Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
1.
Sci Rep ; 11(1): 14192, 2021 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-34262055

RESUMEN

X-ray irradiation of high Z elements causes photoelectric effects that include the release of Auger electrons that can induce localized DNA breaks. We have previously established a tumor spheroid-based assay that used gadolinium containing mesoporous silica nanoparticles and synchrotron-generated monochromatic X-rays. In this work, we focused on iodine and synthesized iodine-containing porous organosilica (IPO) nanoparticles. IPO were loaded onto tumor spheroids and the spheroids were irradiated with 33.2 keV monochromatic X-ray. After incubation in CO2 incubator, destruction of tumor spheroids was observed which was accompanied by apoptosis induction, as determined by the TUNEL assay. By employing the γH2AX assay, we detected double strand DNA cleavages immediately after the irradiation. These results suggest that IPO first generate double strand DNA breaks upon X-ray irradiation followed by apoptosis induction of cancer cells. Use of three different monochromatic X-rays having energy levels of 33.0, 33.2 and 33.4 keV as well as X-rays with 0.1 keV energy intervals showed that the optimum effect of all three events (spheroid destruction, apoptosis induction and generation of double strand DNA breaks) occurred with a 33.2 keV monochromatic X-ray. These results uncover the preferential effect of K-edge energy X-ray for tumor spheroid destruction mediated by iodine containing nanoparticles.


Asunto(s)
Roturas del ADN/efectos de la radiación , Yodo/química , Nanopartículas/química , Neoplasias/patología , Compuestos Orgánicos/química , Dióxido de Silicio/química , Esferoides Celulares/efectos de la radiación , Apoptosis/efectos de la radiación , Línea Celular Tumoral , Roturas del ADN de Doble Cadena/efectos de la radiación , Humanos , Nanopartículas/ultraestructura , Compuestos Orgánicos/síntesis química , Porosidad , Dióxido de Silicio/síntesis química , Rayos X
2.
Med Dosim ; 46(1): 74-79, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32958360

RESUMEN

To simulate an early 20th century viral pneumonia radiotherapy treatment using modern fluoroscopy and evaluated it according to current dose guidelines. Monte Carlo was used to assess the dose distribution on an anthropomorphic phantom. Critical organs were: skin, breasts, esophagus, ribs, vertebrae, heart, thymus, and spinal cord. A 100 kVp beam with 3 mm Al HVL, 25 × 25 cm2 posterior-anterior (PA) field and 50 cm source-to-surface distance were simulated. Simulations had a resolution of 0.4 × 0.4 × 0.06 cm3 and a 6% uncertainty. Hundred percent dose was normalized to the skin surface and results were displayed in axial, coronal, and sagittal planes. Dose volume histograms were generated in MATLAB for further analysis. Prescription doses of 0.3, 0.5, and 1.0 Gy were applied to the 15% isodose for organ-dose comparison to current tolerances and potential risk of detriment. Ninety-five and ninety-seven percent of the right and left lung volumes, respectively, were well-covered by the 15% isodose line. For the 0.3, 0.5, and 1.0 Gy prescriptions, the maximum skin doses were 2.9, 4.8, and 9.6 Gy compared to a 2.0 Gy transient erythema dose threshold; left/right lung maximum doses were 1.44/1.46, 2.4/2.4, and 4.8/4.9 Gy compared to a 6.5 Gy pneumonitis and 30 Gy fibrosis thresholds; maximum heart doses were 0.5, 0.9, and 1.8 Gy compared to the 0.5 Gy ICRP-recommendation; maximum spinal cord doses were 1.4, 2.3, and 4.6 Gy compared to 7.0 Gy single fraction dose threshold. Maximum doses to other critical organs were below modern dose thresholds. A 100 kVp PA field could deliver a 0.3 Gy or 0.5 Gy dose without risk of complications. However, a 1.0 Gy dose treatment could be problematic. Critical organ doses could be further reduced if more than one treatment field is used.


Asunto(s)
Neumonía , Planificación de la Radioterapia Asistida por Computador , Fluoroscopía , Humanos , Método de Montecarlo , Dosificación Radioterapéutica
4.
Sci Rep ; 9(1): 13275, 2019 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-31570738

RESUMEN

Synchrotron generated monochromatic X-rays can be precisely tuned to the K-shell energy of high Z materials resulting in the release of the Auger electrons. In this work, we have employed this mechanism to destruct tumor spheroids. We first loaded gadolinium onto the surface of mesoporous silica nanoparticles (MSNs) producing gadolinium-loaded MSN (Gd-MSN). When Gd-MSN was added to the tumor spheroids, we observed efficient uptake and uniform distribution of Gd-MSN. Gd-MSN also can be taken up into cancer cells and localize to a site just outside of the cell nucleus. Exposure of the Gd-MSN containing tumor spheroids to monochromatic X-ray beams resulted in almost complete destruction. Importantly, this effect was observed at an energy level of 50.25 keV, but not with 50.0 keV. These results suggest that it is possible to use precisely tuned monochromatic X-rays to destruct tumor mass loaded with high Z materials, while sparing other cells. Our experiments point to the importance of nanoparticles to facilitate loading of gadolinium to tumor spheroids and to localize at a site close to the nucleus. Because the nanoparticles can target to tumor, our study opens up the possibility of developing a new type of radiation therapy for cancer.


Asunto(s)
Gadolinio , Nanopartículas del Metal , Neoplasias Ováricas , Línea Celular Tumoral , Femenino , Gadolinio/química , Gadolinio/farmacología , Humanos , Nanopartículas del Metal/química , Nanopartículas del Metal/uso terapéutico , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , Neoplasias Ováricas/radioterapia , Esferoides Celulares/metabolismo , Esferoides Celulares/patología , Terapia por Rayos X
5.
Nature ; 561(7723): 318-319, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30232429
6.
Hum Mov Sci ; 58: 260-267, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29524851

RESUMEN

Reducing external joint moments during gait can lead to a reduction in dynamic joint load. There has yet to be a detailed investigation of gait strategies that can reduce external joint moments by decreasing the magnitude of ground reaction force (GRF) without reducing the walking speed. The objectives of this study were to verify whether it is possible to reduce external joint moments by decreasing the GRF magnitude without reducing the walking speed and to identify the alternative walking strategy involved in young healthy adults. This study included 14 young healthy subjects. They performed two types of walking: normal and impact reduction walking. For impact reduction walking, the subjects walked in a manner that reduced the impact upon foot contact. Cadence and step length were unified between the two conditions. The walking speed, peak value of vertical GRF, braking-accelerating force, loading rate, joint angle, and external joint moments of the two conditions were recorded and compared. No significant difference was noted in the walking speed. However, the first peak of vertical GRF, braking force, and loading rate during loading response were significantly reduced during impact reduction walking, and external joint moments in the hip, knee, and ankle joints were reduced. In contrast, the second peak of vertical GRF, hip extension angle, and external ankle dorsiflexion moment were significantly increased during terminal stance. Our data imply that the ankle joint function during the terminal stance is important in reducing the dynamic joint load in the contralateral leg during the loading response.


Asunto(s)
Articulación del Tobillo/fisiología , Marcha/fisiología , Articulación de la Rodilla/fisiología , Extremidad Inferior/fisiología , Caminata/fisiología , Adulto , Tobillo/fisiología , Fenómenos Biomecánicos , Femenino , Pie/fisiopatología , Voluntarios Sanos , Articulación de la Cadera/fisiología , Humanos , Rodilla/fisiología , Masculino , Movimiento , Velocidad al Caminar , Adulto Joven
7.
Oncol Lett ; 13(1): 45-50, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28123520

RESUMEN

Based on our previous analysis of neutral glycolipids in the human endometrium, the present authors already reported that the concentrations of glucosylceramide, lactosylceramide and globotriaosylceramide (Gb3Cer), in which both fatty acids and sphingosines in the ceramides are hydroxylated, exhibit a marked increase during the luteal phase of the menstrual cycle. It is also well known that poorly differentiated endometrial adenocarcinoma exhibits a more rapid progression and a worse response to therapy than well-differentiated endometrial adenocarcinoma. To examine the molecular background of well-differentiated and poorly differentiated cancers, the levels of neutral glycolipids in tumor tissues from endometrial carcinoma displaying different degrees of differentiation were measured. The composition of neutral glycolipids in tumor tissues was determined, and ceramide structures that were specifically expressed in well-differentiated endometrial carcinomas were investigated using biochemical analytical methods, including lipid extraction, enzyme digestion, thin-layer chromatography (TLC), gas-liquid chromatography and mass spectrometry. Well-differentiated adenocarcinoma contained numerous structurally unknown glycolipids that exhibited slower migration than globotetraosylceramide (Gb4Cer). In the case of Gb3Cer, three bands appeared on TLC in well-differentiated cancer, but only two bands appeared in the poorly-differentiated cancer. This difference was associated with the fatty acid composition of ceramide, since non-hydroxy fatty acids with ≥20 carbon atoms were increased in well-differentiated cancer, while α-hydroxy fatty acids were increased in poorly differentiated cancer. Similarly, there were two bands on TLC of Gb4Cer from well-differentiated cancer, but only one band in poorly differentiated cancer, and the long-chain base of ceramide was observed to contain phytosphingosine in well-differentiated cancer. It was demonstrated in endometrial cancer that the structure of ceramide molecules changes with the extent of tumor differentiation. These findings suggest that hydroxylated ceramides contribute to the well-differentiated phenotype of endometrial adenocarcinoma.

9.
Sci Rep ; 6: 30491, 2016 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-27457890

RESUMEN

The promising ability of a plasma wiggler based on laser wakefield acceleration to produce betatron X-rays with photon energies of a few keV to hundreds of keV and a peak brilliance of 10(22)-10(23) photons/s/mm(2)/mrad(2)/0.1%BW has been demonstrated, providing an alternative to large-scale synchrotron light sources. Most methods for generating betatron radiation are based on two typical approaches, one relying on an inherent transverse focusing electrostatic field, which induces transverse oscillation, and the other relying on the electron beam catching up with the rear part of the laser pulse, which results in strong electron resonance. Here, we present a new regime of betatron γ-ray radiation generated by stimulating a large-amplitude transverse oscillation of a continuously injected electron bunch through the hosing of the bubble induced by the carrier envelope phase (CEP) effect of the self-steepened laser pulse. Our method increases the critical photon energy to the MeV level, according to the results of particle-in-cell (PIC) simulations. The highly collimated, energetic and femtosecond γ-ray bursts that are produced in this way may provide an interesting potential means of exploring nuclear physics in table top photo nuclear reactions.

10.
Tokai J Exp Clin Med ; 41(1): 42-5, 2016 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-27050895

RESUMEN

We report a case of vulvar aggressive angiomyxoma (AA) which is a rare, slow growing and benign tumor of mesenchymal origin, but has a high risk of local recurrence. A 49-year-old Japanese female was referred to us with a large mass of the left vulva, measuring 15×9.5×9 centimeters. She underwent surgical excision of the tumor with no evidence of recurrence on a 5-year follow up. In this case, histopathological examination and immunohistochemical staining after excision revealed a diagnosis of vulvar AA with estrogen and progesterone receptors positive. Aggressive angiomyxoma of the vulva needs to be distinguished from benign myxoid tumor with a low risk of local recurrence as well as from malignant neoplasma. The first line treatment of AA is complete surgical excision with tumor free margins, it will reduce the recurrence.


Asunto(s)
Angiomioma/patología , Angiomioma/cirugía , Neoplasias de la Vulva/patología , Neoplasias de la Vulva/cirugía , Angiomioma/diagnóstico , Angiomioma/metabolismo , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia/prevención & control , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Riesgo , Factores de Tiempo , Neoplasias de la Vulva/diagnóstico , Neoplasias de la Vulva/metabolismo
11.
Science ; 331(6013): 41-2, 2011 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-21212346
12.
Radiol Phys Technol ; 3(1): 16-22, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20821097

RESUMEN

The results of Monte Carlo calculated dose distributions of proton treatment of ocular melanoma are presented. An efficient spot scanning method utilizing active energy modulation, which also minimizes the number of target spots was developed. We simulated various parameter values for the particle energy spread and the pencil beam diameter in order to determine values suitable for medical treatment. We found that a 2.5-mm-diameter proton beam with a 5% Gaussian energy spread was suitable for treatment of ocular melanoma while preserving vision for the typical case that we simulated. The energy spectra and the required proton current were also calculated and are reported. The results are intended to serve as a guideline for a new class of low-cost, compact accelerators.


Asunto(s)
Neoplasias del Ojo/radioterapia , Melanoma/radioterapia , Terapia de Protones , Dosis de Radiación , Neoplasias del Ojo/patología , Humanos , Rayos Láser , Melanoma/patología , Método de Montecarlo , Órganos en Riesgo/efectos de la radiación , Dosificación Radioterapéutica , Carga Tumoral
13.
Appl Opt ; 49(11): 2105-15, 2010 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-20390013

RESUMEN

We have developed a femtosecond high-intensity laser system that combines both Ti:sapphire chirped-pulse amplification (CPA) and optical parametric CPA (OPCPA) techniques and produces more than 30 J broadband output energy, indicating the potential for achieving peak powers in excess of 500 TW. With a cleaned high-energy seeded OPCPA preamplifier as a front end in the system, for the compressed pulse without pumping the final amplifier, we found that the temporal contrast in this system exceeds 10(10) on the subnanosecond time scales, and is near 10(12) on the nanosecond time scale prior to the peak of the main femtosecond pulse. Using diffractive optical elements for beam homogenization of a 100 J level high-energy Nd:glass green pump laser in a Ti:sapphire final amplifier, we have successfully generated broadband high-energy output with a near-perfect top-hat-like intensity distribution.


Asunto(s)
Rayos Láser , Óptica y Fotónica , Óxido de Aluminio/química , Amplificadores Electrónicos , Diseño de Equipo , Riesgo , Procesamiento de Señales Asistido por Computador/instrumentación , Factores de Tiempo , Titanio/química
14.
Artículo en Inglés | MEDLINE | ID: mdl-20228616

RESUMEN

Laser acceleration is based on the concept to marshal collective fields that may be induced by laser. In order to exceed the material breakdown field by a large factor, we employ the broken-down matter of plasma. While the generated wakefields resemble with the fields in conventional accelerators in their structure (at least qualitatively), it is their extreme accelerating fields that distinguish the laser wakefield from others, amounting to tiny emittance and compact accelerator. The current research largely falls on how to master the control of acceleration process in spatial and temporal scales several orders of magnitude smaller than the conventional method. The efforts over the last several years have come to a fruition of generating good beam properties with GeV energies on a table top, leading to many applications, such as ultrafast radiolysis, intraoperative radiation therapy, injection to X-ray free electron laser, and a candidate for future high energy accelerators.


Asunto(s)
Rayos Láser , Aceleradores de Partículas
15.
Fertil Steril ; 94(1): 305-8, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19269632

RESUMEN

OBJECTIVE: To show soluble fms-like tyrosine kinase 1 (sFlt1) levels in sera from patients with hydatidiform mole, which is known to predispose women to severe early-onset preeclampsia. DESIGN: Comparative study. SETTING: University hospital and surrounding community hospitals. PATIENT(S): Seven women with pathologically diagnosed complete hydatidiform mole (mole group), 21 gestational- and maternal-age-matched women who did not develop any pregnant complication during their pregnancy (control group), and eight women who subsequently developed preeclampsia (preclinical preeclampsia group). INTERVENTION(S): Blood samples were taken before and after evacuations of hydatidiform mole. MAIN OUTCOME MEASURE(S): Concentrations of sFlt1 and free placental growth factor (PlGF) in serum were measured by ELISA. RESULT(S): Serum sFlt1 concentrations were significantly higher in the mole group compared with the control group and the preclinical preeclampsia group. In contrast, serum free PlGF concentrations were significantly lower in the mole group. In the mole group, there was a significant negative correlation between sFlt1 and PlGF serum concentrations. After the evacuation of hydatidiform mole, the level of serum sFlt1 decreased dramatically. CONCLUSION(S): Elevated levels of sFlt1 were noted in molar gestations and may play in a role in early-onset preeclampsia reported in such pregnancies.


Asunto(s)
Mola Hidatiforme/diagnóstico , Mola Hidatiforme/enzimología , Receptor 1 de Factores de Crecimiento Endotelial Vascular/sangre , Adulto , Biomarcadores/sangre , Femenino , Humanos , Mola Hidatiforme/sangre , Embarazo , Solubilidad , Receptor 1 de Factores de Crecimiento Endotelial Vascular/biosíntesis , Adulto Joven
16.
Hum Reprod ; 24(2): 408-14, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18978361

RESUMEN

BACKGROUND: The increase in concentration of osteoprotegerin, an antagonist of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), in the peritoneal fluid of women with endometriosis may interfere with TRAIL-induced apoptosis in endometriotic cells and promote the development of endometriosis. In the present study, the effect of tunicamycin, a possible apoptosis enhancer, on TRAIL-induced apoptosis in endometriotic stromal cells (ESC) was determined. METHODS: ESC were isolated from cyst walls of ovarian endometrioma and cultured. ESC were incubated with or without tunicamycin (2 microg/ml) for the first 16 h, and then incubated with or without TRAIL (200 ng/ml) for the following 24 h. To examine whether caspases were involved in TRAIL-induced apoptosis, z-VAD-fmk (30 microM), a general caspase inhibitor, was added 1 h before TRAIL treatment. ESC were transfected with small interfering RNA (siRNA) for DR5, a receptor of TRAIL, before tunicamycin treatment to evaluate its role in ESC. DR5 mRNA level was determined by quantitative RT-PCR. Apoptosis in ESC was evaluated by flow cytometry. RESULTS: Tunicamycin increases both DR5 mRNA (P < 0.005) and TRAIL-induced apoptosis (P < 0.0001) in ESC. The increase in TRAIL-induced apoptosis in ESC by tunicamycin was suppressed (P < 0.05) by z-VAD-fmk. Transfection with DR5 siRNA suppressed the tunicamycin-induced increase in DR5 mRNA and abrogated the up-regulation of TRAIL-induced apoptosis by tunicamycin. CONCLUSIONS: The combined treatment with tunicamycin and TRAIL may have therapeutic potential in the treatment of endometriosis.


Asunto(s)
Antibacterianos/farmacología , Apoptosis/efectos de los fármacos , Endometriosis/patología , Células del Estroma/efectos de los fármacos , Ligando Inductor de Apoptosis Relacionado con TNF/fisiología , Tunicamicina/farmacología , Células Cultivadas , Femenino , Expresión Génica/efectos de los fármacos , Humanos , Interferencia de ARN , ARN Mensajero/metabolismo , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/genética , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Células del Estroma/patología
17.
Endocrinology ; 150(1): 350-6, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18787030

RESUMEN

IL-1, secreted by human embryos and trophoblast cells, is important for successful implantation and pregnancy. We previously reported that IL-1beta induced IL-8 production in human endometrial stromal cells (ESCs) and that induction was regulated by substances implicated in implantation. In the present study using human primary cells in culture, we measured IL-1beta-induced production of IL-8 from endometrial epithelial cells (EECs) and ESCs and examined effects of the endometrium-derived IL-8 on migration and number of first-trimester villous cytotrophoblast cells (vCTs). Both basal and IL-1beta-induced IL-8 levels of cell supernatants were much higher in EECs than ESCs. Addition of IL-1beta to EECs increased the chemotactic activity of the supernatants to vCTs, and this effect was suppressed by immunoneutralization with anti-IL-8 antibody. Supernatants of IL-1beta-stimulated EECs yielded significantly higher number of vCTs compared with those of untreated EECs, and the effect was inhibited by IL-8 antibody. These findings suggest that IL-1 promotes implantation by stimulating EECs to produce IL-8, which subsequently induces migration of vCTs and contributes to survival of vCTs.


Asunto(s)
Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Endometrio/fisiología , Células Epiteliales/fisiología , Interleucina-1beta/farmacología , Interleucina-9/fisiología , Primer Trimestre del Embarazo , Adulto , Técnicas de Cultivo de Célula , Endometrio/citología , Endometrio/efectos de los fármacos , Células Epiteliales/citología , Células Epiteliales/efectos de los fármacos , Femenino , Humanos , Interleucina-8/farmacología , Persona de Mediana Edad , Embarazo
18.
Chem Commun (Camb) ; (41): 5167-9, 2008 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-18956057

RESUMEN

On the basis of the concept of site isolation in electrochemical reactions, we have successfully demonstrated acceleration of the deprotonation step in anodic methoxylation of fluoroethyl phenyl sulfides using silica gel supported bases.

19.
Am J Pathol ; 173(2): 463-9, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18599603

RESUMEN

Several lines of evidence indicate that the Th2 immune response is associated with endometriosis. Although an increased concentration of interleukin (IL)-4, a typical Th2 cytokine, has been reported in endometriotic tissues, the implication of this for endometriosis has not been determined. To investigate a possible role of IL-4 in the development of endometriosis, we examined the presence of IL-4-producing cells in endometriotic tissues and the effect of IL-4 on proliferation of endometriotic stromal cells. Endometriotic stromal cells were isolated from endometriotic tissues obtained from women undergoing surgery for endometrioma. Immunohistochemistry of endometriotic tissues revealed that IL-4-positive cells were abundant in the stroma. The effect of IL-4 on proliferation of endometriotic stromal cells was studied using cell counting and BrdU incorporation assays. IL-4 (0.1 to 10 ng/ml) significantly increased cell number and BrdU incorporation in a dose-dependent manner, and the proliferative effect of IL-4 was inhibited by anti-IL-4 receptor antibody. IL-4-induced activation of mitogen-activated protein kinases in endometriotic stromal cells was examined by Western blotting. IL-4 induced phosphorylation of p38 mitogen-activated protein kinase, stress-activated protein kinase/c-Jun kinase, and p42/44 mitogen-activated protein kinase and inhibitors of these kinases suppressed IL-4-induced proliferation of endometriotic stromal cells. These findings suggest that proliferation of endometriotic stromal cells induced by locally produced IL-4 is involved in the development of endometriosis.


Asunto(s)
Proliferación Celular , Endometriosis/metabolismo , Endometrio/patología , Interleucina-4/fisiología , Adulto , Bromodesoxiuridina , Endometriosis/patología , Femenino , Humanos , Quinasas de Proteína Quinasa Activadas por Mitógenos/fisiología , Receptores de Interleucina-4/metabolismo , Células del Estroma/fisiología
20.
J Org Chem ; 73(17): 6888-90, 2008 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-18652509

RESUMEN

We have developed a novel electrolytic system for Kolbe carbon-carbon coupling electrosynthesis based on the acid-base reaction between carboxylic acids as a substrate and solid-supported bases. On the basis of the electrolytic system, Kolbe electrolysis of various carboxylic acids was successfully carried out to provide the corresponding homocoupling products in moderate to excellent yields.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...