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1.
FEBS Open Bio ; 12(8): 1534-1541, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35638574

RESUMEN

Cry toxins from Bacillus thuringiensis (Bt) have been extensively applied in agriculture to substitute the use of chemical insecticides. We have previously reported the use of a coexpression system in which late embryogenesis abundant (LEA) peptides under the control of the lac promoter increase the expression of insecticidal proteins in Bt. The use of lactose to induce the expression of LEA peptides may be a desirable alternative to isopropyl ß-D-thiogalactopyranoside, the most frequently used inducer for recombinant protein expression. In this study we investigated the use of lactose as an inducer for optimal protein expression. We observed enhanced insecticidal Cry protein expression by applying a simple technique based on intermittent induction, and then optimized concentration and the point of induction time from the 11th h to the 15th h. Our data suggest that intermittent induction of lactose might be a new technique for the enhancement of bacterial protein expression.


Asunto(s)
Bacillus thuringiensis , Insecticidas , Bacillus thuringiensis/metabolismo , Desarrollo Embrionario , Insecticidas/metabolismo , Insecticidas/farmacología , Lactosa/metabolismo , Lactosa/farmacología , Péptidos/metabolismo
2.
ACS Appl Mater Interfaces ; 14(2): 3418-3426, 2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-34985245

RESUMEN

A superconducting joint architecture to join unreacted carbon-doped multifilament magnesium diboride (MgB2) wires with the functionality to screen external magnetic fields for magnetic resonance imaging (MRI) magnet applications is proposed. The intrinsic diamagnetic property of a superconducting MgB2 bulk was exploited to produce a magnetic field screening effect around the current transfer path within the joint. Unprecedentedly, the joint fabricated using this novel architecture was able to screen magnetic fields up to 1.5 T at 20 K and up to 2 T at 15 K and thereby almost nullified the effect of the applied magnetic field by maintaining a constant critical current (Ic). The joint showed an Ic of 30.8 A in 1.5 T at 20 K and an ultralow resistance of about 3.32 × 10-14 Ω at 20 K in a self-field. The magnetic field screening effect shown by the MgB2 joint is expected to be extremely valuable for MRI magnet applications, where the Ic of the joints is lower than the Ic of the connected MgB2 wires in a given magnetic field and temperature.

3.
J Microbiol Methods ; 188: 106207, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33766605

RESUMEN

Bacillus thuringiensis (Bt) is a ubiquitous, gram positive, spore-forming bacterium that synthesizes parasporal crystalline inclusions containing crystal protein, some of which are toxic against a wide range of insect orders like caterpillars, beetles, and flies, including mosquitoes. Regarding the biological control of insects, Bt is the mostly used microorganism worldwide and also alternatives to chemical insecticides for environmental conservation. Some strains of Bt are showing a promising activity against a wide variety of mosquito like Aedes, Culex, and Anopheles and so on with extremely damages in the larval midgut and ultimate death. Here, we introduced a late embryogenesis abundant (LEA) peptide co-expression system based on the expression vector pHT01 with a strong σA-dependent promoter to enhance the expression of insecticidal crystal proteins in native Bt. Two types of LEA peptide (LEA-II and LEA-K) were designed based on the sequence of group-3 LEA protein, which consists of a repetitive sequence of 11 amino acids. The LEA-II mediated co-expression system enhanced the production of crystal protein 3-fold after 12 h of induction of the peptide with 0.5 mM IPTG. Enhanced expression of crystal protein was confirmed by bioassay using 4th instar Aedes albopictus larvae. This unique approach has great potential to produce bio-pesticides by enhanced crystal protein expression not only for mosquitoes but also for other insects.


Asunto(s)
Toxinas de Bacillus thuringiensis/farmacología , Bacillus thuringiensis/metabolismo , Desarrollo Embrionario/efectos de los fármacos , Endotoxinas/farmacología , Proteínas Hemolisinas/farmacología , Insecticidas/farmacología , Péptidos/metabolismo , Animales , Anopheles , Bacillus thuringiensis/genética , Toxinas de Bacillus thuringiensis/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Endotoxinas/química , Endotoxinas/genética , Proteínas Hemolisinas/genética , Insecticidas/metabolismo , Larva/efectos de los fármacos , Péptidos/genética , Proteómica
4.
ACS Appl Mater Interfaces ; 13(2): 3349-3357, 2021 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-33400882

RESUMEN

A superconducting joint of unreacted monofilament internal magnesium diffusion-processed magnesium diboride (MgB2) wires was fabricated by exploiting the phenomenon of magnesium diffusion into the boron layer inside the superconducting joint. Unprecedentedly, the joint was able to carry an almost identical transport current compared to the bare wire in a 2-7 T magnetic field at 20 K. The joint also exhibited very low joint resistance of 2.01 × 10-13 Ω in self-field at 20 K. Among commercially available superconductors, this work is the first to successfully realize a superconducting joint that is capable of transferring current from one conductor to another without any notable degradation under strong magnetic fields. This work demonstrates great potential to apply MgB2 in a range of practical applications, where superconducting joints are essential.

5.
Sci Rep ; 9(1): 14287, 2019 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-31582758

RESUMEN

Superconducting joints are essential for persistent-mode operation in a superconducting magnet system to produce an ultra-stable magnetic field. Herein, we report rationally designed niobium-titanium (Nb-Ti) superconducting joints and their evaluation results in detail. For practical applications, superconducting joints were fabricated by using a solder matrix replacement method with two types of lead-bismuth (Pb-Bi) solder, including Pb42Bi58 as a new composition. All the joints attained a critical current of >200 A below 1.43 T at 4.2 K. Our optimized superconducting joining method was tested in a closed-loop coil, obtaining a total circuit resistance of 3.25 × 10-14 Ω at 4.2 K in self-field. Finally, persistent-mode operation was demonstrated in an Nb-Ti solenoid coil with a persistent-current switch. This work will pave the way to developing high-performance Nb-Ti superconducting joints for practical applications.

6.
J Toxicol Sci ; 44(7): 459-469, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31270302

RESUMEN

Phenobarbital (PB) and Di (2-ethylhexyl) phthalate (DEHP), an anti-epileptic drug and a plasticizer used in flexible polyvinylchloride formulations, respectively, are well-known typical hepatotoxicants. This study investigated the effects of PB (100 mg/kg/day) or DEHP (500 mg/kg/day) on the endocrine system in intact juvenile/peripubertal male rats exposed for 31 days beginning on postnatal day 23. Slight hormone level changes, histopathological changes in thyroid gland or induction of UDP-glucuronosyltransferase in liver were observed in both the PB and DEHP groups. One of the assumed mechanisms inducing thyroid effects is predictable to be secondary changes based on the enhancement in thyroid hormone metabolism via the induction of hepatic microsomal enzymes. No reproductive system-related changes in organ weights, histopathology, and sexual maturation were observed in both groups. Lower testosterone level was observed in the PB group. CYP2B and CYP3A, which are involved in testosterone metabolism, were induced in liver of the PB group. There was no change of 17ß-hydroxysteroid dehydrogenase activity in testis of both groups. Lower testosterone level in the PB-treated male rats was attributed to an indirect, hepatotoxicity-associated effect on the reproductive system and not to direct effects on testis such as the antiandrogenic activity and the inhibition of steroidogenesis. These results did not indicate that PB or DEHP exposure affects the endocrine system directly.


Asunto(s)
Anticonvulsivantes/toxicidad , Dietilhexil Ftalato/toxicidad , Sistema Endocrino/efectos de los fármacos , Sistema Endocrino/patología , Fenobarbital/toxicidad , Plastificantes/toxicidad , Animales , Animales Recién Nacidos , Anticonvulsivantes/administración & dosificación , Sistema Enzimático del Citocromo P-450/metabolismo , Glucuronosiltransferasa/metabolismo , Hígado/enzimología , Masculino , Fenobarbital/administración & dosificación , Ratas Sprague-Dawley , Testosterona/metabolismo , Glándula Tiroides/diagnóstico por imagen , Glándula Tiroides/patología , Factores de Tiempo
7.
Asian Pac J Allergy Immunol ; 37(1): 36-42, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29888925

RESUMEN

BACKGROUND: Lactobacilli show anti-inflammatory effects in the human intestine, and their genomic DNA was identified as one of the anti-inflammatory components. Increased levels of the natural protease inhibitor elafin in the intestine plays an important role in protection against intestinal inflammation. However, there have been no previous reports regarding whether lactobacilli increase elafin levels. OBJECTIVE: This study was performed to investigate whether Lactobacillus plantarum induces elafin secretion from the human epithelial colorectal adenocarcinoma cell line, Caco-2. Moreover, we examined the roles of bacterial genomic DNA and toll-like receptor 9 (TLR9), a specific receptor of bacterial DNA, in this effect. METHODS: Elafin secretion from Caco-2 cells by live and heat-killed L. plantarum was measured. The analysis was also performed using DNase-treated L. plantarum and genomic DNA extracted from L. plantarum. We examined the role of TLR9 in elafin secretion by L. plantarum and its genomic DNA by suppressing TLR9 expression using RNAi in Caco-2 cells. RESULTS: Heat-killed L. plantarum time- and dose-dependently increased elafin secretion, whereas live L. plantarum had no such effect. The elafin secretion by heat-killed L. plantarum was partially abolished by DNase treatment of the bacterium. In addition, L. plantarum genomic DNA also increased elafin secretion. Furthermore, suppression of TLR9 expression partially or completely abolished elafin secretion by heat-killed L. plantarum and its genomic DNA. CONCLUSION: Our results indicated that heat-killed L. plantarum induced genomic DNA-dependent and TLR9-mediated elafin secretion. The anti-inflammatory effects of lactobacilli may be mediated by increases in the levels of elafin in the intestine.


Asunto(s)
ADN Bacteriano , Elafina/biosíntesis , Interacciones Huésped-Patógeno/genética , Lactobacillus plantarum/fisiología , Receptor Toll-Like 9/metabolismo , Células CACO-2 , Infecciones por Bacterias Grampositivas/genética , Infecciones por Bacterias Grampositivas/metabolismo , Infecciones por Bacterias Grampositivas/microbiología , Calor , Humanos
8.
J Labelled Comp Radiopharm ; 61(14): 1095-1105, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30375667

RESUMEN

GluN2B-containing NMDA receptors (NMDARs) play fundamental roles in learning and memory, although they are also associated with various brain disorders. In this study, we synthesized and evaluated three 11 C-labeled N-benzyl amidine derivatives 2-[11 C]methoxybenzyl) cinnamamidine ([11 C]CBA), N-(2-[11 C]methoxybenzyl)-2-naphthamidine ([11 C]NBA), and N-(2-[11 C]methoxybenzyl)quinoline-3-carboxamidine ([11 C]QBA) as PET radioligands for these receptors. The 11 C-benzyl amidines were synthesized via conventional methylation of corresponding des-methyl precursors with [11 C]CH3 I. In vitro binding characteristics were examined in brain sagittal sections using various GluN2B modulators and off-target ligands. Further, in vivo brain distribution studies were performed in normal mice. The 11 C-labeled benzyl amidines showed high-specific binding to the GluN2B subunit at in vitro. In particular, the quinoline derivative [11 C]QBA had the best binding properties in terms of high-brain localization to GluN2B-rich regions and specificity to the GluN2B subunit. Conversely, these 11 C-radioligands showed the brain distributions were inconsistent with GluN2B expression in biodistribution experiments. The majority of the radiolabeled compounds were identified as metabolized forms of which amido derivatives seemed to be the major species. Although these 11 C-ligands had high-specific binding to the GluN2B subunit, significant improvement in metabolic stability is necessary for successful positron emission tomography (PET) imaging of the GluN2B subunit of NMDARs.


Asunto(s)
Amidinas/síntesis química , Amidinas/metabolismo , Radioisótopos de Carbono , Tomografía de Emisión de Positrones/métodos , Receptores de N-Metil-D-Aspartato/metabolismo , Amidinas/química , Animales , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Técnicas de Química Sintética , Marcaje Isotópico , Ligandos , Ratones , Radioquímica
9.
J Med Syst ; 42(6): 114, 2018 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-29744666

RESUMEN

At the University of Miyazaki Hospital (UMH), we have accumulated and semantically structured a vast amount of medical information since the activation of the electronic health record system approximately 10 years ago. With this medical information, we have decided to develop an alert system for aiding in medical treatment. The purpose of this investigation is to not only to integrate an alert framework into the electronic heath record system, but also to formulate a modeling method of this knowledge. A trial alert framework was developed for the staff in various occupational categories at the UMH. Based on findings of subsequent interviews, a more detailed and upgraded alert framework was constructed, resulting in the final model. Based on our current findings, an alert framework was developed with four major items. Based on the analysis of the medical practices from the trial model, it has been concluded that there are four major risk patterns that trigger the alert. Furthermore, the current alert framework contains detailed definitions which are easily substituted into the database, leading to easy implementation of the electronic health records.


Asunto(s)
Registros Electrónicos de Salud/organización & administración , Sistemas Recordatorios , Humanos
10.
Sci Rep ; 7: 43444, 2017 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-28251984

RESUMEN

An efficient cooling system and the superconducting magnet are essential components of magnetic resonance imaging (MRI) technology. Herein, we report a solid nitrogen (SN2) cooling system as a valuable cryogenic feature, which is targeted for easy usability and stable operation under unreliable power source conditions, in conjunction with a magnesium diboride (MgB2) superconducting magnet. The rationally designed MgB2/SN2 cooling system was first considered by conducting a finite element analysis simulation, and then a demonstrator coil was empirically tested under the same conditions. In the SN2 cooling system design, a wide temperature distribution on the SN2 chamber was observed due to the low thermal conductivity of the stainless steel components. To overcome this temperature distribution, a copper flange was introduced to enhance the temperature uniformity of the SN2 chamber. In the coil testing, an operating current as high as 200 A was applied at 28 K (below the critical current) without any operating or thermal issues. This work was performed to further the development of SN2 cooled MgB2 superconducting coils for MRI applications.

11.
Bioorg Med Chem ; 24(16): 3727-33, 2016 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-27325447

RESUMEN

Isomeric iodinated derivatives of nimesulide, with an iodine substituent on the phenoxy ring, were prepared with the aim of identifying potential candidate compounds for the development of imaging agents targeting cyclooxygenase-2 (COX-2) in the brain. Both the experimental logP7.4 and pKa values for these iodinated analogs were in the acceptable range for passive brain penetration. The para-iodo-substituted analog was a more potent and selective COX-2 inhibitor than nimesulide, with a potency that was comparable to the reference drug, celecoxib. Iodination at the ortho- or meta-position of the phenoxy ring was associated with a substantial loss of COX-2 inhibitory activity. Transport studies across Caco-2 cell monolayers in the presence and absence of a P-glycoprotein (P-gp) inhibitor, verapamil, indicated that the para-iodo-substituted analog was not a P-gp transport substrate; this feature is a prerequisite for potential in vivo brain imaging compounds. The para-iodo-substituted analog of nimesulide appears to be an attractive candidate for the development of radioiodine-labeled tracers for in vivo brain imaging of COX-2 levels.


Asunto(s)
Inhibidores de la Ciclooxigenasa 2/química , Inhibidores de la Ciclooxigenasa 2/farmacología , Sulfonamidas/química , Sulfonamidas/farmacología , Animales , Encéfalo/metabolismo , Células CACO-2 , Inhibidores de la Ciclooxigenasa 2/síntesis química , Inhibidores de la Ciclooxigenasa 2/farmacocinética , Humanos , Isomerismo , Ratones , Ratones Endogámicos BALB C , Espectroscopía de Protones por Resonancia Magnética , Espectrometría de Masa por Ionización de Electrospray , Espectroscopía Infrarroja por Transformada de Fourier , Sulfonamidas/síntesis química , Sulfonamidas/farmacocinética
12.
Bioorg Med Chem ; 23(21): 6807-14, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-26455657

RESUMEN

Nimesulide analogs bearing a methoxy substituent either at the ortho-, meta- or para-position on the phenyl ring, were designed, synthesized, and evaluated for potential as radioligands for brain cyclooxygenase-2 (COX-2) imaging. The synthesis of nimesulide and regioisomeric methoxy analogs was based on the copper-mediated arylation of phenolic derivatives for the construction of diaryl ethers. These isomeric methoxy analogs displayed lipophilicity similar to that of nimesulide itself, as evidenced by their HPLC logP7.4 values. In vitro inhibition studies using a colorimetric COX (ovine) inhibitor-screening assay demonstrated that the para-methoxy substituted analog retains the inhibition ability and selectivity observed for parent nimesulide toward COX-2 enzyme, whereas the meta- and ortho-methoxy substituents detrimentally affected COX-2-inhibition activity, which was further supported by molecular docking studies. Bidirectional transport cellular studies using Caco-2 cell culture model in the presence of the P-glycoprotein (P-gp) inhibitor, verapamil, showed that P-gp did not have a significant effect on the efflux of the para-methoxy substituted analog. Further investigations using the radiolabeled form of the para-methoxy substituted analog is warranted for in vivo characterization.


Asunto(s)
Medios de Contraste/síntesis química , Inhibidores de la Ciclooxigenasa 2/síntesis química , Ciclooxigenasa 2/metabolismo , Sulfonamidas/química , Encéfalo/enzimología , Células CACO-2 , Dominio Catalítico , Medios de Contraste/química , Medios de Contraste/metabolismo , Ciclooxigenasa 2/química , Inhibidores de la Ciclooxigenasa 2/química , Inhibidores de la Ciclooxigenasa 2/metabolismo , Humanos , Isomerismo , Conformación Molecular , Simulación de Dinámica Molecular , Unión Proteica , Sulfonamidas/síntesis química , Sulfonamidas/metabolismo
13.
Bioorg Med Chem ; 22(21): 6039-46, 2014 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-25281270

RESUMEN

NAD(P)H: quinone oxidoreductase 1 (NQO1) is an obligate two-electron reductase and is highly expressed in many human solid cancers. Because NQO1 can be induced immediately after exposure to ionizing radiation, we aimed to develop an NQO1-targeted radiolabeled agent to establish a novel internal radiation therapy that amplifies the therapeutic effects when combined with external radiation therapy. We designed three NQO1-targeted radioiodinated compounds including two ether linkage compounds ([(125)I]1 and [(125)I]2) and a sulfide linkage compound ([(125)I]3) based on the selective binding of indolequinone analogs to the active site of NQO1 by the stacking effect. These compounds were successfully prepared using an oxidative iododestannylation reaction with high radiochemical yields and purity. In NQO1-expressing tumor cells, [(125)I]1 and [(125)I]2 were readily metabolized to p-[(125)I]iodophenol or m-[(125)I]iodophenol and [(125)I]I(-), whereas over 85% of the initial radioactivity of [(125)I]3 was observed as an intact form at 1h after incubation. The cellular uptake of [(125)I]3 was significantly higher than those of [(125)I]1 and [(125)I]2. The uptake of [(125)I]3 was specific and was dependent on the expression of NQO1. These data suggest that the novel NQO1-targeted radioiodinated compound [(125)I]3 could be used as a novel internal radiation agent for the treatment of cancer.


Asunto(s)
Indolquinonas/química , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , Neoplasias/radioterapia , Radiofármacos/química , Línea Celular Tumoral , Halogenación , Humanos , Indolquinonas/síntesis química , Indolquinonas/metabolismo , Indolquinonas/farmacocinética , Radioisótopos de Yodo/química , Radioisótopos de Yodo/metabolismo , Radioisótopos de Yodo/farmacocinética , Neoplasias/metabolismo , Radiofármacos/síntesis química , Radiofármacos/metabolismo , Radiofármacos/farmacocinética , Radioterapia/métodos
14.
J Control Release ; 194: 310-5, 2014 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-25238958

RESUMEN

We established a ternary anionic complex constructed with polyamidoamine dendrimer (4th generation; G4) modified with chelating agents (diethylenetriamine pentaacetic acid (DTPA) derivative), polyethyleneimine (PEI), and γ-polyglutamic acid (PGA) as a safe nano-platform for molecular imaging. We prepared indium-111-labeled DTPA-G4/PEI/γ-PGA, and evaluated the effectiveness as a nuclear imaging probe for sentinel lymph node (LN), the first LN that drains the primary tumor. (111)In-DTPA-G4/PEI with strong cationic charge agglutinated with erythrocytes and showed extremely high cytotoxicity. By contrast, the anionic (111)In-DTPA-G4/PEI/γ-PGA had little agglutination activity with erythrocytes and no cytotoxicity, indicating their high biocompatibility. (111)In-DTPA-G4/PEI/γ-PGA was highly taken up by macrophage cells (high populations in LNs) comparable to (111)In-DTPA-G4/PEI. The uptake mechanisms of (111)In-DTPA-G4/PEI/γ-PGA were suggested to be both phagocytosis and γ-PGA-specific pathway. Upon administration of each (111)In-labeled nano-platform into rat footpads intradermally, significantly higher radioactivity of (111)In-DTPA-G4/PEI/γ-PGA was observed in the first draining popliteal LN when compared with that of (111)In-DTPA-G4/PEI. Moreover, (111)In-DTPA-G4/PEI/γ-PGA clearly visualized the sentinel LN with single photon emission computed tomography (SPECT) compared with (111)In-DTPA-G4/PEI. Thus, (111)In-DTPA-G4/PEI/γ-PGA can be useful as a nano-platform for molecular imaging including sentinel LN imaging.


Asunto(s)
Radioisótopos de Indio , Ganglios Linfáticos/diagnóstico por imagen , Nanopartículas , Ácido Poliglutámico/análogos & derivados , Radiofármacos , Animales , Eritrocitos/efectos de los fármacos , Radioisótopos de Indio/química , Radioisótopos de Indio/farmacocinética , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ratones , Ácido Pentético/química , Fagocitosis/efectos de los fármacos , Ácido Poliglutámico/química , Ácido Poliglutámico/farmacocinética , Radiofármacos/química , Radiofármacos/farmacocinética , Ratas , Distribución Tisular , Tomografía Computarizada de Emisión de Fotón Único
15.
J Vet Med Sci ; 76(1): 89-92, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23978900

RESUMEN

Gross lesions characterized by swollen livers and spleens accompanied by diffuse white miliary spots, which resembled those of Marek's disease, were detected in two flocks of local meat-type chickens at a Japanese poultry processing plant in June and August 2010. The microscopic examinations revealed proliferative foci consisting of spindle or polymorphic cells in the interstitium of livers, splenic follicles and the interstitium of kidneys. These cells were positive immunohistochemically with Iba1 antibody, indicating they were histiocytic cells. Some of them contained antigens of avian leukosis virus (ALV) by immunohistochemistry,and the env gene of ALV subgroup J was detected from the spleens by polymerase chain reaction (PCR). Phylogenetic analysis of the PCR product indicated that the env gene might be descended from the American ADOL-7501 strain of ALV-J. These results suggest that the swollen livers and spleens of the meat-type chickens may come from histiocytic proliferation caused by ALV-J infection.


Asunto(s)
Virus de la Leucosis Aviar/genética , Leucosis Aviar/virología , Pollos , Histiocitosis/veterinaria , Riñón/virología , Hígado/virología , Filogenia , Animales , ADN Viral/química , ADN Viral/genética , Productos del Gen env/química , Productos del Gen env/genética , Histiocitosis/virología , Inmunohistoquímica/veterinaria , Reacción en Cadena de la Polimerasa/veterinaria
16.
Biol Pharm Bull ; 36(4): 602-8, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23546294

RESUMEN

On the basis of the findings obtained by X-ray crystallography of Ga-DOTA chelates and the drug design concept of bifunctional radiopharmaceuticals, we previously designed and synthesized a radiogallium-labeled DOTA chelate containing two metronidazole moieties, (67)Ga-DOTA-MN2, for hypoxic tumor imaging. As expected, (67)Ga-DOTA-MN2 exhibited high in vivo stability, although two carboxyl groups in the DOTA skeleton were conjugated with metronidazole moieties. In this study, we evaluated (67/68)Ga-DOTA-MN2 as a nuclear imaging agent for hypoxic tumors. (67)Ga-labeling of DOTA-MN2 with (67)GaCl(3) was achieved with high radiochemical yield (>85%) by 1-min of microwave irradiation (50 W). The pharmacokinetics of (67)Ga-DOTA-MN2 were examined in FM3A tumor-bearing mice, and compared with those of (67)Ga-DOTA-MN1 containing one metronidazole unit and (67)Ga-DOTA. Upon administration, (67)Ga-DOTA-MN2 exhibited higher accumulation in the implanted tumors than (67)Ga-DOTA. Tumor-to-blood ratios of (67)Ga-DOTA-MN2 were about two-fold higher than those of (67)Ga-DOTA-MN1. Autoradiographic analysis showed the heterogeneous localization of (67)Ga-DOTA-MN2 in the tumors, which corresponds to hypoxic regions suggested by well-established hypoxia marker drug, pimonidazole. Furthermore, in positron emission tomography (PET) study, the tumors of mice administered (68)Ga-labeled DOTA-MN2 were clearly imaged by small-animal PET at 1 h after administration. This study demonstrates the potential usefulness of (67/68)Ga-DOTA-MN2 as a nuclear imaging agent for hypoxic tumors and suggests that two functional moieties, such as metronidazole, can be conjugated to radiogallium-DOTA chelate without reducing the complex stability. The present findings provide useful information about the chemical design of radiogallium-labeled radiopharmaceuticals for PET and single photon emission computed tomography (SPECT) studies.


Asunto(s)
Medios de Contraste/farmacocinética , Radioisótopos de Galio/farmacocinética , Compuestos Heterocíclicos con 1 Anillo/farmacocinética , Neoplasias Mamarias Animales/diagnóstico por imagen , Metronidazol/farmacocinética , Animales , Línea Celular Tumoral , Medios de Contraste/química , Femenino , Radioisótopos de Galio/sangre , Radioisótopos de Galio/química , Compuestos Heterocíclicos con 1 Anillo/sangre , Compuestos Heterocíclicos con 1 Anillo/química , Hipoxia , Metronidazol/sangre , Metronidazol/química , Ratones , Ratones Endogámicos C3H , Tomografía de Emisión de Positrones , Distribución Tisular
17.
Chem Pharm Bull (Tokyo) ; 60(2): 235-40, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22293483

RESUMEN

As a part of our efforts to develop potential imaging agents for ascorbate bioactivity, 5-O-(4-[(125)I]iodobenzyl)-L-ascorbic acid ([(125)I]1) was prepared through a two-step sequence which involved radioiodo-destannylation of a protected tributylstannyl precursor 6, followed by hydrolysis in acidic methanol of the protecting groups in 61% overall radiochemical yield, with a radiochemical purity of over 98% and a specific activity of more than 15.4 GBq/µmol. Tissue distribution of [(125)I]1 in tumor-bearing mice showed signs of distribution profiles similar to the reported results for 6-deoxy-6-[(18)F]fluoro-L-ascorbic (6-(18)FAsA) acid and 6-deoxy-6-[(131)I]iodo-L-ascorbic acid (6-(131)IAsA) but with notable differences in the adrenal glands, in which considerably lower uptake of radioactivity and rapid clearance with time were observed. Pretreatment of mice with a known inhibitor of ascorbate transport, sulfinpyrazone, did not produce any significant change in the adrenal uptake of radioactivity after injection of [(125)I]1 compared to the control, suggesting that uptake in the adrenal glands is independent of the sodium-dependent vitamin C transporter 2 transport mechanism. Introduction of a bulky substituent at C-5 on AsA, such as an iodobenzyloxy group, may not be suitable for the design of analogs that may still be able to maintain characteristic distribution properties in vivo seen with AsA itself.


Asunto(s)
Ácido Ascórbico/análogos & derivados , Radiofármacos/química , Radiofármacos/farmacocinética , Animales , Ácido Ascórbico/química , Ácido Ascórbico/farmacocinética , Cromatografía Líquida de Alta Presión , Fibrosarcoma/diagnóstico por imagen , Radioisótopos de Yodo , Ratones , Estructura Molecular , Cintigrafía
18.
J Med Syst ; 36(5): 3261-71, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22198095

RESUMEN

In August 2009, Miyazaki Health and Welfare Network (Haniwa Net, hereafter referred to as "the Net"), centrally led by University of Miyazaki Hospital (UMH), adopted a center hospital-based system offering a unilateral linkage that enables the viewing of UMH's medical records through a web-based browser (electronic medical records (EMR)). By the end of December 2010, the network had developed into a system of 79 collaborating physicians from within the prefecture. Beginning in August 2010, physicians in 12 medical institutions were visited and asked to speak freely on the operational issues concerning the Net. Recordings and written accounts were coded using the text analysis software MAXQDA 10 to understand the actual state of operations. Analysis of calculations of Kendall's rank correlation confirmed that the interdependency between human networks and information networks is significant. At the same time, while the negative opinions concerning the functions of the Net were somewhat conspicuous, the results showed a correlation between requests and proposals for operational improvements of the Net, clearly indicating the need for a more user-friendly system and a better viewer.


Asunto(s)
Sistemas de Información/estadística & datos numéricos , Internet , Médicos , Apoyo Social , Actitud del Personal de Salud , Concienciación , Redes de Comunicación de Computadores , Registros Electrónicos de Salud/organización & administración , Humanos , Japón , Encuestas y Cuestionarios , Interfaz Usuario-Computador
20.
Chem Pharm Bull (Tokyo) ; 59(8): 938-46, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21804236

RESUMEN

There is great potential in the use of positron emission tomography (PET) and suitable radiotracers for the study of cyclooxygenase type 2 (COX-2) enzyme in living subjects. In the present study, we prepared and evaluated five ¹¹C-labeled ester and amide analogs derived from indomethacin as potential PET imaging agents for the in vivo visualization of the brain COX-2 enzyme. Five ¹¹C-labeled COX-2 inhibitors, with different lipophilicities and moderate COX-2 inhibitory activity, were prepared by treatment of the corresponding O-desmethyl precursors with [¹¹C]methyl triflate and purified by HPLC (radiochemical yields of 55-71%, radiochemical purity of >93%, and the specific activities of 22-331 GBq/µmol). In mice, radioactivity in the brain for all radiotracers was low, with very low brain-to-blood ratios. A clear inverse relationship was observed between brain uptake at 1 min postinjection and the lipophilicity (experimental log P7.4) of the studied ¹¹C-radiotracers. Pretreatment of mice with cyclosporine A to block P-glycoproteins caused a significant increase in brain uptake of radioactivity following injection of the ¹¹C-radiotracer compared to control. HPLC analysis showed that each radiotracer was rapidly metabolized, and a few metabolites, which were more polar than the original radiotracers, were found in both plasma and brain. No specific binding of the tracers towards the COX-2 enzyme in the brain was clearly revealed by in vivo blocking study. Further structural refinement of the tracer agent is necessary for better enhancement of brain uptake and for sufficient metabolic stability.


Asunto(s)
Amidas/química , Encéfalo/diagnóstico por imagen , Ciclooxigenasa 2/análisis , Inhibidores de la Ciclooxigenasa/química , Indometacina/análogos & derivados , Tomografía de Emisión de Positrones/métodos , Radiofármacos/química , Amidas/metabolismo , Amidas/farmacocinética , Animales , Encéfalo/metabolismo , Radioisótopos de Carbono/química , Radioisótopos de Carbono/metabolismo , Radioisótopos de Carbono/farmacocinética , Ciclooxigenasa 2/metabolismo , Inhibidores de la Ciclooxigenasa/metabolismo , Inhibidores de la Ciclooxigenasa/farmacocinética , Ésteres/química , Indometacina/metabolismo , Indometacina/farmacocinética , Marcaje Isotópico , Masculino , Ratones , Unión Proteica , Radiofármacos/metabolismo , Radiofármacos/farmacocinética
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