Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 33
Filter
1.
Amino Acids ; 56(1): 1, 2024 Jan 29.
Article in English | MEDLINE | ID: mdl-38285098

ABSTRACT

Breast cancer remains a pressing public health issue primarily affecting women. Recent research has spotlighted bioactive peptides derived from laminin-111, implicated in breast tumor development. Remarkably, the sequences IKVAV, YIGSR, and KAFDITYVRLKF from the α1, ß1, and γ1 chains, respectively, have garnered significant attention. This study aims to assess the potential of these radiolabeled peptides as targeting agents for breast cancer. The three peptides were synthesized using the Fmoc strategy, purified via reversed-phase high-performance liquid chromatography (RP-HPLC), and characterized through mass spectrometry. Iodine-131 (131I) radiolabeling was performed using the chloramine T method, exhibiting high radiochemical yield and stability for [131I]I-YIKVAV and [131I]I-YIGSR. Conversely, [131I]I-KAFDITYVRLKF demonstrated low radiochemical yield and stability and was excluded from the biological studies. The lipophilicity of the compounds ranged from - 2.12 to - 1.10. Serum protein binding assay for [131I]I-YIKVAV and [131I]I-YIGSR reached ≅ 48% and ≅ 25%, respectively. Affinity for breast cancer cells was evaluated using MDA-MB-231 and MCF-7 tumor cell lines, indicating the affinity of the radiopeptides with these tumor cells. Ex vivo biodistribution profiles of the radiopeptides were assessed in the MDA-MB-231 breast tumor animal model, revealing tumor tissue accumulation, supported by a high tumor-to-contralateral muscle ratio and autoradiography. These results signify the effective penetration of YIKVAV and YIGSR into tumor tissue. Therefore, the synthesized α1 and ß1 peptide fragments exhibit favorable characteristics as potential breast cancer-targeting agents, promising future exploration as radiopharmaceuticals for breast cancer.


Subject(s)
Breast Neoplasms , Animals , Female , Humans , Breast Neoplasms/drug therapy , Prospective Studies , Tissue Distribution , Peptides/pharmacology , Laminin
2.
Front Chem ; 11: 1271176, 2023.
Article in English | MEDLINE | ID: mdl-37901160

ABSTRACT

The expression of prostate-specific membrane antigen (PSMA) is upregulated in prostate cancer (PCa) cells and PSMA-ligands have been radiolabeled and used as radiopharmaceuticals for targeted radionuclide therapy (TRT), single photon emission computed tomography (SPECT) or positron emission tomography (PET) molecular imaging, and radioguided surgery in PCa patients. Herein, we aimed at radiolabeling the PSMA-I&S cold kit with 99mTc, resulting in a radiopharmaceutical with high radiochemical yield (RCY) and stability for SPECT imaging and radioguided surgery in PCa malignancies. Various pre-clinical assays were conducted to evaluate the [99mTc]Tc-PSMA-I&S obtained by the cold kit. These assays included assessments of RCY, radiochemical stability in saline, lipophilicity, serum protein binding (SPB), affinity for LNCaP-PCa cells (binding and internalization studies), and ex vivo biodistribution profile in naive and LNCaP-PCa-bearing mice. The radiopharmaceutical was obtained with good RCY (92.05% ± 2.20%) and remained stable for 6 h. The lipophilicity was determined to be -2.41 ± 0.06, while the SPB was ∼97%. The binding percentages to LNCaP cells were 9.41% ± 0.57% (1 h) and 10.45% ± 0.45% (4 h), with 63.12 ± 0.93 (1 h) and 65.72% ± 1.28% (4 h) of the bound material being internalized. Blocking assays, employing an excess of unlabeled PSMA-I&S, resulted in a reduction in the binding percentage by 2.6 times. The ex vivo biodistribution profile confirmed high accumulation of [99mTc]Tc-PSMA-I&S in the tumor and the tumor-to-contralateral muscle ratio was ∼6.5. In conclusion, [99mTc]Tc-PSMA-I&S was successfully obtained by radiolabeling the cold kit using freshly eluted [99mTc]NaTcO4, exhibiting good RCY and radiochemical stability. The preclinical assays demonstrated that the radiopharmaceutical shows favorable characteristics for SPECT imaging and radioguided surgery in PCa patients.

3.
Sci Rep ; 13(1): 4482, 2023 03 18.
Article in English | MEDLINE | ID: mdl-36934143

ABSTRACT

Coronavirus disease 2019 (COVID-19) is a pandemic infection caused by the newly discovered severe acute respiratory syndrome coronavirus 2. Remdesivir (RDV) and corticosteroids are used mainly in COVID-19 patients with acute respiratory failure. The main objective of the study was to assess the effectiveness of remdesivir with and without corticosteroids in the treatment of COVID-19 patients. We conducted a prospective observational study, including adult patients consecutively hospitalized with confirmed COVID-19 and acute respiratory failure. Patients were divided according to treatment strategy: RDV alone versus RDV with corticosteroids. The primary outcome was the time to recovery in both treatment groups. We included 374 COVID-19 adult patients, 184 were treated with RDV, and 190 were treated with RDV and corticosteroid. Patients in the RDV group had a shorter time to recovery in comparison with patients in the RDV plus corticosteroids group at 28 days after admission [11 vs. 16 days (95% confidence Interval 9.7-12.8; 14.9-17.1; p = .016)]. Patients treated with RDV alone had a shorter length of hospital stay. The use of corticosteroids as adjunctive therapy of RDV was not associated with improvement in mortality of COVID-19 patients.


Subject(s)
COVID-19 , Respiratory Insufficiency , Adult , Humans , COVID-19 Drug Treatment , Adenosine Monophosphate/therapeutic use , Alanine/therapeutic use , Adrenal Cortex Hormones/therapeutic use , Antiviral Agents/therapeutic use , Respiratory Insufficiency/chemically induced
4.
Pharmaceuticals (Basel) ; 17(1)2023 Dec 28.
Article in English | MEDLINE | ID: mdl-38256881

ABSTRACT

Human bacterial infections significantly contribute to the increase in healthcare-related burdens. This scenario drives the study of novel techniques for the early and precise diagnosis of infectious processes. Some alternatives include Nuclear Medicine- and Molecular Imaging-based strategies. However, radiopharmaceuticals that are available for routine assessments are not specific to differentiating infectious from aseptic inflammatory processes. In this context, [68Ga]Ga-DOTA-Ubiquicidin29-41 was synthesized using an automated module and radiochemical; in vivo and in vitro studies were performed. The radiopharmaceutical remained stable in saline (up to 180 min) and in rodent serum (up to 120 min) with radiochemical purities > 99 and 95%, respectively. Partition coefficient and serum protein binding at 60 min were determined (-3.63 ± 0.17 and 44.06 ± 1.88%, respectively). Ex vivo biodistribution, as well as in vivo microPET/CT images in mice, showed rapid blood clearance with renal excretion and reduced uptake in other organs in Staphylococcus aureus-infected animals. Higher uptake was observed in the target as compared to the non-target tissue (p < 0.0001) at 60 min post administration. The presented in-human clinical case demonstrates uptake of the radiopharmaceutical by Staphyloccocus aureus bacteria. These results indicate the potential of [68Ga]Ga-DOTA-Ubiquicidin29-41 as a radiopharmaceutical that can be obtained in a hospital radiopharmacy for the diagnosis of infectious processes using PET/CT.

5.
Acta Med Port ; 35(7-8): 558-565, 2022 Jul 01.
Article in English | MEDLINE | ID: mdl-35333155

ABSTRACT

INTRODUCTION: Although raltegravir has been available since 2007, data are lacking on the Portuguese population living with HIV who initiated this antiretroviral therapy. Hence, this study aimed to characterize the patients who initiated raltegravir-based regimens between January 2015 and December 2017, on sociodemographics, clinical features, and treatment satisfaction. MATERIAL AND METHODS: Observational, retrospective, multicentre study conducted at 11 reference sites. Sociodemographic and clinical data were collected retrospectively from hospital medical records. For participants continuing raltegravir at study inclusion, the HIV Treatment Satisfaction Questionnaire was administered to assess satisfaction with raltegravir-based therapy. Descriptive statistics were performed. Treatment-naïve and treatment-experienced subgroups were compared for demographic and clinical variables. RESULTS: A total of 302 patients were included; mostly men (69.5%) with a mean age of 49 years old. Approximately half of the patients had at least one non-AIDS-related comorbidity at baseline (53.3%), such as hypercholesterolemia, arterial hypertension, diabetes mellitus, and depression. Moreover, 52.3% were treatment-experienced patients with up to two treatments prior to raltegravir. Across the study time points, there was a reduction in the viral load and improvement in CD4 counts in both the treatment-naïve and treatment-experienced subgroups. Continuing users of raltegravir reported high treatment satisfaction (55.4 ± 7.2 points). CONCLUSION: Raltegravir-based regimens seem like a valid therapeutic option in heterogeneous populations of HIV-infected patients, in patients with previous ART experience and as part of first-line therapeutic options alongside with the latest generation of drugs from its class.


Introdução: Apesar de o raltegravir estar disponível desde 2007, os dados na população portuguesa com VIH que iniciou esta terapêutica antirretroviral são escassos. Deste modo, este estudo teve por objetivo caracterizar os doentes que iniciaram um regime terapêutico baseado em raltegravir entre janeiro de 2015 e dezembro de 2017, relativamente a dados sociodemográficos, características clínicas e satisfação com o tratamento. Material e Métodos: Estudo observacional, retrospetivo, multicêntrico conduzido em 11 centros de referência. Os dados sociodemográficos e clínicos foram recolhidos retrospetivamente nos processos clínicos. Os participantes que continuaram o regime com raltegravir após a inclusão no estudo preencheram o HIV Treatment Satisfaction Questionnaire para avaliar a satisfação com a terapêutica. Foram efetuadas análises de estatística descritiva e comparações para as variáveis sociodemográficas e clínicas nos subgrupos de doentes naïve de tratamento e de doentes com experiência terapêutica. Resultados: Foram incluídos 302 doentes, maioritariamente do sexo masculino (69,5%) com idade média de 49 anos. Aproximadamente metade dos doentes tinha pelo menos uma comorbilidade não relacionada com SIDA no início do estudo (53,3%), tais como hipercolesterolemia, hipertensão arterial, diabetes mellitus ou depressão. Adicionalmente, 52,3% eram doentes com experiência terapêutica com até dois tratamentos anteriores ao raltegravir. Ao longo do estudo verificou-se uma redução na carga viral e uma melhoria nas contagens de CD4 em ambos os subgrupos de doentes (doentes naïve de tratamento e doentes com experiência terapêutica). Os doentes com uso continuado de raltegravir reportaram uma elevada satisfação com o tratamento (55,4 ± 7,2 pontos). Conclusão: Os regimes terapêuticos baseados em raltegravir parecem ser uma opção terapêutica válida em populações heterogéneas de doentes infetados com VIH, em doentes com experiência em ART e como tratamento de primeira linha, em paralelo com outras terapêuticas de última geração.


Subject(s)
HIV Infections , Male , Humans , Middle Aged , Female , Raltegravir Potassium/therapeutic use , Raltegravir Potassium/adverse effects , Retrospective Studies , Portugal , Viral Load , HIV Infections/drug therapy
6.
Pharmaceuticals (Basel) ; 15(2)2022 Jan 18.
Article in English | MEDLINE | ID: mdl-35215229

ABSTRACT

Radiolabeled peptides with high specificity for overexpressed receptors in tumor cells hold great promise for diagnostic and therapeutic applications. In this work, we aimed at comparing the radiolabeling efficiency and biological properties of two different RGD analogs: GRGDYV and GRGDHV, labeled with iodine-131 (131I) and technetium-99m-tricarbonyl complex [99mTc][Tc(CO)3]+. Additionally, we evaluated their interaction with the αvß3 integrin molecule, overexpressed in a wide variety of tumors, including glioblastoma. Both peptides were chemically synthesized, purified and radiolabeled with 131I and [99mTc][Tc(CO)3]+ using the chloramine-T and tricarbonyl methodologies, respectively. The stability, binding to serum proteins and partition coefficient were evaluated for both radioconjugates. In addition, the binding and internalization of radiopeptides to rat C6 glioblastoma cells and rat brain homogenates from normal animals and a glioblastoma-induced model were assessed. Finally, ex vivo biodistribution studies were carried out. Radiochemical yields between 95-98% were reached for both peptides under optimized radiolabeling conditions. Both peptides were stable for up to 24 h in saline solution and in human serum. In addition, the radiopeptides have hydrophilic characteristics and a percentage of binding to serum proteins around 35% and 50% for the [131I]I-GRGDYV and [99mTc]Tc(CO)3-GRGDHV fragments, respectively. Radiopeptides showed the capacity of binding and internalization both in cell culture (C6) and rat brain homogenates. Biodistribution studies corroborated the results obtained with brain homogenates and confirmed the different binding characteristics due to the exchange of radionuclides and the presence of the tricarbonyl complex. Thereby, the results showed that both radiopeptides might be considered for future clinical applications.

7.
Pharmaceutics ; 13(7)2021 Jun 27.
Article in English | MEDLINE | ID: mdl-34198999

ABSTRACT

The oncogene HER2 is an important molecular target in oncology because it is associated with aggressive disease and the worst prognosis. The development of non-invasive imaging techniques and target therapies using monoclonal antibodies is a rapidly developing field. Thus, this work proposes the study of the radioimmunotheranostic pair, [111In]In-DTPA-trastuzumab and [177Lu]Lu-DOTA-trastuzumab, evaluating the influence of the chelating agents and radionuclides on the biological properties of the radioimmunoconjugates (RICs). The trastuzumab was immunoconjugated with the chelators DTPA and DOTA and radiolabeled with [111In]InCl3 and [177Lu]LuCl3, respectively. The stability of the RICs was evaluated in serum, and the immunoreactive and internalization fractions were determined in SK-BR-3 breast cancer cells. The in vivo pharmacokinetics and dosimetry quantification and the ex vivo biodistribution were performed in normal and SK-BR-3 tumor-bearing mice. The data showed that there was no influence of the chelating agents and radionuclides on the immunoreactive and internalization fractions of RICs. In contrast, they influenced the stability of RICs in serum, as well as the pharmacokinetics, dosimetry and biodistribution profiles. Therefore, the results showed that the nature of the chelating agent and radionuclide could influence the biological properties of the radioimmunotheranostic pair.

8.
Pharmaceuticals (Basel) ; 14(5)2021 Apr 21.
Article in English | MEDLINE | ID: mdl-33918987

ABSTRACT

Prostate-specific membrane antigen (PSMA) is a glycoprotein present in the prostate, that is overexpressed in prostate cancer (PCa). Recently, PSMA-directed radiopharmaceuticals have been developed, allowing the pinpointing of tumors with the Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) imaging techniques. The aim of the present work was to standardize and validate an automatic synthesis module-based radiolabeling protocol for [68Ga]Ga-PSMA-11, as well as to produce a radiopharmaceutical for PET imaging of PCa malignancies. [68Ga]Ga-PSMA-11 was evaluated to determine the radiochemical purity (RCP), stability in saline solution and serum, lipophilicity, affinity to serum proteins, binding and internalization to lymph node carcinoma of the prostate (LNCaP) cells, and ex vivo biodistribution in mice. The radiopharmaceutical was produced with an RCP of 99.06 ± 0.10%, which was assessed with reversed-phase high-performance liquid chromatography (RP-HPLC). The product was stable in saline solution for up to 4 h (RCP > 98%) and in serum for up to 1 h (RCP > 95%). The lipophilicity was determined as -3.80 ± 0.15, while the serum protein binding (SPB) was <17%. The percentages of binding to LNCaP cells were 4.07 ± 0.51% (30 min) and 4.56 ± 0.46% (60 min), while 19.22 ± 2.73% (30 min) and 16.85 ± 1.34% (60 min) of bound material was internalized. High accumulation of [68Ga]Ga-PSMA-11 was observed in the kidneys, spleen, and tumor, with a tumor-to-contralateral-muscle ratio of >8.5 and a tumor-to-blood ratio of >3.5. In conclusion, an automatic synthesis module-based radiolabeling protocol for [68Ga]Ga-PSMA-11 was standardized and the product was evaluated, thus verifying its characteristics for PET imaging of PCa tumors in a clinical environment.

9.
AIDS Res Hum Retroviruses ; 37(11): 846-851, 2021 11.
Article in English | MEDLINE | ID: mdl-33461392

ABSTRACT

Undiagnosed HIV-1 patients still account for 25% of worldwide HIV patients. Studying late presenters (LPs) for HIV care may help to identify characteristics of such patients. The present study aims to identify factors associated with late presentation and late presentation with advanced disease based on a population of patients followed in a Portuguese hospital between 1984 and 2017. Sociodemographic and clinical data from infected patients with HIV-1 aged 18 years and older, followed in Egas Moniz Hospital, in Portugal were collected. Of the 907 patients included in this study, 68.7% were males and the median age was 37 years (interquartile range 30-47). Four hundred fifty-nine patients (50.6%) were LP and, of these, 284 patients (61.9%) were LPAD. The LP population mostly originated from Portugal and sub-Saharan Africa (64.4% and 28.8%; p = .004) and the HIV exposure category, mainly heterosexuals and men have sex with men (57.0% and 24.9%; p < .001). The stage of disease and viral load at diagnosis were significantly associated with both LP and LPAD (p < .001). Factors associated with LP in the logistic regression included age at diagnosis lower than 30 years (adjusted odds ratio [aOR] 0.34; 0.17-0.68; p = .002) and origin from sub-Saharan Africa (aOR 2.24; 1.44-3.50; p < .001). Late presentation is a major obstacle to halt the HIV epidemic. In this population, the majority of newly diagnosed HIV-infected individuals were LPs. Our results characterize vulnerable populations that should be frequently tested for HIV.


Subject(s)
HIV Infections , HIV-1 , Adult , CD4 Lymphocyte Count , Delayed Diagnosis , HIV Infections/epidemiology , HIV-1/genetics , Humans , Male , Portugal/epidemiology , Risk Factors
10.
Bioorg Med Chem ; 33: 115996, 2021 03 01.
Article in English | MEDLINE | ID: mdl-33494011

ABSTRACT

In the present work, the radioimmunoconjugates 111In-DTPA-trastuzumab and 177Lu-DOTA-trastuzumab were evaluated regarding the influence of the chelating agents on the physical-chemical parameters and human epidermal growth factor receptor 2 (HER2) tumor cell binding. Data showed that both chelating agents, at predetermined molar ratios (antibody:chelator - 1:10 and 1:20), did not influence the immunoconjugates integrity, the radiolabeling process and the radiolabeled antibodies stability. However, differences were observed in the lipophilic feature between DOTA and DTPA radioimmunoconjugates and in the specific binding to SK-BR-3 tumor cells (HER2 positive). Therefore, this study showed the importance of assessing the influence of chelating agents and their molar ratios in the development process of radioimmunoconjugates.


Subject(s)
Antibodies, Monoclonal/pharmacology , Chelating Agents/pharmacology , Immunoconjugates/pharmacology , Receptor, ErbB-2/antagonists & inhibitors , Antibodies, Monoclonal/chemistry , Chelating Agents/chemical synthesis , Chelating Agents/chemistry , Dose-Response Relationship, Drug , Humans , Immunoconjugates/chemistry , Molecular Structure , Receptor, ErbB-2/metabolism , Structure-Activity Relationship , Tumor Cells, Cultured
11.
Nucl Med Biol ; 88-89: 14-23, 2020.
Article in English | MEDLINE | ID: mdl-32663774

ABSTRACT

Radiolabeled peptides with high specificity to receptors expressed on tumor cells hold a great promise as diagnostic and therapeutic tracers. The main objective of this study was to evaluate the radiochemical and biological properties of two [131I]I-peptides, as well as their interaction with the epidermal growth factor receptor (EGFR), overexpressed in a wide variety of tumors, including glioblastoma. The EEEEYFELV peptide and its analogue DEDEYFELV, both designed to interact with EGFR, were chemically synthesized, purified and radiolabeled with iodine-131 ([131I]NaI). The radioiodination was evaluated and optimized using the chloramine-T methodology. The stability, serum proteins binding and partition coefficient were assessed for both radioconjugates. Moreover, the binding and internalization of synthesized radiopeptides with rat glioblastoma cells (C6) and with rat brain homogenates from a glioblastoma induced model were evaluated and ex vivo biodistribution studies were performed. Under optimized radiolabeling conditions, the peptides showed an average radiochemical yield of 90-95%. The stability studies showed that both peptides were stable up to 24 h in reaction medium, saline, and human serum. Furthermore, [131I]I-peptides have hydrophilic features and showed binding percentage to serum proteins of around 50%, which is highly compatible with clinical applications. Moreover, the radiopeptides presented capacity for binding and internalization in both tumor cells (C6) and rat brain tissues after tumor induction. Biodistribution studies corroborated the cell culture studies and confirmed the different binding characteristics derived from a simple change of two amino acids (Glu ➔ Asp1,3) in their sequences. The results obtained are consistent enough to motivate further studies. Thereby, these radiolabeled peptides might be useful for diagnostic applications.


Subject(s)
Brain Neoplasms/pathology , Glioblastoma/pathology , Iodine Radioisotopes/pharmacokinetics , Peptide Fragments/metabolism , Radiopharmaceuticals/pharmacokinetics , Animals , Apoptosis , Brain Neoplasms/metabolism , Cell Proliferation , ErbB Receptors/metabolism , Glioblastoma/metabolism , Male , Rats , Rats, Sprague-Dawley , Tissue Distribution , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
12.
IDCases ; 21: e00817, 2020.
Article in English | MEDLINE | ID: mdl-32477870

ABSTRACT

Mycobacterium chelonae can cause chronic skin, soft-tissue or bone infections. and is often associated with the immunocompromised state.We describe a case of a 58-year-old male patient with myasthenia gravis, chronically immunosuppressed, with a four month progression of growing erythematous, nodular and hard cutaneous lesions in the left forearm, leg and foot. He was receiving immunoglobulin every four weeks (2 g/kg) and prednisolone 25 mg/day and had an important previous history of several opportunistic infections while he was receiving corticosteroids. Histopathological examination of a biopsy showed acid-fast bacilli and tissue culture identified a Mycobacterium spp. within seven days of incubation, with Mycobacterium chelonae being identified by polymerase chain reaction assay. Antimicrobial susceptibility testing was performed showing no resistance and the patient was successfully treated during four months with ciprofloxacin, clarithromycin and trimethoprim-sulfamethoxazole with regression of the lesions, leaving some hyperpigmentation scars and without unbalancing his neurological disease. Patients with myasthenia gravis should be closely monitored because first line treatments for M. chelonae infection may be associated with myasthenic crisis.

13.
EJNMMI Res ; 10(1): 12, 2020 Feb 24.
Article in English | MEDLINE | ID: mdl-32140850

ABSTRACT

BACKGROUND: The positron emission tomography (PET) ligand 68Ga-Glu-urea-Lys(Ahx)-HBED-CC (68Ga-PSMA-11) targets the prostate-specific membrane antigen (PSMA), upregulated in prostate cancer cells. Although 68Ga-PSMA-11 PET is widely used in research and clinical practice, full kinetic modeling has not yet been reported nor have simplified methods for quantification been validated. The aims of our study were to quantify 68Ga-PSMA-11 uptake in primary prostate cancer patients using compartmental modeling with arterial blood sampling and to validate the use of standardized uptake values (SUV) and image-derived blood for quantification. RESULTS: Fifteen patients with histologically proven primary prostate cancer underwent a 60-min dynamic 68Ga-PSMA-11 PET scan of the pelvis with axial T1 Dixon, T2, and diffusion-weighted magnetic resonance (MR) images acquired simultaneously. Time-activity curves were derived from volumes of interest in lesions, normal prostate, and muscle, and mean SUV calculated. In total, 18 positive lesions were identified on both PET and MR. Arterial blood activity was measured by automatic arterial blood sampling and manual blood samples were collected for plasma-to-blood ratio correction and for metabolite analysis. The analysis showed that 68Ga-PSMA-11 was stable in vivo. Based on the Akaike information criterion, 68Ga-PSMA-11 kinetics were best described by an irreversible two-tissue compartment model. The rate constants K1 and k3 and the net influx rate constants Ki were all significantly higher in lesions compared to normal tissue (p < 0.05). Ki derived using image-derived blood from an MR-guided method showed excellent agreement with Ki derived using arterial blood sampling (intraclass correlation coefficient = 0.99). SUV correlated significantly with Ki with the strongest correlation of scan time-window 30-45 min (rho 0.95, p < 0.001). Both Ki and SUV correlated significantly with serum prostate specific antigen (PSA) level and PSA density. CONCLUSIONS: 68Ga-PSMA-11 kinetics can be described by an irreversible two-tissue compartment model. An MR-guided method for image-derived blood provides a non-invasive alternative to blood sampling for kinetic modeling studies. SUV showed strong correlation with Ki and can be used in routine clinical settings to quantify 68Ga-PSMA-11 uptake.

14.
J Viral Hepat ; 27(7): 715-720, 2020 07.
Article in English | MEDLINE | ID: mdl-32096268

ABSTRACT

Direct-acting antiviral drugs (DAAs) have recently changed the paradigm of hepatitis C therapy, significantly improving treatment response rates, patient life expectancy and quality of life. In Portugal, sofosbuvir (SOF) and SOF/ledipasvir (SOF/LDV) were fully reimbursed by the National Health System since early 2015 and generalized use of interferon-free DAA based regimens became current practice. During 2016, the remaining DAAs were sequentially added and covered by the same health access policy. The Portuguese Study Group of Hepatitis and HIV Co-infection (GEPCOI) collected data from 15 clinical centres in Portugal, pertaining to the HCV treatment experience with DAA regimens. A cohort of 2133 patients was analysed, representing one of the largest DAA treated HCV/HIV co-infected individuals. The global sustained virologic response (SVR) achieved was 95% in this real-life cohort setting. Linear regression analysis showed significant differences in treatment response rates when using SOF plus ribavirin (RBV) combination in genotype 2 or 3 infected individuals (P < .002) and in those with liver cirrhosis (P < .002). These findings corroborate that early treatment is mandatory in HIV/HCV co-infected patients, as response rates may be negatively influenced by higher fibrosis stages and suboptimal DAA regimens. The current national Portuguese health policy should continue to promote wider treatment access and individualized therapy strategies, aiming at the elimination of HCV infection in this high-risk co-infected population.


Subject(s)
Antiviral Agents , Coinfection , HIV Infections , Hepatitis C, Chronic , Adult , Aged , Antiviral Agents/therapeutic use , Coinfection/drug therapy , Drug Therapy, Combination , Female , Genotype , HIV Infections/drug therapy , Hepacivirus , Hepatitis C, Chronic/drug therapy , Humans , Male , Middle Aged , Nigeria , Portugal , Quality of Life , Sofosbuvir/therapeutic use , Treatment Outcome , Young Adult
15.
Einstein (Sao Paulo) ; 18: eGS4816, 2020.
Article in English, Portuguese | MEDLINE | ID: mdl-31778463

ABSTRACT

OBJECTIVE: To expose the current situation of the Brazilian Nuclear Medicine in relation to innovation, taking into account the Intellectual Property protection and the particularities of this field. METHODS: The number and the origin of patents filings from Brazil, United States and European Patent Convention countries were retrospectively compared in a 20-year period. RESULTS: The number of accumulated patents filings of conventional pharmaceuticals was ten times higher compared to the radiopharmaceuticals in the three regions studied. CONCLUSION: The largest number of Brazilian patents filings corresponded to the international patent applications, which is related to the country development conditions, as well as to the difficulties in the process of patent filing.


Subject(s)
Nuclear Medicine/trends , Patents as Topic/statistics & numerical data , Radiopharmaceuticals , Brazil , Humans , Inventions/legislation & jurisprudence , Inventions/statistics & numerical data , Patents as Topic/legislation & jurisprudence , United States
16.
Einstein (Säo Paulo) ; 18: eGS4816, 2020. graf
Article in English | LILACS | ID: biblio-1056056

ABSTRACT

ABSTRACT Objective To expose the current situation of the Brazilian Nuclear Medicine in relation to innovation, taking into account the Intellectual Property protection and the particularities of this field. Methods The number and the origin of patents filings from Brazil, United States and European Patent Convention countries were retrospectively compared in a 20-year period. Results The number of accumulated patents filings of conventional pharmaceuticals was ten times higher compared to the radiopharmaceuticals in the three regions studied. Conclusion The largest number of Brazilian patents filings corresponded to the international patent applications, which is related to the country development conditions, as well as to the difficulties in the process of patent filing.


RESUMO Objetivo Evidenciar a situação atual da Medicina Nuclear brasileira em relação à inovação, considerando a proteção à Propriedade Intelectual e suas particularidades na área. Métodos Foi realizado um levantamento comparativo do número e da origem de depósitos de patentes relacionadas a essa área no Brasil, nos Estados Unidos e em países participantes da European Patent Convention , em um período de 20 anos retroativos. Resultados O número de depósitos acumulados de patentes de medicamentos convencionais foi dez vezes maior quando comparado às famílias relacionadas aos processos que envolvem radiofármacos, nas três regiões estudadas. Conclusão O maior número de depósitos de patentes brasileiras correspondeu aos pedidos de patentes internacionais, refletindo as condições de desenvolvimento do país, bem como as dificuldades encontradas no processo de depósito de uma patente.


Subject(s)
Humans , Patents as Topic/statistics & numerical data , Radiopharmaceuticals , Nuclear Medicine/trends , Patents as Topic/legislation & jurisprudence , United States , Brazil , Inventions/legislation & jurisprudence , Inventions/statistics & numerical data
17.
Acta Med Port ; 32(3): 189-194, 2019 Mar 29.
Article in English | MEDLINE | ID: mdl-30946789

ABSTRACT

INTRODUCTION: In late 2014, Portugal implemented a national program for the treatment of patients with chronic hepatitis C with directacting antiviral agents. This program has made Portugal one of the first European countries to implement a structured measure of treatment to eliminate this serious public health problem. The aim of this study was to assess the effectiveness of direct-acting antiviral therapy in the treatment of patients with chronic hepatitis C virus infection. MATERIAL AND METHODS: A retrospective observational study was conducted at Centro Hospitalar de Lisboa Ocidental on the national online platform from December 2014 until February 2017 and included patients with hepatitis C virus infection who underwent treatment. The primary endpoint was sustained virologic response at least 12 weeks post treatment. Data was analyzed with the SPSS 17.0 program. RESULTS: During the study period, 820 patients completed therapy and achieved sufficient follow-up time to assess sustained virologic response with an overall response rate of 97.2% (n = 797) and a response rate of 98.0%, 99.5%, 90.9%, 95.1% and 94.2% for genotypes 1a, 1b, 2, 3 and 4, respectively. Data suggested that advanced fibrosis (F3/F4), human immunodeficiency virus co-infection and treatment failure with interferon and ribavirin were not negatively related with sustained virologic response in our population. Most patients (80.1%) completed treatment with ledipasvir/sofosbuvir ± ribavirin. The most common adverse events were fatigue and insomnia followed by headache and weight loss. DISCUSSION: Patients predominantly had genotype 1 infection which correlates with HCV distribution in Europe, but we found a major proportion in genotype 4 which can be explained by immigration from African countries. Our patients' ages ranging from 22 to 90 years, reflected a new approach with no upper age limit. Direct-acting antivirals regimens resulted in remarkably high SVR rates compared to interferon-based regimens, which were consistent with clinical trials data. CONCLUSION: Our data showed that direct-acting antiviral-based regimens are safe and have a high success rate in the treatment of patients with hepatitis C virus infection in a real-world setting.


Introdução: No final de 2014 foi implementado em Portugal um programa nacional para o tratamento de doentes com infecção crónica por vírus da hepatite C com recurso a antivíricos de acção directa. Este programa fez com que Portugal fosse um dos primeiros países europeus a implementar uma medida estruturante para a eliminação da hepatite C. Este estudo tem como objectivo a avaliação da efectividade dos antivíricos de acção directa no tratamento da hepatite C crónica. Material e Métodos: Estudo retrospectivo observacional dos doentes seguidos no Centro Hospitalar de Lisboa Ocidental, entre dezembro de 2014 e fevereiro de 2017. O objectivo primário do estudo é avaliar a resposta virológica sustentada a partir das 12 semanas pós tratamento. Analisámos os dados com o programa SPSS 17.0. Resultados: Durante o período do estudo 820 doentes completaram o tratamento e o tempo necessário para avaliação da resposta virológica sustentada. A resposta virológica sustentada global foi de 97.2% (n = 797), com taxas de resposta de 97,2%, 98,5%, 90,9%, 95,1% e 94,2% para os genótipos 1a, 1b, 2, 3 e 4, respectivamente. Os dados sugerem não haver relação entre a fibrose avançada (F3 / F4), a coinfecção pelo vírus da imunodeficiência humana e a falência do tratamento com interferão e ribavirina e uma menor resposta ao tratamento. A maioria dos doentes (80,1%) concluiu o tratamento com ledipasvir/sofosbuvir ± ribavirina. Os eventos adversos mais frequentes foram a fadiga e a insónia, seguida de dor de cabeça e perda de peso. Discussão: A população em estudo apresentou maior prevalência de infecção pelo genótipo 1, à semelhança dos restantes países Europeus, contudo a prevalência do genótipo 4 foi superior, reflectindo a imigração africana. A faixa etária (22 - 90 anos) dos doentes tratados reflecte uma nova abordagem sem limite superior de idade. A taxa de RVS obtida, muito superior à obtida com regimes baseados em interferão, foi consistente com os dados dos ensaios clínicos. Conclusão: Os dados encontrados demonstram que os regimes baseados em antivirais de acção directa, em contexto de vida real, são seguros e eficazes no tratamento de doentes com infecção por vírus da hepatite C.


Subject(s)
Antiviral Agents/therapeutic use , Benzimidazoles/therapeutic use , Fluorenes/therapeutic use , Hepatitis C, Chronic/drug therapy , Ribavirin/therapeutic use , Uridine Monophosphate/analogs & derivatives , Adult , Aged , Aged, 80 and over , Drug Therapy, Combination , Female , Genotype , Hepacivirus/genetics , Hepatitis C, Chronic/virology , Humans , Male , Middle Aged , Portugal , Retrospective Studies , Sofosbuvir , Sustained Virologic Response , Uridine Monophosphate/therapeutic use , Young Adult
18.
Pharmaceuticals (Basel) ; 12(1)2019 Feb 05.
Article in English | MEDLINE | ID: mdl-30764521

ABSTRACT

Parkinson's disease (PD) is a neurodegenerative disease characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta, leading to alteration of the integrity of dopaminergic transporters (DATs). In recent years, some radiopharmaceuticals have been used in the clinic to evaluate the integrity of DATs. These include tropane derivatives such as radiolabeled ß-CIT and FP-CIT with iodine-123 (123I), and TRODAT-1 with metastable technetium-99 (99mTc). Radiolabeling of ß-CIT with radioactive iodine is based on electrophilic radioiodination using oxidizing agents, such as Chloramine T or Iodo-Gen®. For the first time, the present work performed a comparative study of the radiolabeling of ß-CIT with iodine-131 (131I), using either Chloramine T or Iodo-Gen® as oxidizing agents, in order to improve the radiolabeling process of ß-CIT and to choose the most advantageous oxidizing agent to be used in nuclear medicine. Both radiolabeling methods were similar and resulted in high radiochemical yield (> 95%), with suitable 131I-ß-CIT stability up to 72 h. Although Chloramine T is a strong oxidizing agent, it was as effective as Iodo-Gen® for ß-CIT radiolabeling with 131I, with the advantage of briefer reaction time and solubility in aqueous medium.

19.
Int J Infect Dis ; 79: 94-100, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30529370

ABSTRACT

OBJECTIVE: To characterize the profile of non-AIDS-related comorbidities (NARC) in the older HIV-1-infected population and to explore the factors associated with multiple NARC. METHODS: This was a multicentre, cross-sectional study including HIV-1-infected patients aged ≥50 years, who were virologically suppressed and had been on a stable antiretroviral therapy (ART) regimen for at least 6 months. A multiple regression model explored the association between demographic and clinical variables and the number of NARC. RESULTS: Overall, 401 patients were enrolled. The mean age of the patients was 59.3 years and 72.6% were male. The mean duration of HIV-1 infection was 12.0 years and the median exposure to ART was 10.0 years. The mean number of NARC was 2.1, and 34.7% of patients had three or more NARC. Hypercholesterolemia was the most frequent NARC (60.8%), followed by arterial hypertension (39.7%) and chronic depression/anxiety (23.9%). Arterial hypertension and diabetes mellitus were the most frequently treated NARC (95.6% and 92.6% of cases, respectively). The linear regression analysis showed a positive relationship between age and NARC (B=0.032, 95% confidence interval 0.015-0.049; p=0.0003) and between the duration of HIV-1 infection and NARC (B=0.039, 95% confidence interval 0.017-0.059; p=0.0005). CONCLUSIONS: A high prevalence of NARC was found, the most common being metabolic, cardiovascular, and psychological conditions. NARC rates were similar to those reported for the general population, suggesting a larger societal problem beyond HIV infection. A multidisciplinary approach is essential to reduce the burden of complex multi-morbid conditions in the HIV-1-infected population.


Subject(s)
Anxiety Disorders/epidemiology , Depression/epidemiology , Diabetes Mellitus/epidemiology , HIV Infections/epidemiology , Hypertension/epidemiology , Acquired Immunodeficiency Syndrome , Aged , Anti-Retroviral Agents/therapeutic use , Antihypertensive Agents/therapeutic use , Anxiety Disorders/complications , Comorbidity , Cross-Sectional Studies , Depression/complications , Female , HIV Infections/complications , HIV Infections/drug therapy , HIV-1 , Humans , Hypertension/complications , Hypolipidemic Agents/therapeutic use , Male , Middle Aged , Portugal , Prevalence , Socioeconomic Factors
20.
Braz. arch. biol. technol ; 62: e19180545, 2019. tab, graf
Article in English | LILACS | ID: biblio-1019543

ABSTRACT

Abstract To present optimized chromatographic systems for radiochemical purity (RCP) evaluation of 99mTc-eluate and 99mTc-radiopharmaceuticals, as well as to assess doses calibrator reliability for routine purposes in hospital radiopharmacies. RCP was determined by different systems and radioactivity was quantified by TLC-scanner, doses calibrator and gamma-counter. Suitable and optimized systems were presented for RCP analyses. No significant differences were observed between radioactivity counting devices and, thus, doses calibrator showed reliability for RCP determination in hospital radiopharmacies.


Subject(s)
Radiochemistry/methods , Radiopharmaceuticals/standards , Chromatography/methods , Radiation Dosimeters
SELECTION OF CITATIONS
SEARCH DETAIL
...