 ° C to -40 ° C. These results show that DNA repair and/or synthesis can occur below 0 ° C. More generally, this method can enablethe detection of metabolic activity to lower levels than

  18. Potential for contamination during removal of radioactive seeds from surgically excised tissue.

    PubMed

    Classic, K L; Brunette, J B; Carlson, S K

    2009-08-01

    The purpose of this study was to determine whether the use of a scalpel or electrocautery to remove radioactive sealed sources ("seeds") from surgically excised tissue could damage the seed and cause it to leak its radioactive contents. Attempts were made to cut or burn Oncura Model 6711 non-radioactive seeds while in pig muscle or on a stainless steel plate. Additionally, one active 125I seed was purposely charred using pressure with an electrocautery knife to see whether the casing could be damaged. Electron microscopy scanning was performed on the dummy seeds to determine if the integrity of the metal casing had been compromised. Two types of leak tests were performed on the active seed to verify the presence or absence of loose contamination. The seed casing was not damaged from either use of a scalpel or electrocautery when the seed was in tissue. The active seed was not found to be leaking after applying pressure with an electrocautery knife while the seed was on a stainless steel plate. We conclude that removal of active Model 6711 seeds from surgically excised tissue can be done safely with a scalpel or electrocautery because constant, firm pressure cannot be applied to the seed. This is likely true for seeds made of similar materials.

  19. Evaluation of the new cesium-131 seed for use in low-energy x-ray brachytherapy.

    PubMed

    Murphy, Mark K; Piper, R Kim; Greenwood, Lawrence R; Mitch, Michael G; Lamperti, Paul J; Seltzer, Stephen M; Bales, Matt J; Phillips, Mark H

    2004-06-01

    Characterization measurements and calculations were performed on a new medical seed developed by IsoRay Inc. in Richland, Washington, that utilizes the short-lived isotope 131Cs. This model has recently received FDA 510(k) clearance. The objective of this work was to characterize the dosimetric properties of the new seed according to the AAPM Task Group 43 recommendations. Cesium-131 is a low-energy x-ray emitter, with the most prominent peaks in the 29 keV to 34 keV region. The intended application is brachytherapy for treating cancers in prostate, breast, head and neck, lung, and pancreas. The evaluations performed included air-kerma strength, radial dose function, anisotropy in phantom, half-life, energy spectra, and internal activity. The results indicate the CS-1 seeds have a dose-rate constant of 0.915 cGy hr(-1) U(-1) in water, dose penetration characteristics similar to 125I and 103Pd, anisotropy function values on the order of 0.71 at short distances and small angles, and an average anisotropy factor of 0.964. The overall dosimetric characteristics are similar to 125I and 103Pd seeds with the exception of half-life, which is 9.7 days, as compared to 17 days for 103Pd and 60 days for 125I. The shorter half-life may offer significant advantages in biological effectiveness.

  20. High affinity dopamine D2 receptor radioligands. 2. ( sup 125 I)epidepride, a potent and specific radioligand for the characterization of striatal and extrastriatal dopamine D2 receptors

    SciTech Connect

    Kessler, R.M.; Ansari, M.S.; Schmidt, D.E.; de Paulis, T.; Clanton, J.A.; Manning, R.G.; Gillespie, D. ); Innis, R.; Al-Tikriti, M. )

    1991-01-01

    Epidepride, (S)-N-((1-ethyl-2-pyrrolidinyl)methyl)-5-iodo-2,3-dimethoxybenzamide, the iodine analogue of isoremoxipride (FLB 457), was found to be a very potent dopamine D2 receptor antagonist. Optimal in vitro binding required incubation at 25C for 4 h at pH 7.4 in a buffer containing 120 mM NaCl, 5 mM KCl, 2 mM CaCl{sub 2} and 1 nM MgCl{sub 2}. Scatchard analysis of in vitro binding to striatal, medical frontal cortical, hippocampal and cerebellar membranes revealed a K{sub D} of 24 pM in all regions, with Bmax's of 36.7, 1.04, 0.85, and 0.37 pmol/g tissue, respectively. The Hill coefficients ranged from 0.91-1.00 in all four regions. The IC{sub 50}'s for inhibition of ({sup 125}I)epidepride binding to striatal, medial frontal cortical, and hippocampal membranes for SCH 23390, SKF 83566, serotonin, ketanserin, mianserin, naloxone, QNB, prasozin, clonidine, alprenolol, and norepinephrine ranged from 1 {mu}M to >10 {mu}M. Partial displacement of ({sup 125}I)epidepride by nanomolar concentrations of clonidine was noted in the frontal cortex and hippocampus, but not in the striatum. Scatchard analysis of epidepride binding to {alpha}{sub 2} noradrenergic receptors in the frontal cortex and hippocampus revealed an apparent K{sub D} of 9 nM. At an epidepride concentration equal to the K{sub D} for the D2 receptor, i.e., 25 pM, no striatal {alpha}{sub 2} binding was seen and only 7% of the specific epidepride binding in the cortex or hippocampus was due to binding at the {alpha}{sub 2} site. Correlation of inhibition of ({sup 3}H)spiperone and ({sup 125}I)epidepride binding to striatal membranes by a variety of D2 ligands revealed a correlation coefficient of 0.99, indicating that epidepride labels a D2 site.

  1. Comparison of /sup 125/I-labeled and /sup 14/C-Labeled peptides of the major outer membrane protein of Chlamydia Trachomatis Strain L2/434 separated by high-performance liquid chromatography

    SciTech Connect

    Judd, R.C.; Caldwell, H.D.

    1985-01-01

    The objective of this study was to determine if in-gel chloramine-T radioiodination adequately labels OM proteins to allow for accurate and precise structural comparison of these molecules. Therefore, intrinsically /sup 14/C-amino acid labeled proteins and /sup 125/I-labeled proteins were cleaved with two endopeptidic reagents and the peptide fragments separated by HPLC. A comparison of retention times of the fragments, as determined by differential radiation counting, thus indicated whether /sup 125/Ilabeling identified of all the peptide peaks seen in the /sup 14/Clabeled proteins. Results demonstrated that radioiodination yields complete and accurate information about the primary structure of outer membrane proteins. In addition, it permits the use of extremely small amounts of protein allowing for method optimization and multiple separations to insure reproducibility.

  2. Mass attenuation coefficients of Clear-Pb[reg sign] for photons from [sup 125]I, [sup 103]Pd, [sup 99m]Tc, [sup 192]Ir, [sup 137]Cs, and [sup 60]Co

    SciTech Connect

    Rivard, M.J. . Dept. of Radiation Oncology); Waid, D.S. . Radiation Oncology Dept.); Wierzbicki, J.G. . Cancer Treatment Center)

    1999-11-01

    The mass attenuation coefficients, [mu]/[rho], for Clear-Pb[reg sign] for photon energies ranging from 10 keV to 10 MeV were determined using Monte Carlo methods and simple equations used to manipulate elemental mass attenuation coefficients. It was determined that the effectiveness of Clear-Pb[reg sign] as a radiation shielding material was greater than plain acrylic for all photon energies, especially those less than 150 keV, and for deep penetration problems where the differences in [mu]/[rho] between Clear-Pb[reg sign] as a shielding material when compared with acrylic was determined for the following commonly used radionuclides: [sup 125]I, [sup 103]Pd, [sup 99m]Tc, [sup 192]Ir, [sup 137]Cs, and [sup 60]Co.

  3. Mass attenuation coefficients of Clear-Pb{reg_sign} for photons from {sup 125}I, {sup 103}Pd, {sup 99m}Tc, {sup 192}Ir, {sup 137}Cs, and {sup 60}Co

    SciTech Connect

    Rivard, M.J.; Waid, D.S.; Wierzbicki, J.G.

    1999-11-01

    The mass attenuation coefficients, {mu}/{rho}, for Clear-Pb{reg_sign} for photon energies ranging from 10 keV to 10 MeV were determined using Monte Carlo methods and simple equations used to manipulate elemental mass attenuation coefficients. It was determined that the effectiveness of Clear-Pb{reg_sign} as a radiation shielding material was greater than plain acrylic for all photon energies, especially those less than 150 keV, and for deep penetration problems where the differences in {mu}/{rho} between Clear-Pb{reg_sign} as a shielding material when compared with acrylic was determined for the following commonly used radionuclides: {sup 125}I, {sup 103}Pd, {sup 99m}Tc, {sup 192}Ir, {sup 137}Cs, and {sup 60}Co.

  4. Photoaffinity labeling of opiate (enkephalin) receptor of rat brain plasma membranes with /sup 125/I(D-Ala/sup 2/, p-N/sub 3/-Phe/sup 4/-Met/sup 5/)-enkephalin

    SciTech Connect

    Yeung, C.W.T.

    1986-05-01

    A photoreactive (D-Ala/sup 2/, p-N/sub 3/-Phe/sup 4/-Met/sup 5/)enkephalin derivative was prepared, iodinated with carrier free /sup 125/I and then purified by high performance liquid chromatography. The purified radioactive photoprobe was monoiodinated at the amino terminal tyrosine residue. This radioactive photoprobe was used to photoaffinity label plasma membranes prepared from rat brain, spinal cord and cerebellum. The photolabeled plasma membranes were analyzed by sodium dodecyl sulfate gel electrophoresis. A 46,000-daltons band was specifically photolabeled in the plasma membranes of brain and spinal cord but not in the plasma membranes from cerebellum. The photolabeling of this band was inhibited by peptides related to enkephalin by not but substance P or gastrin tetrapeptide. These data demonstrate that the labeled 46,000-daltons band is a protein of the opiate (enkephalin)receptor.

  5. Design and dosimetric considerations of a modified COMS plaque: The reusable 'seed-guide' insert

    SciTech Connect

    Astrahan, Melvin A.; Szechter, Andrzej; Finger, Paul T.

    2005-08-15

    The Collaborative Ocular Melanoma Study (COMS) developed a standardized set of eye plaques that consist of a 0.5 mm thick bowl-like gold alloy backing with a cylindrical collimating lip. A Silastic seed carrier into which {sup 125}I seeds are loaded was designed to fit within the backing. The carrier provides a standardized seed pattern and functions to offset the seeds by 1.0 mm from the concave (front) surface of the carrier. These Silastic carriers have been found to be difficult to load, preclude flash sterilization, and are a source of dosimetric uncertainty because the effective atomic number of Silastic is significantly higher than that of water. The main dosimetric effect of the Silastic carrier is a dose-reduction (compared to homogeneous water) of approximately 10%-15% for {sup 125}I radiation. The dose reduction is expected to be even greater for {sup 103}Pd radiation. In an attempt to improve upon, yet retain as much of the familiar COMS design as possible, we have developed a thin 'seed-guide' insert made of gold alloy. This new insert has cutouts which match the seed pattern of the Silastic carrier, but allows the seeds to be glued directly to the inner surface of the gold backing using either dental acrylic or a cyanoacrylate adhesive. When glued directly to the gold backing the seeds are offset a few tenths of a millimeter further away from the scleral surface compared to using the Silastic carrier. From a dosimetric perspective, the space formerly occupied by the Silastic carrier is now assumed to be water equivalent. Water equivalency is a desirable attribute for this space because it eliminates the dosimetric uncertainties related to the atomic composition of Silastic and thereby facilitates the use of either {sup 125}I and/or {sup 103}Pd seeds. The caveat is that a new source of dosimetric uncertainty would be introduced were an air bubble to become trapped in this space during or after the surgical insertion. The presence of air in this space

  6. Portal Vein Stenting Combined with Iodine-125 Seeds Endovascular Implantation Followed by Transcatheter Arterial Chemoembolization for Treatment of Hepatocellular Carcinoma Patients with Portal Vein Tumor Thrombus

    PubMed Central

    Zhou, Tanyang; Zhu, Tongyin; Zhang, Yuelin; Nie, Chunhui; Ai, Jing; Zhou, Guanhui; Zhang, Aibin; Dong, Meng-Jie; Wang, Wei-Lin

    2016-01-01

    Aim was to assess the therapeutic value of portal vein stenting (PVS) combined with iodine-125 seed (125I seed) strand endovascular implantation followed by transcatheter arterial chemoembolization (TACE) for treating patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT). This was a retrospective study of 34 patients aged 29–81 years, diagnosed HCC with PVTT, and treated with PVS combined with 125I seed strand endovascular implantation followed by TACE between January 2012 and August 2014. Survival, stent patency, technical success rate, complications related to the procedure, and adverse events were recorded. The technical success rate was 100%. No serious procedure-related adverse event was recorded. The median survival was 147 days. The cumulative survival rates and stent patency rates at 90, 180, and 360 days were 94.1%, 61.8%, and 32.4% and 97.1% (33/34), 76.9% (24/34), and 29.4% (10/34), respectively. PVS combined with 125I seed strand endovascular implantation followed by TACE is feasible for patients with HCC and PVTT. It resulted in appropriate survival and stent patency, with no procedure-related adverse effects. PMID:27999793

  7. Distribution and binding of 18F-labeled and 125I-labeled analogues of ACI-80, a prospective molecular imaging biomarker of disease: a whole hemisphere post mortem autoradiography study in human brains obtained from Alzheimer's disease patients.

    PubMed

    Gulyás, Balázs; Spenger, Christian; Beliczai, Zsuzsa; Gulya, Károly; Kása, Péter; Jahan, Mahabuba; Jia, Zhisheng; Weber, Urs; Pfeifer, Andrea; Muhs, Andreas; Willbold, Dieter; Halldin, Christer

    2012-01-01

    One of the major pathological landmarks of Alzheimer's disease and other neurodegenerative diseases is the presence of amyloid deposits in the brain. The early non-invasive visualization of amyloid is a major objective of recent diagnostic neuroimaging approaches, including positron emission tomography (PET), with an eye on follow-up of disease progression and/or therapy efficacy. The development of molecular imaging biomarkers with binding affinity to amyloid in the brain is therefore in the forefront of imaging biomarker and radiochemistry research. Recently, a dodecamer peptide (amino acid sequence=QSHYRHISPAQV; denominated D1 or ACI-80) was identified as a prospective ligand candidate, binding with high ex vivo affinity to L-Aβ-amyloid (K(d): 0.4 μM). In order to assess the ligand's capacity to visualize amyloid in Alzheimer's disease (AD), two (125)I labeled and three (18)F labeled analogues of the peptide were synthesized and tested in post mortem human autoradiography experiments using whole hemisphere brain slices obtained from deceased AD patients and age matched control subjects. The (18)F-labeled radioligands showed more promising visualization capacity of amyloid that the (125)I-labeled radioligands. In the case of each (18)F radioligands the grey matter uptake in the AD brains was significantly higher than that in control brains. Furthermore, the grey matter: white matter uptake ratio was over ~2, the difference being significant for each (18)F-radioligands. The regional distribution of the uptake of the various radioligands systematically shows a congruent pattern between the high uptake regions and spots in the autoradiographic images and the disease specific signals obtained in adjacent or identical brain slices labeled with histological, immunohistochemical or autoradiographic stains for amyloid deposits or activated astrocytes. The present data, using post mortem human brain autoradiography in whole hemisphere human brains obtained from deceased

  8. ( sup 125 I)Bolton-Hunter neuropeptide-Y-binding sites on folliculo-stellate cells of the pars intermedia of Xenopus laevis: A combined autoradiographic and immunocytochemical study

    SciTech Connect

    De Rijk, E.P.; Cruijsen, P.M.; Jenks, B.G.; Roubos, E.W. )

    1991-02-01

    It has previously been established that neuropeptide-Y (NPY) is a potent inhibitor of alpha MSH release from the pars intermedia of the amphibian Xenopus laevis. The location of binding sites for NPY in the pars intermedia of the pituitary has now been studied with light microscopic autoradiography, using a dispersed cell labeling method with the specific NPY receptor ligand ({sup 125}I)Bolton-Hunter NPY. The majority of radioactive labeling was associated with folliculo-stellate cells; the percentage of labeling as well as the mean number of grains were approximately 5 times higher for folliculo-stellate cells than for melanotropes. An excess of nonlabeled NPY drastically reduced radiolabeling of folliculo-stellate cells, but had no effect on the degree of labeling of melanotropes. These results show that folliculo-stellate cells of X. laevis possess specific binding sites for NPY and indicate that NPY exerts its inhibitory action on the release of alpha MSH in an indirect fashion, by acting on the folliculo-stellate cells.

  9. Effect of immunomodulation on the fate of tumor cells in the central nervous system and systemic organs of mice. Distribution of (/sup 125/I)5-iodo-2'-deoxyuridine-labeled KHT tumor cells after left intracardial injection

    SciTech Connect

    Conley, F.K.

    1982-08-01

    The effect of systemic immunomodulation on tumor cell arrest and retention in the central nervous system was studied by following radioactively labeled tumor cells. KHT mouse sarcoma tumor cells were labeled in vitro with (/sup 125/I)IdUrd, and 1x10/sup 5/ tumor cells were injected into the left side of the hearts of syngeneic C3H mice. Experimental groups consisted of untreated normal mice, mice pretreated iv with Corynebacterium parvum, and mice chronically infected with Toxoplasma gondii; in this model both groups of immunomodulated mice are protected from developing systemic metastatic tumor, but only Toxoplasma-infected mice have protection against metastatic brain tumor. At time intervals from 1 to 96 hours, groups of mice from each experimental group were killed, and the brain and other organs were monitored for radioactivity to determine the number of viable tumor cells that had been present at the time of death. Normal mice demonstrated significant retention of tumor cells in the brain and kidneys plus adrenals at 96 hours. By contrast, in both groups of immunomodulated mice tumor cells were rapidly eliminated from systemic organs, but tumor cells were significantly retained in the central nervous system even at 96 hours after tumor cell injections. The results indicated that generalized immunomodulation had more effect in elimination of tumor cells from systemic organs than from the brain and that the elimination of tumor cells from the brain in Toxoplasma-infected mice was a delayed phenomenon.

  10. External beam radiotherapy boosts to reduce the impact caused by edema in prostate permanent seed implants

    NASA Astrophysics Data System (ADS)

    Yue, Ning; Mori, Jonathan; Nath, Ravinder; Heron, Dwight E.; Saiful Huq, M.

    2006-05-01

    In prostate permanent seed implants, it has been shown that edema caused by the surgical procedure decreases dose coverage and hence may reduce treatment efficacy. This reduction in treatment efficacy has been characterized by an increase in tumour cell survival, and biomathematical models have been developed to calculate the tumour cell survival increases in seed implanted prostates of different edema magnitudes and durations. External beam boosts can be utilized to neutralize the negative impact of edema so that originally desired treatment efficacy can be achieved. In this study, a linear quadratic model is used to determine fractionation sizes of the external beam boosts for both 125I and 103Pd seed implants. Calculations were performed for prostates of different edema magnitudes and durations, and for tumour cells of different repair rates and repopulation rates.

  11. Source strength assay of iodine-125 seeds sealed within sterile packaging.

    PubMed

    Otani, Yuki; Yamada, Takahiro; Kato, Shingo; Shikama, Naoto; Funakoshi, Kazuto; Kuroda, Isao; Numasaki, Hodaka; Nose, Takayuki; Dokiya, Takushi; Oguchi, Masahiko

    2013-03-04

    Early-stage prostate cancer is widely treated by iodine-125 (I-125) seed implantation. While quality assurance methods are in place to assure consistency in I-125 seed source strength, current methods involve the breaking of the sterilization package, raising issues concerning sterility and time limitations. The purpose of this study was to develop a method of characterizing the total source strength of I-125 seeds within a cartridge that has been sealed within a sterilization package and to evaluate the probability of detecting an out-of-calibration seed (aberrant seed). We defined a protocol to determine the ability of a well-type ionization chamber to detect aberrant I-125 seeds within a cartridge sealed in the sterilization package. A novel jig for a well-type ionization chamber was designed to accommodate the sterilization package. One seed was chosen randomly from two cartridges containing five or 15 seeds (0.544 U source strength) and was exchanged with aberrant seeds of six different source strengths. The source strength was measured at each position within the cartridge. The results indicated that the response of the well chamber was sensitive to changes in the aberrant seed position within the cartridge and the source strength of the aberrant seed. The correlation coefficient between single seed and batch assay results was high (0.998). A novel jig and a measurement method using a well ionization chamber were developed, which allowed for a batch assay characterization of the total source strength of I-125 seeds within a cartridge sealed within sterilization package. This method is simple, time-saving, and offers greater practical application.

  12. Hereditary orotic aciduria, Lesch-Nyhan syndrome, and xeroderma pigmentosum probed by herpes simplex virus: /sup 125/I-iododeoxycytidine incorporation as an assay for viral growth. [Human fibroblasts

    SciTech Connect

    Campisi, J.; Hafner, J.; Boorstein, R.; Pardee, A.B.

    1983-01-01

    /sup 125/I-Iododeoxycytidine (/sup 125/IdC) incorporation into acid-insoluble material was a sensitive, rapid, and quantitative assay for the growth of herpes simplex virus type 1 (HSV-1) in human fibroblasts. Cellular utilization of the isotope was 10 to 25% of the incorporation by infected cells and could be 80% inhibited by tetrahydrouridine (THU). Viral utilization was inhibited by acycloguanosine, thioguanine (TG), and cytosine arabinoside. Isotope was incorporated equally well by growing or quiescent infected cells. HSV-1 was used to probe the metabolic capabilities of three mutant human fibroblast strains. /sup 125/IdC incorporation quantitatively measured the ability of the virus to grow in these cells. Viral /sup 125/IdC incorporation was sensitive to TG in normal fibroblasts but showed a 8- to 10-fold greater resistance to TG in fibroblasts derived from patients with Lesch-Nyhan syndrome (LN). Similarly, the growth of ultraviolet irradiated HSV-1 in normal fibroblasts was 5-fold greater than in fibroblasts derived from patients with xeroderma pigmentosum. In fibroblasts derived from patients with hereditary orotic aciduria, viral /sup 125/IdC incorporation was sensitive to adenosine (AD) at concentrations which were slightly stimulatory in normal fibroblasts. This was a 2-fold difference in AD sensitivity, which the radioassay reliably and quantitatively documented. HSV-1 infected cells could be individually identified by their incorporated /sup 125/IdC; such cells had blackened nuclei in autoradiograms prepared 12 hr after infection. Normal cells infected in the presence of TG had many fewer labeled nuclei than LN cells similarly infected in the presence of the drug. (JMT)

  13. Characterization of a series of anabaseine-derived compounds reveals that the 3-(4)-dimethylaminocinnamylidine derivative is a selective agonist at neuronal nicotinic alpha 7/125I-alpha-bungarotoxin receptor subtypes.

    PubMed

    de Fiebre, C M; Meyer, E M; Henry, J C; Muraskin, S I; Kem, W R; Papke, R L

    1995-01-01

    Investigation of the naturally occurring, nicotinic agonist anabaseine and novel derivatives has shown that these compounds have cytoprotective and memory-enhancing effects. The hypothesis that these arise at least in part through actions on brain nicotinic receptors was evaluated by examining the ability of these compounds to displace the binding of nicotinic ligands and to affect the function of the alpha 4 beta 2 and alpha 7 receptor subtypes expressed in Xenopus oocytes. The derivative 3-(4)-dimethylaminocinnamylidine anabaseine (DMAC) was found to be a selective alpha 7 receptor agonist; it was more potent than nicotine, acetylcholine, anabaseine, and other derivatives at activating the alpha 7 receptor subtype, while displaying little agonist activity at alpha 4 beta 2 and other receptor subtypes. Compared with anabaseine and the other derivatives, DMAC was the most potent at displacing 125I-alpha-bungarotoxin binding (putative alpha 7) and the least potent at displacing [3H]cytisine binding (putative alpha 4 beta 2) to brain membranes. Independently of agonist activities, all of the novel compounds displayed secondary inhibitory activity at both receptor subtypes. At the alpha 4 beta 2 receptor subtype, inhibition by the 3-(2,4)-dimethoxybenzylidene derivative was enhanced by coapplication of acetylcholine, suggesting a noncompetitive form of inhibition. Anabaseine and nicotine prolonged the time course of activation of alpha 4 beta 2 receptors, compared with acetylcholine, suggesting sequential channel-blocking activity. As selective agonists, anabaseine derivatives such as DMAC may be useful for elucidating the function of alpha 7 nicotinic receptors, including their potential role(s) in the cytoprotective and memory-enhancing effects of nicotinic agents.

  14. Molecular pharmacology of the calcium channel: evidence for subtypes, multiple drug-receptor sites, channel subunits, and the development of a radioiodinated 1,4-dihydropyridine calcium channel label, (/sup 125/I)iodipine

    SciTech Connect

    Glossmann, H.; Ferry, D.R.; Goll, A.; Rombusch, M.

    1984-01-01

    Radiolabeled Ca2+ antagonists (1,4-dihydropyridines, verapamil, and D-cis-diltiazem) were used to study voltage-operated Ca2+ channels in different excitable tissues. The concept of three subtypes of Ca2+ channels, represented by brain, heart, and skeletal-muscle isoreceptors for 1,4-dihydropyridines, is developed. The three subtypes are characterized by a variety of criteria. Despite the biochemical differences between the subtypes, they have the same Mr in situ by target-size analysis (Mr approximately equal to 180,000, when evaluated by (/sub 3/H)nimodipine). The concept of the metalloprotein nature of the channel and the interaction of channel drugs with the Me2+ binding sites of the ionic pore is demonstrated. Distinct but interacting drug-receptor sites of the Ca2+ channel are found by direct labeling as well as indirectly by drug competition studies. The authors distinguish between the 1,4-dihydropyridine site, the verapamil site, and the D-cis-diltiazem site. Each receptor site can exist in high and low-affinity state; the distribution of receptor sites in these states is regulated by temperature, ions, and drugs. The concept of intrinsic activity of drugs to stabilize the high-affinity state is exemplified for the 1,4-dihydropyridines. A change in the channel architecture is induced by binding of D-cis-diltiazem to its drug receptor site. This is proven by target-size analysis of the channel in situ. Partially purified t-tubule membranes from skeletal muscle are an extremely rich source of Ca2+ channel drug-receptor sites. The stoichiometry was determined in this preparation and found to be four verapamil:two 1,4-dihydropyridine:one D-cis-diltiazem site. A novel Ca2+ channel probe, (/sup 125/I)iodipine (2,200 Ci/mmol), was synthetized, and the properties of this ligand are presented.

  15. Optimized thymidylate kinase assay, based on enzymatically synthesized 5-(/sup 125/I)iododeoxyuridine monophosphate and its application to an immunological study of herpes simplex virus thymidine-thymidylate kinases

    SciTech Connect

    Karlstroem, A.R.G.; Gronowitz, J.S.

    1987-05-01

    The biological synthesis and purification of 5-(/sup 125/I)iododeoxyuridine monophosphate (IdUMP) are described. The specificity of IdUMP as substrate in the thymidylate monophosphate kinase (TMPK) assay is demonstrated, and a 100-fold gain in sensitivity as compared to the conventional TMPK assay is shown. TMPK measurements of isozymes derived from herpes simplex virus (HSV)-infected cells, uninfected cells, and tumor biopsies were performed. The results showed a significant difference in dependence of phosphate donor concentration present for TMPK activity from HSV-infected cells compared to the corresponding activity from uninfected cells, while only a minor difference in pH optima was observed for these enzyme activities. The increased sensitivity made it possible to detect and quantify HSV TMPK-blocking antibodies (ab) present in human sera. Sera from HSV ab-positive individuals were found to block the two HSV TMPKs to varying degrees and with different specificities. The immunological relationship between the TMPK and thymidine kinase (TK) induced by HSV-1 and HSV-2, respectively, was studied by comparing the capacities of different sera to block the two enzymatic activities. The results showed that the capacity to block HSV-1 TK and TMPK was proportional for all of the sera studied, while sera that preferentially blocked only the HSV-2 TMPK or HSV-2 TK were found. It was concluded that the HSV-2 TMPK and TK activities are less related than the corresponding activities for HSV-1 and that the HSV-2 enzyme activities are mediated by different catalytic sites.

  16. SU-E-T-123: Anomalous Altitude Effect in Permanent Implant Brachytherapy Seeds

    SciTech Connect

    Watt, E; Spencer, DP; Meyer, T

    2015-06-15

    Purpose: Permanent seed implant brachytherapy procedures require the measurement of the air kerma strength of seeds prior to implant. This is typically accomplished using a well-type ionization chamber. Previous measurements (Griffin et al., 2005; Bohm et al., 2005) of several low-energy seeds using the air-communicating HDR 1000 Plus chamber have demonstrated that the standard temperature-pressure correction factor, P{sub TP}, may overcompensate for air density changes induced by altitude variations by up to 18%. The purpose of this work is to present empirical correction factors for two clinically-used seeds (IsoAid ADVANTAGE™ {sup 103}Pd and Nucletron selectSeed {sup 125}I) for which empirical altitude correction factors do not yet exist in the literature when measured with the HDR 1000 Plus chamber. Methods: An in-house constructed pressure vessel containing the HDR 1000 Plus well chamber and a digital barometer/thermometer was pumped or evacuated, as appropriate, to a variety of pressures from 725 to 1075 mbar. Current measurements, corrected with P{sub TP}, were acquired for each seed at these pressures and normalized to the reading at ‘standard’ pressure (1013.25 mbar). Results: Measurements in this study have shown that utilization of P{sub TP} can overcompensate in the corrected current reading by up to 20% and 17% for the IsoAid Pd-103 and the Nucletron I-125 seed respectively. Compared to literature correction factors for other seed models, the correction factors in this study diverge by up to 2.6% and 3.0% for iodine (with silver) and palladium respectively, indicating the need for seed-specific factors. Conclusion: The use of seed specific altitude correction factors can reduce uncertainty in the determination of air kerma strength. The empirical correction factors determined in this work can be applied in clinical quality assurance measurements of air kerma strength for two previously unpublished seed designs (IsoAid ADVANTAGE™ {sup 103}Pd and

  17. Project SEED.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1986

    1986-01-01

    Reports on Project SEED (Summer Educational Experience for the Disadvantaged) a project in which high school students from low-income families work in summer jobs in a variety of academic, industrial, and government research labs. The program introduces the students to career possibilities in chemistry and to the advantages of higher education.…

  18. Hierarchical mechanisms of spatially contagious seed dispersal in complex seed-disperser networks.

    PubMed

    Fedriani, José M; Wiegand, Thorsten

    2014-02-01

    Intra- and interspecific spatially contagious seed dispersal has far-reaching implications for plant recruitment, distribution, and community assemblage. However, logistical and analytical limitations have curtailed our understanding concerning the mechanisms and resulting spatial patterns of contagious seed dispersal in most systems and, especially, in complex seed-disperser networks. We investigated mechanisms of seed aggregation using techniques of spatial point pattern analysis and extensive data sets on mutispecific endozoochorous seed rain generated by five frugivorous mammals in three Mediterranean shrublands over two seasons. Our novel analytical approach revealed three hierarchical and complementary mechanisms of seed aggregation acting at different levels (fecal samples, seeds, pairs of seed species) and spatial scales. First, the three local guilds of frugivores tended to deliver their feces highly aggregated at small and intermediate spatial scales, and the overall pattern of fecal delivery could be described well by a nested double-cluster Thomas process. Second, once the strong observed fecal aggregation was accounted for, the distribution of mammal feces containing seeds was clustered within the pattern of all feces (i.e., with and without seeds), and the density of fecal samples containing seeds was higher than expected around other feces containing seeds in two out of the three studied seed-disperser networks. Finally, at a finer level, mark correlation analyses revealed that for some plant species pairs, the number of dispersed seeds was positively associated either at small or large spatial scales. Despite the relatively invariant patterning of nested double-clustering, some attributes of endozoochorous seed rain (e.g., intensity, scales of aggregation) were variable among study sites due to changes in the ecological context in which seeds and their dispersers interact. Our investigation disentangles for the first time the hierarchy of synergic

  19. Seeding for pervasively overlapping communities

    NASA Astrophysics Data System (ADS)

    Lee, Conrad; Reid, Fergal; McDaid, Aaron; Hurley, Neil

    2011-06-01

    In some social and biological networks, the majority of nodes belong to multiple communities. It has recently been shown that a number of the algorithms specifically designed to detect overlapping communities do not perform well in such highly overlapping settings. Here, we consider one class of these algorithms, those which optimize a local fitness measure, typically by using a greedy heuristic to expand a seed into a community. We perform synthetic benchmarks which indicate that an appropriate seeding strategy becomes more important as the extent of community overlap increases. We find that distinct cliques provide the best seeds. We find further support for this seeding strategy with benchmarks on a Facebook network and the yeast interactome.

  20. Effects of rodent species, seed species, and predator cues on seed fate

    NASA Astrophysics Data System (ADS)

    Sivy, Kelly J.; Ostoja, Steven M.; Schupp, Eugene W.; Durham, Susan

    2011-07-01

    Seed selection, removal and subsequent management by granivorous animals is thought to be a complex interaction of factors including qualities of the seeds themselves (e.g., seed size, nutritional quality) and features of the local habitat (e.g. perceived predator risk). At the same time, differential seed selection and dispersal is thought to have profound effects on seed fate and potentially vegetation dynamics. In a feeding arena, we tested whether rodent species, seed species, and indirect and direct predation cues influence seed selection and handling behaviors (e.g., scatter hoarding versus larder hoarding) of two heteromyid rodents, Ord's kangaroo rat ( Dipodomys ordii) and the Great Basin pocket mouse ( Perognathus parvus). The indirect cue was shrub cover, a feature of the environment. Direct cues, presented individually, were (1) control, (2) coyote ( Canis latrans) vocalization, (3) coyote scent, (4) red fox ( Vulpes vulpes) scent, or (5) short-eared owl ( Asio flammeus) vocalization. We offered seeds of three sizes: two native grasses, Indian ricegrass ( Achnatherum hymenoides) and bluebunch wheatgrass ( Pseudoroegneria spicata), and the non-native cereal rye ( Secale cereale), each in separate trays. Kangaroo rats preferentially harvested Indian ricegrass while pocket mice predominately harvested Indian ricegrass and cereal rye. Pocket mice were more likely to scatter hoard preferred seeds, whereas kangaroo rats mostly consumed and/or larder hoarded preferred seeds. No predator cue significantly affected seed preferences. However, both species altered seed handling behavior in response to direct predation cues by leaving more seeds available in the seed pool, though they responded to different predator cues. If these results translate to natural dynamics on the landscape, the two rodents are expected to have different impacts on seed survival and plant recruitment via their different seed selection and seed handling behaviors.

  1. Effects of rodent species, seed species, and predator cues on seed fate

    USGS Publications Warehouse

    Sivy, Kelly J.; Ostoja, Steven M.; Schupp, Eugene W.; Durham, Susan

    2011-01-01

    Seed selection, removal and subsequent management by granivorous animals is thought to be a complex interaction of factors including qualities of the seeds themselves (e.g., seed size, nutritional quality) and features of the local habitat (e.g. perceived predator risk). At the same time, differential seed selection and dispersal is thought to have profound effects on seed fate and potentially vegetation dynamics. In a feeding arena, we tested whether rodent species, seed species, and indirect and direct predation cues influence seed selection and handling behaviors (e.g., scatter hoarding versus larder hoarding) of two heteromyid rodents, Ord's kangaroo rat (Dipodomys ordii) and the Great Basin pocket mouse (Perognathus parvus). The indirect cue was shrub cover, a feature of the environment. Direct cues, presented individually, were (1) control, (2) coyote (Canis latrans) vocalization, (3) coyote scent, (4) red fox (Vulpes vulpes) scent, or (5) short-eared owl (Asio flammeus) vocalization. We offered seeds of three sizes: two native grasses, Indian ricegrass (Achnatherum hymenoides) and bluebunch wheatgrass (Pseudoroegneria spicata), and the non-native cereal rye (Secale cereale), each in separate trays. Kangaroo rats preferentially harvested Indian ricegrass while pocket mice predominately harvested Indian ricegrass and cereal rye. Pocket mice were more likely to scatter hoard preferred seeds, whereas kangaroo rats mostly consumed and/or larder hoarded preferred seeds. No predator cue significantly affected seed preferences. However, both species altered seed handling behavior in response to direct predation cues by leaving more seeds available in the seed pool, though they responded to different predator cues. If these results translate to natural dynamics on the landscape, the two rodents are expected to have different impacts on seed survival and plant recruitment via their different seed selection and seed handling behaviors.

  2. Practical considerations for maximizing heat production in a novel thermobrachytherapy seed prototype

    PubMed Central

    Gautam, Bhoj; Warrell, Gregory; Shvydka, Diana; Subramanian, Manny; Ishmael Parsai, E.

    2014-01-01

    Purpose: A combination of hyperthermia and radiation in the treatment of cancer has been proven to provide better tumor control than radiation administered as a monomodality, without an increase in complications or serious toxicities. Moreover, concurrent administration of hyperthermia and radiation displays synergistic enhancement, resulting in greater tumor cell killing than hyperthermia and radiation delivered separately. The authors have designed a new thermobrachytherapy (TB) seed, which serves as a source of both radiation and heat for concurrent brachytherapy and hyperthermia treatments when implanted in solid tumors. This innovative seed, similar in size and geometry to conventional seeds, will have self-regulating thermal properties. Methods: The new seed's geometry is based on the standard BEST Model 2301 125I seed, resulting in very similar dosimetric properties. The TB seed generates heat when placed in an oscillating magnetic field via induction heating of a ferromagnetic Ni–Cu alloy core that replaces the tungsten radiographic marker of the standard Model 2301. The alloy composition is selected to undergo a Curie transition near 50 °C, drastically decreasing power production at higher temperatures and providing for temperature self-regulation. Here, the authors present experimental studies of the magnetic properties of Ni–Cu alloy material, the visibility of TB seeds in radiographic imaging, and the ability of seed prototypes to uniformly heat tissue to a desirable temperature. Moreover, analyses are presented of magnetic shielding and thermal expansion of the TB seed, as well as matching of radiation dose to temperature distributions for a short interseed distance in a given treatment volume. Results: Annealing the Ni–Cu alloy has a significant effect on its magnetization properties, increasing the sharpness of the Curie transition. The TB seed preserves the radiographic properties of the BEST 2301 seed in both plain x rays and CT images

  3. Practical considerations for maximizing heat production in a novel thermobrachytherapy seed prototype

    SciTech Connect

    Gautam, Bhoj; Warrell, Gregory; Shvydka, Diana; Ishmael Parsai, E.; Subramanian, Manny

    2014-02-15

    Purpose: A combination of hyperthermia and radiation in the treatment of cancer has been proven to provide better tumor control than radiation administered as a monomodality, without an increase in complications or serious toxicities. Moreover, concurrent administration of hyperthermia and radiation displays synergistic enhancement, resulting in greater tumor cell killing than hyperthermia and radiation delivered separately. The authors have designed a new thermobrachytherapy (TB) seed, which serves as a source of both radiation and heat for concurrent brachytherapy and hyperthermia treatments when implanted in solid tumors. This innovative seed, similar in size and geometry to conventional seeds, will have self-regulating thermal properties. Methods: The new seed's geometry is based on the standard BEST Model 2301{sup 125}I seed, resulting in very similar dosimetric properties. The TB seed generates heat when placed in an oscillating magnetic field via induction heating of a ferromagnetic Ni–Cu alloy core that replaces the tungsten radiographic marker of the standard Model 2301. The alloy composition is selected to undergo a Curie transition near 50 °C, drastically decreasing power production at higher temperatures and providing for temperature self-regulation. Here, the authors present experimental studies of the magnetic properties of Ni–Cu alloy material, the visibility of TB seeds in radiographic imaging, and the ability of seed prototypes to uniformly heat tissue to a desirable temperature. Moreover, analyses are presented of magnetic shielding and thermal expansion of the TB seed, as well as matching of radiation dose to temperature distributions for a short interseed distance in a given treatment volume. Results: Annealing the Ni–Cu alloy has a significant effect on its magnetization properties, increasing the sharpness of the Curie transition. The TB seed preserves the radiographic properties of the BEST 2301 seed in both plain x rays and CT

  4. Seed Treatment. Bulletin 760.

    ERIC Educational Resources Information Center

    Lowery, Harvey C.

    This manual gives a definition of seed treatment, the types of seeds normally treated, diseases and insects commonly associated with seeds, fungicides and insecticides used, types of equipment used for seed treatment, and information on labeling and coloring of treated seed, pesticide carriers, binders, stickers, and safety precautions. (BB)

  5. Seed Treatment. Manual 92.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Agricultural Experiment Station.

    This training manual provides information needed to meet minimum EPA standards for certification as a commercial applicator of pesticides in the seed treatment category. The text discusses pests commonly associated with seeds; seed treatment pesticides; labels; chemicals and seed treatment equipment; requirements of federal and state seed laws;…

  6. Effect of chia seed meal on baking quality of cakes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chia seed is a good source of dietary fiber and complete proteins; chia seeds contain many health-promoting compounds and can be incorporated into baking goods for high-protein, high-fiber diet. Food grade chia seeds were obtained from a local grocery store and ground into meal using Retsch Model VD...

  7. Potential impact of prostate edema on the dosimetry of permanent seed implants using the new {sup 131}Cs (model CS-1) seeds

    SciTech Connect

    Chen Zhe; Deng Jun; Roberts, Kenneth; Nath, Ravinder

    2006-04-15

    Our aim in this work was to study the potential dosimetric effect of prostate edema on the accuracy of conventional pre- and post-implant dosimetry for prostate seed implants using the newly introduced {sup 131}Cs seed, whose radioactive decay half-life ({approx}9.7 days) is directly comparable to the average edema resolution half-life ({approx}10 days) observed previously by Waterman et al. for {sup 125}I implants [Int. J. Radiat. Oncol. Biol. Phys. 41, 1069-1077 (1998)]. A systematic calculation of the relative dosimetry effect of prostate edema on the {sup 131}Cs implant was performed by using an analytic solution obtained previously [Int. J. Radiat. Oncol. Biol. Phys. 47, 1405-1419 (2000)]. It was found that conventional preimplant dosimetry always overestimates the true delivered dose as it ignores the temporary increase of the interseed distance caused by edema. The overestimation for {sup 131}Cs implants ranged from 1.2% (for a small edema with a magnitude of 10% and a half-life of 2 days) to approximately 45% (for larger degree edema with a magnitude of 100% and a half-life of 25 days). The magnitude of pre- and post-implant dosimetry error for {sup 131}Cs implants was found to be similar to that of {sup 103}Pd implants for typical edema characteristics (magnitude <100%, and half-life <25 days); both of which are worse compared to {sup 125}I implants. The preimplant dosimetry error for {sup 131}Cs implants cannot be compensated effectively without knowing the edema characteristics before the seed implantation. On the other hand, the error resulted from a conventional post-implant dosimetry can be minimized (to within {+-}6%) for {sup 131}Cs implants if the post-implant dosimetry is performed at 10{+-}2 days post seed implantation. This 'optimum' post-implant dosimetry time is shorter than those determined previously for the {sup 103}Pd and {sup 125}I implants at 16{+-}4 days and 6{+-}1 weeks, respectively.

  8. Urethra-Sparing, Intraoperative, Real-Time Planned, Permanent-Seed Prostate Brachytherapy: Toxicity Analysis

    SciTech Connect

    Zilli, Thomas; Taussky, Daniel; Donath, David; Le, Hoa Phong; Larouche, Renee-Xaviere; Beliveau-Nadeau, Dominique; Hervieux, Yannick; Delouya, Guila

    2011-11-15

    Purpose: To report the toxicity outcome in patients with localized prostate cancer undergoing {sup 125}I permanent-seed brachytherapy (BT) according to a urethra-sparing, intraoperative (IO), real-time planned conformal technique. Methods and Materials: Data were analyzed on 250 patients treated consecutively for low- or intermediate-risk prostate cancer between 2005 and 2009. The planned goal was urethral V{sub 150} = 0. Acute and late genitourinary (GU), gastrointestinal (GI), and erectile toxicities were scored with the International Prostate Symptom Score (IPSS) questionnaire and Common Terminology Criteria for Adverse Events (version 3.0). Median follow-up time for patients with at least 2 years of follow-up (n = 130) was 34.4 months (range, 24-56.9 months). Results: Mean IO urethra V{sub 150} was 0.018% {+-} 0.08%. Mean prostate D{sub 90} and V{sub 100} on day-30 computed tomography scan were 158.0 {+-} 27.0 Gy and 92.1% {+-} 7.2%, respectively. Mean IPSS peak was 9.5 {+-} 6.3 1 month after BT (mean difference from baseline IPSS, 5.3). No acute GI toxicity was observed in 86.8% of patients. The 3-year probability of Grade {>=}2 late GU toxicity-free survival was 77.4% {+-} 4.0%, with Grade 3 late GU toxicity encountered in only 3 patients. Three-year Grade 1 late GI toxicity-free survival was 86.1% {+-} 3.2%. No patient presented Grade {>=}2 late GI toxicity. Of patients with normal sexual status at baseline, 20.7% manifested Grade {>=}2 erectile dysfunction after BT. On multivariate analysis, elevated baseline IPSS (p = 0.016) and high-activity sources (median 0.61 mCi) (p = 0.033) predicted increased Grade {>=}2 late GU toxicity. Conclusions: Urethra-sparing IO BT results in low acute and late GU toxicity compared with the literature. High seed activity and elevated IPSS at baseline increased long-term GU toxicity.

  9. Development of receptors for insulin and insulin-like growth factor-I in head and brain of chick embryos: Autoradiographic localization

    SciTech Connect

    Bassas, L.; Girbau, M.; Lesniak, M.A.; Roth, J.; de Pablo, F. )

    1989-11-01

    In whole brain of chick embryos insulin receptors are highest at the end of embryonic development, while insulin-like growth factor-I (IGF-I) receptors dominate in the early stages. These studies provided evidence for developmental regulation of both types of receptors, but they did not provide information on possible differences between brain regions at each developmental stage or within one region at different embryonic ages. We have now localized the specific binding of (125I)insulin and (125I)IGF-I in sections of head and brain using autoradiography and computer-assisted densitometric analysis. Embryos have been studied from the latter part of organogenesis (days 6 and 12) through late development (day 18, i.e. 3 days before hatching), and the binding patterns have been compared with those in the adult brain. At all ages the binding of both ligands was to discrete anatomical regions. Interestingly, while in late embryos and adult brain the patterns of (125I)insulin and (125I) IGF-I binding were quite distinct, in young embryos both ligands showed very similar localization of binding. In young embryos the retina and lateral wall of the growing encephalic vesicles had the highest binding of both (125I)insulin and (125I)IGF-I. In older embryos, as in the adult brain, insulin binding was high in the paleostriatum augmentatum and molecular layer of the cerebellum, while IGF-I binding was prominent in the hippocampus and neostriatum. The mapping of receptors in a vertebrate embryo model from early prenatal development until adulthood predicts great overlap in any possible function of insulin and IGF-I in brain development, while it anticipates differential localized actions of the peptides in the mature brain.

  10. Improving photoacoustic imaging contrast of brachytherapy seeds

    NASA Astrophysics Data System (ADS)

    Pan, Leo; Baghani, Ali; Rohling, Robert; Abolmaesumi, Purang; Salcudean, Septimiu; Tang, Shuo

    2013-03-01

    Prostate brachytherapy is a form of radiotherapy for treating prostate cancer where the radiation sources are seeds inserted into the prostate. Accurate localization of seeds during prostate brachytherapy is essential to the success of intraoperative treatment planning. The current standard modality used in intraoperative seeds localization is transrectal ultrasound. Transrectal ultrasound, however, suffers in image quality due to several factors such speckle, shadowing, and off-axis seed orientation. Photoacoustic imaging, based on the photoacoustic phenomenon, is an emerging imaging modality. The contrast generating mechanism in photoacoustic imaging is optical absorption that is fundamentally different from co