125I-labelling = 125I-Labelling.
Ontology highlight
ABSTRACT:
SUBMITTER: Murphy MJ
PROVIDER: S-EPMC1164116 | biostudies-other | 1976 Nov
REPOSITORIES: biostudies-other
Similar Datasets
Project description:1. A new method is described for labelling proteins to high specific radioactivities with (125)I. The protein is treated with a (125)I-labelled acylating agent, iodinated 3-(4-hydroxyphenyl)propionic acid N-hydroxysuccinimide ester, which reacts with free amino groups in the protein molecule to attach the (125)I-labelled groups by amide bonds. 2. Three protein hormones have been labelled by this method, human growth hormone, human thyroid-stimulating hormone and human luteinizing hormone. Specific radioactivities of up to 170, 120 and 55muCi/mug respectively have been obtained for these hormones. 3. The immunoreactivity of these labelled hormones has been investigated by using a radioimmunoassay system specific for each hormone. These preparations have also been compared with and found to be equal or superior to labelled hormones prepared by chemical substitution of (125)I into tyrosine residues of the proteins by using the chloramine-t-oxidation procedure. 4. With some antisera the immunoreactivity of the antigen was diminished by the introduction of a single I atom into the tyrosyl groups, whereas antigen containing a single (125)I-labelled 3-(4-hydroxyphenyl)propionamide group showed the same immunoreactivity as the unmodified antigen.
| S-EPMC1177731 | biostudies-other
Project description:In bovine adrenal zona glomerulosa, atrial natriuretic factor (ANF) exerts its physiological effect through high-affinity binding to specific membrane receptors. On studying further the molecular properties of the ANF receptor binding domain, we have observed that incubation of intact or solubilized bovine adrenal zona glomerulosa membranes with 125I-ANF-(99-126) followed by u.v. irradiation results in the irreversible labelling of a 130 kDa protein corresponding to the ANF-RI receptor. This process is time-, protein- and 125I-ANF-dependent. The apparently covalent nature of this complex is documented by its resistance to heat, guanidine hydrochloride, urea and trichloroacetic acid denaturation. Photolabelling with underivatized 125I-ANF is much more efficient with the ANF-R1 than with the ANF-R2 receptor. After photolysis, the covalently linked 125I-ANF is still sensitive to digestion by carboxypeptidase A, suggesting that ANF is linked by its N-terminal end to the receptor upon u.v. irradiation and that its C-terminal end is still freely accessible. Aerobic conditions and lipids are required for the photolabelling, suggesting a role in this process for malondialdehyde, a highly reactive secondary product associated with u.v.-induced lipid peroxidation. This simple method should provide a powerful tool in the accurate characterization of the hormone-binding domain of the ANF receptor.
| S-EPMC1131299 | biostudies-other
Project description:The hydrophobic photosensitive probe 1-azido-4-[125I]iodobenzene (AIB) partitioned preferentially into photoreceptor disc membranes and, upon u.v. irradiation, became covalently bound to opsin and phospholipid. The labelling of both protein and phospholipid was linearly related to AIB concentration. The amount of probe incorporated into protein was not significantly different when membranes were irradiated at -100 degrees, 4 degrees or 25 degrees C, but irreversible aggregation of monomeric opsin was dramatically reduced by performing the photolysis at -100 degrees C. Labelling of opsin after irradiation at -100 degrees or 4 degrees was not significantly reduced by the presence of lysine in the aqueous buffer, indicating that significant amounts of reactive species did not enter the aqueous phase. The incorporation into phospholipid, unlike that into opsin, decreased as the temperature of irradiation increased. Some labelling of opsin occurred on incubation with pre-photoactivated AIB, indicating that reaction may also occur with reactive species of longer lifetimes than the nitrene. Proteolysis of labelled opsin with Staphylococcus aureus V8 proteinase yielded two radiolabelled membrane-bound fragments. The location of the modified sites (cysteine, tryptophan, tyrosine, lysine and histidine residues: all nucleophiles) in the smaller fragment was entirely consistent with putative models for the protein derived from other studies.
| S-EPMC1146580 | biostudies-other
Project description:The purpose of the present study was to assess the results of two different treatment approaches for clinically localized prostate cancer: intensity-modulated radiation therapy (IMRT) followed by 125I seed-implant brachytherapy and 125I seed-implant brachytherapy alone. We studied our 30 most recent consecutive patients. The sample population consisted of 15 cases treated with IMRT (50.4 Gy) followed by 125I seed-implant boost (95 Gy), and 15 cases treated with 125I seed implant only (144 Gy). We analyzed established dosimetric indices and various clinical parameters. In addition, we also evaluated and compared the acute urinary morbidities of the two treatment approaches, as assessed by the international prostate symptom score (IPSS). In our series, acute urinary morbidity was slightly increased with IMRT followed by 125I seed-implant brachytherapy as compared with 125I seed-implant brachytherapy alone. In addition, we observed no statistically significant correlation between the IPSS and the maximum or mean urethral dose. The combination of IMRT and seed-implant brachytherapy presents an alternative opportunity to treat clinically localized prostate cancer. The full potential of the procedure needs to be further investigated.
| S-EPMC5721712 | biostudies-literature
Project description:Purpose:To investigate the biological behavior on the invation, proliferation, and apoptosis, and the molecular mechanism of A549 cell which induced by 125I seed irradiation. Design:The first part cell Experiment: cultured A549 cell in vitro, then divided into 125I seeds group and control group. Using MTT, Transwell experiment, flow cytometric analysis the difference among cell proliferation, invasion, and apoptosis, after 125I seeds different treatment time on the A549 cell. Nimblegen human genome microarray detection to find out the genes expression changes between the two groups. Then screen out target gene, using protein chip technology and western-blot further verified target gene protein expression.
2020-10-23 | GSE159431 | GEO
Project description: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.
| S-EPMC4740417 | biostudies-literature
Project description:Background125I seed implantation has been found to show good therapeutic effects on tumors. Recent studies showed that three-dimensional (3D) print template-assisted 125I seed implantation can optimize radiation dose distribution. This study aimed to compare the dose distribution differences in 125I seed implantation among 3D print noncoplanar template- (3DPNCT), 3D print coplanar template- (3DPCT) assisted implantation and traditional free-hand implantation.MethodsWe systematically searched the PubMed, EMbase, Cochrane Library, Wan Fang Med Online, China National Knowledge Infrastructure (CNKI) from the earliest to November 2020 without time or language restrictions. And the references of primary literature were also searched. The outcome measures were dosimetry and operation time. This meta-analysis was carried out using Stata 12.0.ResultsA total of 16 original articles were selected for inclusion. The differences of D90, D100, V90, and V100 values pre- and post-implantation with traditional free-hand implantation showed statistically significant (p < 0.05). The differences of D90, D100, V100, V150, V200, and D2cc of organs at risk (OAR) values pre- and post-implantation with 3D print template showed no statistically significant (p > 0.05). Compared with traditional free-hand implantation without any templates, 3D print template could improve postoperative D90 (Standard mean difference, SMD = 0.67, 95% confidence interval (CI) = 0.35 to 0.98, p < 0.001), D100 (SMD = 0.82, 95%CI = 0.40 to 1.23, p < 0.001), V90 (SMD = 1.48, 95%CI = 0.95 to 2.00, p < 0.001), V100 (SMD = 1.41, 95%CI = 0.96 to 1.86, p < 0.001), and reduce operation time (SMD = - 0.93, 95%CI = - 1.34 to - 0.51, p < 0.001). In three studies, both 3DPNCT and 3DPCT plans were designed for all patients. The prescribed dose and seed activity were same. Pooled analysis of D90, D100, V100, D2cc of OAR, number of seeds and number of needles showed no significant differences between 3DPNCT and 3DPCT groups (p > 0.05). However, in 3DPNCT group, V150 and V200 were increased (SMD = 0.35, 0.49; 95%CI = 0.04 to 0.67, 0.02 to 0.96; p = 0.028, 0.043); the number of through bone needles was reduced (SMD = - 1.03, 95%CI = - 1.43 to - 0.64, p < 0.001).ConclusionsCompared with traditional free-hand implantation, 3D print template-assisted 125I seeds implantation can optimize dose distribution and reduce the implantation time at the same time. Compared with 3D print coplanar template, 3D print noncoplanar template can increase the volume of high dose within tumor target and is more safer in the respect of puncture route.
| S-EPMC8223396 | biostudies-literature
Project description:PURPOSE:Diagnosis and therapeutic monitoring of chronic bacterial infection requires methods to detect and localize sites of infection accurately. Complement C3 activation fragments are generated and covalently bound to selective bacterial pathogens during the immune response and can serve as biomarkers of ongoing bacterial infection. We have developed several probes for detecting tissue-bound C3 deposits, including a monoclonal antibody (mAb 3d29) that recognizes the tissue-bound terminal processing fragments iC3b and C3d but does not recognize native circulating C3 or tissue-bound C3b. PROCEDURES:To determine whether mAb 3d29 could be used to detect chronic Mycobacterium tuberculosis infection non-invasively, aerosol-infected female C3HeB/FeJ mice were injected with [125I]3d29 mAb and either imaged using single-photon emission computed tomography (SPECT)/X-ray computed tomography (CT) imaging at 24 and 48 h after radiotracer injection or being subjected to biodistribution analysis. RESULTS:Discrete lesions were detected by SPECT/CT imaging in the lungs and spleens of infected mice, consistent with the location of granulomas in the infected animals as detected by CT. Low-level signal was seen in the spleens of uninfected mice and no signal was seen in the lungs of healthy mice. Immunofluorescence microscopy revealed that 3d29 in the lungs of infected mice co-localized with aggregates of macrophages (detected with anti-CD68 antibodies). 3d29 was detected in the cytoplasm of macrophages, consistent with the location of internalized M. tuberculosis. 3d29 was also present within alveolar epithelial cells, indicating that it detected M. tuberculosis phagocytosed by other CD68-positive cells. Healthy controls showed very little retention of fluorescent or radiolabeled antibody across tissues. Radiolabeled 3d29 compared with radiolabeled isotype control showed a 3.5:1 ratio of increased uptake in infected lungs, indicating specific uptake by 3d29. CONCLUSION:3d29 can be used to detect and localize areas of infection with M. tuberculosis non-invasively by 24 h after radiotracer injection and with high contrast.
| S-EPMC6329677 | biostudies-literature
Project description: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.
| S-EPMC4277420 | biostudies-literature
Project description:Two methods were used to label pig kidney microvillar membrane proteins from the luminal and cytoplasmic surfaces of closed membrane vesicles. The first method was lactoperoxidase-catalysed radioiodination. The enzyme reagents, lactoperoxidase and glucose oxidase, were positioned inside the vesicles before sealing or externally after sealing, iodination being initiated by the subsequent addition of glucose and 125I-. After resolution of the labelled proteins by electrophoresis in the presence of dodecyl sulphate, asymmetric labelling patterns on radioautographs were observed. However, the major disadvantage of this method is the high degree of intramembrane labelling of the fatty acid chains of membrane lipids, a reaction that undermines any conclusions about the location of the label in that region of the protein supposedly exposed at the surface of the membrane. The second method overcame this disadvantage. A new hydrophilic photoreagent, 3,5-di[125I]iodo-4-azidobenzesulphonate, was synthesized via the intermediate, diazotized 3,5-di[125I]iodosulphanilic acid. It was transported by a Na+-dependent system into microvillar vesicles, thus permitting labelling from either side of the membrane when the vesicles were photolysed. The labelling of membrane lipids was less than with the first method and was essentially confined to the polar headgroups. The activity of several microvillar peptidases survived the labelling reaction and they could be identified in the immunoprecipitates after resolution of the detergent-solubilized membrane proteins by crossed-immunoelectrophoresis. Treatment with papain converted the detergent-solubilized form of susceptible enzymes into the proteinase-solubilized form, which lacked the intramembrane domain and any portion exposed at the cytoplasmic surface. Radioautography established that aminopeptidases M and A, dipeptidyl peptidase IV and neutral endopeptidase were transmembrane proteins. This novel approach to the investigation of membrane topology may be applicable to other complex membranes.
| S-EPMC1162491 | biostudies-other