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1.
Bioconjug Chem ; 32(7): 1290-1297, 2021 07 21.
Artículo en Inglés | MEDLINE | ID: mdl-33434428

RESUMEN

We report herein the preclinical evaluation of new [64Cu]Cu-gastrin-releasing peptide receptor (GRPR)-targeting tracers, employing the potent peptide antagonist DPhe-Gln-Trp-Ala-VaI-Gly-His-Sta-Leu-NH2 conjugated to NOTA (in 1) or NODAGA (in 2) chelators via a 6-aminohexanoic acid linker. The Cu-1/2 metalated peptides were synthesized by reacting 1/2 with CuCl2 and were characterized by LC-ESI-MS and HR-ESI-MS. Cu-1/2 exhibited high GRPR-binding affinities with IC50 values <3 nM, as measured in a competition assay using the GRPR-expressing human PC-3 prostate cancer cell line and [125I]I-Tyr4-BBN as the competing ligand. Tracers [64Cu]Cu-1/2 were prepared in quantitative radiochemical yield (by radio-HPLC), and their identities were confirmed by coelution with their Cu-1/2 standards via comparative HPLC studies. Lipophilicity was measured in 1-octanol/PBS (pH 7.4), and the negative log D7.4 values (≤-1) confirmed the anticipated hydrophilic character for [64Cu]Cu-1/2. Both tracers demonstrated excellent in vitro stability, with ≥98% remaining intact through 24 h at physiological conditions (PBS, pH 7.4, 37 °C). Biodistribution in PC-3 tumor-bearing mice demonstrated good tumor uptake (%ID/g at 4 h: 4.34 ± 0.71 for [64Cu]Cu-1, 3.92 ± 1.03 for [64Cu]Cu-2) and rapid renal clearance (≥87% ID at 4 h). Tumor uptake was receptor-mediated, as verified by parallel GRPR-blocking studies. Small-animal PET/CT imaging studies validated the biodistribution data. These preclinical data support that the [64Cu]Cu-1/2 tracers show promise for further development as diagnostic PET imaging agents of GRPR-expressing tumors.


Asunto(s)
Radioisótopos de Cobre/metabolismo , Tomografía de Emisión de Positrones/métodos , Neoplasias de la Próstata/diagnóstico por imagen , Receptores de Bombesina/metabolismo , Animales , Humanos , Masculino , Receptores de Bombesina/química
2.
Bioconjug Chem ; 29(12): 4040-4049, 2018 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-30412382

RESUMEN

With the long-term goal of developing theranostic agents for applications in nuclear medicine, in this work we evaluated the well-known NOTA and NODAGA chelators as bifunctional chelators (BFCs) for the [99mTc/186Re]Tc/Re-tricarbonyl core. In particular, we report model complexes of the general formula fac-[M(L)(CO)3]+ (M = Re, 99mTc, 186Re) where L denotes NOTA-Pyr (1) or NODAGA-Pyr (2), which are derived from conjugation of NOTA/NODAGA with pyrrolidine (Pyr). Further, as proof-of-principle, we synthesized the peptide bioconjugate NODAGA-sst2-ANT (3) and explored its complexation with the fac-[Re(CO)3]+ and fac-[99mTc][Tc(CO)3]+ cores; sst2-ANT denotes the somatostatin receptor (SSTR) antagonist 4-NO2-Phe-c(DCys-Tyr-DTrp-Lys-Thr-Cys)-DTyr-NH2. Rhenium complexes Re-1 through Re-3 were synthesized and characterized spectroscopically, and receptor binding affinity was demonstrated for Re-3 in SSTR-expressing cells (AR42J, IC50 = 91 nM). Radiolabeled complexes [99mTc]Tc/[186Re]Re-1/2 and [99mTc]Tc-3 were prepared in high radiochemical yield (>90%, determined by radio-HPLC) by reacting [99mTc]/[186Re][Tc/Re(OH2)3(CO)3]+ with 1-3 and correlated well with the respective Re-1 through Re-3 standards in comparative HPLC studies. All radiotracers remained intact through 24 h (99mTc-labeled complexes) or 48 h (186Re-labeled complexes) against 1 mM l-histidine and 1 mM l-cysteine (pH 7.4, 37 °C). Similarly, rat serum stability studies displayed no decomposition and low nonspecific binding of 9-24% through 4 h. Biodistribution of [99mTc]Tc-3 in healthy CF-1 mice demonstrated a favorable pharmacokinetic profile. Rapid clearance was observed within 1 h post-injection, predominantly via the renal system (82% of the injected dose was excreted in urine by 1 h), with low kidney retention (% ID/g: 11 at 1 h, 5 at 4 h, and 1 at 24 h) and low nonspecific uptake in other organs/tissues. Our findings establish NOTA and NODAGA as outstanding BFCs for the fac-[M(CO)3]+ core in the design and development of organometallic radiopharmaceuticals. Future in vivo studies of [99mTc]Tc- and [186Re]Re-tricarbonyl complexes of NODAGA/NOTA-biomolecule conjugates will further probe the potential of these chelates for nuclear medicine applications in diagnostic imaging and targeted radiotherapy, respectively.


Asunto(s)
Acetatos/química , Complejos de Coordinación/química , Compuestos Heterocíclicos con 1 Anillo/química , Compuestos de Organotecnecio/química , Radiofármacos/química , Receptores de Somatostatina/química , Renio/química , Animales , Quelantes/química , Cromatografía Líquida de Alta Presión/métodos , Riñón/metabolismo , Ratones , Radiofármacos/sangre , Radiofármacos/farmacocinética , Ratas , Distribución Tisular
3.
J Infect Dis ; 215(5): 764-771, 2017 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-28170039

RESUMEN

Background: Methylation of the human papillomavirus (HPV) DNA has been proposed as a novel biomarker. Here, we correlated the mean methylation level of 12 CpG sites within the L1 gene, to the histological grade of cervical precancer and cancer. We assessed whether HPV L1 gene methylation can predict the presence of high-grade disease at histology in women testing positive for HPV16 genotype. Methods: Pyrosequencing was used for DNA methylation quantification and 145 women were recruited. Results: We found that the L1 HPV16 mean methylation (±SD) significantly increased with disease severity (cervical intraepithelial neoplasia [CIN] 3, 17.9% [±7.2] vs CIN2, 11.6% [±6.5], P < .001 or vs CIN1, 9.0% [±3.5], P < .001). Mean methylation was a good predictor of CIN3+ cases; the area under the curve was higher for sites 5611 in the prediction of CIN2+ and higher for position 7145 for CIN3+. The evaluation of different methylation thresholds for the prediction of CIN3+ showed that the optimal balance of sensitivity and specificity (75.7% and 77.5%, respectively) and positive and negative predictive values (74.7% and 78.5%, respectively) was achieved for a methylation of 14.0% with overall accuracy of 76.7%. Conclusions: Elevated methylation level is associated with increased disease severity and has good ability to discriminate HPV16-positive women that have high-grade disease or worse.


Asunto(s)
Proteínas de la Cápside/genética , Metilación de ADN , Proteínas Oncogénicas Virales/genética , Infecciones por Papillomavirus/diagnóstico , Enfermedades del Cuello del Útero/diagnóstico , Adulto , Anciano , Islas de CpG , ADN Viral/química , Femenino , Genotipo , Grecia , Papillomavirus Humano 16 , Humanos , Modelos Lineales , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y Especificidad , Reino Unido , Enfermedades del Cuello del Útero/virología , Adulto Joven , Displasia del Cuello del Útero/diagnóstico , Displasia del Cuello del Útero/virología
4.
Mol Pharm ; 13(7): 2301-17, 2016 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-27170456

RESUMEN

A novel bisphosphonate, 1-(3-aminopropylamino)ethane-1,1-diyldiphosphonic acid (3), was coupled to the tridentate chelators di-2-picolylamine, 2-picolylamine-N-acetic acid, iminodiacetic acid, 3-((2-aminoethyl)thio)-3-(1H-imidazol-4-yl)propanoic acid, and 2-((2-carboxyethyl)thio)-3-(1H-imidazol-4-yl)propanoic acid to form ligands 6, 9, 11, 15, and 19, respectively. Organometallic complexes of the general formula [Re/(99m)Tc(CO)3(κ(3)-L)] were synthesized, where L denotes ligand 6, 9, 11, 15, or 19. The rhenium complexes were prepared at the macroscopic level and characterized by spectroscopic methods. The technetium-99m organometallic complexes were synthesized in high yield and were identified by comparative reversed-phase HPLC with their Re analogues. The (99m)Tc tracers were stable in vitro and exhibited binding to hydroxyapatite. In biodistribution studies, all of the (99m)Tc complexes exhibited high bone uptake superior to that of 25, which is the directly (99m)Tc-labeled bisphosphonate 3, and comparable to that of (99m)Tc-methylene diphosphonate ((99m)Tc-MDP). The tracers [(99m)Tc(CO)3(6)] (26), [(99m)Tc(CO)3(9)] (27), [(99m)Tc(CO)3(11)] (28), and [(99m)Tc(CO)3(15)] (29) exhibited higher bone/blood ratios than (99m)Tc-MDP. 26 had the highest bone uptake at 1 h p.i. The new bisphosphonates showed no substantial growth inhibitory capacity in PC-3, Saos-2, and MCF-7 established cancer cell lines at low concentrations. Incubation of 26 with the same cancer cell lines indicated a rapid and saturated uptake. The promising properties of 26-29 indicate their potential for use as bone-imaging agents.


Asunto(s)
Huesos/efectos de los fármacos , Difosfonatos/química , Tecnecio/química , Huesos/metabolismo , Línea Celular Tumoral , Quelantes/química , Cromatografía Líquida de Alta Presión/métodos , Difosfonatos/metabolismo , Durapatita/química , Humanos , Ligandos , Células MCF-7 , Compuestos de Organotecnecio/administración & dosificación , Compuestos de Organotecnecio/química , Radiofármacos/química , Radiofármacos/metabolismo , Renio/química , Tecnecio/metabolismo , Distribución Tisular
5.
J Labelled Comp Radiopharm ; 59(3): 95-102, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26817576

RESUMEN

The synthesis and biological evaluation of three new biotinylated fac-[(99m)Tc/Re(CO)3](+) complexes with the tridentate ligands L1, L2, and L3 are reported. L1-L3 contain the chelators 2-((5-aminopentyl)(pyridin-2-ylmethyl)amino)acetic acid, 2-(2-aminoethylthio)-3-(1H-imidazol-4-yl)propanoic acid, and 2-amino-3-(1-carboxy-2-(1H-imidazol-4-yl)ethylthio)propanoic acid, respectively, which are conjugated to biotin's carboxylate via their amine group. The fac-[Re(CO)3(L1-L3)] complexes were synthesized and characterized by NMR and IR, where the (N,N,O) coordination for ReL1 and the (N,S,O) coordination for ReL2 and ReL3 were confirmed. The tracer complexes fac-[(99m)Tc(CO)3(L1-L3)] were synthesized in high yield and were found highly stable in 10(-3) M L-histidine and L-cysteine over 24 h. Furthermore, they exhibited high binding affinity (>90%) for avidin. Rat plasma studies showed complete cleavage of biotin from (99m)TcL1 after 1 h and a low percentage of intact (99m)TcL2 and (99m)TcL3 with no biotin cleavage metabolites present, over 24 h. Similarly, rat urine analysis showed the presence of intact (99m)TcL2 and (99m)TcL3, while (99m)TcL1 was cleaved. Biodistribution studies of (99m)TcL2 and (99m)TcL3 revealed fast blood and tissue clearance.


Asunto(s)
Complejos de Coordinación/química , Radiofármacos/síntesis química , Renio/química , Tecnecio/química , Animales , Masculino , Ratones , Ratones Endogámicos BALB C , Radiofármacos/farmacocinética , Ratas , Distribución Tisular
6.
Wellcome Open Res ; 9: 115, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39296369

RESUMEN

Background: The emergency context of the Covid-19 pandemic necessitated the use of national and international public health measures of unprecedented scale to minimize mortality and morbidity, often in conflict with other principles and rights, such as the autonomy of individuals. Concerns have been voiced that for populations facing precarity, such as migrants, a disproportionate and unfair application of restrictive measures, deficient application of protective measures, and even enforcement of restrictive migration policies under the pretext of the pandemic has occurred. Methods: Various principles have been proposed as moral foundations of public health interventions. The author used two public health ethics frameworks to examine the ethical acceptability of movement restrictions on asylum seekers residing in refugee camps in Greece from March 2020 to October 2020. Results: Most of the principles described in the frameworks for the ethical application of movement restrictions were not adhered to. Main concerns include that, measures were prolonged despite lack of evidence about their effectiveness to reduce morbidity and mortality, while posing severe and disproportionate burdens for this population. Conclusions: An ethically acceptable public health response to Covid-19 is incompatible with certain living conditions of refugees, asylum seekers, and migrants. The question of whether and if so the extent to which the discipline of public health inherently has the role of rectifying existing injustices and social inequalities when these can be convincingly related to health outcomes, is central to the design of public health interventions for these populations. The answer can exemplify the need to address moral and political determinants of health. It is essential for public health professionals to be aware of the moral theorizations that underpin their work, so as to ensure that their policies are aligned with those and to contribute to the debate that shapes these determinants.


In recent years, thousands of individuals have sought asylum in Greece. They are initially geographically restricted and accommodated in reception centers. These centers, or camps, have attracted international criticism due to undignified and harmful living conditions. In 2020, in the beginning of the CoViD-19 pandemic, the Greek government, imposed strict movement restrictions for camp residents in the name of public health. In this study, the author attempts to examine if the public health measures imposed on asylum seekers residing in reception centers in Greece in 2020 were ethically sound, drawing information from scientific articles, legislative acts and reports from a range of institutions. Public health measures imposed during the pandemic have challenged individual liberties with the aim to protect human lives. However, for vulnerable populations, such as asylum seekers, it is uncertain if certain measures did more good than harm and if they were used to their best interest. Public health interventions are based on trust and should adhere to ethical principles. Analysis of available evidence using ethics tools seems to be unable to justify the implemented CoViD-19 response policy for asylum seekers in reception centers. Further research, as well as political will, are needed to determine if and how ethical public health policies for migrants are feasible on a national and international level.

7.
Arch Gynecol Obstet ; 286(6): 1563-9, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22941352

RESUMEN

INTRODUCTION: The presence of an endometrioma has been proposed to affect the ovarian function in a negative way. Our aim was to present the key evidence on multiple aspects of endometriomas' management in subfertile couples scheduled for assisted reproduction technologies (ART). MATERIALS AND METHODS: A critical review of the existing literature was performed focusing on the need of endometrioma treatment prior to ART, the relevant options, the potentially participating surgeon's characteristics and the socioeconomic perspective. RESULTS: To date, we have no definitive data to suggest whether the damage to the ovaries observed in women with endometriomas may be related to the mere presence of the cyst, the surgical procedure to remove it, the combination of the two, or factors currently unknown. Moreover, there is no conclusive evidence that, for subfertile couples, removal of endometriomas increases the chance of having a baby. The uncertainty regarding the best treatment strategy and factors such as the limited number of tertiary centers for laparoscopic surgery throughout the world seems to further complicate the decision. CONCLUSIONS: Until research addresses the current "grey areas", the management of endometriomas in patients undergoing ART should be individualized and take into consideration numerous parameters.


Asunto(s)
Endometriosis/terapia , Infertilidad Femenina/terapia , Neoplasias Ováricas/terapia , Técnicas Reproductivas Asistidas , Endometriosis/complicaciones , Femenino , Humanos , Infertilidad Femenina/complicaciones , Neoplasias Ováricas/complicaciones
8.
Oxf Med Case Reports ; 2021(5): omab020, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34055357

RESUMEN

An unresponsive paediatric patient may present a diagnostic challenge for health professionals, as rapid identification of the cause is needed to provide proper interventions. The following report details a challenging diagnosis of unresponsiveness in a refugee child. In the migratory context, observed unresponsiveness states are frequently attributed to psychologic factors, and overlapping psychiatric classifications (resignation syndrome, functional coma and catatonia) are common. Our patient fell into an unresponsive state for 6 months after witnessing a traumatic event. Diagnostic workup for multiple medical comorbidities led to surgical intervention for tethered cord syndrome. Shortly after that, the patient's responsiveness improved, putting to question her condition's underlying cause. This case highlights the need for a biopsychosocial approach in such cases, reflected in thorough clinical examination and diagnostic investigations. A multidisciplinary perspective and expertise proved crucial and may help in the rehabilitation of children in similar situations.

9.
Hum Vaccin Immunother ; 17(11): 4291-4298, 2021 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-34613871

RESUMEN

BACKGROUND: Individuals with type 1 diabetes (T1D) are at increased risk of infections from vaccine-preventable diseases. This study focuses on compliance of T1D patients to the recommended vaccination schedule, vaccination of their close contacts for influenza and on factors potentially contributing to vaccination program deviations. METHODS: The study population comprised children, adolescents and adults with T1D under follow-up at the Department of Pediatrics University Hospital and the Diabetic Center General Hospital, Heraklion, Crete-Greece. Data were extracted, following informed consent, from individual's vaccination booklet, medical files and telephone interview. Vaccination records, demographic parameters, glycemic control and influenza vaccination of close contacts were assessed. RESULTS: The study included 258 participants (111 children/adolescents, 147 adults). Vaccination coverage for influenza was 76.7% for children, 64.4% for adults, for PCV 90.9% for children, but only 10.8% for the 23-valent, for hepatitis B 99% for children and 78.2% for adults. Youngsters were vaccinated against Hib 91.9%, meningococcus C 98.2%, measles-mumps-rubella 90.3%, chickenpox 86.4%, hepatitis A 76.5% and HPV 42.5%. Less than 65% of all individuals were fully vaccinated for diphtheria-tetanus-pertussis and meningococcus ACWY. Approximately 50% of the 605 close contacts were not vaccinated against influenza. Individuals with better glycemic status seemed to adhere to the recommended schedule and had a better vaccinated family environment. CONCLUSIONS: Vaccination coverage for T1D individuals was sufficient regarding the majority of routine childhood vaccines, but less for adolescence and group-specific vaccines. Their family contacts were not sufficiently vaccinated for influenza. Targeted interventions are required in order to increase vaccination rates.


Asunto(s)
Diabetes Mellitus Tipo 1 , Vacunas , Adolescente , Adulto , Niño , Vacuna contra Difteria, Tétanos y Tos Ferina , Grecia , Humanos , Esquemas de Inmunización , Vacuna contra el Sarampión-Parotiditis-Rubéola , Vacunación
10.
J Clin Med ; 10(16)2021 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-34441929

RESUMEN

PURPOSE: Minimal change disease (MCD) is considered a relatively benign glomerulopathy, as it rarely progresses to end-stage kidney disease. The aim of this study was to describe the characteristics and outcomes of adults with MCD and identify potential risk factors for relapse. PATIENTS & METHODS: We retrospectively studied a cohort of adults with biopsy-proven MCD in terms of clinical features and treatment outcomes. Baseline characteristics and outcomes were recorded and predictors of relapse were analyzed using logistic regression multivariate analysis. RESULTS: 59 patients with adult-onset primary MCD with nephrotic syndrome were included. Mean serum creatinine at diagnosis was 0.8 mg/dL (±2.5) and estimated GFR (eGFR) was 87 mL/min/1.73 m2 (±29.5). Mean serum albumin was 2.5 g/dL (±0.8) and 24 h proteinuria 6.8 g (±3.7). Microscopic hematuria was detected in 35 (58.5%) patients. 42 patients received prednisone alone, six patients received prednisone plus cyclophosphamide, five patients received prednisone plus cyclosporine, one patient received prednisone plus rituximab and five patients did not receive immunosuppression at all since they achieved spontaneous remission. During a mean follow up time of 34.7(22.1) months, 46.1% of patients experienced at least one episode of relapse. The mean age of patients who did not experience a relapse was significantly higher than that of patients who relapsed while relapsers had a significantly longer duration of 24 h proteinuria prior to biopsy compared to non-relapsers. Overall, 10% of patients experienced acute kidney injury while the mean eGFR at the end was 82 mL/min/1.73 m2 (±29.1) and one patient ended up in chronic dialysis. Overall, the proportion of non-relapsers, who experienced acute kidney injury (17%) was significantly higher than the one recorded among relapsers (0%). CONCLUSION: In this series of patients, almost 46% of adult-onset nephrotic MCD patients experienced a relapse, although their renal progression was rare. Younger onset age was an independent risk factor for relapse in adult-onset MCD patients.

11.
Mol Imaging Biol ; 23(1): 52-61, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32886303

RESUMEN

PURPOSE: The goal of this work was to develop hydrophilic gastrin-releasing peptide receptor (GRPR)-targeting complexes of the general formula fac-[M(CO)3(L)]+ [M = natRe, 99mTc, 186Re; L: NOTA for 1, NODAGA for 2] conjugated to a powerful GRPR peptide antagonist (DPhe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2) via a 6-aminohexanoic acid linker. PROCEDURES: Metallated-peptides were prepared employing the [M(OH2)3(CO)3]+ [M = Re, 99mTc, 186Re] precursors. Re-1/2 complexes were characterized with HR-MS. IC50 studies were performed for peptides 1/2 and their respective Re-1/2 complexes in a binding assay utilizing GRPR-expressing human PC-3 prostate cancer cells and [125I]I-Tyr4-BBN as the competing ligand. The 99mTc/186Re-complexes were identified by HPLC co-injection with their Re-analogues. All tracers were challenged in vitro at 37 °C against cysteine/histidine (phosphate-buffered saline 10 mM, pH 7.4) and rat serum. Biodistribution and micro-SPECT/CT imaging of [99mTc]Tc-1/2 and [186Re]Re-2 were performed in PC-3 tumor-bearing ICR SCID mice. RESULTS: High in vitro receptor affinity (IC50 2-3 nM) was demonstrated for all compounds. The 99mTc/186Re-tracers were found to be hydrophilic (log D7.4 ≤ - 1.35) and highly stable. Biodistribution in PC-3 xenografted mice revealed good tumor uptake (%ID/g at 1 h: 4.3 ± 0.7 for [99mTc]Tc-1, 8.3 ± 0.9 for [99mTc]Tc-2 and 4.2 ± 0.8 for [186Re]Re-2) with moderate retention over 24 h. Rapid renal clearance was observed for [99mTc]Tc-2 and [186Re]Re-2 (> 84 % at 4 h), indicating favorable pharmacokinetics. Micro-SPECT/CT images for the 99mTc-tracers clearly visualized PC-3 tumors in agreement with the biodistribution data and with superior imaging properties found for [99mTc]Tc-2. CONCLUSIONS: [99mTc]Tc-2 shows promise for further development as a GRPR-imaging agent. [186Re]Re-2 demonstrated very similar in vivo behavior to [99mTc]Tc-2, and further studies are therefore justified to explore the theranostic potential of our approach for targeting of GRPR-positive cancers.


Asunto(s)
Acetatos/química , Compuestos Heterocíclicos con 1 Anillo/química , Neoplasias/diagnóstico por imagen , Radioisótopos/química , Receptores de Bombesina/metabolismo , Renio/química , Tecnecio/química , Animales , Concentración 50 Inhibidora , Ligandos , Ratones SCID , Péptidos/química , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único , Distribución Tisular , Imagen de Cuerpo Entero
12.
Nucl Med Biol ; 94-95: 46-52, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33515899

RESUMEN

INTRODUCTION: With the long-term goal of developing a diagnostic (99mTc) and therapeutic (186Re) agent pair for targeting somatostatin receptor (SSTR)-positive neuroendocrine tumors (NETs), we developed novel metal-cyclized peptides through direct labeling of the potent SSTR2 antagonist Ac-4-NO2-Phe-c(DCys-Tyr-DTrp-Lys-Thr-Cys)-DTyr-NH2 (1) with Re (in Re-1), 99mTc (in [99mTc]Tc-1) and 186Re (in [186Re]Re-1). METHODS: Re-1 was characterized by LC-ESI-MS and HR-ESI-MS and was tested for receptor affinity in SSTR-expressing cells (AR42J). Radiolabeling of the peptide was achieved via ligand exchange from 99mTc-labeled glucoheptonate or [186Re]ReOCl3(PPh3)2, yielding [99mTc]Tc-1 or [186Re]Re-1, respectively. In vitro stability of [99mTc]Tc-1/[186Re]Re-1 in PBS (10 mM) at pH 7.4 and 37 °C was determined by HPLC analysis. Moreover, [99mTc]Tc-1 stability was tested in cysteine (1 mM) and rat serum under the same conditions. RESULTS: Re-1 consisted of two isomers, confirmed by LC-ESI-MS, with good SSTR2 affinity (IC50 = 43 ± 6 nM). Optimization of the 99mTc labeling through varying reaction parameters such as pH, reaction time, and Sn2+ and ligand concentrations resulted in high radiochemical yield (RCY ≥92%). Similarly, [186Re]Re-1 was prepared in reasonable RCY (≥50%). Both 99mTc/186Re-tracers consisted of two product isomers as identified by HPLC co-injection with Re-1. While [99mTc]Tc-1 was sufficiently stable in vitro (≥71% intact through 4 h in PBS, cysteine and rat serum), [186Re]Re-1 exhibited more moderate in vitro stability (58% intact after 1 h in PBS). CONCLUSIONS: Novel 99mTc/186Re-cyclized SSTR2 antagonist peptides were synthesized and characterized using the Re-cyclized analogue as a reference. Due to the nanomolar SSTR2 affinity of Re-1 and good in vitro stability of [99mTc]Tc-1, the latter shows early promise for development as a radiodiagnostic agent for SSTR-expressing NETs. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE: The 99mTc-cyclized complex showed promising in vitro properties, and future in vivo studies will determine the potential for translating such a design into the human clinic.


Asunto(s)
Compuestos de Organotecnecio/química , Péptidos/química , Radioisótopos/química , Renio/química , Animales , Ciclización , Marcaje Isotópico , Radioquímica , Ratas , Receptores de Somatostatina
13.
Oncol Rev ; 14(2): 439, 2020 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-33505608

RESUMEN

The purpose of the present study is to examine the diagnostic and predictive accuracy of the thyroglobulin (Tg) to thyroid stimulating hormone (TSH) and TSH/Tg ratios in normothyroid patients with differentiated thyroid cancer (DTC). We conducted a retrospective cohort study evaluating the diagnostic accuracy of the serum Tg/TSH and TSH/Tg ratios in normothyroid patients with thyroid nodules. We also systematically searched the international literature using the Medline, Cochrane's CENTRAL, Scopus, Clinicaltrials.gov, EMBASE, and Google Scholar databases for evidence concerning the diagnostic and predictive accuracy of these ratios. Overall, 374 patients were identified in our cohort study of whom 240 were treated for benign disease and 134 were treated for DTC. Significant differences were noted in the Tg/TSH and TSH/Tg values among cases with malignant and benign disease (P=0.020). However, the diagnostic ROC curve did not confirm these results (Tg/TSH=0.572 and TSH/Tg=0.428). After searching the international literature, we identified 8 studies. The majority of the included data reported significant differences among patients with benign/malignant disease and those with successful iodine therapy compared to those with disease relapse. However, the clinical relevance was clearer among studies that investigated the usefulness of these ratios in predicting recurrent disease. The findings of our study support that the Tg/TSH ratio increases in patients with DTC and can, thus, become useful in the future as a predictive marker of ablative 131I therapy success. However, given the significant variability of Tg its diagnostic accuracy remains to date minimal; thus, the actual cut-off value that can be used to discriminate cancer cases from benign disease has not been determined yet.

14.
Nucl Med Biol ; 71: 39-46, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-31129499

RESUMEN

INTRODUCTION: The aim of this work was to develop diagnostic (99mTc) and therapeutic (186Re) agents for targeting somatostatin receptor (SSTR)-positive neuroendocrine tumors (NETs). In this regard, we evaluated in vitro complexes of the general formula [M(CO)3(L-sst2-ANT)] (M = 99mTc, 186Re), where L denotes NODAGA or NOTA and sst2-ANT denotes the potent SSTR2 antagonist 4-NO2-Phe-c(DCys-Tyr-DTrp-Lys-Thr-Cys)-DTyr-NH2. Moreover, we assessed the in vivo properties of the 99mTc-complexes in an animal SSTR-tumor model. METHODS: The [99mTc]/[186Re][Tc/Re(OH2)3(CO)3]+ precursors were utilized to prepare the 99mTc/186Re-complexes, which were identified by HPLC co-injection with their natRe analogues. The tracers were challenged in vitro at 37 °C against cysteine and histidine in phosphate-buffered saline (pH 7.4) and in rat serum. Biodistribution and micro-SPECT/CT imaging studies of the 99mTc-tracers were performed in AR42J tumor-bearing female ICR SCID mice. RESULTS: The 99mTc-complexes were prepared in high radiochemical yield (RCY > 90%, by HPLC), with lower RCY (≤30%) obtained for 186Re-complexes. Tracers remained intact in vitro and displayed low non-specific binding (10-25%) to rat serum proteins. Biodistribution of [99mTc]Tc-NODAGA-sst2-ANT revealed low tumor uptake (2.78 ±â€¯0.27 %ID/g) at 1 h, while high tumor uptake (16.70 ±â€¯3.32 %ID/g) was found for [99mTc]Tc-NOTA-sst2-ANT. Moderate to low tumor retention was observed for both tracers after 4 and 24 h. Tumor uptake for [99mTc]Tc-NOTA-sst2-ANT was receptor-mediated, as demonstrated by parallel SSTR blocking studies. Rapid renal clearance was observed for both tracers, and SPECT/CT images clearly delineated the tumors, in agreement with the biodistribution data. CONCLUSIONS: The [99mTc]Tc-NOTA-sst2-ANT complex demonstrated high tumor uptake and rapid clearance in a SSTR-tumor mouse model, showing potential for further development. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE: Preclinical data support the feasibility of the [99mTc]Tc/[186Re]Re-NOTA/NODAGA labeling strategy for use in the development of theranostic radiopharmaceuticals for translation into the human clinic for targeting of SSTR-expressing NETs.


Asunto(s)
Acetatos/química , Compuestos Heterocíclicos con 1 Anillo/química , Interacciones Hidrofóbicas e Hidrofílicas , Compuestos de Organotecnecio/química , Compuestos de Organotecnecio/metabolismo , Radioisótopos/química , Receptores de Somatostatina/metabolismo , Renio/química , Animales , Ratones , Compuestos de Organotecnecio/farmacocinética , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único , Distribución Tisular
15.
Acta Crystallogr Sect F Struct Biol Cryst Commun ; 62(Pt 11): 1164-7, 2006 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-17077506

RESUMEN

DNA topoisomerase IV removes undesirable topological features from DNA molecules in order to help maintain chromosome stability. Two constructs of 56 and 59 kDa spanning the DNA-cleavage domain of the A subunit of topoisomerase IV from Staphylococcus aureus (termed GrlA56 and GrlA59) have been crystallized. Crystals were grown at 291 K using the sitting-drop vapour-diffusion technique with PEG 3350 as a precipitant. Preliminary X-ray analysis revealed that GrlA56 crystals belong to space group P2(1), diffract to a resolution of 2.9 A and possess unit-cell parameters a = 83.6, b = 171.5, c = 87.8 A, beta = 90.1 degrees, while crystals of GrlA59 belong to space group P2(1)2(1)2, with unit-cell parameters a = 41.5, b = 171.89, c = 87.9 A. These crystals diffract to a resolution of 2.8 A. This is the first report of the crystallization and preliminary X-ray analysis of the DNA-cleavage domain of a topoisomerase IV from a Gram-positive organism.


Asunto(s)
Topoisomerasa de ADN IV/química , Staphylococcus aureus/enzimología , Proteínas Bacterianas/química , Proteínas Bacterianas/aislamiento & purificación , Topoisomerasa de ADN IV/aislamiento & purificación , Fragmentos de Péptidos/química , Fragmentos de Péptidos/aislamiento & purificación , Difracción de Rayos X
16.
ACS Appl Mater Interfaces ; 8(14): 9345-60, 2016 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-26984632

RESUMEN

Magnetic nanoparticles (MNPs) can play a distinct role in magnetic drug delivery via their distribution to the targeted area. The preparation of such MNPs is a challenging multiplex task that requires the optimization of size, magnetic, and surface properties for the achievement of desirable target selectivity, along with the sustained drug release as a prerequisite. In that context, CoFe2O4 MNPs with a small size of ∼7 nm and moderate saturation magnetization of ∼60 emu g(-1) were solvothermally synthesized in the presence of octadecylamine (ODA) with a view to investigate the functionalization route effect on the drug release. Synthetic regulations allowed us to prepare MNPs with aminated (AmMNPs) and amine-free (FAmMNPs) surface. The addition of the nonsteroidal anti-inflammatory drug with a carboxylate donor, Naproxen (NAP), was achieved by direct coupling with the NH2 groups, rendered by ODA, through the formation of an amide bond in the case of AmMNPs. In the case of FAmMNPs, indirect coupling of NAP was performed through an intermediate linker (polyethylenimine) and on PEG-ylated MNPs. FT-IR, (1)H NMR, (13)C NMR, and UV-vis data confirmed the addition of NAP, whereas diverse drug-release behavior was observed for the different functionalization approaches. The biological behavior of the MNPs@NAP was evaluated in vitro in rat serum and in vivo in mice, after radiolabeling with a γ-emitting radionuclide, (99m)Tc. The in vivo fate of MNPs@NAP carriers was in straightforward relation with the direct or indirect coupling of NAP. Furthermore, an inflammation was induced intramuscularly, where the directly coupled (99m)Tc-MNPs@NAP carriers showed increased accumulation at the inflammation site.


Asunto(s)
Sistemas de Liberación de Medicamentos , Inflamación/tratamiento farmacológico , Nanopartículas de Magnetita/administración & dosificación , Naproxeno/administración & dosificación , Aminas/administración & dosificación , Aminas/química , Animales , Antiinflamatorios/administración & dosificación , Antiinflamatorios/química , Cobalto/química , Compuestos Férricos/química , Humanos , Inflamación/patología , Nanopartículas de Magnetita/química , Ratones , Naproxeno/química , Tamaño de la Partícula , Ratas , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie
17.
Diagn Cytopathol ; 44(11): 888-901, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27653446

RESUMEN

BACKGROUND: There have been various attempts to assess endometrial lesions on cytological material obtained via direct endometrial sampling. The majority of efforts focus on the description of cytological criteria that lead to classification systems resembling histological reporting formats. These systems have low reproducibility, especially in cases of atypical hyperplasia and well differentiated carcinomas. Moreover, they are not linked to the implied risk of malignancy. METHODS: The material was collected from women examined at the outpatient department of four participating hospitals. We analyzed 866 consecutive, histologically confirmed cases. The sample collection was performed using the EndoGyn device, and processed via Liquid Based Cytology, namely ThinPrep technique. The diagnostic categories and criteria were established by two cytopathologists experienced in endometrial cytology; performance of the proposed reporting format was assessed on the basis of histological outcome; moreover, the implied risk of malignancy was calculated. RESULTS: The proposed six diagnostic categories are as follows: (i) nondiagnostic or unsatisfactory; (ii) without evidence of hyperplasia or malignancy; (iii) atypical cells of endometrium of undetermined significance; (iv) atypical cells of endometrium of low probability for malignancy; (v) atypical cells of endometrium of high probability for malignancy; and (vi) malignant. The risk of malignancy was 1.42% ± 0.98%, 44.44% ± 32.46% (nine cases), 4.30% ± 4.12%, 89.80% ± 8.47%, and 97.81% ± 2.45%, respectively. CONCLUSION: We propose a clinically oriented classification scheme consisting of diagnostic categories with well determined criteria. Each diagnostic category is linked with an implied risk of malignancy; thus, clinicians may decide on patient management and eventually reduce unnecessary interventional diagnostic procedures. Diagn. Cytopathol. 2016;44:888-901. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Carcinoma/patología , Neoplasias Endometriales/patología , Prueba de Papanicolaou/normas , Índice de Severidad de la Enfermedad , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma/clasificación , Neoplasias Endometriales/clasificación , Femenino , Humanos , Persona de Mediana Edad , Prueba de Papanicolaou/métodos
18.
Case Rep Obstet Gynecol ; 2015: 429740, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25737786

RESUMEN

Background. Abdominal masses in female adolescents are uncommon. A rare cause of this condition is hematocolpos due to imperforate hymen. Case. We present a case of an unusually massive asymptomatic abdominal bulk in a 14-year-old female patient, who sought for medical advice after unusual abdominal pain lasting for few weeks. The patient was otherwise asymptomatic, apart from an unusual dramatic expansion of her abdominal wall during the last month. We describe the surgical management and the follow-up of the patient. Summary and Conclusion. Clinicians should keep in mind that an imperforate hymen can cause abdominal growth due to hematocolpos and include it in the differential diagnosis of such a clinical entity in female adolescents. 2D ultrasound is usually efficient for the confirmation of the diagnosis of hematocolpos, but 3D ultrasound is more accurate. Wide excision should be undertaken, as an initial approach, to avoid recurrence.

19.
Artículo en Inglés | MEDLINE | ID: mdl-14600694

RESUMEN

Transplantation is the transfer of tissue or an organ from 1 site to another in the same person or between different persons. A transplantation in which donor and recipient are the same individual has been termed autogenous transplantation, autoplastic transplantation, or autotransplantation. The purpose of this report was to describe a patient undergoing autotransplantation of an impacted mandibular canine to its normal position in the mandible and the 12-year follow-up. Five years after the surgical procedure, the patient presented with pulp canal obliteration in the autotransplanted tooth. Twelve years after the autotransplantation, the tooth position was stable despite pulp canal obliteration, but with no sign of inflammatory resorption or a periapical lesion. In addition, there was no sign of replacement resorption (ankylosis). The endodontic literature has shown that the prognosis of patients undergoing autotransplantation may be good under specific considerations. Therefore, the technique may be a treatment plan option for the replacement of missing teeth.


Asunto(s)
Diente Canino/trasplante , Niño , Enfermedades de la Pulpa Dental/etiología , Prueba de la Pulpa Dental , Femenino , Estudios de Seguimiento , Humanos , Mandíbula/cirugía , Tejido Periapical/diagnóstico por imagen , Pronóstico , Radiografía , Diente Impactado/cirugía , Trasplante Autólogo , Resultado del Tratamiento
20.
Circ Cardiovasc Interv ; 7(2): 233-9, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24668226

RESUMEN

BACKGROUND: In patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention, a suboptimal degree of platelet inhibition for the first 2 hours after the standard 60 mg loading dose of prasugrel has been described. METHODS AND RESULTS: In a prospective, 3-center, nonrandomized, controlled study, 2 sequential groups of P2Y12 inhibitor-naive consecutive patients were loaded with either 100 mg (n=47) or 60 mg (n=35) of prasugrel. Platelet reactivity was assessed by VerifyNow at hours 0, 0.5, 1, 2, and 4. At hour 2, there was a strong trend for the primary end point of platelet reactivity (in P2Y12 reaction units) to be lower (least squares estimates of the mean difference [95% confidence interval], -45.5 [-91.2 to 0.3]; P=0.051), whereas platelet reactivity percentage inhibition (median, first to third quartile) was higher (75.5% [24%-91.8%] versus 23.5% [0%-78.3%]; P=0.02) in the 100-mg compared with 60-mg loading dose group. At hour 2, prasugrel 100 mg over 60 mg loading dose significantly reduced high platelet reactivity rates from 28.6% to 8.5% (≥230 P2Y12 reaction units threshold; P=0.036) and from 31.4% to 10.6% (≥208 P2Y12 reaction units threshold; P=0.024), whereas resulted in lower rate of ≤20% platelet inhibition (23.4% versus 51.4%; P=0.009). CONCLUSIONS: In patients with ST-segment-elevation myocardial infarction treated with primary percutaneous coronary intervention, a higher (100 mg) than the standard loading dose of prasugrel results in greater and more consistent platelet inhibition, yet this will need to be further validated in additional studies. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01835353.


Asunto(s)
Electrocardiografía , Infarto del Miocardio/sangre , Infarto del Miocardio/terapia , Intervención Coronaria Percutánea , Piperazinas/farmacocinética , Inhibidores de Agregación Plaquetaria/farmacocinética , Tiofenos/farmacocinética , Adulto , Anciano , Coagulación Sanguínea/efectos de los fármacos , Plaquetas/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Persona de Mediana Edad , Piperazinas/farmacología , Activación Plaquetaria/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/farmacología , Clorhidrato de Prasugrel , Estudios Prospectivos , Tiofenos/farmacología , Factores de Tiempo , Resultado del Tratamiento
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