Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
2.
J Med Ultrason (2001) ; 40(3): 261-3, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27277246

RESUMEN

We report a case of persistent left superior vena cava (LSVC) with absent right superior vena cava (RSVC) diagnosed prenatally. At 27 weeks' gestation, routine fetal ultrasonography showed an abnormal four-chamber view. Fetal echocardiography revealed a markedly enlarged coronary sinus in the four-chamber view. An absent RSVC and a persistent LSVC were demonstrated in the three-vessel view. No additional cardiac malformations were seen before birth. Postnatal imaging confirmed the prenatal diagnosis. The combination of persistent LSVC and absent RSVC without any other cardiac malformations is an extremely rare cardiac anomaly and less commonly detected in utero. Identification of a dilated coronary sinus in the four-chamber view, with atypical features in the three-vessel view, may lead to the antenatal diagnosis of this condition.

3.
Biomed Phys Eng Express ; 9(2)2023 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-36623292

RESUMEN

This paper presents a method for estimating the x-ray energy spectrum for computed tomography (CT) in the diagnostic energy range from the reconstructed CT image itself. To this end, a virtual CT system was developed, and datasets, including CT images for the Gammex phantom labeled by the corresponding energy spectra, were generated. Using these datasets, an artificial neural network (ANN) model was trained to reproduce the energy spectrum from the CT values in the Gammex inserts. In the actual application, an aluminum-based bow-tie filter was used in the virtual CT system, and an ANN model with a bow-tie filter was also developed. Both ANN models without/with a bow-tie filter can estimate the x-ray spectrum within the agreement, which is defined as one minus the absolute error, of more than 80% on average. The agreement increases as the tube voltage increases. The estimation was occasionally inaccurate when the amount of noise on the CT image was considerable. Image quality with a signal-to-noise ratio of more than 10 for the basis material of the Gammex phantom was required to predict the spectrum accurately. Based on the experimental data acquired from Activion16 (Canon Medical System, Japan), the ANN model with a bow-tie filter produced a reasonable energy spectrum by simultaneous optimization of the shape of the bow-tie filter. The present method requires a CT image for the Gammex phantom only, and no special setup, thus it is expected to be readily applied in clinical applications, such as beam hardening reduction, CT dose management, and material decomposition, all of which require exact information on the x-ray energy spectrum.


Asunto(s)
Redes Neurales de la Computación , Tomografía Computarizada por Rayos X , Rayos X , Tomografía Computarizada por Rayos X/métodos , Relación Señal-Ruido , Fantasmas de Imagen
4.
J Med Ultrason (2001) ; 39(1): 25-7, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27278702

RESUMEN

Congenitally corrected transposition of the great arteries (cTGA) is an uncommon cardiac malformation characterized by discordant atrioventricular and ventriculoarterial connections. Most cases of cTGA are associated with cardiac anomalies. As the ventricular outflow tract may appear to arise correctly from the right and left ventricles, cases of cTGA with a mild associated anomaly are rarely detected prenatally. Parallel vessels are evident in cTGA, but this sign is also present in complete TGA. We report a case of cTGA diagnosed in utero at 29 weeks' gestation. The fetus was diagnosed as TGA and referred to our hospital at 28 weeks' gestation. cTGA was found at 29 weeks' gestation in our hospital, and no additional cardiac anomalies were seen prenatally. After birth, patent ductus arteriosus with bidirectional flow was present. Careful examination of the four-chamber view suggested atrioventricular discordance. Identification of a parallel course of the great vessels, with the aorta anterior and to the left of the pulmonary trunk (l-transposition), may help accurate prenatal diagnosis of cTGA.

5.
J Med Ultrason (2001) ; 39(3): 177-80, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27278979

RESUMEN

We report a case of amniotic band syndrome diagnosed prenatally by serial sonographic examinations. Our initial sonographic image showed a large fetal nuchal translucency (NT) at 12 weeks' gestation. Repeated fetal ultrasound images revealed an amniotic band and right upper limb anomaly. Fetal MRI at 19 weeks' gestation revealed right forearm hypoplasia and pseudosyndactyly. The fetus was prenatally diagnosed with amniotic band syndrome and was suspected of having severe functional impairment of the deformed limb. The parents decided to terminate the pregnancy at 21 weeks' gestation. In fetuses with aneuploidy and various structural and genetic abnormalities, the NT thickness is increased in the first trimester. As far as we are aware, this is the first case report of increased NT and limb anomaly associated with amniotic band syndrome. In chromosomally normal fetuses with increased NT, intensive sonographic follow-up should provide grounds for a precise antenatal diagnosis.

6.
Appl Opt ; 50(34): H183-8, 2011 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-22193006

RESUMEN

We firstly demonstrate the three-dimensional (3D) measurement of a nanometer-sized sphere held in optical tweezers in water using an in-line digital holographic microscope with a green light emitting diode. Suppressing the movement with optical tweezers enabled us to detect the three-dimensional position of a polystyrene sphere with a diameter of 200 nm. The positioning resolutions of the microscope were 3.2 nm in the transverse direction and 3.4 nm in the axial direction, from the standard deviation of measurements of the 200 nm sphere fixed on glass. Changes in the Brownian motion in response to a change in the trapping laser power were measured. We also demonstrated that this holographic measurement is an effective method for determining the threshold power of the optical trapping.

7.
J Matern Fetal Neonatal Med ; 33(9): 1628-1630, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-30196740

RESUMEN

Background: We aimed to investigate whether there was a high incidence of young Japanese mothers being underweight (pregravid body mass index [BMI] < 18.5 kg/m2) and if they delivered infants who were small for gestational age (SGA).Materials and methods: Our study was carried out from 2013 to 2017 and included adolescent women (maternal age at delivery: <20 years old; n = 94), women in their early twenties (maternal age at delivery: 20-24 years; n = 479), and controls (maternal age at delivery: 25-34 years; n = 2061).Results: In both the adolescent and early twenties groups, the incidence of being underweight, based on prepregnancy BMI, was significantly higher than controls (p < .0001 and p < .05, respectively). In both groups, gestational weight gain (GWG) was significantly higher than controls (p < .0001). There were no notable group differences in the incidences of SGA.Conclusion: The incidence of being underweight was higher in younger mothers than in controls. However, the risk of SGA did not increase in younger mothers, possibly because their GWG overcame the influence of their pre-pregnancy body composition.


Asunto(s)
Composición Corporal , Recién Nacido Pequeño para la Edad Gestacional , Delgadez/epidemiología , Adolescente , Adulto , Estudios de Casos y Controles , Femenino , Ganancia de Peso Gestacional , Humanos , Incidencia , Japón/epidemiología , Embarazo , Complicaciones del Embarazo/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Adulto Joven
8.
Gynecol Minim Invasive Ther ; 9(2): 54-58, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32676280

RESUMEN

OBJECTIVES: There are no data describing the correlation between placenta implantation at prior myomectomy locations and perinatal outcomes in pregnant women after transcervical resection myomectomy (TCR-M). The aim of the study is to investigate the correlations between placenta implantation at prior myomectomy locations and perinatal outcomes in pregnant women who had previously undergone TCR-M. MATERIALS AND METHODS: This was a retrospective, single-center study. We reviewed the records of 34 pregnant women who had previously undergone TCR-M for submucosal myoma and perinatal care in our hospital between January 2012 and January 2019. We examined surgical and pregnancy outcomes and evaluated correlations between placenta implantation at prior myomectomy locations and perinatal outcomes in women who delivered after 22 gestational weeks (n = 24). RESULTS: Median maternal age at conception was 38 years (range, 28-44) and median duration between TCR-M and conception was 1.4 years (range, 0.3-5.8). There were 24 deliveries after 22 gestational weeks and 10 pregnancy losses. Among these 24 deliveries, the median gestational age at delivery was 39 weeks (range, 34-41); median birthweight, 3025 g (range, 2092-4012); and median blood loss at delivery, 573 g (range, 100-3000). There were no cases of placenta accreta and uterine rupture. Placenta implantation at a prior myomectomy location was detected in 14/24 women using transabdominal ultrasonography. Median blood loss was significantly higher in the implantation than in the nonimplantation group (P < 0.01). CONCLUSION: Our one-step TCR-M is useful for women with submucosal myoma. However, we suggest that clinicians should review and check the association between prior myomectomy locations and placenta implantation.

9.
Fetal Diagn Ther ; 25(1): 76-8, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19218806

RESUMEN

We report a case of retroperitoneal teratoma diagnosed prenatally by serial sonographic examinations in the third trimester. A 29-year-old woman was referred for sonographic evaluation at 33 weeks' gestation because of a fetal intra-abdominal mass. Our initial sonographic image suggested a neuroblastoma. Repeat ultrasound images demonstrated an increase in size of the tumor, while the content of the tumor became predominantly solid with areas of calcification. Teratoma should be considered on detection of any cystic or mixed semisolid mass, especially when calcification is present. The fetus was prenatally diagnosed with retroperitoneal teratoma. After birth at 39 weeks, the tumor was removed and histological analysis revealed an immature retroperitoneal teratoma. Intensive monitoring of the changes in ultrasound images of the tumor should provide ground for a precise antenatal diagnosis.


Asunto(s)
Neoplasias Retroperitoneales/diagnóstico por imagen , Teratoma/diagnóstico por imagen , Ultrasonografía Prenatal , Adulto , Femenino , Feto/patología , Humanos , Imagen por Resonancia Magnética , Embarazo , Neoplasias Retroperitoneales/cirugía , Teratoma/cirugía
10.
J Clin Endocrinol Metab ; 93(6): 2402-8, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-18364383

RESUMEN

CONTEXT: Although the inner fetal zone (FZ) of the mid-gestation human fetal adrenal (HFA) produces dehydroepiandrosterone sulfate, the function of the outer definitive zone (DZ) remains less clear. We have proposed that the DZ phenotype is that of a pool of progenitor cells, many of which are mitotically active. Recently, we studied HFA expression of a family of vascular endothelial cell-specific angiogenic factors, the angiopoietins (Angs), and demonstrated that Ang2 was localized predominantly in the periphery of the gland. Ang1 stabilizes, whereas Ang2 destabilizes, vessels, increasing responsiveness to angiogenic stimuli such as vascular endothelial growth factor (VEGF)-A and fibroblast growth factor (FGF)-2. OBJECTIVE: Our objective was to test the hypothesis that the periphery of the HFA is a site of angiogenesis. DESIGN: Studies were conducted involving RNA, frozen sections, and primary cell cultures from midgestation HFAs. MAIN OUTCOME MEASURES: Immunofluorescence, laser capture microdissection, and real-time quantitative RT-PCR were used. RESULTS: Double immunostaining demonstrated that proliferating endothelial cells were limited to the DZ and DZ/FZ border. Ang2 mRNA was primarily expressed in the DZ, whereas Ang1 mRNA was primarily in the FZ. VEGF-A and FGF-2 mRNA levels were higher in the DZ. FGF-2 (10 ng/ml) induced Ang2 mRNA by 4-fold in both zones of cells (P < 0.01, at 24 h), but not Ang1 or VEGF-A mRNA. CONCLUSION: Data suggest that angiogenesis occurs at the periphery of the HFA. The DZ-predominant expression of Ang2 may be explained, in part, by the parallel pattern of FGF-2 expression.


Asunto(s)
Glándulas Suprarrenales/irrigación sanguínea , Glándulas Suprarrenales/embriología , Proteínas Angiogénicas/genética , Proteínas Angiogénicas/metabolismo , Diferenciación Celular/genética , Neovascularización Fisiológica/genética , Glándulas Suprarrenales/metabolismo , Angiotensina I/genética , Angiotensina I/metabolismo , Angiotensina II/genética , Angiotensina II/metabolismo , Células Cultivadas , Células Endoteliales/metabolismo , Células Endoteliales/fisiología , Femenino , Feto/irrigación sanguínea , Feto/metabolismo , Factor 2 de Crecimiento de Fibroblastos/genética , Factor 2 de Crecimiento de Fibroblastos/metabolismo , Regulación del Desarrollo de la Expresión Génica , Edad Gestacional , Humanos , Modelos Biológicos , Neovascularización Fisiológica/fisiología , Embarazo , ARN Mensajero/metabolismo , Distribución Tisular , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo
11.
J Clin Endocrinol Metab ; 91(10): 4050-6, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16895951

RESUMEN

CONTEXT: In the human fetal adrenal gland (HFA), the inner fetal zone (FZ) secretes dehydroepiandrosterone sulfate. The function of the outer definitive zone (DZ) is less clear; however, the DZ phenotype is that of a reservoir of progenitor cells, many of which are mitotically active. Midkine (MK) is a heparin-binding growth factor with various bioactivities. OBJECTIVE: The objective of this study was to investigate expression, proliferative effects, and ACTH regulation of MK in the HFA. DESIGN AND SETTING: RNA, cryosections, and primary cell cultures from HFAs (14-24 wk) and adult adrenal RNA were used. MAIN OUTCOME MEASURES: The main outcome measures were MK mRNA levels (measured by quantitative real-time RT-PCR); MK localization (measured by immunostaining); MK proliferative effects and mechanism (measured by proliferation assays, flow cytometry, pharmacological interventions); and ACTH regulation (measured by quantitative real-time RT-PCR). RESULTS: HFA MK mRNA levels were 4-fold higher than in adult adrenals (P < 0.05) and were comparable to levels in fetal and adult brains (positive controls). MK immunoreactivity was abundant throughout the HFA. Exogenous MK caused proliferation of isolated DZ cells but not FZ cells (72 h, P < 0.05). In contrast, basic fibroblast growth factor induced proliferation of cells from both zones. Pharmacological interventions indicated that MK-induced DZ cell proliferation may be mediated by phosphatidylinositol 3-kinase, MAPK kinase, and Src family kinases. ACTH (1 nm) increased MK mRNA by 3.5-fold (48 h, P < 0.01) in isolated FZ cells. CONCLUSIONS: MK likely plays a key role in HFA development. MK's selective in vitro mitotic effects on DZ cells may provide insights into the mechanism underlying the distinct in vivo differences in mitotic activity between the DZ and FZ.


Asunto(s)
Glándulas Suprarrenales/embriología , Citocinas/fisiología , Hormona Adrenocorticotrópica/farmacología , Proteínas Portadoras/genética , Proliferación Celular , Citocinas/análisis , Citocinas/genética , Femenino , Humanos , Midkina , Embarazo , ARN Mensajero/análisis
12.
Jpn J Radiol ; 31(4): 289-92, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23385378

RESUMEN

We report a case of body stalk anomaly detected prenatally by fetal magnetic resonance imaging (MRI) at 14 weeks' gestation. A 29-year-old woman was followed during her first pregnancy. At 11-12 weeks' gestation, our sonographic images showed multiple fetal deformities. An abdominal wall defect was suspected. The exteriorized abdominal contents and the lower limb appeared within the extraembryonic celom with an intact amniotic membrane. Fetal MRI at 14 weeks' gestation confirmed a large anterior wall defect with herniation of the liver and bowel. In addition, abnormally rotated lower limb and scoliosis could be demonstrated. The fetus was prenatally diagnosed with body stalk anomaly, expected to be lethal in nature. The parents decided to terminate the pregnancy at 15 weeks' gestation. Prenatal diagnosis of body stalk anomaly is usually based on sonographic findings. As far as we are aware, this is the first case report of body stalk anomaly satisfactorily diagnosed by fetal MRI in the early second trimester. Fetal MRI scans should provide ground for a precise antenatal diagnosis of body stalk anomaly from early gestation.


Asunto(s)
Anomalías Múltiples/diagnóstico , Anomalías Múltiples/embriología , Imagen por Resonancia Magnética , Adulto , Femenino , Humanos , Embarazo , Segundo Trimestre del Embarazo , Diagnóstico Prenatal/métodos
13.
Endocrinology ; 150(7): 3353-9, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19325000

RESUMEN

Ovary-specific acidic protein (OSAP) is a novel molecule discovered from a genomic project designed to identify ovary-selective genes in mice. Whereas public databases suggest extraovarian expression of OSAP, its tissue distribution has not yet been well documented. Thus, the expression profile of mouse and human OSAP was determined by quantitative real-time RT-PCR using RNAs isolated from various tissues. The results demonstrate that the human and mouse OSAP expression profiles are similar; OSAP is prominently expressed in steroidogenic tissues with the highest level of expression observed in the adrenal gland. Placenta served as an exception and possessed minimal level of OSAP mRNA. Immunohistochemical studies show that mouse OSAP localizes almost exclusively to the steroid-producing cells of the ovary, adrenal gland, and testis. Consistent with predictions made by several subcellular localization algorithms, dual labeling studies in Y-1 mouse adrenocortical cells indicate OSAP resides in the mitochondria. Because of its abundant expression in steroidogenic cells and mitochondrial localization, a role for OSAP in steroidogenesis was determined. OSAP silencing by specific small interfering RNAs significantly inhibits 8-bromoadenosine-cAMP-induced progesterone production in Y-1 cells. Reduction in OSAP levels results in mitochondrial fragmentation and a decrease in the cellular content of mitochondrial DNA, indicative of decreased mitochondrial abundance. Lastly, 8-bromoadenosine-cAMP does not regulate OSAP protein expression in Y-1 cells as is the case for other steroidogenic components known to be induced by cAMP. Collectively these results suggest that OSAP is involved in steroidogenesis, potentially through its ability to maintain mitochondrial abundance and morphology.


Asunto(s)
Ovario/metabolismo , Proteínas/metabolismo , Esteroides/biosíntesis , Glándulas Suprarrenales/metabolismo , Animales , Proteínas del Ojo , Femenino , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Humanos , Masculino , Proteínas de la Membrana , Ratones , Mitocondrias/metabolismo , Proteínas Mitocondriales , Progesterona/biosíntesis , Proteínas/genética , Interferencia de ARN , Testículo/metabolismo , Distribución Tisular
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA