Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
1.
Rev Sci Instrum ; 86(1): 013501, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25638080

RESUMEN

The objective of the present study was to investigate the feasibility of stretching an arc discharge in produced water to increase the volume of produced water treated by plasma. Produced water is the wastewater generated by hydraulic fracturing of shale during the production phase in shale-oil or shale-gas exploration. The electric conductivity of produced water is in the range of 50-200 mS/cm, which provides both a challenge and opportunity for the application of plasmas. Stretching of an arc discharge in produced water was accomplished using a ground electrode and two high-voltage electrodes: one positioned close to the ground electrode and the other positioned farther away from the ground. The benefit of stretching the arc is that the contact between the arc and water is significantly increased, resulting in more efficient plasma treatment in both performance and energy cost.

2.
Cell Prolif ; 40(1): 75-90, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17227297

RESUMEN

OBJECTIVES: To characterize mesenchymal stem cell-like cells isolated from human amniotic fluid for a new source of therapeutic cells. MATERIALS: Fibroblastoid-type cells obtained from amniotic fluid at the time of birth. METHODS: The ability of ex vivo expansion was investigated until senescence, and stem cell-like characteristics were analyzed by examining differentiation potential, messenger RNA expression and immunophenotypes. RESULTS AND CONCLUSIONS: A morphologically homogenous population of fibroblastoid-type (HAFFTs) cells, similar to mesenchymal stem cells from bone marrow (BM-MSCs), was obtained at the third passage. The cells became senescent after 27 passages over a period of 8 months while undergoing 66 population doublings. Under appropriate culture conditions, by the 8th passage they differentiated into adipocytes, osteocytes, chondrocytes and neuronal cells, as revealed by oil red O, von Kossa, Alcian blue and anti-NeuN antibody staining, respectively. Immunophenotype analyses at the 17th passage demonstrated the presence of TRA-1-60; SSEA-3 and-4; collagen types I, II, III, IV and XII; fibronectin; alpha-SMA; vimentin; desmin; CK18; CD44; CD54; CD106; FSP; vWF; CD31; and HLA ABC. Reverse transcriptase-polymerase chain reaction analysis of the HAFFTs from passages 6-20 showed consistent expression of Rex-1, SCF, GATA-4, vimentin, CK18, FGF-5 and HLA ABC genes. Oct-4 gene expression was observed up to the 19th passage but not at the 20th passage. HAFFTs showed telomerase activity at the 5th passage with a decreased level by the 21st passage. Interestingly, BMP-4, AFP, nestin and HNF-4alpha genes showed differential gene expression during ex vivo expansion. Taken together, these observations suggest that HAFFTs are pluripotent stem cells that are less differentiated than BM-MSCs, and that their gene expression profiles vary with passage number during ex vivo expansion.


Asunto(s)
Líquido Amniótico/citología , Células Madre Multipotentes/fisiología , Células Madre/fisiología , Líquido Amniótico/inmunología , Técnicas de Cultivo de Célula/métodos , Diferenciación Celular , Células Cultivadas , Femenino , Humanos , Inmunohistoquímica , Células Madre Multipotentes/inmunología , Células Madre Multipotentes/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Madre/inmunología , Células Madre/metabolismo , Telomerasa/metabolismo
3.
Hum Reprod ; 22(3): 843-9, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17077107

RESUMEN

BACKGROUND: Endometriosis is considered a frequent, benign disease with the ability to undergo neoplastic processes. The aim of this study was to evaluate the limitless replication potential of the endometrium in patients with endometriosis by examining human telomerase reverse transcriptase (hTERT) mRNA expression and telomerase activity. METHODS: Endometrium samples from 30 endometriosis patients and 30 patients without endometriosis were obtained via endometrial biopsy. The expression of hTERT mRNA was determined by real-time RT-PCR assay, and telomerase activity was measured by telomerase repeat amplification protocol (TRAP) assay. RESULTS: The mean normalized hTERT (N hTERT) mRNA level was significantly higher in the endometriosis than in the control group (P = 0.013). The mean hTERT mRNA levels during the proliferative phase and during the secretory phase were higher in the endometriosis group than in the control group, although the difference was only significant for the secretory phase (P = 0.036). We found a prominent difference in endometrial telomerase activity between moderate-to-severe endometriosis and the control group (P = 0.048). The levels of hTERT mRNA and telomerase activity increased as the disease became more severe (P = 0.038, P = 0.016). CONCLUSIONS: This study showed the overexpression of hTERT mRNA and telomerase activity in the endometrium of endometriosis patients. These finding suggest that replication potential of endometrial cells may have an important role in the pathogenesis of endometriosis.


Asunto(s)
Endometriosis/enzimología , Endometrio/enzimología , Telomerasa/metabolismo , Adulto , Femenino , Humanos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Telomerasa/genética
4.
Yonsei Med J ; 42(3): 345-8, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11456402

RESUMEN

A phenotypically normal couple was referred for cytogenetic evaluation due to three consecutive first-trimester spontaneous abortions. Chromosomal analysis from peripheral blood was performed according to standard cytogenetic methods using G-banding technique. The husband's karyotype was normal. The wife's karyotype showed a balanced complex chromosome rearrangement (CCR) involving chromosomes 9, 14, and 13. There were three breakpoints: 9p21.2, 14q21, and 13q12.2. The karyotype was designated as 46, XX, t (9;14;13)(p21.2;q21;q12.2). Fluorescence in situ hybridization (FISH) analysis with chromosome-specific libraries of chromosomes 9, 14, and 13 was performed to confirm this rare chromosome rearrangement. The result of FISH coincided with that obtained by standard cytogenetic techniques.


Asunto(s)
Aborto Habitual/genética , Aberraciones Cromosómicas , Cromosomas Humanos Par 13 , Cromosomas Humanos Par 14 , Cromosomas Humanos Par 9 , Adulto , Femenino , Humanos , Hibridación Fluorescente in Situ , Embarazo
5.
Yonsei Med J ; 42(2): 199-203, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11371107

RESUMEN

The purpose of this article is to assess the value of maternal serum triple marker screening of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE3) for the prenatal diagnosis of fetal chromosomal abnormalities in Korean women of advanced maternal age. Maternal sera were collected from 458 pregnant Korean women aged 35 between 15 and 20 weeks gestation before amniocentesis. A patient- specific second trimester risk for fetal Down's syndrome was calculated using the median values for AFP, hCG, uE3 and maternal age. Twelve fetal chromosomal abnormalities were identified. These included six cases of trisomy 21, one case of 46,XY/47,XY,+21, two cases of trisomy 18, one case of trisomy 13, and two cases of 45, X. A cutoff level of 1:200 detected 85.7% (6/7) of the cases of Down's syndrome and 20% (1/5) of the other aneuploidies, with a 27.3% false positive rate. However, a cutoff level of 1:270 did not result in any gains in detecting Down's syndrome or other aneuploidies at the expense of a false positive rate of 34.3%. Second trimester triple marker testing is an effective screening tool for detecting fetal Down's syndrome in Korean women > or = 35 years old. However, it is not an effective screening tool for non-Down's chromosomal abnormalities.


Asunto(s)
Aberraciones Cromosómicas/genética , Feto/fisiología , Pruebas Genéticas , Edad Materna , Embarazo de Alto Riesgo , Adulto , Trastornos de los Cromosomas , Femenino , Marcadores Genéticos , Humanos , Embarazo
6.
AJR Am J Roentgenol ; 175(5): 1381-6, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11044048

RESUMEN

OBJECTIVE: The objective of this study was to investigate the usefulness of helical CT angiography in the evaluation of total anomalous pulmonary venous connections. MATERIALS AND METHODS: Fourteen patients with total anomalous pulmonary venous connections underwent helical CT angiography and subsequent three-dimensional (3D) reconstruction. They ranged in age from 3 days to 8 months (median age, 2.3 months) and in weight from 2.3 to 7.1 kg (median weight, 4.3 kg). The types of total anomalous pulmonary venous connections and the number of pulmonary veins were evaluated on axial and 3D images. Qualitative evaluations were performed for extent of pulmonary vascular enhancement and contrast- or motion-induced artifacts. RESULTS: In all patients, helical CT angiography correctly depicted total anomalous pulmonary venous connections. Seven cases were the supracardiac type, four cases were the cardiac type, one case was the infracardiac type, and two cases were the mixed type. The detection rate of the pulmonary vein in 3D reconstruction images (95-98%) was slightly lower than that of the pulmonary vein in the axial images (100%), but the difference between axial and 3D reconstruction images was not statistically significant (p > 0.1). No statistically significant differences were noted among 3D reconstruction images in the detection rates of the pulmonary vein (p > 0.1). The extent of contrast enhancement of the pulmonary vein was good or excellent in all patients. In five patients, there were contrast-induced artifacts that made some surrounding vascular distortion but did not interfere with the pulmonary vein analysis, except in one patient. Motion-induced artifacts were observed in nine patients. One of them had an obstacle in pulmonary vein analysis. CONCLUSION: The combination of axial and 3D images in helical CT angiography is helpful in the assessment of a total anomalous pulmonary venous connection containing the individual pulmonary vein, and this combination can be a good diagnostic tool in preoperative evaluation of neonates and infants with a total anomalous pulmonary venous connection.


Asunto(s)
Angiografía/métodos , Imagenología Tridimensional , Yohexol/análogos & derivados , Venas Pulmonares/anomalías , Tomografía Computarizada por Rayos X/métodos , Artefactos , Venas Braquiocefálicas/anomalías , Venas Braquiocefálicas/diagnóstico por imagen , Medios de Contraste , Anomalías de los Vasos Coronarios/diagnóstico por imagen , Presentación de Datos , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Lactante , Recién Nacido , Variaciones Dependientes del Observador , Vena Porta/anomalías , Vena Porta/diagnóstico por imagen , Venas Pulmonares/diagnóstico por imagen , Intensificación de Imagen Radiográfica/métodos , Vena Cava Superior/anomalías , Vena Cava Superior/diagnóstico por imagen
7.
J Obstet Gynaecol Res ; 26(3): 209-13, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10932984

RESUMEN

OBJECTIVE: To assess the adverse pregnancy outcome of post-chorionic villus sampling (CVS) amniocentesis and chorionic villus sampling. METHODS: Adverse pregnancy outcomes of 32 post-CVS amniocentesis cases and 264 CVS only cases were compared. The base-line characteristics were comparable in the 2 groups. RESULTS: One (3.1%) chromosomal abnormality was detected in the post-CVS amniocentesis group, compared to 5 (1.8%) in the CVS only group (p > 0.05). The fetal loss rate (spontaneous abortions and stillbirths) among continuing pregnancies was 3.2% in the post-CVS amniocentesis group and 3.5% in the CVS only group (p > 0.05). No statistically significant difference was found in the incidence of neonatal death, preterm delivery, fetal growth restriction, or congenital anomalies between the 2 groups. CONCLUSION: Adverse pregnancy outcome occurred at a similar frequency in the post-CVS amniocentesis group as in the CVS only group. Therefore, a subsequent amniocentesis after CVS can be considered as a safe procedure that does not introduce any additional adverse pregnancy outcome compared to that of CVS only.


Asunto(s)
Amniocentesis/efectos adversos , Muestra de la Vellosidad Coriónica/efectos adversos , Resultado del Embarazo , Adulto , Aberraciones Cromosómicas , Femenino , Muerte Fetal , Retardo del Crecimiento Fetal , Humanos , Mortalidad Infantil , Recién Nacido , Trabajo de Parto Prematuro , Embarazo
8.
Ann Thorac Surg ; 70(6): 1918-22, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11156095

RESUMEN

BACKGROUND: A high incidence of pulmonary arteriovenous fistulas (PAVF) has been reported after bidirectional cavopulmonary shunt (BCPS) or total cavopulmonary shunt (TCPS; BCPS in patients with interrupted inferior vena cava). However, the definite diagnostic criteria or standard diagnostic modality of PAVF has not yet been defined. The goal of this study was to evaluate the diagnostic modalities and the prevalence of PAVF. METHODS: We selected 10 patients with TCPS and 27 patients with BCPS. Lung perfusion scan, contrast echocardiogram, and pulmonary angiogram were performed. The results were compared among groups of patients and among each diagnostic modality. RESULTS: All 10 patients with TCPS and 16 and 13 patients with BCPS showed positive results on contrast echocardiograms and lung scans, respectively. Six patients with TCPS and 4 patients with BCPS showed positive results on pulmonary angiograms. All patients with TCPS developed subclinical or clinical PAVF and 19 patients with BCPS developed subclinical PAVF and none of them had clinical PAVF during the short-term follow-up. CONCLUSIONS: Most patients with bidirectional cavopulmonary anastomosis have subclinical evidence of right-to-left intrapulmonary shunting. This problem can be demonstrated with various diagnostic modalities.


Asunto(s)
Fístula Arteriovenosa/diagnóstico , Puente Cardíaco Derecho , Cardiopatías Congénitas/cirugía , Complicaciones Posoperatorias/diagnóstico , Arteria Pulmonar , Venas Pulmonares/cirugía , Fístula Arteriovenosa/cirugía , Niño , Preescolar , Diagnóstico por Imagen , Femenino , Estudios de Seguimiento , Humanos , Lactante , Masculino , Complicaciones Posoperatorias/cirugía , Arteria Pulmonar/cirugía , Reoperación
9.
Yonsei Med J ; 40(5): 450-3, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10565255

RESUMEN

To determine how endometrium alone would contribute to maintaining the circulating levels of Insulin-like growth factor binding protein-1 in vivo, serum immunoreactive IGFBP-1 levels were measured in 19 patients undergoing endometrial ablation using gynecologic resectoscopy. After endometrial ablation there was a significant decrease in the mean levels of circulating IGFBP-1, which was not correlated with the menstrual cycle. This result indicates that the endometrium is one of the sources of the circulating IGFBP-1.


Asunto(s)
Endometrio/cirugía , Proteína 1 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Adulto , Endoscopios , Femenino , Humanos , Menstruación , Persona de Mediana Edad
10.
Opt Lett ; 23(12): 969-71, 1998 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-18087400

RESUMEN

Spatial and temporal characteristics of a 128x128 zero-twist nematic liquid-crystal spatial light modulator are investigated for wave-front generation at a wavelength of 632.8 nm. The modulator is found to have the capability of producing at least eight phase levels between 0 and 2pi , and the rate of arbitrary phase modulation is limited to approximately 4.5 Hz. Wave-front generation of the first 55 Zernike polynomials is demonstrated.

11.
Arch Pharm Res ; 20(2): 176-9, 1997 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18975197

RESUMEN

Purine nucleosides were chlorinated by the reaction of acyl chloride in DMF with MCPBA under mild conditions with moderate yields. And, satisfactory method for the synthesis of ribonucleoside-3',5'-cyclic phosphates and its characterization by(1)H and(13)C nmr spectroscopy is described.

12.
Arch Pharm Res ; 20(1): 80-4, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18975217

RESUMEN

Substituted cinnamoyl-tyramine derivatives were synthesized by DCC-coupling of substituted cinnamic acid with tyramine or tyramine methyl-1-ether to evaluate PAF-receptor binding antagonistic activities and inhibitory activities on PAF-induced platelet aggregation with interest on structure-activity relations. The results show that 3,4-dimethoxy-cinnamoyl tyramine-amide or its methyl ether have significant PAF-receptor binding antagonistic activity and platelet anti-aggregatory activities.

13.
Appl Opt ; 34(5): 854-64, 1995 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-21037605

RESUMEN

A laboratory experiment that demonstrates near-diffraction-limited imaging of a detailed object in the presence of unknown fixed aberrations in the imaging system is described. A random-phase plate is introduced in a pupil plane of the imaging system to eliminate the effect of fixed aberrations in the system. We employ a bispectral speckle imaging technique to recover the object from speckled images affected by both the random-phase fluctuations induced by the random-phase plate and the fixed aberrations present in the imaging system. For the case where the random phase is assumed to obey Gaussian statistics an approximate form of the bispectral speckle transfer function is obtained with an asymptotic expansion. This approximate form of the transfer function shows the diffraction-limited nature of bispectral speckle imaging when the standard deviation of the random-phase fluctuations is of the order of a wavelength of light. Experimental results are presented for fixed aberrations associated with lens tilt and defocus in the imaging system.

14.
Fertil Steril ; 59(2): 468-9, 1993 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8425652

RESUMEN

A 28-year-old married, Korean woman was diagnosed with a right unicornuate uterus, a left hypoplastic tube, and a right ovarian necrotic corpus luteal cyst. We performed a right oophorectomy and an excision of the left hypoplastic tube and then transferred the left ovary to the right broad ligament with intact vascular pedicles. Thus the remaining left ovary and right fallopian tube were placed in proximity. The patient conceived 2 months after the operation and delivered a living male infant.


Asunto(s)
Enfermedades de los Genitales Femeninos/complicaciones , Infertilidad Femenina/terapia , Ovario/cirugía , Embarazo , Adulto , Trompas Uterinas/anomalías , Trompas Uterinas/patología , Femenino , Enfermedades de los Genitales Femeninos/cirugía , Humanos , Infertilidad Femenina/etiología , Necrosis , Quistes Ováricos/complicaciones , Ovario/patología , Adherencias Tisulares/complicaciones , Adherencias Tisulares/cirugía , Útero/anomalías
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA