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1.
Environ Geochem Health ; 46(7): 219, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38849667

RESUMEN

This study investigates the removal of amoxicillin micropollutants (AM) from hospital wastewater using CoMoO4-modified graphitic carbon nitride (CMO/gCN). Consequently, CMO/gCN exhibits notable improvements in visible light absorption and electron-hole separation rates compared to unmodified gCN. Besides, CMO/gCN significantly enhances the removal efficiency of AM, attaining an impressive 96.5%, far surpassing the performance of gCN at 48.6%. Moreover, CMO/gCN showcases outstanding reusability, with AM degradation performance exceeding 70% even after undergoing six cycles of reuse. The removal mechanism of AM employing CMO/gCN involves various photoreactions of radicals (•OH, •O2-) and amoxicillin molecules under light assistance. Furthermore, CMO/gCN demonstrates a noteworthy photodegradation efficiency of AM from hospital wastewater, reaching 92.8%, with a near-complete reduction in total organic carbon levels. Detailed discussions on the practical applications of the CMO/gCN photocatalyst for removal of micropollutants from hospital wastewater are provided. These findings underline the considerable potential of CMO/gCN for effectively removing various pollutants in environmental remediation strategies.


Asunto(s)
Amoxicilina , Grafito , Oxidación-Reducción , Aguas Residuales , Contaminantes Químicos del Agua , Amoxicilina/química , Aguas Residuales/química , Grafito/química , Contaminantes Químicos del Agua/química , Fotólisis , Hospitales , Compuestos de Nitrógeno/química , Catálisis , Purificación del Agua/métodos
2.
Sex Transm Dis ; 48(1): 1-4, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32826481

RESUMEN

BACKGROUND: Effectiveness of sexually transmitted disease (STD)/HIV mobile van outreach programs has been shown to assist in identifying new cases of syphilis and HIV among high-risk populations. However, specific types of mobile outreach testing and their varying abilities to assist in STD/HIV case identification have not been thoroughly explored. METHODS: We analyzed data from the Baltimore City Health Department syphilis and HIV testing intake interviews and subsequent laboratory results for clients at any of the 6 different Baltimore City Health Department mobile outreach testing setting types between 2015 and 2018. A total of 8098 syphilis and 7946 HIV testing encounters were included. Cross-tabulation and proportion estimates were used to obtain the volume of new syphilis and HIV diagnoses across the different mobile outreach testing setting types. Multivariable firth logistic regressions for rare events were used to obtain odds ratios for new syphilis diagnoses across the different mobile outreach setting categories. RESULTS: Testing at street corners yielded the highest proportion of new syphilis cases (0.83%), whereas at community centers, it produced the highest proportion of new HIV cases (0.48%). The adjusted odds for new syphilis were 2.14 among street corners compared with community centers. CONCLUSIONS: The findings indicated that street corners were the most successful at detecting new syphilis cases, whereas community centers were the most successful at detecting new HIV cases. However, because of the small number of new cases detected and low uptake per testing event between 2015 and 2018, STD/HIV mobile testing does not seem to be effective overall.


Asunto(s)
Infecciones por VIH , Enfermedades de Transmisión Sexual , Sífilis , Baltimore/epidemiología , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Humanos , Oportunidad Relativa , Enfermedades de Transmisión Sexual/diagnóstico , Enfermedades de Transmisión Sexual/epidemiología , Sífilis/diagnóstico , Sífilis/epidemiología
3.
Nanotechnology ; 31(33): 335712, 2020 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-32357358

RESUMEN

We integrate superparamagnetic iron oxide nanoparticles with polyaspartamide (PA) biopolymer to form a biological construct that functions as a tracking, targeting and drug-delivery system for cancer diagnosis and therapy. Iron oxide nanoparticles with uniformly distributed average spherical diameters of around 10 nm and superparamagnetic characteristics play a key role in increasing the transverse 1/T 2 relaxation rate or darkening the T 2-weighted MR image for cancer diagnosis using MRI. In in vitro MRI testing on cancer cells, the MR images of samples with the bio-constructshow a much clearer contrast effect than those of controls. The PA biopolymer plays an essential role in enhancing the hydrophilicity and biocompatibility of the bio-construct. In addition, as a multifunctional polymer, PA is conjugated with biotin and doxorubicin (Dox) functional groups to enhance targeting and impairment of cancer cells. In in vivo testing on cancer tumors, injection with the bio-construct decreased the magnitude of cancer tumor volume growth by three times compared with that of uninjected controls. The physicochemical characteristics of the bio-construct and the roles of biotin and Dox functional groups are examined and discussed in detail.


Asunto(s)
Antineoplásicos/administración & dosificación , Biopolímeros/administración & dosificación , Biotina/química , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/tratamiento farmacológico , Medios de Contraste/administración & dosificación , Células 3T3 , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Biopolímeros/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Medios de Contraste/química , Doxorrubicina , Sistemas de Liberación de Medicamentos , Femenino , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Nanopartículas Magnéticas de Óxido de Hierro , Imagen por Resonancia Magnética , Ratones , Ensayos Antitumor por Modelo de Xenoinjerto
4.
Water Sci Technol ; 80(1): 59-66, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31461422

RESUMEN

This paper presents the design of a constructed wetland (CW) system in an area with limited land availability, resulting in high hydraulic loads. The CW was constructed to act as a buffering/ polishing step after stabilization ponds for steel industry wastewater post-treatment. A pilot test with two different filter media (50-100mm vs 40-60mm diameter) indicated that a flow rate increase from 49.5 m3/h to 122.4 m3/h would lead to a head loss increase from 2.9cm to 8.7cm, and more than double that for the finer gravel. This was substantially higher than the calculated theoretical values, though the relation with flow rate was similar. Four full scale wetland cells (CW1, CW2, CW3 and CW4) were constructed using the coarser gravel. A design value of total head loss of 1.01m over the total system length, with a design flow of 36,000 m3/day, was expected based on pilot test results. During the first operation year (September 2017 to July 2018), the pond-CW system has received wastewater already meeting required discharge standards. The effluent from the CWs had consistently lower concentrations of all measured variables, and met the predicted values for biochemical oxygen demand (BOD5), total nitrogen (TN) and NH4 +-N. Highest removal efficiencies were achieved for NH4 +-N (>90%), Mn (>60%) and Fe (45%) with removal efficiencies for TN (14%), BOD5 and chemical oxygen demand (COD) (around 30%). Concentrations of phenol, CN- and Cr6+ were below 10, 4 and 3µg/l, respectively, in in- and outflows. An appreciated benefit of the wetland was the 'green element' in the industrial landscape.


Asunto(s)
Acero , Eliminación de Residuos Líquidos/métodos , Aguas Residuales , Humedales , Análisis de la Demanda Biológica de Oxígeno , Metalurgia , Nitrógeno
5.
Biomacromolecules ; 18(8): 2402-2409, 2017 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-28678473

RESUMEN

Biocompatible adhesive nanoaggregates were synthesized based on polyaspartamide copolymers grafted with octadecylamine (C18) and 3,4-dihydroxyphenylalanine (DOPA), and their adhesive properties were investigated with regard to wound healing. The chemical structure and morphology of the synthesized polyaspartamide-g-C18/DOPA nanoaggregates were analyzed using 1H-nuclear magnetic resonance spectroscopy (1H NMR), dynamic light scattering (DLS), and transmission electron microscope (TEM). The in vitro adhesive energy was up to 31.04 J m-2 for poly(dimethylacrylamide) gel substrates and 0.1209 MPa for mouse skin, and the in vivo wound breaking strength after 48 h was 1.8291 MPa for C57BL/6 mouse. The MTT assay demonstrated that the synthesized polymeric nanoaggregates were nontoxic. The polyaspartamide-g-C18/DOPA nanoaggregates were in vivo tested to mouse model and demonstrated successful skin adhesion, as the mouse skin was perfectly cured in their dermis within 6 d. As this material has biocompatibility and enough adhesive strength for wound closure, it is expected to be applied as a new type of bioadhesive agent in the human body.


Asunto(s)
Adhesivos , Dihidroxifenilalanina , Nylons , Piel , Cicatrización de Heridas/efectos de los fármacos , Adhesivos/química , Adhesivos/farmacología , Animales , Línea Celular , Dihidroxifenilalanina/química , Dihidroxifenilalanina/farmacología , Humanos , Ratones , Nylons/química , Nylons/farmacología , Piel/lesiones , Piel/metabolismo , Piel/patología
7.
Can J Microbiol ; 61(11): 799-810, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26382712

RESUMEN

In bacteria, 2-component regulatory systems (TCSs) are the critical information-processing pathways that link stimuli to specific adaptive responses. Signals perceived by membrane sensors, which are generally histidine kinases, are transmitted by response regulators (RRs) to allow cells to cope rapidly and effectively with environmental challenges. Over the past few decades, genes encoding components of TCSs and their responsive proteins have been identified, crystal structures have been described, and signaling mechanisms have been elucidated. Here, we review recent findings and interesting breakthroughs in bacterial TCS research. Furthermore, we discuss structural features, mechanisms of activation and regulation, and cross-regulation of RRs, with a focus on the largest RR family, OmpR/PhoB, to provide a comprehensive overview of these critically important signaling molecules.


Asunto(s)
Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica , Transducción de Señal , Transactivadores/metabolismo , Bacillus subtilis/metabolismo , Membrana Celular/enzimología , ADN/química , Escherichia coli/metabolismo , Histidina Quinasa , Fosforilación , Unión Proteica , Proteínas Quinasas/metabolismo , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína
8.
Environ Microbiome ; 19(1): 7, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38254194

RESUMEN

BACKGROUND: Bilberry (Vaccinium myrtillus L.) is one of the most important economic and natural resources in Northern Europe. Despite its importance, the endophytic fungal community of the fruits has rarely been investigated. Biogeographic patterns and determinants of the fungal diversity in the bilberry fruit are poorly understood, albeit fungal endophytes can have a close relationship with the host plants. Here, we investigated the effect of climatic regions, and their weather conditions within growth season and soil properties on fungal endophytic communities of bilberry fruits collected from northern and southern regions of Finland using high-throughput sequencing technology targeting the internal transcribed spacer 2 ribosomal DNA region for fungi. RESULTS: Species richness and beta diversity (variation in community structure) were higher in the southern compared to the studied northern region. The weather condition of the growth season drove both fungal richness and community structure. Furthermore, abundance of the genera Venturia, Cladosporium, and Podosphaera was influenced by the weather, being different between the south and north regions. CONCLUSIONS: We conclude that diversity and assembly structure of the fungal endophytes in bilberry fruits follow similar patterns as for foliar fungal endophytes, being shaped by various environmental factors, such as the climate and surrounding vegetation.

9.
Heliyon ; 10(9): e30647, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38765090

RESUMEN

Lifestyle, diet, socioeconomic status and genetics all contribute to heterogeneity in immune responses. Vietnam is plagued with a variety of health problems, but there are no available data on immune system values in the Vietnamese population. This study aimed to establish reference intervals for immune cell parameters specific to the healthy Vietnamese population by utilizing multi-color flow cytometry (MCFC). We provide a comprehensive analysis of total leukocyte count, quantitative and qualitative shifts within lymphocyte subsets, serum and cytokine and chemokine levels and functional attributes of key immune cells including B cells, T cells, natural killer (NK) cells and their respective subpopulations. By establishing these reference values for the Vietnamese population, these data contribute significantly to our understanding of the human immune system variations across diverse populations. These data will be of substantial comparative value and be instrumental in developing personalized medical approaches and optimizing diagnostic strategies for individuals based on their unique immune profiles.

10.
Artículo en Inglés | MEDLINE | ID: mdl-39002082

RESUMEN

Dioxins are endocrine disruptors that may disturb male sexual and reproductive function. Studies on human populations are limited, and their results are controversial. This study evaluated the impact of dioxin exposure on reproductive and thyroid hormone levels and sexual function in men. A total of 140 men working in four military airbases (three bases were formerly contaminated with dioxin by the herbicide spraying campaign in the Vietnam War) were recruited to measure the serum dioxin levels. Four reproductive hormones (testosterone, follicle-stimulating hormone, luteinizing hormone (LH), and prolactin) and three thyroid hormones (free triiodothyronine (FT3), free thyroxin (FT4), and thyroid stimulating hormone) were measured. Male sexual function endpoints including sexual drive, erection, ejaculation, problems, and overall satisfaction were assessed by the Brief Male Sexual Function Inventory. The percentage of subjects with low testosterone and LH levels was 19.6% and 16.7%, respectively. Dioxins, especially 2,3,7,8-tetrachlorodibenzo-P-dioxin and toxic equivalent concentrations of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans, were inversely associated with testosterone and prolactin levels, but positively associated with FT3 and FT4, and showed adverse relationships with sexual function, such as sexual drive, problems, and overall satisfaction. Our results suggested that exposure to dioxin disrupts the homeostasis of reproductive and thyroid hormones leading to adverse effects on male sexual function.

11.
Phys Med Biol ; 68(7)2023 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-36848684

RESUMEN

Microscopic nuclear imaging down to spatial resolutions of a few hundred microns can already be achieved using low-energy gamma emitters (e.g.125I, ∼30 keV) and a basic single micro-pinhole gamma camera. This has been applied toin vivomouse thyroid imaging, for example. For clinically used radionuclides such as99mTc, this approach fails due to penetration of the higher-energy gamma photons through the pinhole edges. To overcome these resolution degradation effects, we propose a new imaging approach: scanning focus nuclear microscopy (SFNM). We assess SFNM using Monte Carlo simulations for clinically used isotopes. SFNM is based on the use of a 2D scanning stage with a focused multi-pinhole collimator containing 42 pinholes with narrow pinhole aperture opening angles to reduce photon penetration. All projections of different positions are used to iteratively reconstruct a three-dimensional image from which synthetic planar images are generated. SFNM imaging was tested using a digital Derenzo resolution phantom and a mouse ankle joint phantom containing99mTc (140 keV). The planar images were compared with those obtained using a single-pinhole collimator, either with matched pinhole diameter or with matched sensitivity. The simulation results showed an achievable99mTc image resolution of 0.04 mm and detailed99mTc bone images of a mouse ankle with SFNM. SFNM has strong advantages over single-pinhole imaging in terms of spatial resolution.


Asunto(s)
Microscopía Nuclear , Tomografía Computarizada de Emisión de Fotón Único , Ratones , Animales , Tomografía Computarizada de Emisión de Fotón Único/métodos , Cintigrafía , Fantasmas de Imagen , Simulación por Computador
12.
Pharmaceuticals (Basel) ; 15(12)2022 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-36558899

RESUMEN

Recently, silver nanoparticles (AgNPs) have been extensively explored in a variety of biological applications, especially cancer treatment. AgNPs have been demonstrated to exhibit anti-tumor effects through cell apoptosis. This study intends to promote cell apoptosis further by increasing oxidative stress. AgNPs are encapsulated by biocompatible and biodegradable polyaspartamide (PA) (PA-AgNPs) that carries the anti-cancer drug Doxorubicin (Dox) to inhibit cancer cells primarily. PA-AgNPs have an average hydrodynamic diameter of 130 nm, allowing them to move flexibly within the body. PA-AgNPs show an excellent targeting capacity to cancer cells when they are conjugated to biotin. In addition, they release Dox efficiently by up to 88% in cancer environments. The DCFDA experiment demonstrates that the Dox-carried PA-AgNPs generate reactive oxidation species intensively beside 4T1 cells. The MTT experiment confirms that PA-AgNPs with Dox may strongly inhibit 4T1 cancer cells. Furthermore, the in vivo study confirms that PA-AgNPs with Dox successfully inhibit tumors, which are about four times smaller than the control group and have high biosafety that can be applied for chemotherapy.

13.
Artículo en Inglés | MEDLINE | ID: mdl-36231600

RESUMEN

BACKGROUND: Medical students play important frontline roles in the prevention, early detection, and treatment of hepatitis C. This study investigated knowledge and attitudes toward hepatitis C among 5th- and 6th-year medical students and possible associated factors. METHODS: A cross-sectional survey was conducted among 2000 students from eight medical universities using a self-administered structured questionnaire. RESULTS: The mean knowledge and attitude scores for hepatitis C were 20.1 ± 4.0 (out of 26) and 10.6 ± 2.9 (out of 20), respectively. Approximately, three-quarters (74.4%) of the participants had a good knowledge score, but only a small proportion (3.1%) obtained a good attitude score. Although the participants had fairly high knowledge about the causes, consequences, and transmission routes of hepatitis C, there were important gaps in their knowledge about hepatitis C screening and treatment. In multivariate analysis, female students, 5th-year students, and students from the central provinces had significantly higher knowledge and attitude scores. There was a low positive correlation between knowledge and attitude scores. CONCLUSION: This study points out the need to update the medical training curriculum to improve the knowledge and attitude of students about hepatitis C infection.


Asunto(s)
Hepatitis C Crónica , Hepatitis C , Estudiantes de Medicina , Antivirales/uso terapéutico , Estudios Transversales , Femenino , Conocimientos, Actitudes y Práctica en Salud , Hepacivirus , Hepatitis C/tratamiento farmacológico , Hepatitis C/epidemiología , Humanos , Encuestas y Cuestionarios , Vietnam
14.
FEMS Microbiol Ecol ; 97(8)2021 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-34251452

RESUMEN

Wild berries are interesting research subjects due to their rich sources of health-beneficial phenolic compounds. However, the internal microbial communities, endophytes, associated with the wild berry fruits are currently unknown. Endophytes are bacteria or fungi inhabiting inside plant tissues, and their functions vary depending on the host species and environmental parameters. The present study aimed to examine community composition of fungal and bacterial endophytes in fruits of three wild berry species (bilberry Vaccinium myrtillus L., lingonberry Vaccinium vitis-idaea L. and crowberry Empetrum nigrum L.) and the effects of host plant species and their growth sites on shaping the endophytic communities. We found that the endophytic community structures differed between the berry species, and fungi were predominant over bacteria in the total endophytic taxa. We identified previously unknown endophytic fungal taxa including Angustimassarina, Dothidea, Fellozyma, Pseudohyphozyma, Hannaella coprosmae and Oberwinklerozyma straminea. A role of soluble phenolic compounds, the intracellular components in wild berry fruits, in shaping the endophytic communities is proposed. Overall, our study demonstrates that each berry species harbors a unique endophytic community of microbes.


Asunto(s)
Vaccinium myrtillus , Vaccinium vitis-Idaea , Basidiomycota , Endófitos/genética , Frutas , Humanos
15.
Phys Med Biol ; 66(12)2021 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-34049291

RESUMEN

The use of multi-pinhole collimation has enabled ultra-high-resolution imaging of SPECT and PET tracers in small animals. Key for obtaining high-quality images is the use of statistical iterative image reconstruction with accurate energy-dependent photon transport modelling through collimator and detector. This can be incorporated in a system matrix that contains the probabilities that a photon emitted from a certain voxel is detected at a specific detector pixel. Here we introduce a fast Monte-Carlo based (FMC-based) matrix generation method for pinhole imaging that is easy to apply to various radionuclides. The method is based on accelerated point source simulations combined with model-based interpolation to straightforwardly change or combine photon energies of the radionuclide of interest. The proposed method was evaluated for a VECTor PET-SPECT system with (i) a HE-UHR-M collimator and (ii) an EXIRAD-3D 3D autoradiography collimator. Both experimental scans with99mTc,111In, and123I, and simulated scans with67Ga and90Y were performed for evaluation. FMC was compared with two currently used approaches, one based on a set of point source measurements with99mTc (dubbed traditional method), and the other based on an energy-dependent ray-tracing simulation (ray-tracing method). The reconstruction results show better image quality when using FMC-based matrices than when applying the traditional or ray-tracing matrices in various cases. FMC-based matrices generalise better than the traditional matrices when imaging radionuclides with energies deviating too much from the energy used in the calibration and are computationally more efficient for very-high-resolution imaging than the ray-tracing matrices. In addition, FMC has the advantage of easily combining energies in a single matrix which is relevant when imaging radionuclides with multiple photopeak energies (e.g.67Ga and111In) or with a continuous energy spectrum (e.g.90Y). To conclude, FMC is an efficient, accurate, and versatile tool for creating system matrices for ultra-high-resolution pinhole SPECT.


Asunto(s)
Fotones , Tomografía Computarizada de Emisión de Fotón Único , Animales , Procesamiento de Imagen Asistido por Computador , Método de Montecarlo , Fantasmas de Imagen
16.
Artículo en Inglés | MEDLINE | ID: mdl-34281017

RESUMEN

BACKGROUND: Building capacity in hepatitis B virus prevention and management for medical students and health professionals is one of the pillars of the national viral hepatitis control strategy. METHODS: A cross-sectional study was conducted at eight medical universities from the northern, central and southern regions of the country between May and November 2020 using a systematic random sampling technique. RESULTS: Among 2000 participants, 84.2% reported they had been tested for hepatitis B and 83.9% had received the hepatitis B vaccine. The mean knowledge, attitude, practice score was 40.2 out of 54 (74.4%) with only 19.9% of the study participants obtaining a good score. In multivariate analysis, fifth year students, students from central universities, students who had tested positive for hepatitis B and students who had received hepatitis B vaccine or had encountered patients with chronic hepatitis B had significantly higher knowledge score (p < 0.05). The study showed lack of trust in the hepatitis B vaccine safety and lack of confidence in providing counselling, testing and management of patients with chronic hepatitis B. CONCLUSION: Findings from our research emphasized an immediate need to improve the medical schools' training curriculum in Vietnam to enable students' readiness in hepatitis B prevention and management.


Asunto(s)
Hepatitis B , Estudiantes de Medicina , Estudios Transversales , Conocimientos, Actitudes y Práctica en Salud , Hepatitis B/epidemiología , Hepatitis B/prevención & control , Vacunas contra Hepatitis B , Virus de la Hepatitis B , Humanos , Encuestas y Cuestionarios , Vietnam/epidemiología
17.
Cell Death Differ ; 28(4): 1251-1269, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33116296

RESUMEN

Inactivation of tumor suppressor Runt-related transcription factor 3 (RUNX3) plays an important role during early tumorigenesis. However, posttranslational modifications (PTM)-based mechanism for the inactivation of RUNX3 under hypoxia is still not fully understood. Here, we demonstrate a mechanism that G9a, lysine-specific methyltransferase (KMT), modulates RUNX3 through PTM under hypoxia. Hypoxia significantly increased G9a protein level and G9a interacted with RUNX3 Runt domain, which led to increased methylation of RUNX3 at K129 and K171. This methylation inactivated transactivation activity of RUNX3 by reducing interactions with CBFß and p300 cofactors, as well as reducing acetylation of RUNX3 by p300, which is involved in nucleocytoplasmic transport by importin-α1. G9a-mediated methylation of RUNX3 under hypoxia promotes cancer cell proliferation by increasing cell cycle or cell division, while suppresses immune response and apoptosis, thereby promoting tumor growth during early tumorigenesis. Our results demonstrate the molecular mechanism of RUNX3 inactivation by G9a-mediated methylation for cell proliferation and antiapoptosis under hypoxia, which can be a therapeutic or preventive target to control tumor growth during early tumorigenesis.


Asunto(s)
Carcinogénesis/genética , Hipoxia de la Célula/genética , Subunidad alfa 3 del Factor de Unión al Sitio Principal/genética , Metilación de ADN/genética , Acetilación , Animales , Apoptosis , Línea Celular Tumoral , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Antígenos de Histocompatibilidad/metabolismo , N-Metiltransferasa de Histona-Lisina/metabolismo , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Ensayos Antitumor por Modelo de Xenoinjerto
18.
Phys Med Biol ; 65(22): 225029, 2020 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-33231199

RESUMEN

We recently developed a dedicated focusing multi-pinhole collimator for a stationary SPECT system that offers down to 120 µm (or 1.7 nL) spatial resolution SPECT images of cryo-cooled tissue samples (EXIRAD-3D). This collimator is suitable for imaging isotopes that are often used in small animal and diagnostic SPECT such as 125I (27 keV), 201Tl (71 keV), 99mTc (140 keV), and 111In (171 and 245 keV). The goal of the present work is to develop high-resolution pinhole imaging of tissue samples containing isotopes with high-energy photon emissions, for example, therapeutic alpha and beta emitters that co-emit high energy gammas (e.g. 213Bi (440 keV) and 131I (364 keV)) or 511 keV annihilation photons from PET isotopes. To this end, we optimise and evaluate a new high energy small-bore multi-pinhole collimator through simulations. The collimator-geometry was first optimised by simulating a Derenzo phantom scan with a biologically realistic activity concentration of 18F at two system sensitivities (0.30% and 0.60%) by varying pinhole placements. Subsequently, the wall thickness was selected based on reconstructions of a Derenzo phantom and a uniform phantom. The obtained collimators were then evaluated for 131I (364 keV), 213Bi (440 keV), 64Cu (511 keV), and 124I (511 + 603 keV) with biologically realistic activity concentrations, and also for some high activity concentrations of 18F, using digital resolution, mouse knee joint, and xenograft phantoms. Our results show that placing pinhole centres at a distance of 8 mm from the collimator inner wall yields good image quality, while a wall thickness of 43 mm resulted in sufficient shielding. The collimators offer resolutions down to 0.35 mm, 0.6 mm, 0.5 mm, 0.6 mm, and 0.5 mm when imaging 131I, 213Bi, 18F, 64Cu, and 124I, respectively, contained in tissue samples at biologically achievable activity concentrations.


Asunto(s)
Radioisótopos , Tomografía Computarizada de Emisión de Fotón Único/métodos , Animales , Diseño de Equipo , Miembro Posterior/diagnóstico por imagen , Ratones , Modelos Teóricos , Fantasmas de Imagen , Fotones , Tomografía Computarizada de Emisión de Fotón Único/instrumentación
19.
Expert Rev Gastroenterol Hepatol ; 14(3): 185-196, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32098516

RESUMEN

Introduction: Hepatocyte transplantation (HT) is a promising alternative to liver transplantation for the treatment of liver-based metabolic diseases and acute liver failure (ALF). However, shortage of good-quality liver tissues, early cell loss post-infusion, reduced cell engraftment and function restricts clinical application.Areas covered: A comprehensive literature search was performed to cover pre-clinical and clinical HT studies. The review discusses the latest developments to address HT limitations: cell sources from marginal/suboptimal donors to neonatal livers, differentiating pluripotent stem cells into hepatocyte-like cells, in vitro expansion, prevention of immune response to transplanted cells by encapsulation or using innate immunity-inhibiting agents, and enhancing engraftment through partial hepatectomy or irradiation.Expert opinion: To date, published data are highly encouraging specially the alginate-encapsulated hepatocyte treatment of children with ALF. Hepatocyte functions can be further improved through co-culturing with mesenchymal stromal cells. Moreover, ex-vivo genetic correction will enable the use of autologous cells in future personalized medicine.


Asunto(s)
Trasplante de Células/normas , Hepatocitos/trasplante , Hepatopatías/terapia , Trasplante de Células/métodos , Células Cultivadas/trasplante , Humanos , Hepatopatías/metabolismo , Hepatopatías/cirugía , Trasplante de Hígado
20.
Nucl Med Biol ; 86-87: 59-65, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32534896

RESUMEN

INTRODUCTION: Autoradiography is an established technique for high-resolution imaging of radiolabelled molecules in biological tissue slices. Unfortunately, creating a 3D image from a set of these 2D images is extremely time-consuming and error-prone. MicroSPECT systems provide such 3D images but have a low resolution. Here we present EXIRAD-3D, a fast automated method as an alternative for 3D autoradiography from coupes based on ultra-high resolution microSPECT technology. METHODS: EXIRAD-3D uses a very small bore focusing multi-pinhole collimator mounted in a SPECT system with stationary detectors (U-SPECT/CT, MILabs B.V. The Netherlands) using a sample holder with integrated tissue cooling to avoid activity leaking or tissue deformation during the scan. The system performance was experimentally evaluated using various phantoms and tissue samples of animals in vivo injected with technetium-99m and iodine-123. RESULTS: The reconstructed spatial resolution obtained with a Derenzo hot rod phantom was 120 µm (or 1.7 nl). The voxel values of a syringe phantom image appear to be uniform and scale linearly with activity. Uptake in tiny details of the mouse knee joint, thyroid, and kidney could be clearly visualized. CONCLUSION: EXIRAD-3D opens up the possibility for fast and quantitative 3D imaging of radiolabelled molecules at a resolution far better than in vivo microSPECT and saves tremendous amounts of work compared to obtaining 3D data from a set of 2D autoradiographs. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE: EXIRAD-3D offers superior image resolution over microSPECT, and it can be a very efficient alternative for autoradiography in pharmaceutical and biological studies.


Asunto(s)
Autorradiografía/métodos , Automatización , Autorradiografía/instrumentación , Humanos , Radioisótopos de Yodo , Relación Señal-Ruido , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único , Tecnecio , Factores de Tiempo
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