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1.
Telemed J E Health ; 29(12): 1781-1791, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37092975

RESUMO

Introduction: To examine the use of telehealth for delivery of health care in persons with sickle cell disease in a resource-constrained country during the COVID-19 pandemic. Methods: This study was a retrospective review of patient encounters at the Sickle Cell Unit (SCU), Jamaica during a 3-year period, March 10, 2019 to March 9, 2022 and a comparison of endpoints between 1 year before and 2 years during the pandemic. Primary endpoints of registration numbers, day-care admissions, and study visits were obtained from logbooks and the electronic medical records. Additional endpoints included well visits, hydroxyurea (HU) visits, and bone pain crisis. Results: Patients registered at the clinic on 17,295 occasions, with 7,820 in the pre-pandemic year decreasing by 43.8% and 35% in the 2 subsequent pandemic years. Overall, study visits increased by 4.9% and 1.3% in the pandemic years. They increased in adults by 13.1% and 8.9% but fell by 3.2% and 6.2% in children. Fewer people were seen in the pandemic years, with children showing a 20.7% decline in numbers. Tele-visits accounted for 31.4% of all study visits during the pandemic years and increased by 23.6% between the pandemic years. There were more well-visits and HU visits, but fewer pain visits and day-care admissions in the pandemic years. Conclusions: The SCU maintained health care delivery for a high-risk population during the pandemic, with tele-visits mitigating the short-fall from in-person visits. Tele-visits may be more acceptable to adults with a chronic illness and may be a suitable alternative for delivering health care.


Assuntos
Anemia Falciforme , COVID-19 , Telemedicina , Adulto , Criança , Humanos , Pandemias , COVID-19/epidemiologia , Instituições de Assistência Ambulatorial , Anemia Falciforme/epidemiologia , Anemia Falciforme/terapia , Hidroxiureia , Dor
2.
Nutrients ; 15(20)2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37892402

RESUMO

Teaching kitchens are physical and virtual forums that foster practical life skills through participation in experiential education. Given the well-supported connection between healthy eating patterns and the prevention and management of chronic diseases, both private and public organizations are building teaching kitchens (TKs) to enhance the health and wellness of patients, staff, youth, and the general community. Although implementation of TKs is becoming more common, best practices for starting and operating programs are limited. The present study aims to describe key components and professionals required for TK operations. Surveys were administered to Teaching Kitchen Collaborative (TKC) members and questions reflected seven primary areas of inquiry: (1) TK setting(s), (2) audiences served, (3) TK model(s), (4) key lines of operations, (5) team member who manages or directs the TK, (6) team member(s) who performs key operations and other professionals or partnerships that may be needed, and (7) the primary funding source(s) to build and operate the TK (among various other topics). Findings were used to articulate recommendations for organizations seeking to establish a successful TK as well as for TKs to expand their collective reach, research capacity, and impact.


Assuntos
Culinária , Ensino , Humanos
3.
PLoS One ; 17(5): e0266041, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35511937

RESUMO

Increased preoperative red cell distribution width (RDW) is associated with higher mortality following non-cardiac surgery in patients older than 65 years. Little is known if this association holds for all adult emergency laparotomy patients and whether it affects 30-day or long-term mortality. Thus, we examined the relationship between increased RDW and postoperative mortality. Furthermore, we investigated the prognostic worth of anisocytosis and explored a possible association between increased RDW and frailty in this cohort. We conducted a retrospective, single centre National Emergency Laparotomy Audit (NELA) database study at St Mary's Hospital Imperial NHS Trust between January 2014 and April 2018. A total of 356 patients were included. Survival models were developed using Cox regression analysis, whereas RDW and frailty were analysed using multivariable logistic regression. Underlying model assumptions were checked, including discrimination and calibration. We internally validated our models using bootstrap resampling. There were 33 (9.3%) deaths within 30-days and 72 (20.2%) overall. Median RDW values for 30-day mortality were 13.8% (IQR 13.1%-15%) in survivors and 14.9% (IQR 13.7%-16.1%) in non-survivors, p = 0.007. Similarly, median RDW values were lower in overall survivors (13.7% (IQR 13%-14.7%) versus 14.9% (IQR 13.9%-15.9%) (p<0.001)). Mortality increased across quartiles of RDW, as did the proportion of frail patients. Anisocytosis was not associated with 30-day mortality but demonstrated a link with overall death rates. Increasing RDW was associated with a higher probability of frailty for 30-day (Odds ratio (OR) 4.3, 95% CI 1.22-14.43, (p = 0.01)) and overall mortality (OR 4.9, 95% CI 1.68-14.09, (p = 0.001)). We were able to show that preoperative anisocytosis is associated with greater long-term mortality after emergency laparotomy. Increasing RDW demonstrates a relationship with frailty. Given that RDW is readily available at no additional cost, future studies should prospectively validate the role of RDW in the NELA cohort nationally.


Assuntos
Índices de Eritrócitos , Fragilidade , Adulto , Estudos de Coortes , Humanos , Prognóstico , Estudos Retrospectivos , Fatores de Risco
4.
Clin J Pain ; 37(8): 583-590, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34008506

RESUMO

OBJECTIVES: Acute pain is the main complication of sickle cell disease. Chronic pain (CP) and neuropathic pain (NP) may also be experienced, but have not been formally described in Jamaican patients. A cross-sectional study was conducted to determine their prevalence and characteristics, and to determine the common pain locations and modalities of management. MATERIALS AND METHODS: All well individuals with sickle cell disease patients 14 years and older, not pregnant and without a history of clinical stroke were consecutively recruited. Anthropometric measurements, hematology studies, an analgesia checklist, and the Adult Sickle Cell Quality of Life Measurement Information System questionnaire were completed. The painDETECT questionnaire was completed to describe NP and pain patterns-from which CP was defined. RESULTS: There were 257 patients in total, with 55.6% being females; the mean age of the patients was 31.7±12 years, and 75% had the SS genotype. Almost all patients (92.6%) had had an acute pain crisis in their lifetime and 72.4% in the last year. The mean severity at last attack was 6.8±3.1 on a scale of 0 to 10. The prevalences of CP and NP were 21.5% and 17.9%, respectively. Female sex, the presence of current leg ulcers, and the use of a strong opioid in the last 4 weeks produced higher odds of NP, whereas older age, milder genotypes, and daily analgesic use had the highest odds of CP. Opioids were used by 40.1% of the patients in the previous 4 weeks, whereas nonpharmacological treatments such as physiotherapy was less used, but reported to be very effective. DISCUSSION: CP and NP should be assessed during routine care of sickle cell pain so that targeted therapies can be applied.


Assuntos
Dor Aguda , Anemia Falciforme , Adulto , Idoso , Analgésicos , Anemia Falciforme/complicações , Anemia Falciforme/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Gravidez , Qualidade de Vida , Adulto Jovem
5.
Health Equity ; 5(1): 210-217, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33937607

RESUMO

Purpose: In an effort to transition toward universal health coverage (UHC), Jamaica abolished user fees at all public health facilities in 2008. We aimed to determine the extent of out-of-pocket payments (OPPs) and the other cost barriers to UHC among patients with sickle cell disease (SCD). Methods: Patients presenting to the Sickle Cell Unit in Kingston, Jamaica, for routine care between October 2019 and August 2020 were consecutively recruited and interviewed about their latest hospitalization within the previous 4 weeks. Parents or guardians completed the questionnaire on behalf of pediatric patients. The questionnaire included the Patient Satisfaction Questionnaire Short Form (PSQ)-18 and the health module of the Jamaica Survey of Living Conditions. Results: There were 103 patients with ages ranging from 7 months to 56 years (51.5% female, 60.2% public hospitalizations, and 54.4% pediatric). The modal income (J$6200-$11,999 per week) was similar to the minimum wage and 48.5% lived in overcrowded households. Government drug-subsidy cards were owned by 39.8%. OPPs were made by 19.4% of persons for items and tests that were unavailable at public facilities. There were no costs reported by 69.6%, who visited public pharmacies. Similarly, the cost of admission to public hospitals was free for 95.4% of subjects. Using public transportation, private hospitalization, and having more disease complications were predictive of a perception that health care is unaffordable. Conclusion: Most SCD subjects reported no expense with public hospitalizations; however, approximately one in five reported OPPs. Efforts are needed to increase the availability of subsidized items, and the use of drug-subsidy cards, to improve UHC.

6.
Disabil Health J ; 14(4): 101107, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33867318

RESUMO

BACKGROUND: Health related quality of Life (HRQOL) is an important consideration when managing chronic diseases, like sickle cell disease (SCD). Assessment of neuropathic pain (NP) and its association with HRQOL in SCD are rarely reported. OBJECTIVES: To examine the prevalence of NP and its association with HRQOL in adult Jamaicans with SCD. METHODS: Adult SCD patients were recruited consecutively and data were collected on socio-demographics, NP using Douleur Neuropathique 4 (DN4), and HRQOL using the Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me). Means, medians, t-tests, ANOVA tests, Wilcoxon Rank-sum tests, Kruskal-Wallis tests, Pearson's correlation and multivariate linear regression analyses were performed using STATA 14.2. RESULTS: There were 236 respondents, with 56.8% female, mean age 33.2 years (SD: 11.6; range: 18-67 years), and 75% had homozygous SS genotype. NP was likely present in 26.7% of the population. The standardized ASCQ-Me (mean ± SD; ordered from lowest to best HRQOL domain scores) were: emotional impact 53.3 ± 10.1; sleep impact 56.1 ± 9.7; social function 57.7 ± 10.6; pain impact 58.6 ± 7.8; and stiffness impact 61.0 ± 7.3. On multivariate analyses, NP significantly reduced emotional and social functioning and worsened sleep and stiffness. Higher acute pain scores significantly worsened all HRQOL domains, while higher disease severity worsened all except stiffness. Obesity was associated with worse sleep and greater stiffness. Females with leg ulcers reported lower social functioning and unemployed females had greater pain impact. CONCLUSIONS: NP is increasingly prevalent in SCD and worsens HRQOL. Gender specific studies are needed to understand the significantly poorer HRQOL in women.


Assuntos
Anemia Falciforme , Pessoas com Deficiência , Neuralgia , Adulto , Anemia Falciforme/complicações , Feminino , Humanos , Jamaica , Masculino , Neuralgia/etiologia , Qualidade de Vida
7.
Transl Behav Med ; 9(4): 669-681, 2019 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-30107586

RESUMO

Although social marketing principles have been successfully employed in school-based interventions to prevent obesity, use in early care and education (ECE) settings has been limited. This paper describes the use of the social marketing approach to develop an ECE-based intervention that encourages an ECE provider-parent partnership to improve the quality of preschool children's diets and their level of physical activity. A six-step social marketing approach for public health interventions guided the development of this ECE-based intervention. These steps were as follows: (i) initial planning, (ii) formative research, (iii) strategy development, (iv) program development, (v) implementation, and (vi) monitoring and evaluation. During this process, we reviewed current literature, conducted focus groups with ECE providers and parents, developed a detailed conceptual model and content map, created and tested the campaign concept, and developed final campaign materials along with strategies for its implementation. The final intervention resulting from this process was an 8-month campaign known as Healthy Me, Healthy We. The campaign is delivered by the child care center and includes branded materials for use in the classroom and at home. The final campaign is being evaluated in a cluster-randomized trial. Healthy Me, Healthy We offers an innovative approach to promoting healthy eating and physical activity during early childhood, a key developmental period, that leverages partnership between ECE providers and parents to affect behavior change.


Assuntos
Exercício Físico/fisiologia , Promoção da Saúde/métodos , Estado Nutricional/fisiologia , Obesidade/prevenção & controle , Comportamento Infantil/psicologia , Pré-Escolar , Análise por Conglomerados , Dieta/métodos , Dieta Saudável/estatística & dados numéricos , Grupos Focais/estatística & dados numéricos , Humanos , Lactente , Estado Nutricional/etnologia , Obesidade/etnologia , Pais/educação , Serviços de Saúde Escolar/normas , Marketing Social
8.
Lung Cancer ; 126: 119-124, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30527175

RESUMO

BACKGROUND: Previous evaluations of low-dose CT (LDCT) lung cancer screening programmes have taken very different approaches in the design of the informative trials and the methods applied to determine cost-effectiveness. Therefore, it has not been possible to determine if differences in cost-effectiveness are due to different screening approaches or the evaluation methodology. This study reports the findings of an evaluation of the first round of a community-based, LDCT screening pilot Manchester, applying previously published methodology to ensure consistency. METHODS: Using the economic evaluation method reported in the UKLS trial, applying Manchester specific evidence where possible, we estimate the cost-effectiveness of LDCT for lung cancer. Estimates of the total costs and quality adjusted life years (QALYs) were calculated. RESULTS: The Manchester programme cost £663,076, diagnosed 42 patients with lung cancer resulting in a gain in population health of 88.13 discounted life years, equivalent to 65.85 QALYs. This implied an incremental cost-effectiveness ratio of £10,069/QALY. CONCLUSIONS: We found the Manchester programme to be a cost-effective use of limited NHS resources. The findings suggest that further research is now needed not as to whether LDCT screening is cost-effective but under what conditions can it improve patient health by the most while remaining cost-effective.


Assuntos
Serviços de Saúde Comunitária/economia , Análise Custo-Benefício , Detecção Precoce de Câncer/economia , Neoplasias Pulmonares/diagnóstico , Programas de Rastreamento/economia , Idoso , Serviços de Saúde Comunitária/métodos , Detecção Precoce de Câncer/métodos , Inglaterra , Feminino , Humanos , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Projetos Piloto , Anos de Vida Ajustados por Qualidade de Vida , Análise de Sobrevida , Tomografia Computadorizada por Raios X/métodos
9.
Clin Nucl Med ; 40(4): e236-40, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25608166

RESUMO

PURPOSE: Dynamic FDG imaging for prostate cancer characterization is limited by generally small size and low uptake in prostate tumors. Our aim in this pilot study was to explore feasibility of simultaneous PET/MRI to guide localization of prostate lesions for dynamic FDG analysis using a graphical approach. METHODS: Three patients with biopsy-proven prostate cancer underwent simultaneous FDG PET/MRI, incorporating dynamic prostate imaging. Histology and multiparametric MRI findings were used to localize tumors, which in turn guided identification of tumors on FDG images. Regions of interest were manually placed on tumor and benign prostate tissue. Blood activity was extracted from a region of interest placed on the femoral artery on PET images. FDG data were analyzed by graphical analysis using the influx constant Ki (Patlak analysis) when FDG binding seemed irreversible and distribution volume VT (reversible graphical analysis) when FDG binding seemed reversible given the presence of washout. RESULTS: Given inherent coregistration, simultaneous acquisition facilitated use of MRI data to localize small lesions on PET and subsequent graphical analysis in all cases. In 2 cases with irreversible binding, tumor had higher Ki than benign using Patlak analysis (0.023 vs 0.006 and 0.019 vs 0.008 mL/cm3 per minute). In 1 case appearing reversible, tumor had higher VT than benign using reversible graphical analysis (0.68 vs 0.52 mL/cm3). CONCLUSIONS: Simultaneous PET/MRI allows localization of small prostate tumors for dynamic PET analysis. By taking advantage of inclusion of the femoral arteries in the FOV, we applied advanced PET data analysis methods beyond conventional static measures and without blood sampling.


Assuntos
Fluordesoxiglucose F18 , Imageamento por Ressonância Magnética , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Neoplasias da Próstata/diagnóstico por imagem , Compostos Radiofarmacêuticos , Idoso , Interpretação Estatística de Dados , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/diagnóstico
10.
Int J Radiat Oncol Biol Phys ; 84(3): e393-9, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-22727887

RESUMO

PURPOSE: The behavior of copper-64-diacetyl-bis(N(4)-methylthiosemicarbazone) ((64)Cu-ATSM) in hypoxic tumors was examined through a combination of in vivo dynamic positron emission tomography (PET) and ex vivo autoradiographic and histologic evaluation using a xenograft model of head-and-neck squamous cell carcinoma. METHODS AND MATERIALS: (64)Cu-ATSM was administered during dynamic PET imaging, and temporal changes in (64)Cu-ATSM distribution within tumors were evaluated for at least 1 hour and up to 18 hours. Animals were sacrificed at either 1 hour (cohort A) or after 18 hours (cohort B) postinjection of radiotracer and autoradiography performed. Ex vivo analysis of microenvironment subregions was conducted by immunohistochemical staining for markers of hypoxia (pimonidazole hydrochloride) and blood flow (Hoechst-33342). RESULTS: Kinetic analysis revealed rapid uptake of radiotracer by tumors. The net influx (K(i)) constant was 12-fold that of muscle, whereas the distribution volume (V(d)) was 5-fold. PET images showed large tumor-to-muscle ratios, which continually increased over the entire 18-hour course of imaging. However, no spatial changes in (64)Cu-ATSM distribution occurred in PET imaging at 20 minutes postinjection. Microscopic intratumoral distribution of (64)Cu-ATSM and pimonidazole were not correlated at 1 hour or after 18 hours postinjection, nor was (64)Cu-ATSM and Hoechst-33342. CONCLUSIONS: The oxygen partial pressures at which (64)Cu-ATSM and pimonidazole are reduced and bound in cells are theorized to be distinct and separable. However, this study demonstrated that microscopic distributions of these tracers within tumors are independent. Researchers have shown (64)Cu-ATSM uptake to be specific to malignant expression, and this work has also demonstrated clear tumor targeting by the radiotracer.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Hipóxia Celular , Neoplasias de Cabeça e Pescoço/metabolismo , Compostos Organometálicos/farmacocinética , Tiossemicarbazonas/farmacocinética , Animais , Autorradiografia , Biomarcadores/metabolismo , Carcinoma de Células Escamosas/diagnóstico por imagem , Complexos de Coordenação , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Humanos , Imuno-Histoquímica , Músculos/diagnóstico por imagem , Músculos/metabolismo , Nitroimidazóis/metabolismo , Pressão Parcial , Cintilografia , Ratos , Ratos Nus , Distribuição Tecidual , Transplante Heterólogo , Microambiente Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
11.
J Nucl Med ; 53(9): 1438-45, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22872741

RESUMO

UNLABELLED: The lymphatic system plays a critical role in the maintenance of healthy tissues. Its function is an important indicator of the presence and extent of disease. In oncology, metastatic spread to local lymph nodes (LNs) is a strong predictor of poor outcome. Clinical methods for the visualization of LNs involve regional injection and tracking of (99m)Tc-sulfur colloid ((99m)Tc-SC) along with absorbent dyes. Intraoperatively, these techniques suffer from the requirement of administration of multiple contrast media ((99m)Tc-SC and isosulfan blue), unwieldy γ-probes, and a short effective surgical window for dyes. Preclinically, imaging of transport through the lymphatics is further hindered by the resolution of lymphoscintigraphy and SPECT. We investigated multimodal imaging in animal models using intradermal administration of (18)F-FDG for combined diagnostic and intraoperative use. PET visualizes LNs with high sensitivity and resolution and low background. Cerenkov radiation (CR) from (18)F-FDG was evaluated to optically guide surgical resection of LNs. METHODS: Imaging of (18)F-FDG uptake used PET and sensitive luminescent imaging equipment (for CR). Dynamic PET was performed in both sexes and multiple strains (NCr Nude, C57BL/6, and Nu/Nu) of mice. Biodistribution confirmed the uptake of (18)F-FDG and was compared with that of (99m)Tc-SC. Verification of uptake and the ability to use (18)F-FDG CR to guide nodal removal were confirmed histologically. RESULTS: Intradermal injection of (18)F-FDG clearly revealed lymphatic vessels and LNs by PET. Dynamic imaging revealed rapid and sustained labeling of these structures. Biodistribution of the radiotracer confirmed the active transport of radioglucose in the lymphatics to the local LNs and over time into the general circulation. (18)F-FDG also enabled visualization of LNs through CR, even before surgically revealing the site, and guided LN resection. CONCLUSION: Intradermal (18)F-FDG can enhance the preclinical investigation of the lymphatics through dynamic, high-resolution, and quantitative tomographic imaging. Clinically, combined PET/Cerenkov imaging has significant potential as a single-dose, dual-modality tracer for diagnostics (PET/CT) and guided resection of LNs (Cerenkov optical).


Assuntos
Elétrons , Fluordesoxiglucose F18/administração & dosagem , Linfonodos/diagnóstico por imagem , Linfonodos/cirurgia , Linfografia/métodos , Animais , Feminino , Fluordesoxiglucose F18/farmacocinética , Injeções Intradérmicas , Linfonodos/metabolismo , Masculino , Camundongos , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Período Pré-Operatório , Tomografia Computadorizada por Raios X
12.
J Nucl Med ; 53(10): 1608-15, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22933821

RESUMO

UNLABELLED: (18)F-fluoromisonidazole PET, a noninvasive means of identifying hypoxia in tumors, has been widely applied but with mixed results, raising concerns about its accuracy. The objective of this study was to determine whether kinetic analysis of dynamic (18)F-fluoromisonidazole data provides better discrimination of tumor hypoxia than methods based on a simple tissue-to-plasma ratio. METHODS: Eleven Dunning R3327-AT prostate tumor-bearing nude rats were immobilized in custom-fabricated whole-body molds, injected intravenously with (18)F-fluoromisonidazole, and imaged dynamically for 105 min. They were then transferred to a robotic system for image-guided measurement of intratumoral partial pressure of oxygen (Po(2)). The dynamic (18)F-fluoromisonidazole uptake data were fitted with 2 variants of a 2-compartment, 3-rate-constant model, one constrained to have K(1) equal to k(2) and the other unconstrained. Parametric images of the rate constants were generated. The Po(2) measurements were compared with spatially registered maps of kinetic rate constants and tumor-to-plasma ratios. RESULTS: The constrained pharmacokinetic model variant was shown to provide fits similar to that of the unconstrained model and did not introduce significant bias in the results. The trapping rate constant, k(3), of the constrained model provided a better discrimination of low Po(2) than the tissue-to-plasma ratio or the k(3) of the unconstrained model. CONCLUSION: The use of kinetic modeling on a voxelwise basis can identify tumor hypoxia with improved accuracy over simple tumor-to-plasma ratios. An effective means of controlling noise in the trapping rate constant, k(3), without introducing significant bias, is to constrain K(1) equal to k(2) during the fitting process.


Assuntos
Misonidazol/análogos & derivados , Oxigênio/metabolismo , Tomografia por Emissão de Pósitrons , Pressão , Animais , Hipóxia Celular , Cinética , Masculino , Misonidazol/farmacocinética , Modelos Biológicos , Ratos , Neoplasias Cutâneas/diagnóstico por imagem , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia
13.
Toxicol Sci ; 122(2): 551-6, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21546347

RESUMO

Prenatal in utero conditions are thought to play a role in the development of adult diseases including Parkinson's disease (PD). Paraquat is a common herbicide with chemical structure similar to 1-methyl-4-phenyl 1,2,3,6-tetrahydropyridine, a neurotoxin known to induce parkinsonism. In order to assess the role of in utero paraquat exposure in PD, uptake in maternal and fetal brains were measured using positron emission tomography (PET)/computed tomography (CT) imaging. Two anesthetized pregnant rhesus macaques in the late second trimester of pregnancy were given bolus iv injections of ¹¹C-paraquat, and whole-body PET/CT imaging was performed. Using maternal ventricular blood pool as the input function, the unidirectional influx rate constants (K(i)s), a measure of the irreversible transport of paraquat from plasma to brain, were calculated for the maternal and fetal brains using Patlak graphical analysis. Results indicate minimal uptake of paraquat by both maternal and fetal brains with average K(i)s of 0.0009 and 0.0016 per minute, respectively. The highest regional cerebral uptake in the maternal brain (0.0009% injected dose) was seen in the pineal gland, a structure known to lack a blood brain barrier. The finding of minimal paraquat uptake in maternal and fetal brains is similar to previous findings in adult male macaques and extends the contention that a single acute paraquat exposure, prenatally or postnatally, is unlikely to play a role in PD.


Assuntos
Encéfalo/metabolismo , Feto/efeitos dos fármacos , Imagem Multimodal/métodos , Paraquat/farmacocinética , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Animais , Barreira Hematoencefálica/diagnóstico por imagem , Feminino , Macaca mulatta , Paraquat/toxicidade , Gravidez
14.
J Nucl Med ; 51(2): 288-92, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20080884

RESUMO

UNLABELLED: Estimating the radiation dose received by the fetus from nuclear medicine procedures is important because of the greater sensitivity of rapidly developing fetal tissues to ionizing radiation. (18)F-fluoro-L-thymidine (FLT) uptake is related to cellular proliferation and is currently used to monitor tumor progression and response to therapy. This study was undertaken to estimate-on the basis of biodistribution data obtained by PET/CT in pregnant rhesus monkeys-radiation absorbed dose to a human fetus administered (18)F-FLT. METHODS: Three pregnant rhesus macaques (gestational age, 113 +/- 8 d) were administered (18)F-FLT and imaged for 2 h on a PET/CT scanner. Time-activity curves for maternal and fetal organs were generated in anatomic regions of interest identified via CT. Doses were estimated using OLINDA/EXM and the 6-mo-pregnant human model. RESULTS: The extrapolated whole-body maternal dose obtained, 11.4 microGy/MBq, is similar to the previously reported adult female dose of 15.6 microGy/MBq. The estimated total-body dose to a human fetus is 24 microGy/MBq. Significant long-term (18)F-FLT accumulation in fetal liver resulted in a fetal liver dose of 53 microGy/MBq. CONCLUSION: The fetal dose estimate in a 6-mo-pregnant human using (18)F-FLT is slightly greater than that reported for (18)F-FDG. (18)F-FLT trapping in the fetal liver should be considered in the risk-benefit analysis of (18)F-FLT PET examination in pregnant patients.


Assuntos
Didesoxinucleosídeos/efeitos adversos , Feto/efeitos da radiação , Tomografia por Emissão de Pósitrons/efeitos adversos , Compostos Radiofarmacêuticos/efeitos adversos , Adulto , Animais , Feminino , Feto/diagnóstico por imagem , Humanos , Modelos Animais , Gravidez , Doses de Radiação , Medição de Risco , Especificidade da Espécie , Distribuição Tecidual , Tomografia Computadorizada por Raios X/efeitos adversos
15.
J Cereb Blood Flow Metab ; 30(8): 1437-40, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20531464

RESUMO

Any tracer in fetal tissue comes from maternal arterial blood. Provided steady state is achieved and intermediate compartments are reversible, the Logan graphical methods should be applicable to the assessment of binding parameters in the fetal brain. Two pregnant rhesus macaques were studied with fallypride and the Logan method was used to assess dopamine receptor distribution volume ratios (DVRs) in both maternal and fetal striatum. The agreement between fetal striatal DVRs using maternal arterial blood and maternal and fetal cerebellum as input functions strongly supports our hypothesis that the conditions necessary for graphical analysis have been met.


Assuntos
Benzamidas , Corpo Estriado/metabolismo , Feto/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Pirrolidinas , Receptores Dopaminérgicos/metabolismo , Animais , Corpo Estriado/diagnóstico por imagem , Feminino , Feto/diagnóstico por imagem , Macaca mulatta , Gravidez , Receptores Dopaminérgicos/sangue
18.
Brain Res ; 1259: 74-9, 2009 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-19135428

RESUMO

Environmental factors have long been thought to have a role in the etiology of idiopathic Parkinson's disease (PD). Since the discovery of the selective neurotoxicity of MPTP to dopamine cells, suspicion has focused on paraquat, a common herbicide with chemical structure similar to 1-methyl-4-phenylpyridinium (MPP+), the MPTP metabolite responsible for its neurotoxicity. Although in vitro evidence for paraquat neurotoxicity to dopamine cells is well established, its in vivo effects have been ambiguous because paraquat is di-cationic in plasma, which raises questions about its ability to cross the blood brain barrier. This study assessed the brain uptake of [(11)C]-paraquat in adult male rhesus macaques using quantitative PET imaging. Results showed minimal uptake of [(11)C]-paraquat in the macaque brain. The highest concentrations of paraquat were seen in the pineal gland and the lateral ventricles. Global brain concentrations including those in known dopamine areas were consistent with the blood volume in those structures. This acute exposure study found that paraquat is excluded from the brain by the blood brain barrier and thus does not readily support the causative role of paraquat exposure in idiopathic Parkinson's disease.


Assuntos
Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Neurotoxinas/farmacocinética , Paraquat/farmacocinética , Animais , Encéfalo/irrigação sanguínea , Radioisótopos de Carbono , Processamento de Imagem Assistida por Computador , Macaca mulatta , Imageamento por Ressonância Magnética , Masculino , Paraquat/sangue , Paraquat/química , Tomografia por Emissão de Pósitrons
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