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RESUMEN Las arbovirosis son enfermedades virales transmitidas por artrópodos (arthropod-borne virus). Dengue, zica y chikungunya se destacan entre los arbovirus emergentes y reemergentes en los últimos años en todo el mundo. La similitud de los síntomas de estas infecciones hace que el diagnóstico clínico sea ineficaz, dificultando las medidas profilácticas y preventivas para nuevos brotes. El diagnóstico molecular mediante la técnica de reacción en cadena de la polimerasa (PCR) en tiempo real es una de las formas de diagnosticar esas enfermedades. En este estudio se recopiló y evaluó la literatura sobre el diagnóstico de arbovirosis. Nuestro objetivo era responder a una pregunta orientadora: ¿la metodología de PCR en tiempo real es eficaz para diagnosticar arbovirosis? Se buscaron artículos científicos de acceso abierto en las bases de datos Pubmed (50 artículos) y Scielo (107 artículos), entre 2014 y 2019. La selección se realizó utilizando los criterios de inclusión y exclusión, quedando solo 20 artículos. Entre estos, el 85% fueron estudios transversales, el 10% fueron revisiones sistemáticas y el 5% fueron estudios de casos. El período de publicaciones fue del 50% en 2017; 35% en 2016; y 5% en 2014, 2015 y 2019, cada. En cuanto a los virus tratados en los artículos, el 25% de los estudios investigaron sobre el dengue; el 25% el chikungunya y el 20% el virus del Zica. La efectividad del diagnóstico molecular se publicó en el 21% de los artículos (sensibilidad y especificidad); el 53% destacó el límite de detección; 70%, ausencia de reacciones cruzadas; y el 80%, la diferenciación entre virus.
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RESUMEN El diseño eficiente de compuestos aprovechando las características estructurales de las moléculas y la búsqueda eficiente de dianas terapéuticas, ha proporcionado herramientas efectivas en la investigación de nuevos tratamientos cuando esta se enfoca en mecanismos celulares de la enfermedad. Los cambios fenotípicos producidos por la interacción in vitro entre molécula-diana, pueden controlarse cuantitativamente mediante imagenología de células vivas. Para garantizar una interacción adecuada, es necesario considerar diferentes elementos cruciales: 1. Las características estructurales y la dinámica molecular del compuesto a evaluar. 2. La relevancia del blanco para la fisiopatología de interés. Sin embargo, el desconocimiento del panorama general en el descubrimiento de fármacos, desde problemáticas estructurales y celulares, ha enlentecido la búsqueda de nuevos tratamientos. Esta revisión descriptiva de tema presenta algunos aspectos estructurales importantes para la caracterización de compuestos como candidatos terapéuticos, y aproximaciones experimentales para desarrollo de sistemas celulares. Los tópicos discutidos se enfocan en la monitorización por imagenología de células vivas y así mismo proporcionamos ejemplos relevantes. La monitorización de efectos fenotípicos producidos por interacciones entre candidato químico y blanco terapéutico en un sistema celular puede favorecer la búsqueda eficiente de moléculas potencialmente terapéuticas.
SUMMARY The efficient compounds' design taking advantage of the molecule's structural characteristics and efficient search for therapeutic targets has provided effective tools for the research of new treatments when this is focused on disease cellular mechanisms. Phenotypic changes produced by in vitro interaction between molecules and targets can be monitored quantitatively by live cell imaging. To guarantee adequate interaction, it is necessary to consider different crucial elements: 1. Structural characteristics and molecular dynamics of the evaluated compound. 2. Target relevance for the concern physiopathology. However, overview's ignorance of the drug discovery, from structural and cellular problems, has slowed the new treatments research. This literature review presents some important structural aspects for compounds' characterization as therapeutic candidates and experimental approaches for cellular systems development. Subjects discussed are focused on live cell imaging and we also provide relevant examples. Phenotypic monitoring of interactions' produced effects between the chemical candidate and therapeutic target in a cellular system can favor the efficient search of potentially therapeutic molecules.
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BACKGROUND: In recent years, molecular imaging combined with medical imaging technology and targeted molecular probes have gradually become a research focus. The targeted tissues at the molecular level can be observed using molecular imaging, medical imaging technology, and targeted molecular probes in combination to realize non-invasive imaging of the occurrence and development of the diseases. OBJECTIVE: To develop the magnetic targeted nanoparticle probes, observe the ultrasound/CT/MRI imaging properties in vitro, and investigate their targeting ability to rat hepatic stellate cells in vitro. METHODS: Taking poly(lactic-co-glycolic acid) (PLGA) polymer as the shell, cyclic arginine-glycine-aspartic acid (cRGD) octapeptide as the ligand, targeted magnetic nanoparticles with superparamagnetic Fe3O4 embedded in the shell and perfluorooctyl bromide(PFOB) loaded in the core were prepared by double emulsion evaporation method. The physical and chemical properties of the nanoparticles were detected. The ultrasound/CT/MRI multi-modal imaging properties of the nanoparticles at different concentrations diluted with double-distilled water were tested in vitro. Cyclic RGD peptide immobilization on PLGA-Fe3O4-PFOB NPs was completed through the amide condensation reaction. The conjugation efficiency of the cRGD on PLGA-Fe3O4-PFOB NPs and targeting ability of targeted magnetic nanoparticles in vitro were verified. Cytotoxicity experiments were used to measure the toxic effects of nanoparticles at different concentrations on BRL-3A cells in each group. RESULTS AND CONCLUSION: The targeted magnetic nanoparticles with the average size of (221. 5±60. 3) nm were uniform in dispersion and size. The prepared individual nanoparticle was spherical with the superparamagnetic Fe3O4 scattered on the shell. The encapsulation rate of Fe3O4 was 38%. In vitro ultrasound imaging and CT imaging signal decreased gradually as the concentrations of the nanoparticle suspension decreased. The T2-weighted signal of MRI decreased gradually with the increase of the concentrations of magnetic particle Fe3O4. Flow cytometry results showed that 94. 13% of the cRGD was bound to the nanoparticles. In vitro cell targeting experiments showed that compared to PLGA-Fe3O4-PFOB NPs, cRGD-PLGA-Fe3O4-PFOB NPs exhibited greater cell targeting and affinity efficiency to hepatic stellate cells. Cytotoxicity experiments results showed the nanoparticles had no significant influence on cell viability of the BRL-3A cells. These results suggest that targeted magnetic nanoprobe cannot only be used as a multi-modal imaging contrast agent for ultrasound/CT/MRI, but also exhibits a strong specific affinity to rat hepatic stellate cells in vitro. It has great potential for the early diagnosis of liver fibrosis.
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Objective@#To construct 131I-the fifth generation polyamidoamine (PAMAM(G5.0)) with targeting peptide Ser-Arg-Glu-Ser-Pro-His-Pro (SRESPHP; SR) or Gly-Pro-Leu-Pro-Leu-Arg (GPLPLR; GP) and double targeting peptide SR/GP, and evaluate the targeting ability in medullary thyroid carcinoma (MTC) model.@*Methods@#PAMAM(G5.0), PAMAM(G5.0)-SR, PAMAM(G5.0)-GP and PAMAM(G5.0)-SR/GP were radiolabeled with 131I by chloramine T method. The radiolabeled yield and radiochemical purity were determined by thin layer chromatography. MTC xenografts were developed and the percentage radio-activity of injection dose per gram of tissue (%ID/g) in tumor and organs was measured at 24 h post-injection. Region of interest (ROI) was drawn and the tumor/non-tumor (T/NT) ratios at 4, 8 and 24 h post-injection were calculated and compared among different groups. One-way analysis of variance, repetitive measurement analysis of variance and Dunnett-t test were used to compare the data of different groups. The relationship between %ID/g and T/NT was analyzed with Pearson correlation.@*Results@#The radiolabeled yield was more than 75% and radiochemistry purity was more than 90%. The difference of %ID/g at 24 h post-injection was significant (F=14.400, P<0.001) in tumors of all groups. The radioactive uptake in tumor of 131I-PAMAM(G5.0)-SR group was the highest at 24 h post-injection((1.80±0.18) %ID/g). There were significant differences of T/NT ratios among different groups(F=4.776, P<0.05)and between different time points(F=8.630, P<0.05). Compared with negative control group (Na131I), the T/NT ratios significantly increased in 131I-PAMAM(G5.0)-SR group at 4, 8 and 24 h post-injection (t=4.169, 7.123 and 4.032, all P<0.05) and in 131I-PAMAM(G5.0)-GP group at 4 h post-injection (t=5.893, P<0.05). The T/NT ratio in 131I-PAMAM(G5.0)-SR group was higher than that in 131I-PAMAM(G5.0)-GP group at 24 h post-injection (t=2.871, P<0.05).@*Conclusions@#PAMAM(G5.0)-SR, PAMAM(G5.0)-GP and PAMAM(G5.0)-SR/GP can target the MTC models. 131I-PAMAM(G5.0)-SR has the best biological properties and may provide a new precision method for MTC diagnosis, treatment and prognosis evaluation.
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Unlike conventional imaging technologies, fluorescent imaging benefits from its safety, high-spatial resolution and real-time capability, which make it a highly adoptable imaging method for tumor detection and image-guided surgery in clinics. There are two types of fluorescent probes, including always-on type and environment-responsive type, wherein environment-responsive probes are preferred due to higher target-to-background ratios, which can improve sensitivity and specificity. The environment-responsive probes include enzyme-reactive probes, pH-sensitive probes and hypoxia responsive probes. This review summarizes recent progress in environment-responsive probes, and discusses their potentials in tumor detection and image-guided surgery.
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Objective To construct 131 I-the fifth generation polyamidoamine (PAMAM(G5.0)) with targeting peptide Ser-Arg-Glu-Ser-Pro-His-Pro (SRESPHP;SR) or Gly-Pro-Leu-Pro-Leu-Arg (GPLPLR;GP) and double targeting peptide SR/GP,and evaluate the targeting ability in medullary thyroid carcinoma (MTC) model.Methods PAMAM(GS.0),PAMAM(GS.0)-SR,PAMAM(GS.0)-GP and PAMAM(GS.0)-SR/GP were radiolabeled with 131I by chloramine T method.The radiolabeled yield and radiochemical purity were determined by thin layer chromatography.MTC xenografts were developed and the percentage radio-activity of injection dose per gram of tissue (％ID/g) in tumor and organs was measured at 24 h post-injection.Region of interest (ROI) was drawn and the tumor/non-tumor (T/NT) ratios at 4,8 and 24 h post-injection were calculated and compared among different groups.One-way analysis of variance,repetitive measurement analysis of variance and Dunnett-t test were used to compare the data of different groups.The relationship between ％ID/g and T/NT was analyzed with Pearson correlation.Results The radiolabeled yield was more than 75％ and radiochemistry purity was more than 90％.The difference of ％lD/g at 24 h post-injection was significant (F=14.400,P＜0.001) in tumors of all groups.The radioactive uptake in tumor of 131I-PAMAM (G5.0)-SR group was the highest at 24 h post-injection ((1.80± 0.18) ％ID/g).There were significant differences of T/NT ratios among different groups (F =4.776,P＜ 0.05)and between different time points (F =8.630,P＜0.05).Compared with negative control group (Na131 I),the T/NT ratios significantly increased in 131I-PAMAM(G5.0)-SR group at 4,8 and 24 h post-injection (t=4.169,7.123 and 4.032,all P＜0.05) and in 131I-PAMAM(G5.0)-GP group at 4 h post-injection (t =5.893,P＜0.05).The T/NT ratio in 131I-PAMAM (G5.0)-SR group was higher than that in 131 I-PAMAM (G5.0)-GP group at 24 h post-injection (t=2.871,P＜0.05).Conclusions PAMAM(G5.0)-SR,PAMAM(G5.0)-GP and PAMAM(G5.0)-SR/GP can target the MTC models.131I-PAMAM(G5.0)-SR has the best biological properties and may provide a new precision method for MTC diagnosis,treatment and prognosis evaluation.
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Objective@#A new type of molecular probe design method was established to improve the sensitivity and specificity of microRNA detection. @*Methods@#This is an experimental study. The target hybridization sequence was designed on the stem side of the molecular beacon using the strand displacement principle and based on this, a new probe was designed by using the nucleic acid structure analysis software DNAman to optimize the secondary structure of the molecular probe, which was called as strand displacement molecular probe (MB-D) and MB-D plus. Taking microRNA-21 as an example, microRNA-21 and its related single nucleotide mutations were detected using conventional molecular probe (MB-C) and redesigned MBs (MB-D and MB-D plus) to analyze the differences on minimum detection limit, repeatability and specificity for microRNA detection among these three probes. @*Results@#The minimum detection limit of MB-C for microRNA-21 was 1 nmol/L, and the minimum detection limits for MB-D and MB-D plus were 0.1 nmol/L and 0.01 nmol/L, respectively. The established MB-D plus can significantly distinguish between miR-21 and single nucleotide mutations. @*Conclusion@#The molecular probe based on the principle of strand displacement and optimized by secondary structure can significantly increase the sensitivity and specificity of the probe for microRNA detection.(Chin J Lab Med, 2018, 41: 541-546)
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Purpose To develop the folate-targeted theranostic nanoprobe, investigate the active targeting behavior of nanoprobes to hepatocellular carcinoma(HCC)in vitro,and discuss the effect of enhanced US/MRI dual-mode imaging in vitro and the synergistic effect of high intensity focused ultrasound on HCC killing. Materials and Methods The folate-targeted nanoprobe loaded with iron oxide nanoparticles (Fe3O4) and phase-shift material perfluorohexane (PFH) was prepared by double emulsion method and carbodiimide method. The average particle size, morphological structure and the ability of liquid-gas phase transition were detected. The active targeting ability of the nanoprobe to HCC BEL-7402 was observed in vitro.The ultrasonic imaging effect of nanoprobe was observed by HIFU irradiation in vitro.MRI was performed on the Fe3O4nanoprobe with different content of magnetic particles.The synergistic killing ability of the nanoprobe combined with HIFU on liver cancer cells was detected with in vitro apoptosis experiment. Results The folate-targeted nanoprobe loading iron oxide nanoparticles (Fe3O4) and phase-shift material PFH was prepared, with the average size of (402.50±66.43) nm. It was in the shape of regular sphere with the magnetic particle Fe3O4scattered inside. The HIFU irradiation caused liquid and gas phase transition.In vitro targeting experiments showed that BEL-7402 cells were surrounded by a large number of nanoscale probes.In vitro dual mode imaging showed that the ultrasonic echo intensity was obviously enhanced after HIFU irradiates nanoscale probes. The MR negative imaging ability of the nanoprobe was also enhanced with the enhancement of Fe3O4concentration in nanoparticles. In vitro apoptosis experiments showed that the nanoscale probe had the ability to significantly enhance the effect of HIFU on the killing of HCC. Conclusion The prepared folate-targeted theranostic nanoprobes exhibit the excellent capability for in vitro targeting.They can be used for ultrasound and MRI as multimodal imaging agents and coordinates with HIFU to enhance the effect on killing HCC, which realizes the early diagnosis of tumor and targeted precision therapy.
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Alzheimer's disease (AD) is a neurodegenerative disease,which is insidious onset and progressive.The pathological features of AD include senile plaques composed of amyloid β (Aβ) and neurofibrillary tangles composed of Tau protein.Aβ and Tau protein targeted imaging agents,which make a non-invasive and high specificity diagnosis,might be useful for early diagnosis,efficacy monitoring and drug evaluation for AD.This review summarizes the progress and clinical applications of those agents in AD.
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As an advanced imaging technology,PET provides high sensitivity and accuracy for the diagnostic research of Alzheimer's disease (AD).Various pathophysiological information of AD can be illustrated by applying different molecular imaging probes.Three series of molecular imaging probes including glucose metabolism probes,neurotransmitter and neuroreceptor probes and neuropathological marker probes are introduced in this review.
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Objective To optimize the synthetic method for the fluorescent molecule CH1055 and perform a preliminary study on its water solubility and optical properties. Methods Starting from triphenylamine and benzothiadiazole, the desired products were synthesized via a series of reactions, such as Vilsmeier-Haack reaction, acylation, catalytic hydrogenation, bromination, condensation, silylation protection, Suzuki coupling, nitrification and reduction. The structures of the intermediates and targeted compound were confirmed by MS and1 H NMR. At the same time, the key reaction steps were optimized, and the solubility and optical properties of CH1055 were investigated both in vitro and in vivo. Results After improvement of the synthetic method, the total yield increased from 9.13％ in the literature to 12.1％ in the present study. The PEGylated product improved water solubility by about 300 times. At the wavelength of 750 nm long excitation light, CH1055 had better imaging characteristics than the traditional Cy5.5. Conclusion The present method for the CH1055 synthesis has appeared to be cheaper in cost, easy to operate, and higher in yield. After PEGylation modification, the water solubility of the target compound was greatly improved, which was highly advantageous to the development of a water-soluble NIR-Ⅱ fluorescent molecule. CH1055 showed excellent imaging properties in the long wavelength range, which implicated a new potential application of the fluorescent molecule.
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With the development of medical nanotechnology, scientists have found that nanoparticle drug delivery system can improve the accumulation of anti-tumor drugs inside the tumor and reduce the damage to normal tissues, so as to increase the treatment effect while decrease its side effect. In recent years, the nanoparticle drug delivery system has been gradually developing towards intellectualization, and various smart probes which are stimuli-responsive and sensitive to microenvironment of tumor have been designed. Those probes can be divided into two categories: internal (including pH, enzyme, and redox) and external (including light, temperature, ultrasound, and magnetic field) environment-responsive probes. In this paper, the latest research progress in the two kinds of environment-responsive smart probes in the field of tumor therapy is reviewed, and the further research direction is also prospected.
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Objetivo: las mujeres inmigrantes enfrentan problemas para acceder a programas de salud, en relación al tamizaje del cáncer cervical y su prevención. Estudios demuestran que mientras más reciente es la migración (<10 años), es menos probable la realización de exámenes para detectar cáncer cervical. Se plantea la hipótesis de que las mujeres inmigrantes tendrán índices menores de tamizaje de lesiones cervicales causadas por el virus del papiloma humano (HPV) comparadas con las mujeres ecuatorianas. Métodos: se realizó un estudio observacional en 113 mujeres de 17 a 55 años de edad: 56 mujeres inmigrantes/refugiadas y 57 mujeres ecuatorianas Se usó citología cérvico-vaginal y una prueba de detección de ADN del HPV basada en Captura Híbrida II. Las participantes fueron reclutadas mediante selección no probabilística (desde mayo 2014 hasta junio 2015). Las mujeres ecuatorianas fueron incluidas por solicitud voluntaria una vez que recibieron toda la información del proceso; mientras que las mujeres inmigrantes se incluyeron mediante información gráfica y entrevistas, lográndose alianzas entre organizaciones comunitarias dedicadas a ayudarlas y proveedores médicos privados. Resultados: tanto las ecuatorianas (14.15%, n=16) como las inmigrantes (5.3%, n=6) que nunca se realizaron un examen de citología, presentan resultados positivos en el examen de ADN-HPV (alto o bajo riesgo). Las ecuatorianas acceden a la citología cérvico-vaginal, independientemente de su edad, mientas que las mujeres inmigrantes menores de 30 años no han conseguido, hasta el momento del estudio, acceder a este servicio (p < 0.05). Conclusiones: existe una diferencia significativa en los índices de tamizaje de cáncer cervical entre los grupos de inmigrantes /refugiadas y residentes, de acuerdo al lugar de nacimiento y la duración de su estadía en Ecuador.
Objective: immigrant women face health problems and challenges to access health care, no matter what destination country they choose. Regarding cervical cancer screening and prevention, migrant women access to a health care programme is an important issue. Some studies have shown that while migration is recent (under 10 years), is less likely to get cervical cancer examination services comparing with non-immigrant women. The hypothesis stated that immigrant women would have lower rates of screening and a higher prevalence of HPV related lesions, compared to those women from Ecuador. Methods: a 12 months period study was performed including 113 women age 17 to 55, split into two groups: 56 migrant/refugee and 57 Ecuadorian residents, using cervical cytology and a DNA for HPV test based on hybrid capture II. Agreements between community organizations and private providers were reached to help the groups. Results: both groups, Ecuadorian women (14.15%, n=16) and immigrant women (5.3%, n=6) that never had a Papanicolaou test, have HPV-DNA test positive for high and low risk types. Ecuadorian residents have access to cervical cytology regardless their age, while immigrant/refugee women under 30 years have not access to the test, the difference is statistically significant. Conclusions: there is a significant difference in screening levels for cervical cancer between immigrant/refugee women according to place of origin and duration of stay in Ecuador.
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Humans , Female , Uterine Cervical Neoplasms , Cervix Uteri , Urogenital Neoplasms , Transients and Migrants , Straining of LiquidsABSTRACT
Radio-synthesis of PET tracers in microfluidic chip system for imaging research could fa-cilitate synthesis and screening of radiotracer. Moreover, modular and multi-functional microfluidic chip syn-thesis system could realize the combination of functional modules, synthetic automation, system integration and improvement of radiochemical protection. In this review, research progress in microfluidic chip system for radio-synthesis of PET tracers has been summarized.
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Objective To prepare a novel dual-modality imaging probe based on Cerasome nano-materials, and evaluate its in vivo biodistribution and pharmacokinetic properties. Methods ICG encapsu-lated Cerasome was modified with chelating agent DOTA for 111 In-labeling. Normal mice firstly were used for in vivo studies. Animals were sacrificed at different time points after tail vein administration, blood samples were taken and the organs of interest were captured to evaluate the pharmacokinetic properties and in vivo biodistribution of 111 In-ICG-DPDCs. The subcutaneous Lewis lung carcinoma ( LLC ) tumor model in C57BL/6 mouse was established. The tumor-bearing mice were subjected to optical imaging in small animal IVIS and SPECT imaging in small animal nanoScanSPECT/CT system for tumor uptake of 111 In-ICG-DPDCs. Results The size of the nanoparticle probe was about 90 nm, and the 111 In-labeling was successfully per-formed with 99.93% radiochemical purity after purification. 111 In-ICG-DPDCs showed excellent in vitro sta-bility with 97.10% radiochemical purity at 48 h post-purification. In vivo blood clearance experiments showed that 111 In-ICG-DPDCs had a relative long blood circulation time with the fast and slow phase half-lives of 40 and 132.7 min. 111In-ICG-DPDCs accumulated mainly in the liver and spleen, with long retention time. NanoScanSPECT/CT imaging showed that LLC tumors were significantly visualized at 4 h post-injection, and the other major accumulated organs were the liver and spleen, which were consistent with the results of biodistribution. Optical imaging showed significant uptake of the nanoparticle probe in the tumor, confirming the SPECT imaging results. Conclusion The Cerasome based probe designed could be used for tumor SPECT and optical dual-modality imaging, and has potential for therapeutic use.
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Nanoprobes are new contrast agents used in medical imaging. Nanomaterials have con-trollable size and surface charge, high porosity, large specific surface area, and they are easily to be modi-fied. Due to the advantages of excellent imaging effect, nanoprobes have a variety prospect of clinical appli-cation, such as tumor imaging, angiography, drug delivery. This review summarizes nanoprobes researches on cancer diagnosis and treatment in recent years.
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Purpose Liver fibrosis,liver cirrhosis and liver cancerseriously threaten human health.To detect liver diseases by specific nanoprobes,and to provide reference for the formulation of treatment strategies.Materials and Methods In this study,bovine serum albumin was used as a skeleton and modified with galactose groups for targeting asialoglycoproteinreceptors on liver.The albumin was labeled with radioactive iodine by chloramines T method,and indocyanine green molecules was encapsulated to form liver-targeting nanoparticles.Physical and chemical characterization (particle size and spectral characterization),bio-distribution,SPECT imaging and photoacoustic imaging were carried out respectively.Results The size of the nanoparticles was about 86.4 nm and there were two obvious absorption peaks at 705 nm and 780 nm.Bio-distribution showed that the radiolabeled nanoparticles had a high distribution in liver at 60 min [(55.52 ± 5.39)％ID/g],while after the receptor was inhibited,the uptake in liver was reduced to (37.01 ± 7.38)％ID/g,indicating a significant inhibitory effect (P＜0.05);the uptake of this material at 240nm still remained (34.22±4.44)％ID/g,while in other organs,the detected uptake was quite low,with a statistically significant difference (P＜0.05).The results of SPECT and photoacoustic imaging were consistent with the data of bio-distribution,and images showed highest signal on liver.Thus,the probe was suitable for liver imaging.Conclusion 131I-labeled albumin nanoparticle is an excellent liver-targeting dual modal imaging probe,which can be used for the detection of liver diseases.
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Purpose To prepare superparamagnetic iron oxide nanoparticles (SPION) probe targeted and modified by MUC1 murin (MUC1) in order to explore its MRI characteristics in pancreatic cancer transplantation model.Materials and Methods Chemical conjugate method was adopted for coupled response of MUC1 and SPION to construct targeted probe and tested its basic physical properties,including water and diameter,surface charge and MR signal measuring.Meanwhile,nude mice model of pancreatic cancer transplant subcutaneous sarcoma was set up to study imaging effect inside the nude mice.Transplant sarcoma specimen was taken and immunohistochemical and Western blot were adopted to measure MUC1 expression.Results Partial size of the prepared particle probe was approximately 63.5 nm and surface charge was about 10.2 mV.The probe solution could obviously decrease MR transverse relaxation time (T2 value).In vitro experiment,MUC 1 could selectively gather on nude mice transplant sarcoma model could greatly lower T2 signal intensity.Conclusion Prepared probe has small partial size,superparamagnetic and other advantages.It can realize combination with pancreatic cancer tissue specificity and provide reliable in vivo iconology in early stage for disease diagnosis through vitro imaging.
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Purpose To prepare 68Ga-NOTA-SPIO as PET/MRI dual mode imaging probe with high sensitivity and resolution,and further evaluate its in vitro and partly in vivo biological properties.Materials and Methods The precursor SPIO-PEG2000-NOTA was prepared and characterized.The precursor was radiolabeled by using one step method to prepare 68Ga-NOTA-SPIO as dual mode imaging probe.The labeling rate of the probe was determined by rapid thin-layer chromatography.Besides,the in vitro stability and lipid water partition coefficient of the probe were evaluated,and its biodistribution in normal mice was also observed.Results The precursor SPIO-PEG2000-NOTA with uniform dispersion and uniform particle size was prepared,and the dual mode probe 68Ga-NOTA-SPIO was synthesized.The labeling rate reached 99％,and the lipid water partition coefficient (Log P) was (-2.60±0.13).The radiochemical purity of the probe was higher than 95％,as it was incubated in the phosphate buffer and fetal bovine serum within 2 hours.The probe was mainly distributed in the liver and spleen of mice,and its clearance velocity in blood was fast.Conclusion The double mode probe 68Ga-NOTA-SPIO synthesized by one step method has high labeling rate with no need of purification,which has good physic-chemical properties and biocompatibility.The probe can be used in the further research of PET/MRI dual modality imaging.
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Objective To establish a homothermal and fast detecting method on pathogenic bacteria by combining recombinase-aid amplification (RAA) with molecular beacon.Methods The establishment of the methodology.Staphylococcus aureus specific primers were designed from the relative region of the staphylococcal protein A (SPA).Asymmetry amplification was optimized by adjusting the primer concentration ratios.The results of amplification and hybridization were visualized and analyzed by agarose gel electrophoresis and fluorescence detection.The sensitivity was identified by detecting dilute positive plasmids.And the specificity was determined using RAA method by detecting 72 pathogenic bacteria,including Staphylococcus aureus and other Staphylococcus spp.from the Department of Clinical Laboratory of Daping Hospital in December 2016.Besides,the Kappa analysis and the clinical diagnosis efficiency were investigated by analyzing 39 extra strains in the laboratory in December 2016.Results When the concentration ratio of restrictive and non-restrictive primer was 1:20,the yield efficiency of single-stranded DNA (ssDNA) reached the peak.And as for the hybridization efficiency,the asymmetry amplification was higher than symmetry amplification.Twenty copies/μl was proposed as the limits of detection by testing dilute plasmids.And the RAA hybridization method could distinguish Staphylococcus aureus with other Staphylococcus spp.Comparing with traditional detection methods with a Kappa index of 0.860,this method shows a good consistency.By analyzing the 111 bacteria,the sensitivity of the method is 92.5％ (37/40),the specificity is 97.2％ (69/71),the positive predictive value is 94.9％ (37/39),the negative predictive value is 95.8％ (69/72),the positive likelihood radio is 33.04,the negative likelihood radio is 0.077,the Youden index is 0.897 and the Kappa index is 0.902.Conclusion Through the combination of asymmetry recombinase-aid amplification optimization and molecular beacon probe,a new method of detecting bacteria DNA with RAA hybridization technique is established,providing the foundation for its clinical application.