Some quantitative aspects of the labelling of proteins with 125 I by the iodine monochloride method.
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ABSTRACT:
SUBMITTER: Ceska M
PROVIDER: S-EPMC1176496 | biostudies-other | 1971 Jan
REPOSITORIES: biostudies-other
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Project description:OBJECTIVE: Brachytherapy employing iodine-125 seeds is an established treatment for low-risk prostate cancers. Post-implant dosimetry (PID) is an important tool for identifying suboptimal implants. The aim of this work was to improve suboptimal implants by a subsequent iodine-125 seed top-up (reimplantation), based on the PID results. METHODS: Of 255 patients treated between 2009 and 2012, 6 were identified as having received suboptimal implants and were scheduled for seed top-up. Needle configurations and the number of top-up seeds were determined based on post-implant CT images as well as a reimplantation treatment plan. An average of 14 seeds per patient were implanted during each top-up. Dosimetric outcome was assessed via target parameters and doses received by organs at risk. RESULTS: All six patients had a successful top-up, with a 67% increase in the mean dose delivered to 90% of the prostate volume and a 40% increase in the volume that receives 100% of the prescribed dose. However, the final dosimetric assessment was based on the same seed activity, as the planning system does not account for the decay of the initially implanted seeds. Although physical dosimetry is not influenced by different seed activities (doses are calculated to infinity), the radiobiological implications might be slightly different from the situation when optimal implantation is achieved with one treatment only. CONCLUSION: Seed reimplantation in suboptimal prostate implants is feasible and leads to successful clinical outcomes. ADVANCES IN KNOWLEDGE: Suboptimal prostate implants can occur for various reasons. This work shows that seed reimplantation as salvage therapy can lead to an optimal dosimetric outcome with manageable normal tissue effects.
| S-EPMC3664978 | biostudies-other
Project description:Iodine-125 (125I) brachytherapy, a promising form of radiotherapy, is increasingly applied in the clinical treatment of a wide range of solid tumors. However, the extremely hypoxic microenvironment in solid tumors can cause hypoxia-induced radioresistance to 125I brachytherapy, resulting in therapeutic inefficacy. In this study, the aim is to sensitize hypoxic areas in solid tumors using ultrasound-activated oxygen microbubbles for 125I brachytherapy. A modified emulsion freeze-drying method is developed to prepare microbubbles that can be lyophilized for storage and easily reconstituted in situ before administration. The filling gas of the microbubbles is modified by the addition of sulfur hexafluoride to oxygen such that the obtained O2/SF6 microbubbles (OS MBs) achieve a much longer half-life (>3×) than that of oxygen microbubbles. The OS MBs are tested in nasopharyngeal carcinoma (CNE2) tumor-bearing mice and oxygen delivery by the OS MBs induced by ultrasound irradiation relieve hypoxia instantly. The post-treatment results of brachytherapy combined with the ultrasound-triggered OS MBs show a greatly improved therapeutic efficacy compared with brachytherapy alone, illustrating ultrasound-mediated oxygen delivery with the developed OS MBs as a promising strategy to improve the therapeutic outcome of 125I brachytherapy in hypoxic tumors.
| S-EPMC8025033 | biostudies-literature
Project description:Patients with radioactive iodine refractory differentiated thyroid cancer (RAIR-DTC) are resistant to radioactive iodine-131(131I) treatment, and the clinical treatment for these patients is complex. The implantation of iodine-125 (125I) seeds in the lesion has been successfully applied to treat malignant tumors, but there are few reports on using 125I particles in the treatment of RAIR-DTC. This retrospective study collected data of 92 patients with RAIR-DTC. Patients treated with sorafenib were included in a control group (50 cases with 72 lesions) and patients treated with 125I implantation were included in an observation group (42 cases with 68 lesions). The results showed that compared with those in the control group, the lesion volume was lower and the VVR was higher in the observation group (P<0.05). The Tg and Tg-Ab levels 6 months after treatment were lower than those before treatment in both groups, and the post-treatment Tg and Tg-Ab levels of the observation group were lower than those of the control group (P<0.05). The efficacy, disease control rate, and objective remission rate were not significantly different between the observation group and the control group (P>0.05). Overall survival of patients in the observation group was longer than that in the control group, χ2 = 4.430, P = 0.035. The incidence of total adverse reactions in the observation group was lower than that in the control group (P<0.05). In conclusion, 125I seed implantation is effective in RAIR-DTC treatment as it can prolong the overall survival of patients while maintaining a safe profile.
| S-EPMC10636672 | biostudies-literature
Project description:BackgroundTo assess the feasibility and efficacy of using 125I seed implantation under intraoperative ultrasound guidance for unresectable pancreatic carcinoma.MethodsFourteen patients with pancreatic carcinoma that underwent laparotomy and considered unresectable were included in this study. Nine patients were pathologically diagnosed with Stage II disease, five patients with Stage III disease. Fourteen patients were treated with 125I seed implantation guided by intraoperative ultrasound and received D90 of 125I seeds ranging from 60 to 140 Gy with a median of 120 Gy. Five patients received an additional 35-50 Gy from external beam radiotherapy after seed implantation and six patients received 2-6 cycles of chemotherapy.Results87.5% (7/8) of patients received partial to complete pain relief. The response rate of tumor was 78.6%, One-, two-and three-year survival rates were 33.9% and 16.9%, 7.8%, with local control of disease achieved in 78.6% (11/14), and the median survival was 10 months (95% CI: 7.7-12.3).ConclusionThere were no deaths related to 125I seed implant. In this preliminary investigation, 125I seed implant provided excellent palliation of pain relief, local control and prolong the survival of patients with stage II and III disease to some extent.
| S-EPMC2715376 | biostudies-literature
Project description:Purpose:To investigate chronological changes in lower urinary tract symptoms (LUTS) in patients who received iodine-125 brachytherapy (BT) for prostate cancer. Methods:We enrolled 706 patients who received BT. Of these, 265 (38%) received BT combined with external beam radiation therapy (EBRT). An International Prostate Symptom Score (IPSS), IPSS quality of life (IPSS-QOL) score, and overactive bladder symptom score (OABSS) were recorded before BT (baseline, BL), and 1, 3, 6, 12, 24, 36, 48, and 60?months after BT. The sum of frequency (2), urgency (4) and nocturia (7) of the IPSS questionnaire was defined as the storage symptoms score, whereas the sum of emptying (1), intermittency (3), weak stream (5), and hesitancy (6) was defined as the voiding symptom score. Results:Total IPSS significantly increased at 3?months following BT compared with BL (mean score: 17.1 vs. 7.99, P?<?0.001) and returned to BL by 36?months. The storage symptom score did not return to BL 36?months after BT. Total OABSS significantly increased 3?months after BT compared with BL (mean score: 6.52 vs. 3.45, P?<?0.001), and returned to BL 48?months after BT. The IPSS-QOL score was the highest score (mean score: 2.46 vs. 3.9, P?<?0.001) 3?months after BT and returned to BL 48?months after BT, however the IPSS-QOL score was lower than BL (mean score: 2.01 vs 2.46, P?<?0.001) at 60?months. The risk factors for LUTS within 1?year after BT were BL IPSS (P?<?0.001) and PV (P?<?0.001). Patients who received combined EBRT experienced transient storage symptoms 24 and 36?months after BT, whereas those who received BT alone did not. However, the storage symptom score of the patients who received combined EBRT was improving 48?months after BT and eventually showed no significant difference compared with those treated with BT alone. Conclusion:Three months after BT, LUTS, including storage symptoms, deteriorated the most but improved with time. The urinary symptom in patients who received combined EBRT can potentially flare again in 24 and 36?months after BT. Knowledge of changes in LUTS associated with BT may influence treatment recommendations and enable patients to make better-informed decisions.
| S-EPMC6282112 | biostudies-literature
Project description:IntroductionImpalpable breast lesions generally require image-guided localisation for breast-conserving surgery. A standard technique is to place a hook wire (HW) within the lesion. Radioguided occult lesion localisation using iodine seeds (ROLLIS) involves inserting a 4.5 mm iodine-125 seed (seed) into the lesion. We hypothesised that a seed could be more precisely positioned in relation to the lesion than a HW and that this may be associated with a lower re-excision rate.MethodsRetrospective review of consecutive participant data from three ROLLIS RCT (ACTRN12613000655741) sites. Participants underwent preoperative lesion localisation (PLL) with seed or HW between September 2013 and December 2017. Lesion and procedural characteristics were recorded. Distances between (1) any part of the seed or thickened segment of the HW ('TSHW') and the lesion/clip ('distance to device' DTD) and (2) centre of the TSHW/seed and centre of the lesion/clip (device centre to target centre 'DCTC') were measured on immediate postinsertion mammograms. Pathological margin involvement and re-excision rates were compared.ResultsA total of 390 lesions (190 ROLLIS and 200 HWL) were analysed. Lesion characteristics and guidance modality used were similar between groups. Ultrasound-guided DTD and DCTC for seed were smaller than for HW (77.1% and 60.6%, respectively, P-value < 0.001). Stereotactic-guided DCTC for seeds was 41.6% smaller than for HW (P-value = 0.001). No statistically significant difference in the re-excision rates was found.ConclusionIodine-125 seeds can be more precisely positioned for preoperative lesion localisation than HW, however, no statistically significant difference in re-excision rates was detected.
| S-EPMC10500114 | biostudies-literature
Project description:BackgroundTumor recurrence is a major problem after curative resection of hepatocellular carcinoma (HCC). The current study evaluated the effects of adjuvant iodine-125 ((125)I) brachytherapy on postoperative recurrence of HCC.Methodology/principal findingsFrom July 2000 to June 2004, 68 HCC patients undergoing curative hepatectomy were randomly assigned into a (125)I adjuvant brachytherapy group (n?=?34) and a group of best care (n?=?34). Patients in the (125)I adjuvant brachytherapy group received (125)I seed implantation on the raw surface of resection. Patients in the best care control group received identical treatments except for the (125)I seed implantation. Time to recurrence (TTR) and 1-, 3- and 5-year overall survival (OS) were compared between the two groups. The follow-up ended in January 2010, and lasted for 7.7-106.4 months with a median of 47.6 months. TTR was significantly longer in the (125)I group (mean of 60.0 months vs. 36.7 months in the control). The 1-, 3- and 5-year recurrence-free rates of the (125)I group were 94.12%, 76.42%, and 73.65% vs. 88.24%, 50.00%, and 29.41% compared with the control group, respectively. The 1-, 3- and 5-year OS rates of the (125)I group were 94.12%, 73.53%, and 55.88% vs. 88.24%, 52.94%, and 29.41% compared with the control group, respectively. The (125)I brachytherapy decreased the risk of recurrence (HR?=?0.310) and the risk of death (HR?=?0.364). Most frequent adverse events in the (125)I group included nausea, vomiting, arrhythmia, decreased white blood cell and/or platelet counts, and were generally mild and manageable.Conclusions/significanceAdjuvant (125)I brachytherapy significantly prolonged TTR and increased the OS rate after curative resection of HCC.Trial registrationAustralian New Zealand Clinical Trials Registry ACTRN12610000081011.
| S-EPMC3585398 | biostudies-literature
Project description:Iodination has long been employed as a successful labelling strategy to gain structural insights into proteins and other biomolecules via several techniques, including Small Angle X-ray Scattering, Inductively Coupled Plasma Mass Spectrometer (ICP-MS), and single-crystal crystallography. However, when dealing with smaller biomolecular systems, interactions driven by iodine may significantly alter their self-assembly behaviour. The engineering of amyloidogenic peptides for the development of ordered nanomaterials has greatly benefitted from this possibility. Still, to date, iodination has exclusively been applied to aromatic residues. In this work, an aliphatic bis-iodinated amino acid was synthesized and included into a custom pentapeptide, which showed enhanced fibrillogenic behaviour. Peptide single crystal X-ray structure and powder X-ray diffraction on its dried water solution demonstrated the key role of iodine atoms in promoting intermolecular interactions that drive the peptide self-assembly into amyloid fibrils. These findings enlarge the library of halogenated moieties available for directing and engineering the self-assembly of amyloidogenic peptides.
| S-EPMC9306938 | biostudies-literature
Project description:Most eukaryotic RNA regulators recognise their RNA and protein partners by the combinatorial use of several RNA binding domains. Inter-domain dynamics and interactions play a key role in recognition and can be analysed by techniques such as NMR or FRET, provided that the information relative to the individual interactions can be de-convoluted. Segmentally labelling the proteins by ligating labelled and unlabelled peptide chains allows one to filter out unwanted information and observe the labelled moieties only. Several strategies have been implemented to ligate two protein fragments, but multiple ligations, which are necessary to segmentally label proteins of more than two domains, are more challenging and often dependent on the structure and solubility of the domains. Here we report a method to ligate multiple protein segments that allows the fast, high yield labelling of both internal and end domains, depending on the requirements. We use TCEP and mercaptophenylacetic acid (MPAA) in an optimised reaction environment to achieve an efficient ligation of protein domains independently from their structure or solubility. We expect the method will provide a useful tool for the molecular study of combinatorial protein-RNA recognition in RNA regulation.
| S-EPMC5658380 | biostudies-literature
Project description:Lysine acetylation (Kac) is an important post-translational modification (PTM) of proteins in all organisms, but its functions have not been extensively explored in filamentous fungi. In this study, a Tandem Mass Tag (TMT) labelling lysine acetylome was constructed, and differentially modified Kac proteins were quantified during mycoparasitism and vegetative growth in the biocontrol fungus Clonostachys chloroleuca 67-1, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total of 1448 Kac sites were detected on 740 Kac proteins, among which 126 sites on 103 proteins were differentially regulated. Systematic bioinformatics analyses indicate that the modified Kac proteins were from multiple subcellular localizations and involved in diverse functions including chromatin assembly, glycometabolism and redox activities. All Kac sites were characterized by 10 motifs, including the novel CxxKac motif. The results suggest that Kac proteins may have effects of broadly regulating protein interaction networks during C. chloroleuca parasitism to Sclerotinia sclerotiorum sclerotia. This is the first report of a correlation between Kac events and the biocontrol activity of C. chloroleuca. Our findings provide insight into the molecular mechanisms underlying C. chloroleuca control of plant fungal pathogens regulated by Kac proteins.
| S-EPMC8599485 | biostudies-literature