ABSTRACT
BACKGROUND: Neuroendocrine tumours (NETs) are a group of cancers that can produce hormones and other metabolically active compounds. The majority of NETs have specific tissue characteristics, such as the expression of somatostatin receptors (SSTR). Metabolic testing with [99mTc]Tc-EDDA/HYNIC-Tyr3-octreotide ([99mTc]Tc-EDDA/HYNIC-TOC) can be used in patients with NETs to visualize the presence of receptors in different locations of pathological lesions, including the skeletal system. The study aimed to calculate the body weight maximum standardized uptake value (SUVbwmax) of pathological bone lesions and healthy bone tissues, estimate the size of lesions, and identify a relationship between the SUVbwmax of the bone tissues, age and body mass of the study participants. MATERIAL AND METHODS: The somatostatin receptor scintigraphies (SRS) with [99mTc]Tc-EDDA/HYNIC-TOC were carried out at the Department of Nuclear Medicine, University Clinical Hospital No. 1, Pomeranian Medical University (PMU) in Szczecin from 2019 to 2022. Whole body and single photon emission computed tomography/computed tomography (SPECT/CT) scans were performed four hours after the injection of 700-800 MBq of [99mTc]Tc-EDDA/HYNIC-TOC in 344 patients with neuroendocrine tumours of various primary lesion locations. In 19 patients, who showed foci of increased radiopharmaceutical accumulation in bone location, the SUVbwmax was measured. The SUVbwmax of pathological bone lesions and healthy tissues were determined on SPECT/CT cross-sectional images using Xeleris 4 software. RESULTS: The total number of foci with increased SSTR expression in bone regions seen on scintigraphic images was 89. Among them, 32 bone lesions were visible on the corresponding CT scans. The mean SUVbwmax of these lesions was 31.39 [standard deviation (SD) 34.31]. For the other 57 lesions that were not visible on corresponding CT scans, the mean SUVbwmax was 19.12 (SD 24.24). The smallest bone lesion detected on the scintigram and visible on the corresponding CT location was 5 mm × 5 mm, measured in cross-section, and was located in the Th8 vertebral body; the largest, measuring 20 mm × 22 mm, was detected in the L3 vertebral body. The SUVbwmax of these lesions was 24.70 and 142.40, respectively. CONCLUSIONS: Bone lesions seen on SPECT/CT in [99mTc]Tc-EDDA/HYNIC-TOC scintigraphy can be quantitatively analysed using the SUV index. Even a very small pathological bone lesion can be detected on [99mTc]Tc-EDDA/HYNIC-TOC scintigraphy. It was shown that in cases where bone lesions were visible on CT scans, the SUVbwmax of bone tumour lesions was higher than when lesions were not visible on CT. Body mass does not affect the SUVbwmax of bone lesions. SUVbwmax of healthy bone tissue decreased with age.
Subject(s)
Bone Neoplasms , Neuroendocrine Tumors , Octreotide , Organotechnetium Compounds , Humans , Neuroendocrine Tumors/diagnostic imaging , Neuroendocrine Tumors/metabolism , Neuroendocrine Tumors/pathology , Bone Neoplasms/diagnostic imaging , Bone Neoplasms/metabolism , Bone Neoplasms/secondary , Organotechnetium Compounds/pharmacokinetics , Middle Aged , Female , Male , Octreotide/analogs & derivatives , Octreotide/pharmacokinetics , Adult , Aged , Biological Transport , Single Photon Emission Computed Tomography Computed Tomography , Radionuclide Imaging , Aged, 80 and overABSTRACT
Recognizing the significance of SPECT in nuclear medicine and the pivotal role of fibroblast activation protein (FAP) in cancer diagnosis and therapy, this study focuses on the development of 99mTc-labeled dimeric HF2 with high tumor uptake and image contrast. The dimeric HF2 was synthesized and radiolabeled with 99mTc in one pot using various coligands (tricine, TPPTS, EDDA, and TPPMS) to yield [99mTc]Tc-TPPTS-HF2, [99mTc]Tc-EDDA-HF2, and [99mTc]Tc-TPPMS-HF2 dimers. SPECT imaging results indicated that [99mTc]Tc-TPPTS-HF2 exhibited higher tumor uptake and tumor-to-normal tissue (T/NT) ratio than [99mTc]Tc-EDDA-HF2 and [99mTc]Tc-TPPMS-HF2. Notably, [99mTc]Tc-TPPTS-HF2 exhibited remarkable tumor accumulation and retention in HT-1080-FAP and U87-MG tumor-bearing mice, thereby surpassing the monomeric [99mTc]Tc-TPPTS-HF. Moreover, [99mTc]Tc-TPPTS-HF2 achieved acceptable T/NT ratios in the hepatocellular carcinoma patient-derived xenograft (HCC-PDX) model, which provided identifiable contrast and imaging quality. In conclusion, this study presents proof-of-concept research on 99mTc-labeled FAP inhibitor dimers for the visualization of multiple tumor types. Among these candidate compounds, [99mTc]Tc-TPPTS-HF2 showed excellent clinical potential, thereby enriching the SPECT tracer toolbox.
Subject(s)
Organotechnetium Compounds , Tomography, Emission-Computed, Single-Photon , Animals , Humans , Mice , Tomography, Emission-Computed, Single-Photon/methods , Organotechnetium Compounds/chemistry , Organotechnetium Compounds/pharmacokinetics , Organotechnetium Compounds/chemical synthesis , Cell Line, Tumor , Drug Design , Radiopharmaceuticals/chemistry , Radiopharmaceuticals/chemical synthesis , Radiopharmaceuticals/pharmacokinetics , Technetium/chemistry , Tissue Distribution , Dimerization , Mice, Nude , Membrane Proteins/antagonists & inhibitors , Membrane Proteins/metabolism , Membrane Proteins/chemistry , Endopeptidases/metabolism , Serine Endopeptidases/metabolism , Serine Endopeptidases/chemistryABSTRACT
Chlorambucil is an alkylating drug that finds application towards chemotherapy of different types of cancers. In order to explore the possibility of utilization of this drug as an imaging agent for early diagnosis of solid tumors, attempt was made to synthesize a 99mTc complex of chlorambucil and evaluate its potential in tumor bearing small animal model. HYNIC-chlorambucil was synthesized by conjugation of HYNIC with chlorambucil via an ethylenediamine linker. All the intermediates and final product were purified and characterized by standard spectroscopic techniques viz. FT-IR, 1H/13C-NMR as well as by mass spectrometry. HYNIC-chlorambucil conjugate was radiolabeled with [99mTc]Tc and found to be formed with > 95 % radiochemical purity via RP-HPLC studies. The partition coefficient (Log10Po/w) of the synthesized complex was found to be -0.78 ± 0.25 which indicated the moderate hydrophilic nature for the complex. Biological behaviour of [99mTc]Tc-HYNIC-chlorambucil, studied in fibrosarcoma bearing Swiss mice, revealed a tumor uptake of about 4.16 ± 1.52 %IA/g at 30 min post-administration, which declined to 1.91 ± 0.13 % IA/g and 1.42 ± 0.14 %IA/g at 1 h and 2 h post-administration, respectively. A comparison of different [99mTc]Tc-chlorambucil derivatives (reported in the contemporary literature) formulated using different methodologies revealed that tumor uptake and pharmacokinetics exhibited by these agents strongly depend on the lipophilicity/hydrophilicity of such agents, which in turn is dependent on the bifunctional chelators used for formulating the radiolabeled chlorambucils.
Subject(s)
Chlorambucil , Organotechnetium Compounds , Animals , Humans , Mice , Antineoplastic Agents, Alkylating/chemical synthesis , Antineoplastic Agents, Alkylating/chemistry , Antineoplastic Agents, Alkylating/pharmacology , Cell Line, Tumor , Chlorambucil/chemistry , Chlorambucil/chemical synthesis , Chlorambucil/pharmacology , Molecular Structure , Nicotinic Acids/chemistry , Nicotinic Acids/chemical synthesis , Organotechnetium Compounds/chemistry , Organotechnetium Compounds/chemical synthesis , Organotechnetium Compounds/pharmacokinetics , Radiopharmaceuticals/chemical synthesis , Radiopharmaceuticals/chemistry , Technetium/chemistry , Tissue DistributionABSTRACT
Aß42 plaque formation is one of the preliminary pathologic events that occur post traumatic brain injury (TBI) which is also among the most noteworthy hallmarks of AD. Their pre symptomatic detection is therefore vital for better disease management. Chalcone-picolinic acid chelator derivative, 6-({[(6-carboxypyridin-2-yl)methyl](2-{4-[(2E)-3-[4-(dimethyl amino)phenyl]prop-2-enoyl]phenoxy}ethyl)amino}methyl)pyridine-2-carboxylic acid, Py-chal was synthesized to selectively identify amyloid plaques formed post head trauma using SPECT imaging by stable complexation to 99mTc with > 97% efficiency without compromising amyloid specificity. The binding potential of the Py-chal ligand to amyloid plaques remained high as confirmed by in vitro binding assay and photophysical spectra. Further, the Py-chal complex stained amyloid aggregates in the brain sections of rmTBI mice model. In vivo scintigraphy in TBI mice model displayed high uptake followed by high retention while the healthy rabbits displayed higher brain uptake followed by a rapid washout attributed to absence of amyloid plaques. Higher uptake in brain of TBI model was also confirmed by ex vivo biodistribution analysis wherein brain uptake of 3.38 ± 0.2% ID/g at 2 min p.i. was observed for TBI mice model. This was followed by prolonged retention and more than twofold higher activity as compared to sham mice brain. This preliminary data suggests the specificity of the radiotracer for amyloid detection post head trauma and applicability of 99mTc labeled Py-chal complex for TBI-induced ß-amyloid SPECT imaging.
Subject(s)
Amyloid beta-Peptides , Brain Injuries, Traumatic , Chalcone , Tomography, Emission-Computed, Single-Photon , Animals , Male , Mice , Amyloid beta-Peptides/metabolism , Brain/diagnostic imaging , Brain/metabolism , Brain Injuries, Traumatic/diagnostic imaging , Brain Injuries, Traumatic/metabolism , Chalcone/chemistry , Chalcone/pharmacology , Craniocerebral Trauma/diagnostic imaging , Organotechnetium Compounds/chemistry , Organotechnetium Compounds/pharmacokinetics , Radiopharmaceuticals/chemistry , Radiopharmaceuticals/pharmacokinetics , Radiopharmaceuticals/chemical synthesis , Technetium/chemistry , Technetium/pharmacology , Tissue DistributionSubject(s)
Amyloid Neuropathies, Familial , Organotechnetium Compounds , Radionuclide Imaging , Humans , Amyloid Neuropathies, Familial/diagnostic imaging , Organotechnetium Compounds/pharmacokinetics , Bone and Bones/diagnostic imaging , Bone and Bones/metabolism , Biological Transport , Radiopharmaceuticals/pharmacokinetics , Follow-Up Studies , Myocardium/metabolism , Diphosphonates/therapeutic use , Biomarkers/metabolism , Heart/diagnostic imagingABSTRACT
Pancreatic adenocarcinoma is important in oncology because of its high mortality rate. Deaths may be avoided if an early diagnosis could be achieved. Several types of tumors overexpress gastrin-releasing peptide receptors (GRPr), including pancreatic cancer cells. Thus, a radiolabeled peptide derivative of gastrin-releasing peptide (GRP) may be useful as a specific imaging probe. The purpose of the present study was to evaluate the feasibility of using99mTc-HYNIC-βAla-Bombesin(7-14)as an imaging probe for Capan-1 pancreatic adenocarcinoma. Xenographic pancreatic tumor was developed in nude mice and characterized by histopathological analysis. Biodistribution studies and scintigraphic images were carried out in tumor-bearing nude mice. The two methods showed higher uptake by pancreatic tumor when compared to muscle (used as control), and the tumor-to-muscle ratio indicated that99mTc-HYNIC-βAla-Bombesin(7-14)uptake was four-fold higher in tumor cells than in other tissues. Scintigraphic images also showed a clear signal at the tumor site. The present data indicate that99mTc-HYNIC-βAla-Bombesin(7-14)may be useful for the detection of pancreatic adenocarcinoma.
Subject(s)
Animals , Humans , Male , Adenocarcinoma , Bombesin/analogs & derivatives , Organotechnetium Compounds/pharmacokinetics , Pancreatic Neoplasms , Adenocarcinoma/pathology , Bombesin/pharmacokinetics , Cell Line, Tumor , Gastrin-Releasing Peptide/analogs & derivatives , Heterografts/pathology , Heterografts , Mice, Nude , Muscles , Pancreatic Neoplasms/pathology , Peptide Fragments/pharmacokineticsABSTRACT
PURPOSE: People consume vegetables without the knowledge of the side effects of the biological and chemical contents and interactions between radiopharmaceuticals and herbal extract. To this end, current study is focused on the effects of broccoli extract on biodistribution of radiolabeled glucoheptonate (99mTc-GH) and radiolabeling of blood components. METHODS: GH was labeled with 99mTc. Quality control studies were done utilizing TLC method. Biodistribution studies were performed on male rats which were treated via gavage with either broccoli extract or SF as control group for 15 days. Blood samples were withdrawn from rats' heart. Radiolabeling of blood constituents performed incubating with GH, SnCl2 and 99m Tc. RESULTS: Radiochemical yield of 99mTc-GH is 98.46±1.48 percent (n=8). Biodistribution studies have shown that according to the control, the treated group with broccoli has approximately 10 times less uptake in kidney. The percentage of the radioactivity ratios of the blood components is found to be same in both groups. CONCLUSIONS: Although there is no considerable effect on the radiolabeling of blood components, there is an outstanding change on the biodistribution studies especially on kidneys. The knowledge of this change on kidney uptake may contribute to reduce the risk of misdiagnosis and/or repetition of the examinations in Nuclear Medicine.
OBJETIVO: As pessoas consomem verduras sem o conhecimento dos efeitos colaterais dos conteúdos biológicos e químicos e interações entre os medicamentos radiofarmacêuticos e os extratos vegetais. Para este fim, o estudo atual é focado sobre os efeitos do extrato de brócolis na biodistribuição do fármaco glucoheptonato (99mTc-GH) e da marcação de componentes do sangue. MÉTODOS: GH foi marcado com 99mTc. Estudos de controle de qualidade foram feitos utilizando o método do TLC. Os estudos de biodistribuição foram realizados em ratos machos que foram tratados por gavagem com um extrato de brócolis ou SF como grupo controle para 15 dias. Amostras de sangue foram retiradas do coração de ratos. Marcação de constituintes sanguíneos realizados incubação com SnCl2 GH e 99mTc. RESULTADOS: Radioquímica rendimento de 99mTc-GH é 98,46 ± 1,48 por cento (n = 8). Os estudos de biodistribuição mostraram que de acordo com o controle, o grupo tratado com brócolis tem aproximadamente 10 vezes menor absorção no rim. O percentual do ratio de radioatividade dos componentes do sangue é encontrado para ser igual nos dois grupos. CONCLUSÕES: Embora não haja nenhum efeito considerável sobre a marcação dos componentes do sangue há uma mudança notável na biodistribuição especialmente nos rins. O conhecimento desta mudança na captação de rim pode contribuir para reduzir o risco de erro diagnóstico e/ou a repetição dos exames de Medicina Nuclear.
Subject(s)
Animals , Male , Rats , Blood Cells/metabolism , Brassica/chemistry , Organotechnetium Compounds/pharmacokinetics , Plant Extracts/pharmacokinetics , Radiopharmaceuticals/pharmacokinetics , Sugar Acids/pharmacokinetics , Organ Specificity , Organotechnetium Compounds/blood , Plant Extracts/blood , Rats, Wistar , Radiopharmaceuticals/blood , Sugar Acids/blood , Time Factors , Tissue DistributionABSTRACT
La preparación de derivados de glucosa marcados con 99mTc reviste gran interés para la evaluación del consumo de glucosa in vivo en oncología y cardiología nuclear. Este trabajo presenta la marcación de un análogo de glucosa (GLU-DTC) mediante la formación de un complejo Tc(V)-nitruro simétrico. Para ello se incorporó a la biomolécula un grupo ditiocarbamato capaz de coordinar al metal. La marcación fue realizada mediante sustitución de ligandos, obteniéndose una única especie con pureza radioquímica superior al 90 por cientp, la que se mantuvo durante al menos 4 hs. La caracterización fisicoquímica y biológica muestra que el complejo 99mTc(V)-nitruro(GLU-DTC)2 es un compuesto estable y altamente hidrofílico, aunque su unión a proteínas plasmáticas es mayor a la esperada, hecho que justificaría la alta actividad retenida en sangre y en hígado durante la evaluación biológica en ratones CD1 normales. Estos resultados indican que la marcación con 99mTc de este derivado de glucosa produce una alteración significativa de su comportamiento biológico.
The preparation of 99mTc-labeled glucose derivatives is of great interest to evaluate the in vivo glucose uptake in nuclear oncology and cardiology. This paper presents the labelling of a glucose analogue (GLU-DTC) through the formation of a Tc(V)-nitride symmetrical complex. For this purpose, a dithiocarbamate group was incorporated to the biomolecule, in order to coordinate the metal. The labelling reaction was carried out by substitution yielding a single complex with radiochemical purity above 90 percent. This complex was stable for at least 4 hours. The physicochemical and biological characterization shows that the 99mTc(V)-nitride(GLU-DTC)2 complex is a stable and highly hydrophilic compound, although its plasma protein binding is greater than expected, a fact which justifies the high activity retained in blood and liver during the biological evaluation in normal CD1 mice. These results indicate that 99mTc labelling of this glucose derivate alters significantly its biological behaviour.
Subject(s)
Animals , Rats , Organotechnetium Compounds/chemical synthesis , Glucose/chemistry , Isotope Labeling/methods , Radiopharmaceuticals/chemical synthesis , Cardiology/methods , Organotechnetium Compounds/pharmacokinetics , Tissue Distribution , Time Factors , Glucose/analogs & derivatives , Ligands , Nuclear Medicine/methods , Medical Oncology/methods , Radiopharmaceuticals/pharmacokinetics , Technetium/pharmacokineticsABSTRACT
Purpose: Angiogenesis involves many mediators including integrins, and the tripeptide RGD is a target amino acid recognition sequence for many of them. Hindlimb ischemia is a simple and convenient animal model however standardization of the injection procedures in the devascularized and control limb is lacking, thus rendering difficult the interpretation of results. The aim of this investigations was to evaluate neovascularization in a hindlimb murine model by means of 99mTc-HYNIC-ß-Ala-RGD. Methods: 99mTc-HYNIC-RGD analog was prepared using coligands. Ischemia was induced in Wistar rats by double- ligation of the common femoral artery. Radiolabeled RGD was injected after 2h, as well as 1, 3, 5, 7, 10 and 14 days. Uptake was evaluated by planar imaging and biodistribution studies. Results: The highest ratio between ischemia and control was achieved at the 7th day (2.62 ± 0.95), with substantial decrease by the 14th day. For pertechnetate the 7th day ratio was 0.87 ± 0.23. Scintigraphic image confirmed different uptakes. Conclusion: 99mTc-HYNIC-RGD analog concentrated in ischemic tissue by the time of widespread angiogenesis and pertechnetate confirmed reduction in blood flow. In this sense, the protocol can be recommended for ischemic models.
Objetivo: A angiogênese em resposta a fenômenos isquêmicos envolve vários mediadores como as integrinas, sendo que o tripeptídeo RGD possui uma seqüência de aminoácidos com reconhecimento para este alvo. O modelo animal de isquemia de pata traseira é simples e conveniente, porém não há uma padronização do procedimento de injeção e controle radioisotópico em membro desvascularizado, dificultando, portanto a interpretação de resultados. O objetivo deste estudo foi avaliar a neovascularização em modelo murino de isquemia de pata traseira através do radiotraçador 99mTc-HYNIC-ß-Ala-RGD. Métodos: O análogo 99mTc-HYNIC-RGD foi preparado usando coligantes. A isquemia foi induzida em ratos Wistar por dupla-ligação da artéria femoral comum na prega inguinal. Peptídeo RGD radiomarcado foi injetado após 2h, assim como 1, 3, 5, 7, 10 e 14 dias. A captação foi avaliada por imagem planar e estudos de biodistribuição. Resultados: A maior diferença de captação entre isquemia e pata controle foi obtida no 7º dia (2,62 ± 0,95), com decréscimo acentuado no 14º dia. Para o pertecnetato a razão no 7º dia foi 0,87 ± 0,23. A imagem cintilográfica confirmou as diferentes captações. Conclusões: O análogo 99mTc-HYNIC-RGD concentrou-se no tecido isquêmico na etapa em que a angiogênese é mais acentuada, e o estudo do pertecnetato confirmou a redução no fluxo sanguíneo. Desta maneira, este protocolo diagnóstico pode ser recomendado para modelos isquêmicos.
Subject(s)
Animals , Male , Rats , Hindlimb/blood supply , Ischemia/physiopathology , Neovascularization, Physiologic/physiology , Organotechnetium Compounds , Radiopharmaceuticals , Amino Acid Sequence , Conserved Sequence , Hindlimb/metabolism , Hindlimb , Ischemia , Oligopeptides , Organotechnetium Compounds/pharmacokinetics , Rats, Wistar , Radiopharmaceuticals/pharmacokinetics , Tissue DistributionABSTRACT
La gammagrafía con radiotrazadores que tienen afinidad por los receptores de somatostatina se ha convertido en metodología eficaz para el diagnóstico y estadificación de los tumores neuroendocrinos. Se presenta un caso en el cual el procedimiento radioisotópico muestra su efectividad en la localización del tumor primario.
Somatostatin receptor scintigraphy has become an important tool for diagnosis and evaluation of neuroendocrine tumors. This case report shows about the importance of the radionuclide procedure for the localization of the primary tumor.
Subject(s)
Humans , Female , Middle Aged , Carcinoma, Medullary , Carcinoma, Medullary/metabolism , Organotechnetium Compounds , Thyroid Neoplasms , Thyroid Neoplasms/metabolism , Receptors, Somatostatin/metabolism , Carcinoma, Medullary/pathology , Organotechnetium Compounds/pharmacokinetics , Thyroid Neoplasms/pathology , Octreotide/analogs & derivatives , Octreotide/pharmacokinetics , Octreotide , Radiopharmaceuticals/pharmacokinetics , RadiopharmaceuticalsABSTRACT
El propósito de la presente investigación fue evaluar el comportamiento biocinético de la 99mTc-ciprofloxacina obtenida de una nueva formulación. Un ensayo in vitro y un modelo de infección experimental demostraron su afinidad por bacterias vivas. La vida media en sangre fue de 5,89 +/- 0,85 horas. La biodistribución mostró alta acumulación en músculos infectados y baja en tejidos sanos.
The aim of the present investigation was to evaluate the biokinetics performance of 99mTc-ciprofloxacin obtained from a new formulation. Both in vitro assays and experimental infection models demonstrated its affinity for viable bacteria.Half life in blood was 5.89 +/- 0.85 hours. The biodistribution showed high accumulation on infected muscles and low on healthy tissues.
Subject(s)
Animals , Rats , Ciprofloxacin/analogs & derivatives , Ciprofloxacin/pharmacokinetics , Organotechnetium Compounds/pharmacokinetics , Tissue Distribution , Bacterial Infections , Time Factors , Tin Fluorides/pharmacokinetics , Radiopharmaceuticals/pharmacokinetics , Rats, WistarABSTRACT
No disponible
Subject(s)
Humans , Female , Child , Histiocytosis, Langerhans-Cell/complications , Osteitis , Osteolysis , Radiopharmaceuticals/pharmacokinetics , Staphylococcal Infections , Tomography, X-Ray Computed , Zygoma , Zygoma , Histiocytosis, Langerhans-Cell , Organotechnetium Compounds/pharmacokinetics , Osteitis/etiology , Osteitis/microbiology , Osteitis , Osteolysis/etiology , Osteolysis , Peptide Fragments/pharmacokinetics , Staphylococcal Infections/etiology , Staphylococcal InfectionsSubject(s)
Humans , Male , Middle Aged , Tomography, Emission-Computed, Single-Photon , Glioblastoma , Central Nervous System Neoplasms , Cerebrovascular Circulation , Organophosphorus Compounds/pharmacokinetics , Organotechnetium Compounds/pharmacokinetics , Glioblastoma/physiopathology , Glioblastoma/therapy , Prognosis , Radiopharmaceuticals/pharmacokineticsABSTRACT
El objetivo del presente trabajo es investigar como se modifica el comportamiento in vitro e in vivo (localización de sitios de infección experimental con Staphilococcus aureus (S.a.)) del UBI 29-41 cuando es marcado con 99mTc por cuatro métodos distintos: a) con borohidruro de potasio y pirofosfato de estaño, b) con hidróxido de sodio y cloruro estañoso (métodos directos), c) con NHS-MAG3 y d) con NHS-HYNIC (métodos indirectos). En segundo lugar comparar los valores PI/PN (Pata Infectada / Pata Normal) del 99mTc-UBI 29-41 (método a), con el 99mTc-scrambled (Sc) UBI 29-41 (péptido control) y con 99mTc-IgG (radiofármaco no específico para infecciones) en ratones infectados con S.a. viables; y los valores pata inflamada/ PN del 99mTc-UBI 29-41 99mTc (método a) con 99mTc-IgG en ratones con inflamación estéril. Cuando el 99mTc-UBI 29-41 fue obtenido por el método a, se obtuvieron los mejores resultados in vitro y las biodistribuciones mostraron la máxima acumulación en sitios con S.a. viables y muy baja acumulación en sitios con inflamación estéril, demostrando su potencial uso en el diagnóstico de infecciones.
Subject(s)
Mice , Animals , Peptide Fragments/pharmacokinetics , Staphylococcal Infections , Isotope Labeling/methods , Radiopharmaceuticals/pharmacology , Technetium , Anti-Bacterial Agents , Organotechnetium Compounds/pharmacokinetics , Quality Control , Tissue Distribution , Drug Stability , Culture Media , Succinimides/pharmacokineticsABSTRACT
El objetivo de este estudio fue evaluar la estabilidad del d,l-HMPAO reconstituido y almacenado a -20º C. El kit se reconstituyó con un mililitro de solución salina. Fracciones de 0.333 mililitros fueron almacenadas a -20°C. El marcaje y el control de calidad se realizaron entre los 0-300 minutos posteriores. Fueron realizados estudios de SPECT cerebral y de cuerpo entero a 5 pacientes, con el kit intacto y con más de 30, 60 y 90 minutos de reconstituidos y almacenados. La calidad de las imágenes fue valorada por un observador experimentado. La integridad química se conservó por un tiempo de 2 horas (>80 por ciento de marcaje). Se acumuló en el cerebro entre 3,5-7 por ciento del 99mTc-d,l-HMPAO utilizando el producto hasta 90 minutos después de reconstituido. Las imágenes obtenidas fueron de adecuada utilidad clínica con un significativo ahorro de un 33,4 por ciento por cada dosis.
Subject(s)
Humans , Male , Adult , Female , Middle Aged , Cerebrum , Organotechnetium Compounds/pharmacokinetics , Tissue Distribution , /pharmacokinetics , Tomography, Emission-Computed, Single-Photon , Cerebrum , Drug Stability , Time Factors , Data Interpretation, Statistical , Reagent Kits, Diagnostic , Radiopharmaceuticals/pharmacokineticsABSTRACT
El objetivo del presente trabajo es evaluar la capacidad del 99mTc-UBI 29-41 marcado por un método directo en la localización de sitios de infección experimental con Staphilococcus aureus (S.a.). En segundo lugar comparar los valores PI/PN (Pata Infectada / Pata Normal) de las biodistribuciones en ratones portadores de S.a. viables, S.a. no viables obtenidos por irradiación gamma y por calentamiento y en sitios de inflamación estéril y cuantificar las relaciones sitio infectado / sitio normal (SI / SN) através de autorradiografía digital. El UBI 29-41 es un fragmento sintético de la ubiquicidina y el scrambled (Sc) UBI 29-41 es el péptido control. 99mTc-IgG fue el control positivo para inflamaciones estériles. Cuando el 99mTc-UBI 29-41 fue obtenido por este método rápido y reproducible, se visualizaron sitios de infección a 2h p.i.. Las biodistribuciones mostraron mayor acumulación en sitios con S.a. viables que con S.a. irradiados y no hubo acumulación en inflamaciones estériles.
Subject(s)
Mice , Animals , Organotechnetium Compounds/pharmacokinetics , Peptide Fragments/pharmacokinetics , Staphylococcal Infections/diagnosis , Tissue Distribution , Radiographic Image Enhancement , Isotope Labeling , Antimicrobial Cationic Peptides/pharmacokineticsABSTRACT
Objetivo. Comparar la calidad de las imágenes de gammagrafía ósea obtenidas con un radiofármaco nuevo, el 99mTc-ABP, con aquéllas obtenidas con el 99mTc-MDP. Material y métodos. Fue un estudio comparativo en un mismo sujeto. Se estudiaron 9 voluntarios sanos (5 mujeres y 4 hombres) de 23 a 39 años de edad. A todos se les inyectaron 740 MBq de los radiofármacos Tc-ABP y Tc-MDP con un intervalo de 72 horas entre uno y otro. Dos horas después de cada inyección se les realizó un gammagrama óseo de cuerpo entero con una cámara de centello MultiSpect 2 y se determinaron los parámetros radiofarmacocinéticos. Tres médicos nucleares evaluaron por separado la calidad de las imágenes mediante el trazado de regiones de interés (RDI) sobre vértebras, costillas, esternón, fémur, articulaciones y cráneo. Se obtuvieron relaciones hueso/músculo con RDI sobre diferentes huesos. Los resultados se compararon etadísticamente con las pruebas de kappa y de Wilcoxon. Resultados. La concordancia sobre la calidad de las imágenes de los dos radiofármacos por los tres observadores fue moderada (kappa 0.4). La relación fémur/músculo mostró una distribución normal y no manifestó diferencias significativas entre radiofármacos. Conclusiones. La calidad de las imágenes con ambas preparaciones fue similar. Recomendamos utilizar al 99mTc-ABP en la gammagrafía ósea debido a la menor exposición a radiación del paciente
Subject(s)
Humans , Male , Female , Adult , Alendronate , Bone and Bones , Organotechnetium Compounds , Organotechnetium Compounds/pharmacokinetics , Technetium Tc 99m Medronate , Technetium Tc 99m Medronate/pharmacokineticsABSTRACT
We present a patient with Fanconi syndrome who demonstrated poor renal uptake of 99mTc-DMSA and high urinary concentration of the tracer. A 99mTc-DTPA scan was normal and the creatinine clearance only minimally decreased. These findings suggest that 99mTc-DMSA may be accumulated in the kidney by glomerular filtration and subsequent tubular reabsorption, with the nonabsorbed fraction appearing in the urine. In Fanconi Syndrome the tubular reabsorption of DMSA may also be reduced, thus explaining the poor renal uptake in this patient. A 99mTc-MDP bone scan showed faint renal uptake and diffuse high uptake mainly in the spine, demonstrating that the metabolic bone disease associated with Fanconi Syndrome can be another mechanism for poor renal visualization on bone scan.
Subject(s)
Female , Humans , Middle Aged , Fanconi Syndrome/metabolism , Glomerular Filtration Rate , Kidney/metabolism , Kidney Glomerulus/physiology , Organotechnetium Compounds/pharmacokinetics , Spine/metabolism , Succimer/pharmacokinetics , Technetium Tc 99m Dimercaptosuccinic Acid , Technetium Tc 99m Medronate/pharmacokineticsABSTRACT
Prepararam-se conjuntos de reativos liofilizados do ácido trimetil iodoacetanilido iminodiacético (IODOFENIN) para marcar com 99mTc, contendo em cada frasco 20 mg de iodofenin 0,2 mg de SnCl2.2H2O, pH5,5. Realizaram-se controles de qualidade radioquímico e biológico. No controle de pureza radioquímica analisaram-se os seguintes parâmetros: a) volume de 99mTc(1,3 e 5 mL), b) atividade de 99mTc (37, 370, 1110 e 1850 MBq) e c) tempo de estocagem do conjunto de reativo (1, 3, 6 e 12 meses). Os resultados demonstraram que o produto apresenta uma pureza radioquímica de 95-99// nos parâmetros estudados, com uma estabilidade de 12 meses para seu uso. Utilizaram-se ratos (Wistar) de peso médio 200 g para avaliar o comportamento biológico. Neste estudo observou-se uma captaçäo de 67// pelo fígado, aos 5 minutos decrescendo em 2 horas e apresentando no decorrer do metabolismo uma alta captaçäo gastro-intestinal (98//). Na bilis, o produto manteve a sua integridade (93//) até 20 minutos após sua eliminaçäo