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1.
Int J Pharm ; 651: 123734, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38142017

RESUMO

The present investigation was focused on the development of Soluplus®-based nanomicelles (NMs) (10 % w/v) loaded with Efavirenz (EFV) (5 mg/mL) and Curcumin (natural bio-enhancer) (CUR) (5, 10 and 15 mg/mL) to improve the oral bioavalability of EFV. Micellar formulations were obtained employing an acetone-diffusion technique. Apparent aqueous solubility was increased up to ∼1250-fold and 25,000-fold for EFV and CUR, respectively. Drug-loaded nanoformulations showed an excellent colloidal stability with unimodal size distribution and PDI values < 0.30. In vitro drug release was 41.5 % (EFV) and 2.6 % (CUR) from EFV-CUR-NMs over 6 h in simulated gastrointestinal fluids. EFV-CUR-loaded NMs resulted as safe nanoformulations according to the in vitro cytocompatibility assays in Caco-2 cells. Furthermore, CUR bio-enhancer activity was demonstrated for those nanoformulations. A CUR concentration of 15 mg/mL produced a significant (p < 0.05) increment (2.64-fold) of relative EFV oral bioavailability. Finally, the active role of the lymphatic system in the absorption process of EFV, after its oral administration was assessed in a comparative pharmacokinetic study in presence and absence of cycloheximide, a lymphatic transport inhibitor. Overall our EFV-CUR-NMs denoted their potential as a novel nanotechnological platform, representing a step towards an optimized "nano-sized" therapy for AIDS patients.


Assuntos
Alcinos , Curcumina , Ciclopropanos , Humanos , Células CACO-2 , Disponibilidade Biológica , Benzoxazinas , Solubilidade , Micelas , Portadores de Fármacos , Administração Oral , Tamanho da Partícula
2.
EJNMMI Radiopharm Chem ; 8(1): 35, 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37889361

RESUMO

BACKGROUND: The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biannual highlight commentary to update the readership on trends in the field of radiopharmaceutical development. MAIN BODY: This selection of highlights provides commentary on 21 different topics selected by each coauthoring Editorial Board member addressing a variety of aspects ranging from novel radiochemistry to first-in-human application of novel radiopharmaceuticals. CONCLUSION: Trends in radiochemistry and radiopharmacy are highlighted. Hot topics cover the entire scope of EJNMMI Radiopharmacy and Chemistry, demonstrating the progress in the research field in many aspects.

3.
Toxicology ; 464: 153020, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34740673

RESUMO

There is an increasing concern over the harmful effects that metallic nanoparticles (NP) may produce on human health. Due to their redox properties, nickel (Ni) and Ni-containing NP are particularly relevant. Hence, the aim of this study was to establish the toxicological mechanisms in the cardiorespiratory oxidative metabolism initiated by an acute exposure to Ni-doped-NP. Mice were intranasally instilled with silica NP containing Ni (II) (Ni-NP) (1 mg Ni (II)/kg body weight) or empty NP as control, and 1 h after exposure lung, plasma, and heart samples were obtained to assess the redox metabolism. Results showed that, NP were mainly retained in the lungs triggering a significantly increased tissue O2 consumption rate, leading to Ni-NP-increased reactive oxygen species production by NOX activity, and mitochondrial H2O2 production rate. In addition, an oxidant redox status due to an altered antioxidant system showed by lung GSH/GSSG ratio decreased, and SOD activity increased, resulting in an increased phospholipid oxidation. Activation of circulating polymorphonuclear leukocytes, along with GSH/GSSG ratio decreased, and phospholipid oxidation were found in the Ni-NP-group plasma samples. Consequently, in distant organs such as heart, Ni-NP inhalation alters the tissue redox status. Our results showed that the O2 metabolism analysis is a critical area of study following Ni-NP inhalation. Therefore, this work provides novel data linking the redox metabolisms alterations elicited by exposure to Ni (II) adsorbed to NP and cardiorespiratory toxicity.


Assuntos
Nanopartículas Metálicas/toxicidade , Níquel/química , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Feminino , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Masculino , Nanopartículas Metálicas/química , Camundongos , Mitocôndrias/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Dióxido de Silício/química
4.
Free Radic Biol Med ; 166: 324-336, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33596456

RESUMO

Along with the AgNP applications development, the concern about their possible toxicity has increasingly gained attention. As the respiratory system is one of the main exposure routes, the aim of this study was to evaluate the harmful effects developed in the lung after an acute AgNP exposure. In vivo studies using Balb/c mice intranasally instilled with 0.1 mg AgNP/kg b.w, were performed. 99mTc-AgNP showed the lung as the main organ of deposition, where, in turn, AgNP may exert barrier injury observed by increased protein content and total cell count in BAL samples. In vivo acute exposure showed altered lung tissue O2 consumption due to increased mitochondrial active respiration and NOX activity. Both O2 consumption processes release ROS triggering the antioxidant system as observed by the increased SOD, catalase and GPx activities and a decreased GSH/GSSG ratio. In addition, increased protein oxidation was observed after AgNP exposure. In A549 cells, exposure to 2.5 µg/mL AgNP during 1 h resulted in augment NOX activity, decreased mitochondrial ATP associated respiration and higher H2O2 production rate. Lung 3D tissue model showed AgNP-initiated barrier alterations as TEER values decreased and morphological alterations. Taken together, these results show that AgNP exposure alters O2 metabolism leading to alterations in oxygen metabolism lung toxicity. AgNP-triggered oxidative damage may be responsible for the impaired lung function observed due to alveolar epithelial injury.


Assuntos
Nanopartículas Metálicas , Prata , Animais , Peróxido de Hidrogênio , Pulmão , Nanopartículas Metálicas/toxicidade , Camundongos , Oxigênio
5.
Pharmaceuticals (Basel) ; 11(1)2018 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-29462915

RESUMO

Sudden unexpected death in epilepsy (SUDEP) is the major cause of death in those patients suffering from refractory epilepsy (RE), with a 24-fold higher risk relative to the normal population. SUDEP risk increases with seizure frequency and/or seizure-duration as in RE and Status Epilepticus (SE). P-glycoprotein (P-gp), the product of the multidrug resistant ABCB1-MDR-1 gene, is a detoxifying pump that extrudes drugs out of the cells and can confer pharmacoresistance to the expressing cells. Neurons and cardiomyocytes normally do not express P-gp, however, it is overexpressed in the brain of patients or in experimental models of RE and SE. P-gp was also detected after brain or cardiac hypoxia. We have previously demonstrated that repetitive pentylenetetrazole (PTZ)-induced seizures increase P-gp expression in the brain, which is associated with membrane depolarization in the hippocampus, and in the heart, which is associated with fatal SE. SE can produce hypoxic-ischemic altered cardiac rhythm (HIACR) and severe arrhythmias, and both are related with SUDEP. Here, we investigate whether SE induces the expression of hypoxia-inducible transcription factor (HIF)-1α and P-gp in cardiomyocytes, which is associated with altered heart rhythm, and if these changes are related with the spontaneous death rate. SE was induced in Wistar rats once a week for 3 weeks, by lithium-pilocarpine-paradigm. Electrocardiograms, HIF-1α, and P-gp expression in cardiomyocytes, were evaluated in basal conditions and 72 h after SE. All spontaneous deaths occurred 48 h after each SE was registered. We observed that repeated SE induced HIF-1α and P-gp expression in cardiomyocytes, electrocardiographic (ECG) changes, and a high rate of spontaneous death. Our results suggest that the highly accumulated burden of convulsive stress results in a hypoxic heart insult, where P-gp expression may play a depolarizing role in cardiomyocyte membranes and in the development of the ECG changes, such as QT interval prolongation, that could be related with SUDEP. We postulate that this mechanism could explain, in part, the higher SUDEP risk in patients with RE or SE.

6.
World J Gastroenterol ; 24(3): 397-407, 2018 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-29391762

RESUMO

AIM: To evaluate the association of Helicobacter pylori (H. pylori), cagA genotype, and type of gastric pathology with ghrelin, leptin and nutritional status. METHODS: Fasted dyspeptic adults (18-70 years) referred for an upper digestive endoscopy were enrolled in this cross-sectional study. Height and weight were assessed for body mass index (BMI) calculation. A sociodemographic survey was administered and nutrient intake was evaluated with 24 h dietary recalls. Serum total ghrelin and leptin levels were analyzed by enzyme-linked immunosorbent assay. 13C-Urea Breath Test was performed and four gastric biopsies were obtained during endoscopy for histopathology and H. pylori DNA amplification and genotyping. Data analysis was performed using χ2, Mann-Whitney U, Kruskal-Wallis tests, Spearman's correlation and linear regression. RESULTS: One hundred and sixty-three patients (40.8 ± 14.0 years), 98/65 females/males, were included. Overall, persistent H. pylori prevalence was 53.4% (95%CI: 45.7%-65.8%). Neither nutrient intake nor BMI differed significantly between H. pylori positive and negative groups. Serum ghrelin was significantly lower in infected patients [median 311.0 pg/mL (IQR 230.0-385.5)] than in uninfected ones [median 355.0 pg/mL (IQR 253.8-547.8)] (P = 0.025), even after adjusting for BMI and gender (P = 0.03). Ghrelin levels tended to be lower in patients carrying cagA positive strains both in the antrum and the corpus; however, differences with those carrying cagA negative strains did not reach statistical significance (P = 0.50 and P = 0.49, respectively). In addition, the type and severity of gastric pathology in the corpus was associated with lower serum ghrelin (P = 0.04), independently of H. pylori status. Conversely, leptin levels did not differ significantly between infected and uninfected patients [median 1.84 ng/mL (0.80-4.85) vs 1.84 ng/mL (0.50-5.09), (P = 0.51)]. CONCLUSION: H. pylori infection and severity of gastric corpus pathology are associated with lower serum ghrelin. Further studies could confirm a lower ghrelin prevalence in cagA-positive patients.


Assuntos
Dispepsia/sangue , Mucosa Gástrica/patologia , Grelina/sangue , Infecções por Helicobacter/sangue , Helicobacter pylori/isolamento & purificação , Adulto , Antígenos de Bactérias/isolamento & purificação , Proteínas de Bactérias/isolamento & purificação , Biópsia , Testes Respiratórios , Estudos Transversais , Dispepsia/diagnóstico por imagem , Dispepsia/microbiologia , Dispepsia/patologia , Ensaio de Imunoadsorção Enzimática , Jejum/sangue , Feminino , Mucosa Gástrica/diagnóstico por imagem , Mucosa Gástrica/microbiologia , Gastroscopia , Infecções por Helicobacter/diagnóstico por imagem , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Helicobacter pylori/genética , Humanos , Leptina/sangue , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
7.
Biomed Pharmacother ; 95: 894-903, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28903185

RESUMO

Doxorubicin (DOX) is used as a "first-line" antineoplastic drug in ovarian and metastatic breast cancer. However, serious side effects, such as cardiotoxicity have been reported after DOX intravenous administration. Hence, we investigated different micelle-former biomaterials, as Soluplus®, Pluronic F127, Tetronic T1107 and d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) to develop a potential mixed micellar nanocarrier for DOX delivery. Since DOX hydrochloride is a poor candidate to be encapsulated inside the hydrophobic core of the mixed micelles, we assayed a hydrophobic complex between DOX and sodium deoxycholate (NaDC) as an excellent candidate to be encapsulated within polymeric micelles. The combination of T1107:TPGS (1:3, weight ratio) demonstrated the best physicochemical properties together with a high DL capacity (6.43% w/v). Particularly, DOX in vitro release was higher at acidic tumour microenvironment pH value (5.5) than at physiological counterpart (7.4). The hydrodynamic diameter of the DOX/NaDC-loaded mixed micellar system was 10.7nm (PDI=0.239). The in vitro cytotoxicity of the mixed micellar formulation resulted significantly (p<0.05) higher than Doxil® against ovarian (SKOV-3) and triple-negative breast cancer cells (MDA-MB- 231). Further, the in vitro cellular uptake assays demonstrated a significant increment (p<0.05) of the DOX intracellular content for the mixed micelles versus Doxil® for both, SKOV-3 (at 2, 4 and 6h of incubation) and MDA-MB-231 (at 4h of incubation) cells. These findings suggest that T1107:TPGS (1:3) mixed micelles could be employed as a potential nanotechnological platform for drug delivery of DOX.


Assuntos
Neoplasias da Mama/patologia , Doxorrubicina/análogos & derivados , Doxorrubicina/uso terapêutico , Micelas , Neoplasias Ovarianas/patologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Neoplasias da Mama/ultraestrutura , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Endocitose/efeitos dos fármacos , Feminino , Humanos , Concentração Inibidora 50 , Neoplasias Ovarianas/ultraestrutura , Tamanho da Partícula , Polietilenoglicóis/farmacologia , Polietilenoglicóis/uso terapêutico , Eletricidade Estática
9.
Eur J Pharm Biopharm ; 114: 305-316, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28192249

RESUMO

Breast cancer represents the top cancer among women, accounting 521.000 deaths per year. Development of targeted nanomedicines to breast cancer tissues represents a milestone to reduce chemotherapy side effects. Taking advantage of the over-expression of glucose (Glu) membrane transporters in breast cancer cells, we aim to expand the potential of a paclitaxel (PTX)-loaded mixed micellar formulation based on polyvinyl caprolactam-polyvinylacetate-polyethylene glycol graft copolymer (Soluplus®) and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) by its surface decoration with Glu moieties. The glycopolymer (Soluplus(Glu)) was obtained by microwave-assisted ring opening reaction of δ-gluconolactone initiated by Soluplus®. The glycosylation was confirmed by 1H NMR and by agglutination assays employing Concanavalin A. The hydrodynamic diameter of Soluplus(Glu) micelles was characterized by dynamic light scattering (100.3±3.8nm) as well as the critical micellar concentration value (0.0151% w/v). Then, a mixed micelle formulation employing Soluplus®, Soluplus(Glu) and TPGS (3:1:1wt ratio) loaded with PTX (4mg/mL) was developed as a multifunctional nanocarrier. Its in vitro anticancer performance in MCF-7 (1.6-fold) and MDA-MB-231 (14.1-fold) was significantly enhanced (p<0.05) versus the unique commercially available micellar-based PTX-nanoformulation (Genexol®). Furthermore, the in vitro PTX cellular uptake assays revealed that the drug intracellular/cell content was significantly (p<0.05) higher for the Glu-containing mixed micelles versus Genexol® after 6h of incubation with MCF-7 (30.5-fold) and MDA-MB-231 (5-fold). Overall, results confirmed the potential of our Glu-decorated mixed colloidal formulation as an intelligent nanocarrier for PTX-targeted breast cancer chemotherapy.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Proteínas Facilitadoras de Transporte de Glucose/efeitos dos fármacos , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos , Composição de Medicamentos , Excipientes , Feminino , Humanos , Micelas , Nanomedicina , Paclitaxel/química , Paclitaxel/farmacologia , Polietilenoglicóis/química , Polivinil/química
10.
Eur J Pharm Biopharm ; 113: 211-228, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28087380

RESUMO

During the past few decades, polymeric micelles have raised special attention as novel nano-sized drug delivery systems for optimizing the treatment and diagnosis of numerous diseases. These nanocarriers exhibit several in vitro and in vivo advantages as well as increased stability and solubility to hydrophobic drugs. An interesting approach for optimizing these properties and overcoming some of their disadvantages is the combination of two or more polymers in order to assemble polymeric mixed micelles. This review article gives an overview on the current state of the art of several mixed micellar formulations as nanocarriers for drugs and imaging probes, evaluating their ongoing status (preclinical or clinical stage), with special emphasis on type of copolymers, physicochemical properties, in vivo progress achieved so far and toxicity profiles. Besides, the present article presents relevant research outcomes about polymeric mixed micelles as better drug delivery systems, when compared to polymeric pristine micelles. The reported data clearly illustrates the promise of these nanovehicles reaching clinical stages in the near future.


Assuntos
Micelas , Nanomedicina , Polímeros/química , Portadores de Fármacos
11.
Anticancer Agents Med Chem ; 17(3): 359-364, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-26552391

RESUMO

BACKGROUND: Chemotherapy is one of the most common approaches for cancer treatment. Particularly Doxorubicin has been proven to be effective in the treatment of many soft and solid tumors for locally advanced and metastatic cancer. It is not easy to clinically evaluate the chemotoxic or chemoprotective effect of some drugs, even more when there is a subclinical toxicity. OBJECTIVE: To determine the usefulness of the hepatobiliary, colloid and cardiac scintigraphies, employing99mTcdisida, 99mTc-phytate and 99mTc-sestamibi respectively, in the evaluation of the hepato and cardiotoxicity of two chemotherapeutic treatments assessed in rats. METHOD: Two groups were submitted to doxorubicin (DOX) treatment and one was co-administered with histamine (DOX+HIS). Static 99mTc-phytate and 99mTc-sestamibi scintigraphies as well as a dynamic 99mTc-disida study were performed in a small field of view gamma camera at: 0 weeks (control), 1 week and 2 weeks of treatment. Imagenological parameters were calculated: Liver/Bone Marrow ratio (L/BM), Heart/Background ratio (H/B) and time to the maximum (Tmax) for 99mTc-phytate, 99mTc-sestamibi and 99mTc-disida extraction, respectively. RESULTS: Control (L/BM= 98±3; H/B=2.3±0.4; Tmax=8±3), DOX (L/BM: 85±3, 80±3; H/B, 3.5±0.5, 3.3±0.5 and Tmax 6±1, 4±1) for 1 and 2 weeks respectively and DOX+HIS (L/BM: 99±0.3, 98±1; H/B 2.9±0.5, 2.9±0.5 and Tmax, 8±2, 9±2) for 1 and 2 weeks, respectively. Histological analysis showed cardio and hepatotoxicity induced by doxorubicin. CONCLUSION: Imagenological parameters showed differences among treated and control groups and between both chemotherapy treatments. Thus, these radiopharmaceutical functional approaches were able to reflect heart and liver toxicity produced by doxorubicin.


Assuntos
Antineoplásicos/efeitos adversos , Doxorrubicina/efeitos adversos , Coração/efeitos dos fármacos , Histamina/efeitos adversos , Fígado/efeitos dos fármacos , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Cardiotoxicidade , Relação Dose-Resposta a Droga , Doxorrubicina/administração & dosagem , Doxorrubicina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Histamina/administração & dosagem , Histamina/farmacologia , Masculino , Estrutura Molecular , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade
12.
Nucl Med Biol ; 44: 62-68, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27821346

RESUMO

INTRODUCTION: In recent years, nanomedicines have raised as a powerful tool to improve prevention, diagnosis and treatment of different pathologies. Among the most well investigated biomaterials, D-α-tocopheryl polyethylene glycol succinate (also known as TPGS) has been on the spot for the last decade. We therefore designed a method to biologically characterize TPGS-based nanomicelles by labeling them with 99mTc. METHODS: Labeling process was performed by a direct method. The average hydrodynamic diameter of TPGS nanomicelles was measured by dynamic light scattering and radiochemical purity was assessed by thin layer chromatography. Imaging: a dynamic study was performed during the first hour post radioactive micelles administration in a gamma camera (TcO4- was also administered for comparative purposes). Then two static images were acquired in ventral position: 1h and 12h post injection. Blood pharmacokinetics of 99mTc-TPGS during 24h was performed. RESULTS: Images revealed whole body biodistribution at an early and delayed time and semiquantification was performed in organs of interest (%Total counts: soft tissue 6.1±0.5; 3.9±0.1, Bone 1.2±0.2; 1±0.1, Heart 1.5±0.6; 0.7±0.3, Kidneys 16.6±1.3; 26.5±1.7, Liver 8.6±1.1; 11.1±0.1 for 1 and 12 h post injection respectively). CONCLUSION: This work demonstrated that TPGS based nanomicelles are susceptible to be radiolabeled with 99mTc thus they can be used to perform imaging studies in animal models. Moreover radiolabeling of these delivery nano systems reveals their possibility to be used as diagnostic agents in the near future.


Assuntos
Micelas , Imagem Molecular/métodos , Nanotecnologia , Vitamina E/química , Animais , Marcação por Isótopo , Ratos , Ratos Sprague-Dawley , Tecnécio/química , Distribuição Tecidual , Vitamina E/farmacocinética
13.
Br J Nutr ; 113(7): 1113-9, 2015 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-25761510

RESUMO

It has been postulated that Helicobacter pylori infection could affect growth and appetite, consequently influencing body weight. Therefore, the association between H. pylori infection and the dietary and anthropometric indicators of nutritional status of a paediatric population were investigated. A total of 525 children (aged 4-16 years) who were referred to the gastroenterology unit of the Sor Maria Ludovica Children's Hospital from Buenos Aires, Argentina, were enrolled and completed an epidemiological questionnaire. H. pylori infection was diagnosed using the ¹³C-urea breath test (¹³C-UBT). Height and weight were assessed for calculation of anthropometric indicators. Energy and macronutrient intakes were estimated by 24 h dietary recall. Data analysis was performed using a χ² test, a Student's t test, a Mann-Whitney U test and linear and logistic regressions. The prevalence of H. pylori infection was 25·1 % (with a mean age of 10·1 (SD 3·1) years). A tendency towards lower energy, carbohydrate, protein and fat intakes was observed in infected patients; however, it was not associated with H. pylori infection in any of the evaluated age groups (4-8, 9-13 and 14-16 years). Underweight, stunting, overweight and obesity were also not associated with the infection. Although height-for-age and BMI-for-age Z scores tended to be lower in infected patients, the differences between H. pylori-positive and H. pylori-negative children were not statistically significant. In conclusion, H. pylori infection was not associated with dietary intake or with anthropometric indicators in the present population of children with gastrointestinal symptoms; however, an increased sample size would be needed to confirm the observed tendency towards lower dietary intake and lower anthropometric indicators of nutritional status in H. pylori-infected children.


Assuntos
Fenômenos Fisiológicos da Nutrição Infantil , Dieta/efeitos adversos , Gastroenterite/fisiopatologia , Infecções por Helicobacter/fisiopatologia , Helicobacter pylori/isolamento & purificação , Estado Nutricional , Adolescente , Desenvolvimento do Adolescente , Argentina/epidemiologia , Índice de Massa Corporal , Criança , Desenvolvimento Infantil , Pré-Escolar , Estudos de Coortes , Estudos Transversais , Ingestão de Energia , Feminino , Gastroenterite/epidemiologia , Gastroenterite/microbiologia , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/microbiologia , Hospitais Pediátricos , Humanos , Masculino , Sobrepeso/epidemiologia , Sobrepeso/etiologia , Prevalência , Estudos Retrospectivos , Magreza/epidemiologia , Magreza/etiologia
14.
J Nucl Med Technol ; 42(4): 292-5, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25342185

RESUMO

UNLABELLED: In accord with as-low-as-reasonably-achievable and good-manufacturing-practice concepts, the present study evaluated the efficiency of radioactivity decontamination of materials commonly used in laboratory surfaces and whether solvent spills on these materials affect the findings. METHODS: Four materials were evaluated: stainless steel, a surface comprising one-third acrylic resin and two-thirds natural minerals, an epoxy cover, and vinyl-based multipurpose flooring. Radioactive material was eluted from a (99)Mo/(99m)Tc generator, and samples of the surfaces were control-contaminated with 37 MBq (100 µL) of this eluate. The same procedure was repeated with samples of surfaces previously treated with 4 solvents: methanol, methyl ethyl ketone, acetone, and ethanol. The wet radioactive contamination was allowed to dry and then was removed with cotton swabs soaked in soapy water. The effectiveness of decontamination was defined as the percentage of activity removed per cotton swab, and the efficacy of decontamination was defined as the total percentage of activity removed, which was obtained by summing the percentages of activity in all the swabs required to complete the decontamination. RESULTS: Decontamination using our protocol was most effective and most efficacious for stainless steel and multipurpose flooring. Moreover, treatment with common organic solvents seemed not to affect the decontamination of these surfaces. Decontamination of the other two materials was less efficient and was interfered with by the organic solvents; there was also great variability in the overall results obtained for these other two materials. CONCLUSION: In expanding our laboratory, it is possible for us to select those surface materials on which our decontamination protocol works best.


Assuntos
Descontaminação/métodos , Laboratórios , Radioisótopos/isolamento & purificação , Composição de Medicamentos , Controle de Qualidade , Radioatividade , Radioisótopos/química , Propriedades de Superfície
15.
Appl Radiat Isot ; 82: 322-4, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24140984

RESUMO

[(99m)Tc]pentetate ([(99m)Tc]DTPA) is the most commonly used radiopharmaceutical renography agent. The aim of this work was to validate an alternative method for assessing [(99m)Tc]DTPA radiochemical purity (RCP), according to the ICH Q2(R1) guidance: "Validation of Analytical Procedures". The proposed method is composed of two chromatographic systems. System A is a miniaturized system of thin layer chromatography (TLC) silica gel impregnated aluminum strips as stationary phase (SP) and distilled water as mobile phase (MP). System B consists of Whatman 1 paper strips as SP and methyl ethyl ketone as MP. Results indicate that the proposed RCP method has been validated, as it is specific, precise, accurate, linear and robust. Therefore, it can be used as an alternative method for RCP quality control purposes and as stability indicator as well.


Assuntos
Compostos Radiofarmacêuticos/normas , Pentetato de Tecnécio Tc 99m/normas , Butanonas , Cromatografia em Papel/métodos , Cromatografia em Papel/normas , Cromatografia em Camada Delgada/métodos , Cromatografia em Camada Delgada/normas , Estabilidade de Medicamentos , Humanos , Controle de Qualidade , Renografia por Radioisótopo
16.
J Nucl Med Technol ; 40(4): 271-4, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23024339

RESUMO

UNLABELLED: The aim of the present work was to validate a paper chromatography system as an alternative way to determine the radiochemical purity of Na(18)F. METHODS: The evaluated parameters were specificity, limit of quantification, measurement interval, linearity, precision, accuracy, and robustness. RESULTS: The proposed method proved to be linear (P > 0.05; r(2) = 1.000), precise (relative SD, 8.6%), accurate (mean recovery, 95.9%; relative SD, 1.5%-1.8%), and robust under different conditions since no influence of the operative variables on the chromatographic performance was observed. CONCLUSION: This system can be used as a reliable alternative method to determine the radiochemical purity of Na(18)F samples that can be easily performed in PET radiopharmacies at low cost.


Assuntos
Cromatografia em Papel/métodos , Radioisótopos de Flúor , Radioquímica/métodos , Fluoreto de Sódio/análise , Fluoreto de Sódio/química , Fenômenos Químicos , Controle de Qualidade
17.
Rev. med. nucl. Alasbimn j ; 14(54)oct. 2011. ilus, tab, graf
Artigo em Espanhol | LILACS | ID: lil-609895

RESUMO

El objetivo consistió en evaluar la utilidad del 99mTc-MIBI como marcador para diagnóstico y seguimiento de la progresión tumoral del NMSC en un modelo de carcinogénesis completa en ratones. Los animales en estudio fueron inyectados con 99mTc-MIBI a diferentes tiempos y eutanasiados. Se disecaron muestras de tumor y piel sana para evaluar la captación del radiofármaco y realizar el diagnóstico histológico. En animales con 22 semanas de progresión tumoral se observó una diferencia significativa en la captación del 99mTc-MIBI entre piel sana y NMSC. El protocolo que mejor se adapta al uso del 99mTc-MIBI como marcador para el diagnóstico y seguimiento de la progresión tumoral en ratones portadores de NMSC inducidos es la administración i.v de 1 mCi de 99mTc-MIBI con adquisición de datos a los 30 minutos post inyección. Se observó que a medida que los tumores progresan, la captación de 99mTc-MIBI disminuye respecto a la piel normal.


The aim of the work was to evaluate the usefulness of 99mTc-MIBI as a tracer for the tumor diagnosis and progression of NMSC in a chemically induced model in mice. After administration of 99mTc-MIBI animals were sacrificed at different times. Samples of tumor and healthy skin were dissected in order to perform histological analysis and to evaluate 99mTc-MIBI uptake. Animals under 22 weeks of tumor evolution showed a statistically difference in 99mTc-MIBI uptake between healthy skin and NMSC. Our results showed that the better protocol for the study of the tumor diagnosis and progression of NMSC in mice is the administration of 1 mCi of 99mTc-MIBI and acquisition of images 30 minutes post injection. Results showed that, as tumor progresses, the uptake of 99mTc-MIBI is significantly lower than healthy skin.


Assuntos
Animais , Camundongos , Neoplasias Cutâneas , Compostos Radiofarmacêuticos , Distribuição Tecidual , Fatores de Tempo , Modelos Animais de Doenças , Compostos Radiofarmacêuticos/farmacocinética , /farmacocinética
18.
Helicobacter ; 16(4): 316-9, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21762272

RESUMO

BACKGROUND: Helicobacter pylori infection is declining in developed and developing countries. The aim of this study was to retrospectively evaluate over an 8-year period the rate of H. pylori infection in children with gastrointestinal symptoms from Buenos Aires, Argentina. MATERIALS AND METHODS: We reviewed the records of children referred from 2002 to 2009 to the gastroenterology unit of the Children Hospital "Superiora Sor Maria Ludovica" for evaluation of upper gastrointestinal signs and symptoms in which the (13) C-urea breath test was performed to diagnose H. pylori infection and a sociodemographic questionnaire was obtained. RESULTS: Records of a total of 1030 children and adolescents with a mean age of 9.99 years were included in the analysis. We found an H. pylori prevalence of 41.2% (95% CI, 36.9-46.0%) for the triennium 2002-2004, dropping to 26.0% (95% CI, 20.7-31.8%) in the triennium 2007-2009. CONCLUSION: Our results showed a significant decrease in H. pylori infection rates from children referred for upper gastrointestinal symptoms evaluation from 2002 to 2009, following the H. pylori epidemiologic trend reported in other countries.


Assuntos
Gastroenteropatias/epidemiologia , Gastroenteropatias/patologia , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/patologia , Adolescente , Argentina/epidemiologia , Testes Respiratórios , Criança , Pré-Escolar , Feminino , Helicobacter pylori , Humanos , Masculino , Prevalência , Estudos Retrospectivos , Inquéritos e Questionários , Ureia/análise
19.
Vet Microbiol ; 152(1-2): 138-45, 2011 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-21592686

RESUMO

The mammalian gastric and oral mucosa may be colonized by mixed Helicobacter and Campylobacter species, respectively, in individual animals. To better characterize the presence and distribution of Helicobacter and Campylobacter among marine mammals, we used PCR and 16S rDNA sequence analysis to examine gastric and oral samples from ten dolphins (Tursiops gephyreus), one killer whale (Orcinus orca), one false killer whale (Pseudorca crassidens), and three wild La Plata river dolphins (Pontoporia blainvillei). Helicobacter spp. DNA was widely distributed in gastric and oral samples from both captive and wild cetaceans. Phylogenetic analysis demonstrated two Helicobacter sequence clusters, one closely related to H. cetorum, a species isolated from dolphins and whales in North America. The second related cluster was to sequences obtained from dolphins in Australia and to gastric non-H. pylori helicobacters, and may represent a novel taxonomic group. Dental plaque sequences from four dolphins formed a third cluster within the Campylobacter genus that likely represents a novel species isolated from marine mammals. Identification of identical Helicobacter spp. DNA sequences from dental plaque, saliva and gastric fluids from the same hosts, suggests that the oral cavity may be involved in transmission. These results demonstrate that Helicobacter and Campylobacter species are commonly distributed in marine mammals, and identify taxonomic clusters that may represent novel species.


Assuntos
Campylobacter/classificação , Cetáceos/microbiologia , Helicobacter/classificação , Filogenia , Animais , Austrália , Campylobacter/genética , Campylobacter/isolamento & purificação , DNA Bacteriano/genética , Helicobacter/genética , Helicobacter/isolamento & purificação , Infecções por Helicobacter/microbiologia , Boca/microbiologia , América do Norte , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Estômago/microbiologia
20.
J Pediatr Gastroenterol Nutr ; 51(1): 85-9, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20410842

RESUMO

OBJECTIVE: : Helicobacter pylori colonizes the gastric mucosa of about half of the world's population and it has been related to extragastrointestinal diseases. The present study sought to evaluate the association between H pylori infection and iron, zinc, and copper nutritional status in symptomatic children. PATIENTS AND METHODS: : A cross-sectional study was carried out in 395 children (4-16 years) with upper gastrointestinal symptoms, who were tested for H pylori infection by the C-urea breath test. Iron status was determined by hemoglobin, serum ferritin, and serum transferrin receptors. Copper and zinc serum concentrations were also evaluated. Epidemiological data, dietary assessment, and anthropometric indicators were analyzed as potential confounding factors. RESULTS: : Prevalence of H pylori infection was 24.3%. Anemia and iron deficiency (ID) were found in 12.0% and 14.3% of the H pylori-positive and 8.9% and 11.0% of the H pylori-negative children, respectively. There was no association between H pylori infection and anemia (odds ratio = 1.54 [95% confidence interval [CI] 0.73%-3.24%]) or ID (odds ratio = 1.35 [95% CI 0.67-2.70]). Crude beta coefficients showed that H pylori has no significant effect on hemoglobin, serum ferritin, serum transferrin receptors, copper, and zinc concentrations. However, adjusted results suggested that H pylori-infected children had an increase of 9.74 microg/dL (95% CI 2.12-17.37 microg/dL) in copper concentrations. CONCLUSIONS: : This study revealed that H pylori infection was not associated with iron deficiency, anemia, or zinc concentrations; however, a positive relation with copper status was found after adjusting for confounding factors. The contribution of H pylori infection to higher copper concentrations needs to be confirmed by additional studies.


Assuntos
Anemia Ferropriva/complicações , Cobre/sangue , Infecções por Helicobacter/complicações , Helicobacter pylori , Ferro/sangue , Estado Nutricional , Zinco/sangue , Adolescente , Anemia Ferropriva/microbiologia , Criança , Estudos Transversais , Feminino , Ferritinas/sangue , Infecções por Helicobacter/sangue , Infecções por Helicobacter/microbiologia , Hemoglobinas/metabolismo , Humanos , Masculino , Razão de Chances , Prevalência , Receptores da Transferrina/sangue
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