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1.
J Eur Acad Dermatol Venereol ; 34(7): 1590-1594, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31994253

RESUMEN

BACKGROUND: For clinical care and research in vitiligo, photographs with the use of ultraviolet (UV) light or Wood's lamp are often made. Conventional cameras are insensitive to UV light. The use of a UV camera (UV photography) might improve image quality and ameliorate the assessment of target lesions in vitiligo. OBJECTIVES: To determine image quality and the validity and reliability of UV photography for the assessment of vitiligo target lesions. METHODS: Images of patients with vitiligo were made with UV photography and a conventional camera, and lesions were drawn on graph paper and transparent sheets. Image quality was scored by vitiligo experts and medical interns. The intraclass correlation coefficients (ICCs) of the lesion size determined with UV photography combined with digital surface measurement and the other techniques were hypothesized to be above 0.6. The ICCs between UV images taken by the same physician and between two different physicians were calculated for determining inter- and intra-reliability. RESULTS: In total, 31 lesions of 17 patients were included. Image quality was assessed as good or very good for 100% and 26% for UV photography and the conventional camera, respectively. ICCs of UV photography and the conventional camera, drawing the lesions on transparent sheets and graph paper, were 0.984, 0.988 and 0.983, respectively, confirming our hypotheses. The ICCs of the intra-rater and inter-rater were 0.999 and 0.998, respectively. CONCLUSIONS: The results of this study indicate that the use of UV photography for the assessment of vitiligo lesions improves image quality and is valid and reliable.


Asunto(s)
Vitíligo , Humanos , Fotograbar , Reproducibilidad de los Resultados , Rayos Ultravioleta
2.
Nanotechnology ; 28(48): 485601, 2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-29105645

RESUMEN

GaN microrods are used as a basis for subsequent InGaN quantum well (QW) and quantum dot deposition by metal-organic vapor phase epitaxy. The coverage of the shell along the sidewall of rods is dependent on the rod growth time and a complete coverage is obtained for shorter rod growth times. Transmission electron microscopy measurements are performed to reveal the structural properties of the InGaN layer on the sidewall facet and on the top facet. The presence of layers in the microrod and on the microrod surface will be discussed with respect to GaN and InGaN growth. A detailed model will be presented explaining the formation of multiple SiN layers and the partial and full coverage of the shell around the core. Cathodoluminescence measurements are performed to analyze the InGaN emission properties along the microrod and to study the microresonator properties of such hexagonal core-shell structures. High quality factor whispering gallery modes with [Formula: see text] are reported for the first time in a GaN microrod/InGaN non-polar QW core-shell geometry. The GaN/InGaN core-shell microrods are expected to be promising building blocks for low-threshold laser diodes and ultra-sensitive optical sensors.

3.
Nanotechnology ; 28(5): 055201, 2017 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-28008871

RESUMEN

Nanotextured surfaces provide an ideal platform for efficiently capturing and emitting light. However, the increased surface area in combination with surface defects induced by nanostructuring e.g. using reactive ion etching (RIE) negatively affects the device's active region and, thus, drastically decreases device performance. In this work, the influence of structural defects and surface states on the optical and electrical performance of InGaN/GaN nanorod (NR) light emitting diodes (LEDs) fabricated by top-down RIE of c-plane GaN with InGaN quantum wells was investigated. After proper surface treatment a significantly improved device performance could be shown. Therefore, wet chemical removal of damaged material in KOH solution followed by atomic layer deposition of only 10 [Formula: see text] alumina as wide bandgap oxide for passivation were successfully applied. Raman spectroscopy revealed that the initially compressively strained InGaN/GaN LED layer stack turned into a virtually completely relaxed GaN and partially relaxed InGaN combination after RIE etching of NRs. Time-correlated single photon counting provides evidence that both treatments-chemical etching and alumina deposition-reduce the number of pathways for non-radiative recombination. Steady-state photoluminescence revealed that the luminescent performance of the NR LEDs is increased by about 50% after KOH and 80% after additional alumina passivation. Finally, complete NR LED devices with a suspended graphene contact were fabricated, for which the effectiveness of the alumina passivation was successfully demonstrated by electroluminescence measurements.

4.
Nano Lett ; 16(6): 3415-25, 2016 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-27187840

RESUMEN

Vertically aligned hexagonal InN nanorods were grown mask-free by conventional metal-organic vapor phase epitaxy without any foreign catalyst. The In droplets on top of the nanorods indicate a self-catalytic vapor-liquid-solid growth mode. A systematic study on important growth parameters has been carried out for the optimization of nanorod morphology. The nanorod N-polarity, induced by high temperature nitridation of the sapphire substrate, is necessary to achieve vertical growth. Hydrogen, usually inapplicable during InN growth due to formation of metallic indium, and silane are needed to enhance the aspect ratio and to reduce parasitic deposition beside the nanorods on the sapphire surface. The results reveal many similarities between InN and GaN nanorod growth showing that the process despite the large difference in growth temperature is similar. Transmission electron microscopy, spatially resolved energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy have been performed to analyze the structural properties. Spatially resolved cathodoluminescence investigations are carried out to verify the optical activity of the InN nanorods. The InN nanorods are expected to be the material of choice for high-efficiency hot carrier solar cells.

5.
Br J Cancer ; 107(8): 1409-17, 2012 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-23047593

RESUMEN

BACKGROUND: Using mRNA expression-derived signatures as predictors of individual patient outcome has been a goal ever since the introduction of microarrays. Here, we addressed whether analyses of tumour mRNA at the exon level can improve on the predictive power and classification accuracy of gene-based expression profiles using neuroblastoma as a model. METHODS: In a patient cohort comprising 113 primary neuroblastoma specimens expression profiling using exon-level analyses was performed to define predictive signatures using various machine-learning techniques. Alternative transcript use was calculated from relative exon expression. Validation of alternative transcripts was achieved using qPCR- and cell-based approaches. RESULTS: Both predictors derived from the gene or the exon levels resulted in prediction accuracies >80% for both event-free and overall survival and proved as independent prognostic markers in multivariate analyses. Alternative transcript use was most prominently linked to the amplification status of the MYCN oncogene, expression of the TrkA/NTRK1 neurotrophin receptor and survival. CONCLUSION: As exon level-based prediction yields comparable, but not significantly better, prediction accuracy than gene expression-based predictors, gene-based assays seem to be sufficiently precise for predicting outcome of neuroblastoma patients. However, exon-level analyses provide added knowledge by identifying alternative transcript use, which should deepen the understanding of neuroblastoma biology.


Asunto(s)
Exones/genética , Neuroblastoma/genética , Proteínas Nucleares/genética , Proteínas Oncogénicas/genética , Receptor trkA/genética , Línea Celular Tumoral , Preescolar , Perfilación de la Expresión Génica , Humanos , Lactante , Proteína Proto-Oncogénica N-Myc , Neuroblastoma/mortalidad , Pronóstico , ARN Mensajero , Factores de Riesgo , Análisis de Supervivencia
6.
Rev Sci Instrum ; 92(11): 113306, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34852560

RESUMEN

The upcoming commissioning of the superconducting (SC) continuous wave Helmholtz linear accelerators first of series cryomodule is going to demand precise alignment of the four internal SC cavities and two SC solenoids. For optimal results, a beam-based alignment method is used to reduce the misalignment of the whole cryomodule, as well as its individual components. A symmetric beam of low transverse emittance is required for this method, which is to be formed by a collimation system. It consists of two separate plates with milled slits, aligned in the horizontal and vertical direction. The collimation system and alignment measurements are proposed, investigated, and realized. The complete setup of this system and its integration into the existing environment at the GSI High Charge State Injector are presented, as well as the results of the recent reference measurements.

7.
Magn Reson Med ; 62(3): 672-81, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19585599

RESUMEN

The aim of this study was to propose and evaluate a methodology to analyze simultaneously acquired T2*-weighted dynamic susceptibility contrast (DSC) MRI and T(1)-weighted dynamic contrast enhanced (DCE) MRI data. Two generalized models of T2*-relaxation are proposed to account for tracer leakage, and a two-compartment exchange model is used to separate tracer in intra- and extravascular spaces. The methods are evaluated using data extracted from ROIs in three mice with subcutaneously implanted human colorectal tumors. Comparing plasma flow values obtained from DCE-MRI and DSC-MRI data defines a practical experimental paradigm to measure T2*-relaxivities, and reveals a factor of 15 between values in tissue and blood. Comparing mean transit time values obtained from DCE-MRI and DSC-MRI without leakage correction, indicates a significant reduction of susceptibility weighting in DSC-MRI during tracer leakage. A one-parameter gradient correction model provides a good approximation for this susceptibility loss, but redundancy of the parameter limits the practical potential of this model for DSC-MRI. Susceptibility loss is modeled more accurately with a variable T2*-relaxivity, which allows to extract new parameters that cannot be derived from DSC-MRI or DCE-MRI alone. They reflect the cellular and vessel geometry, and thus may lead to a more complete characterization of tissue structure.


Asunto(s)
Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/metabolismo , Medios de Contraste/farmacocinética , Imagen de Difusión por Resonancia Magnética/métodos , Interpretación de Imagen Asistida por Computador/métodos , Meglumina/farmacocinética , Compuestos Organometálicos/farmacocinética , Algoritmos , Animales , Línea Celular Tumoral , Simulación por Computador , Humanos , Aumento de la Imagen/métodos , Ratones , Ratones Desnudos , Modelos Biológicos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
8.
Pneumologie ; 61(12): 759-63, 2007 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-18098068

RESUMEN

When the sanatorium "Heidehaus" was founded on June 1, 1907 in the northern countryside of Hannover with Dr. Otto Ziegler as head about 120 beds for patients with tuberculosis were available. By 1914 about 200 patients were being treated by 4 physicians and 10 nurses. An operating theatre and a modern radiology unit were added in 1927. Shortly after the 2nd World War 400 patients with tuberculosis were hospitalised simultaneously. With the introduction of antituberculous triple drug treatment the number of patients dropped significantly. During this period many traditional facilities, used to care for patients with tuberculosis lost their financial basis and closed. However in the 1960s Prof. Schindler, the head of Heidehaus, widened the spectrum of the hospital into a modern chest hospital, focused on lung and airway diseases. In particular in the 1980s and 1990s this trend continued and 2 independent departments, i. e., pneumology and thoracic surgery were founded. In 2005 due to restructuring by the community of Hannover the "Heidehaus" moved completely and merged with another traditional hospital to become the new "Oststadt-Heidehaus". In its new surroundings both departments for pulmonary medicine and thoracic surgery offer a broad spectrum of modern thoracic medicine in cooperation with other disciplines.


Asunto(s)
Colonias de Salud/historia , Hospitales Especializados/historia , Centros de Rehabilitación/historia , Cirugía Torácica/historia , Tuberculosis Pulmonar/historia , Alemania , Historia del Siglo XX , Historia del Siglo XXI , Humanos
9.
Sci Rep ; 6: 27553, 2016 06 10.
Artículo en Inglés | MEDLINE | ID: mdl-27282258

RESUMEN

The electrical behaviour of Schottky barrier diodes realized on vertically standing individual GaN nanorods and array of nanorods is investigated. The Schottky diodes on individual nanorod show highest barrier height in comparison with large area diodes on nanorods array and epitaxial film which is in contrast with previously published work. The discrepancy between the electrical behaviour of nanoscale Schottky diodes and large area diodes is explained using cathodoluminescence measurements, surface potential analysis using Kelvin probe force microscopy and 1ow frequency noise measurements. The noise measurements on large area diodes on nanorods array and epitaxial film suggest the presence of barrier inhomogeneities at the metal/semiconductor interface which deviate the noise spectra from Lorentzian to 1/f type. These barrier inhomogeneities in large area diodes resulted in reduced barrier height whereas due to the limited role of barrier inhomogeneities in individual nanorod based Schottky diode, a higher barrier height is obtained.

10.
J Cancer ; 7(13): 1861-1866, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27698926

RESUMEN

Introduction: FOLFIRINOX is emerging as new standard of care for fit patients with locally advanced pancreatic cancer (LAPC) and metastatic pancreatic cancer (MPC). However, some of the physicians are reluctant to use FOLFIRINOX due to high toxicity rates reported in earlier studies. We reviewed our experience with FOLFIRINOX in LAPC and MPC, focussing on dose adjustments, toxicity and efficacy. Methods: We reviewed all patients with LAPC or MPC treated with FOLFIRINOX in our institution between April 2011 and December 2015. Unresectability (stage III and IV) was determined by the institution's multidisciplinary team for pancreatic cancer. Results: Fifty patients (18 LAPC and 32 MPC) were enrolled, with a median age of 55 years (IQR 49-66) and WHO performance status of 0/1. FOLFIRINOX was given as first-line treatment in 82% of patients. Dose modifications were applied in 90% of patients. The median number of completed cycles was 8 (IQR 5-9). Grade 3-4 toxicity occurred in 52% and grade 5 toxicity in 2%. The response rate was 25% (12% in LAPC, 32% in MPC). Median overall survival and progression-free survival were 14.8 and 10.3 months in LAPC, and 9.0 and 5.9 months in MPC, respectively. Overall 1- and 2-year survival was 65% and 10% in LAPC and 40% and 5% in MPC. Within the LAPC group, 6 patients (33%) underwent local ablative therapy and 1 patient (6%) a resection, leading to a median survival of 21.8 months. Conclusion: FOLFIRINOX treatment with nearly routine dose modification was associated with acceptable toxicity rates, relatively high response rates and an encouraging overall survival.

11.
Transplantation ; 68(7): 1054-6, 1999 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-10532550

RESUMEN

A new case of anti-factor V inhibitor is described in a 46-year-old man, who received a liver transplantation for hepatocellular carcinoma, without exposure to bovine thrombin or fibrin glue during the operative course. The inhibition occurred on the 14th postoperative day, while the patient was being treated with oxacillin, azathioprine, and a new immunosuppressive drug, FK506. The inhibition was of short duration (3 days), and no bleeding complication occurred despite a very low plasmatic level of factor V activity and antigen (<5%). Plasma samples drawn after cessation of FK506 disclosed a dose-dependent inhibitory activity when alcoholic solutions of FK506 were exogeneously added; this suggests a possible role of the FK506 drug in the occurrence of this anti-factor V inhibitor.


Asunto(s)
Factor V/antagonistas & inhibidores , Inmunoglobulinas/sangre , Inmunosupresores/uso terapéutico , Trasplante de Hígado , Tacrolimus/uso terapéutico , Carcinoma Hepatocelular/cirugía , Relación Dosis-Respuesta a Droga , Humanos , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad
12.
Thromb Haemost ; 82(3): 1088-92, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10494768

RESUMEN

We studied two polymorphisms located close to or within the 3'-untranslated (3'-UT) region of the PROS1 gene [an A to G transition at nt 2148 (Pro 626) and an A to C substitution at nt 2698] in 110 healthy volunteers. The allele frequency of the nt 2148 G variant was 35%, and that of the nt 2698 A variant was 27%. We found a relationship between the two dimorphisms (both separately and together) and the plasma total protein S antigen (tPS) level. The impact of the neutral Pro 626 dimorphism was more significant than that of nt 2698 C/A (p = 0.0003 and p = 0.013, respectively). The lowest tPS values were observed in subjects with the Pro 626;nt 2698 GG;CC genotype, and the highest values in those with the AA;AA genotype. Both polymorphisms acted independently of sex and age. The mechanisms by which the two polymorphisms regulate tPS synthesis were not revealed by the studies of platelet mRNA. This study provides the first evidence of a genetic modulation of tPS levels, which, in addition to age and sex, contributes to the wide normal range of tPS in plasma. Determination of these two polymorphisms could be a valuable additional tool for studying PS.


Asunto(s)
Polimorfismo Genético , Proteína S/genética , Proteína S/metabolismo , Regiones no Traducidas 3' , Adolescente , Adulto , Factores de Edad , Alelos , Secuencia de Bases , Cartilla de ADN/genética , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Masculino , Persona de Mediana Edad , ARN Mensajero/genética , Valores de Referencia , Caracteres Sexuales
13.
Thromb Haemost ; 75(1): 4-10, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8713771

RESUMEN

Four hundred fifty subjects were screened for the 1691 G-->A mutation in the factor V gene. Two hundred ninety-seven patients were referred to us for unexplained thrombosis, 133 were family members of these patients and 20 were normal subjects. We studied the relationships between the mutation, resistance to APC and thrombosis. Among the 450 subjects tested, 65 belonging to 42 families were found to have the 1691 G-->A mutation in one (n = 61) or both alleles (n = 4). The prevalence of the mutation in the thrombotic patients was 13%. Resistance to APC was tested for in 247 subjects not on anticoagulant treatment (4 homozygous and 44 heterozygous for the mutation, and 199 individuals without the mutation). Incomplete cosegregation of heterozygosity for the 1691 G-->A mutation with APC resistance (APC-SR < 2.4 or n-APC-SR < 0.75) was observed, showing that the functional assay alone is insufficient for a firm diagnosis. In patients carrying the mutation, elevated levels of prothrombin fragment 1 + 2 and D-dimers pointed to increased thrombin generation in vivo. Clinical manifestations in the heterozygous subjects were very similar to those reported in heterozygous PC or PS deficiencies, but the first thrombotic event occurred later than in PC- or PS-deficient patients. Homozygosity for the factor V gene mutation appears to be a far more benign thrombotic disorder than homozygous PC and PS deficiencies.


Asunto(s)
Adenina , Factor V/genética , Fibrinolíticos/farmacología , Guanina , Proteína C/farmacología , Trombosis/genética , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Resistencia a Medicamentos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Linaje , Fenotipo , Trombosis/tratamiento farmacológico
14.
Eur J Endocrinol ; 148(5): 551-7, 2003 May.
Artículo en Inglés | MEDLINE | ID: mdl-12720539

RESUMEN

OBJECTIVE: Delayed sexual maturation and low body weight is common in cystic fibrosis (CF). Concomitant data on sex hormones and concomitant body composition are lacking in men with CF. DESIGN: Cross-sectional study. SUBJECTS AND METHODS: Serum levels of testosterone, 17beta-oestradiol (E(2)), 25-hydroxyvitamin D (25(OH)D), sex hormone-binding globulin (SHBG) and LH were measured by RIA and total and regional lean body mass (LBM), fat body mass (FBM), bone mineral content and bone mineral density (BMD) were assessed by dual-energy X-ray absorptiometry, in men with CF (n=40; age 24.7+/-5.4 years) and age-matched healthy controls (n=28; age 25.7+/-3.7). Only men without acute disease exacerbation or systemic glucocorticoid treatment were included. RESULTS: Mean levels of hormonal serum parameters differed significantly between healthy controls (testosterone=20.2+/-5.5 nmol/l; E(2)=95.0+/-20.2 pmol/l; 25(OH)D=62.8+/-28.3 nmol/l) and patients (testosterone=15.9+/-4.1 nmol/l; E(2)=60.7+/-19.4 pmol/l; 25(OH)D=39.5+/-17.8 nmol/l; P<0.001) while no difference was found for SHBG or LH. Eleven (for E(2), 19 of 40, for 25(OH)D, 20 of 40) out of 40 patients had serum testosterone levels 2 s.d. below the mean of normal. Men with CF showed a relative shift from FBM to LBM and a different body fat distribution compared with healthy controls (P<0.01). Testosterone was not correlated with weight, total or regional LBM or FBM, but significantly with BMD (r=0.32; P<0.05) independently from body height and 25(OH)D levels. E(2) was correlated with regional and total FBM (r=0.48; P<0.05). In a multiple regression analysis of the joint effect of testosterone and body components on E(2), a testosterone-independent effect was found for FBM. CONCLUSIONS: CF patients with stable disease have moderately reduced serum testosterone levels. This might already imply detrimental effects on bone. The change in LBM of patients appears to have no direct association with sex hormone levels while low FBM might cause reduced net conversion of serum testosterone to E(2) with possible effects on FBM distribution.


Asunto(s)
Composición Corporal , Fibrosis Quística/metabolismo , Hormonas Esteroides Gonadales/sangre , Absorciometría de Fotón , Adulto , Densidad Ósea , Estudios Transversales , Fibrosis Quística/sangre , Humanos , Masculino , Testosterona/sangre
15.
Hum Pathol ; 28(8): 944-52, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9269831

RESUMEN

The absence or mislocalization of cystic fibrosis transmembrane conductance regulator (CFTR) is regarded as being specific for cystic fibrosis (CF). In principle, the supply of a non-CF lung transplant to a CF patient should bring up normal CFTR expression in the lower airways. Immunolocalization of CFTR and of epithelial differentiation markers (ie, cytokeratins 13, 14, and 18, and desmoplakins 1 and 2) was carried out on 21 mucosal biopsies from the upper lobe of grafts in non-CF (n = 12) and CF patients (n = 9) retrieved between days 23 and 1,608 after lung transplantation. Biopsy specimens from seven non-CF and four CF patients presented either a pseudostratified respiratory epithelium or slight basal cell hyperplasia. CFTR was distributed at the apical membrane of the ciliated cells. In remodeled epithelia with basal cell hyperplasia or squamous metaplasia, CFTR was either weakly expressed in the cytoplasm of the superficial epithelial cells or was undetectable. The extent of epithelium remodeling was significantly correlated with an impairment of lung function. The results suggest that posttransplant airway epithelium dedifferentiation of the graft leads to the loss of properly targeted CFTR irrespective of the underlying disease of the recipient.


Asunto(s)
Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Fibrosis Quística/metabolismo , Fibrosis Quística/patología , Trasplante de Pulmón , Pulmón/metabolismo , Adulto , Factores de Edad , Biopsia , Diferenciación Celular , Proteínas del Citoesqueleto/metabolismo , Desmoplaquinas , Células Epiteliales , Epitelio/metabolismo , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Volumen Espiratorio Forzado , Humanos , Queratinas/metabolismo , Pulmón/patología , Pulmón/fisiopatología , Trasplante de Pulmón/fisiología , Masculino , Persona de Mediana Edad
16.
J Clin Pathol ; 32(10): 1030-5, 1979 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-316435

RESUMEN

This report describes a patient without evident underlying disease, in whom an acquired von Willebrand's syndrome was discovered before surgery. Coagulation abnormalities included a borderline bleeding time, a low retention of platelets on glass beads, decreased levels of factor VIII procoagulant activity (VIIIAHF), factor VIII-related antigen (VIIIAg), and ristocetin-induced agglutination cofactor (VIIIVWF). After cryoprecipitate infusion the patient did not have the expected rise and there was no secondary increment in VIIIAHF. The patient was treated with prednisone for three weeks without significant improvement in the laboratory findings. Spontaneous resolution was observed long after this therapy. The haemostatic abnormalities were attributable to the presence of an inhibitor directed against VIIIVWF. The inhibitor was found in the IgM fraction. Its autoimmune nature is probable although we failed to demonstrate any inhibitory effect of Fab obtained from the patient's purified IgM. Despite the lack of inhibitory effect against VIIIAHF and VIIIAg, the low levels of all three activities of the factor VIII complex could be explained by the short half-life of immune complexes between factor VIII and the inhibitor.


Asunto(s)
Factores de Coagulación Sanguínea/inmunología , Inmunoglobulina M/inmunología , Enfermedades de von Willebrand/inmunología , Factor de von Willebrand/inmunología , Anciano , Complejo Antígeno-Anticuerpo , Autoanticuerpos/análisis , Pruebas de Coagulación Sanguínea , Factor XIII/inmunología , Humanos , Masculino , Remisión Espontánea , Enfermedades de von Willebrand/sangre
17.
Intensive Care Med ; 13(2): 126-30, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-3571712

RESUMEN

We evaluated the antithrombotic efficacy of the low molecular weight heparin (LMWH) fraction PK 10169 in nine consecutive patients with acute pulmonary embolism documented by pulmonary angioscan and angiography. Therapy with PK 10169 was initiated by an i.v. bolus of 0.5 mg/kg, followed by a continuous intravenous infusion during the first 10 days; the drug was then given subcutaneously twice daily during the following 15 days. The dosage of PK 10169 was adjusted by daily measurements of anti-Xa and anti-IIa activities using amidolytic methods. For a dosage ranging from 1.4 to 4.1 mg/kg per day during the i.v. period and from 0.7 to 3.5 mg/kg per day during the s.c. period, the anti-Xa activity ranged from 4 to 8.7 PK U/ml and from 4.5 to 7.2 PK U/ml respectively. Clinical improvement was observed in all the patients and was consistent with progressive reperfusion evaluated by successive angioscans. No recurrence of pulmonary embolism occurred. No deleterious hemorrhagic side-effects were observed, even in two patients at high risk of bleeding. In this pilot study, the LMWH fraction PK 10169 proved to be an effective anticoagulant therapy during the first three weeks after pulmonary embolism in man.


Asunto(s)
Heparina/uso terapéutico , Embolia Pulmonar/tratamiento farmacológico , Enfermedad Aguda , Esquema de Medicación , Femenino , Heparina/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto
18.
J Neurosci Methods ; 64(1): 105-14, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8869490

RESUMEN

A dimensionally accurate clear model of the human scala tympani has been produced to evaluate the insertion and position of clinically applied intracochlear electrodes for electrical stimulation. Replicates of the human scala tympani were made from low melting point metal alloy (LMA) and from polymethylmeth-acrylate (PMMA) resin. The LMA metal casts were embedded in blocks of epoxy and in clear silicone rubber. After removal of the metal alloy, a cavity was produced that accurately models the human scala tympani. Investment casting molds were made from the PMMA scala tympani casts to enable production of multiple LMA casts from which identical models were fabricated. Total dimensional distortion of the LMA casting process was less than 1% in length and 2% in diameter. The models have been successfully integrated into the design process for the iterative development of advanced intracochlear electrode arrays at UCSF. These fabrication techniques are applicable to a wide range of biomedical design problems that require modelling of visually obscured cavities.


Asunto(s)
Modelos Anatómicos , Rampa Timpánica/anatomía & histología , Aleaciones , Implantes Cocleares , Molde por Corrosión , Estimulación Eléctrica/instrumentación , Humanos , Metales , Metilmetacrilatos
19.
Thromb Res ; 74(4): 399-407, 1994 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-8085241

RESUMEN

In this study, we evaluated the effects of anticoagulants used in blood sampling on the measurements of coagulation activation markers F1 + 2, TAT, D-Dimers by Elisa methods. The study was carried out on normal subjects and patients with inherited deficiency of coagulation inhibitors, antithrombin III (ATIII) protein C (PC) and protein S (PS). Three different anticoagulant solutions were compared: 1) ACD/EDTA/adenosine/heparin, 2) EDTA/aprotinin/a synthetic thrombin inhibitor and 3) sodium citrate. The results showed that sodium citrate, commonly used in coagulation laboratories, is a suitable anticoagulant for the study of coagulation activation markers. In addition, the type of tubes (plastic tubes vs glass Vacutainer R tubes) used for blood sampling as well as the order of sampling (early or late after the phlebotomy procedure) did not influence the results. We concluded that assays of coagulation activation markers F1 + 2 and D-Dimers can be performed in samples collected routinely by haemostasis laboratory staff using Vacutainer R tubes with sodium citrate. Further investigations are needed to understand why TAT measurements gave a pattern of results quite different from F1 + 2 or D-Di measurements.


Asunto(s)
Antifibrinolíticos/metabolismo , Antitrombina III/metabolismo , Trastornos de la Coagulación Sanguínea/sangre , Recolección de Muestras de Sangre/métodos , Productos de Degradación de Fibrina-Fibrinógeno/metabolismo , Fragmentos de Péptidos/metabolismo , Péptido Hidrolasas/metabolismo , Protrombina/metabolismo , Anticoagulantes/farmacología , Biomarcadores/sangre , Recolección de Muestras de Sangre/instrumentación , Humanos , Valores de Referencia
20.
Thromb Res ; 85(4): 357-62, 1997 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-9062960

RESUMEN

Since the first description by Dahlbäck et al (1) of a hereditary defect in the plasma of three unrelated thrombophilic patients characterized by a poor anticoagulant response to activated protein C (APC), many reports have shown a high prevalence of the APC resistance in both the general and thrombophilic populations (2-6). In almost all cases APC resistance is due to a single point mutation in the factor V gene, (a G to A substitution at nucleotide position 1691), which predicts the synthesis of a factor V molecule (FVQ506 or FV Leiden) in which the Arg 506 in one of the APC cleavage sites is replaced by Gln (7), rendering factor Va resistant to inactivation by APC. The FVQ506 mutation is the most frequent hereditary risk factor for venous thrombosis (2, 5, 6, 8-10) making an assay for APC resistance with a high predictive value for the mutation highly desirable, especially when molecular diagnosis at the gene level is not possible. The aim of this study was to evaluate the performance of a new factor Xa-based assay for the FV Leiden-dependent APC resistance.


Asunto(s)
Factor V/metabolismo , Factor Xa/metabolismo , Proteína C/metabolismo , Análisis Químico de la Sangre , Heparina , Heparina de Bajo-Peso-Molecular , Humanos , Inhibidor de Coagulación del Lupus/sangre , Proteína S/metabolismo
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