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1.
Public Health ; 220: 33-34, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37263175

RESUMEN

OBJECTIVES: Vaccination is the most effective way to prevent herpes zoster (HZ) and related complications. This study aimed to investigate the preference of HZ vaccine among older people. STUDY DESIGN: A discrete choice experiment was performed. METHODS: In total, 178 adults aged ≥50 years were invited to choose between HZ vaccination scenarios using six vaccine attributes. Two equations were used to calculate participants' willingness to pay for the vaccine and their predicted choice probability. RESULTS: The attributes that significantly influenced participants' vaccine choices were lower cost, higher effectiveness, reduced side-effects and vaccination of others in their surroundings. CONCLUSIONS: Improving medical insurance coverage or reducing the cost of the HZ vaccine will encourage more people to be vaccinated, resulting in reduced burden of disease among older people.


Asunto(s)
Vacuna contra el Herpes Zóster , Herpes Zóster , Adulto , Humanos , Anciano , Análisis Costo-Beneficio , Herpes Zóster/prevención & control , China , Vacunación/métodos
2.
Diagn Interv Imaging ; 101(12): 771-781, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32800505

RESUMEN

Three-dimensional (3D) visualizations of volumetric data from computed tomography (CT) acquisitions can be important adjuncts to interpretation of two-dimensional (2D) reconstructions. Recently, the 3D technique known as cinematic rendering (CR) was introduced, allowing photorealistic images to be created from standard CT acquisitions. CR methodology is under increasing investigation for use in the display of regions of complex anatomy and as a tool for education and preoperative planning. In this article, we will illustrate the potential utility of CR for evaluating the urinary bladder and associated pathology. The urinary bladder is susceptible to a multitude of neoplastic and inflammatory conditions and their sequelae. The intrinsic properties of CR may prove useful for the display of subtle mucosal/luminal irregularities, the simultaneous display of soft tissue detail with high-resolution maps of associated tumor neovasculature, and the improved display of spatial relationships to aid pre-procedural planning. Further refinement of presets for CR image creation and prospective evaluation of urinary bladder CR in real-world settings will be important for widespread clinical adoption.


Asunto(s)
Imagenología Tridimensional , Tomografía Computarizada por Rayos X , Vejiga Urinaria , Humanos , Estudios Prospectivos , Vejiga Urinaria/diagnóstico por imagen
4.
Diagn Interv Imaging ; 101(9): 555-564, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32278586

RESUMEN

PURPOSE: The purpose of this study was to determine whether computed tomography (CT)-based machine learning of radiomics features could help distinguish autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC). MATERIALS AND METHODS: Eighty-nine patients with AIP (65 men, 24 women; mean age, 59.7±13.9 [SD] years; range: 21-83 years) and 93 patients with PDAC (68 men, 25 women; mean age, 60.1±12.3 [SD] years; range: 36-86 years) were retrospectively included. All patients had dedicated dual-phase pancreatic protocol CT between 2004 and 2018. Thin-slice images (0.75/0.5mm thickness/increment) were compared with thick-slices images (3 or 5mm thickness/increment). Pancreatic regions involved by PDAC or AIP (areas of enlargement, altered enhancement, effacement of pancreatic duct) as well as uninvolved parenchyma were segmented as three-dimensional volumes. Four hundred and thirty-one radiomics features were extracted and a random forest was used to distinguish AIP from PDAC. CT data of 60 AIP and 60 PDAC patients were used for training and those of 29 AIP and 33 PDAC independent patients were used for testing. RESULTS: The pancreas was diffusely involved in 37 (37/89; 41.6%) patients with AIP and not diffusely in 52 (52/89; 58.4%) patients. Using machine learning, 95.2% (59/62; 95% confidence interval [CI]: 89.8-100%), 83.9% (52:67; 95% CI: 74.7-93.0%) and 77.4% (48/62; 95% CI: 67.0-87.8%) of the 62 test patients were correctly classified as either having PDAC or AIP with thin-slice venous phase, thin-slice arterial phase, and thick-slice venous phase CT, respectively. Three of the 29 patients with AIP (3/29; 10.3%) were incorrectly classified as having PDAC but all 33 patients with PDAC (33/33; 100%) were correctly classified with thin-slice venous phase with 89.7% sensitivity (26/29; 95% CI: 78.6-100%) and 100% specificity (33/33; 95% CI: 93-100%) for the diagnosis of AIP, 95.2% accuracy (59/62; 95% CI: 89.8-100%) and area under the curve of 0.975 (95% CI: 0.936-1.0). CONCLUSIONS: Radiomic features help differentiate AIP from PDAC with an overall accuracy of 95.2%.


Asunto(s)
Enfermedades Autoinmunes , Pancreatitis Autoinmune , Neoplasias Pancreáticas , Pancreatitis , Anciano , Enfermedades Autoinmunes/diagnóstico por imagen , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Conductos Pancreáticos , Neoplasias Pancreáticas/diagnóstico por imagen , Pancreatitis/diagnóstico por imagen , Estudios Retrospectivos , Tomografía Computarizada por Rayos X
6.
Diagn Interv Imaging ; 101(1): 35-44, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31358460

RESUMEN

PURPOSE: The purpose of this study was to report procedures developed to annotate abdominal computed tomography (CT) images from subjects without pancreatic disease that will be used as the input for deep convolutional neural networks (DNN) for development of deep learning algorithms for automatic recognition of a normal pancreas. MATERIALS AND METHODS: Dual-phase contrast-enhanced volumetric CT acquired from 2005 to 2009 from potential kidney donors were retrospectively assessed. Four trained human annotators manually and sequentially annotated 22 structures in each datasets, then expert radiologists confirmed the annotation. For efficient annotation and data management, a commercial software package that supports three-dimensional segmentation was used. RESULTS: A total of 1150 dual-phase CT datasets from 575 subjects were annotated. There were 229 men and 346 women (mean age: 45±12years; range: 18-79years). The mean intra-observer intra-subject dual-phase CT volume difference of all annotated structures was 4.27mL (7.65%). The deep network prediction for multi-organ segmentation showed high fidelity with 89.4% and 1.29mm in terms of mean Dice similarity coefficients and mean surface distances, respectively. CONCLUSIONS: A reliable data collection/annotation process for abdominal structures was developed. This process can be used to generate large datasets appropriate for deep learning.


Asunto(s)
Abdomen/diagnóstico por imagen , Aprendizaje Profundo , Tomografía Computarizada por Rayos X/métodos , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
7.
Diagn Interv Imaging ; 100(9): 467-476, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31047840

RESUMEN

Cinematic rendering (CR) is a recently described three-dimensional (3D) rendering technique that generates photorealistic images based on a new lighting model. This review illustrates the potential application of CR in the evaluation of focal liver masses. CR shows promise in improving the visualization of enhancement pattern and internal architecture, local tumor extension, and global disease burden, which may be helpful in focal liver mass characterization and pretreatment planning.


Asunto(s)
Imagenología Tridimensional/métodos , Neoplasias Hepáticas/diagnóstico por imagen , Hígado/diagnóstico por imagen , Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X , Carcinoma Hepatocelular/diagnóstico por imagen , Colangiocarcinoma/diagnóstico por imagen , Hiperplasia Nodular Focal/diagnóstico por imagen , Hemangioma/diagnóstico por imagen , Humanos , Absceso Hepático/diagnóstico por imagen
8.
Diagn Interv Imaging ; 100(9): 477-483, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30928470

RESUMEN

Cinematic rendering (CR) is a new 3D visualization methodology for volumetric diagnostic imaging including computed tomography (CT) datasets composed of isotropic voxels. CR produces photorealistic images with enhanced detail relative to other 3D visualization methods and realistic shadowing. In this review, we provide a number of examples of splenic pathology visualized with CR including conditions affecting the splenic vasculature, neoplasms, and accessory spleens. These examples are compared to 2D CT and traditional 3D CT techniques and the potential advantages of CR are highlighted. CR displays textural changes in the splenic parenchyma to particular advantage, and a portion of this review will be devoted to examples of how textural features can help distinguish intrapancreatic accessory spleens from neuroendocrine tumors.


Asunto(s)
Imagenología Tridimensional/métodos , Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Bazo/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Diagnóstico Diferencial , Humanos , Invasividad Neoplásica/diagnóstico por imagen , Tumores Neuroendocrinos/diagnóstico por imagen , Neoplasias Pancreáticas/diagnóstico por imagen , Neoplasias Pancreáticas/patología , Bazo/anomalías , Neoplasias del Bazo/diagnóstico por imagen
9.
Anesth Analg ; 127(5): 1118-1126, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-29533264

RESUMEN

BACKGROUND: Globally, >300 million patients have surgery annually, and ≤20% experience adverse postoperative events. We studied the impact of both cardiac and noncardiac adverse events on 1-year disability-free survival after noncardiac surgery. METHODS: We used the study cohort from the Evaluation of Nitrous oxide in Gas Mixture of Anesthesia (ENIGMA-II) trial, an international randomized trial of 6992 noncardiac surgical patients. All were ≥45 years of age and had moderate to high cardiac risk. The primary outcome was mortality within 1 postoperative year. We defined 4 separate types of postoperative adverse events. Major adverse cardiac events (MACEs) included myocardial infarction (MI), cardiac arrest, and myocardial revascularization with or without troponin elevation. MI was defined using the third Universal Definition and was blindly adjudicated. A second cohort consisted of patients with isolated troponin increases who did not meet the definition for MI. We also considered a cohort of patients who experienced major adverse postoperative events (MAPEs), including unplanned admission to intensive care, prolonged mechanical ventilation, wound infection, pulmonary embolism, and stroke. From this cohort, we identified a group without troponin elevation and another with troponin elevation that was not judged to be an MI. Multivariable Cox proportional hazard models for death at 1 year and assessments of proportionality of hazard functions were performed and expressed as an adjusted hazard ratio (aHR) and 95% confidence intervals (CIs). RESULTS: MACEs were observed in 469 patients, and another 754 patients had isolated troponin increases. MAPEs were observed in 631 patients. Compared with control patients, patients with a MACE were at increased risk of mortality (aHR, 3.36 [95% CI, 2.55-4.46]), similar to patients who suffered a MAPE without troponin elevation (n = 501) (aHR, 2.98 [95% CI, 2.26-3.92]). Patients who suffered a MAPE with troponin elevation but without MI had the highest risk of death (n = 116) (aHR, 4.29 [95% CI, 2.89-6.36]). These 4 types of adverse events similarly affected 1-year disability-free survival. CONCLUSIONS: MACEs and MAPEs occur at similar frequencies and affect survival to a similar degree. All 3 types of postoperative troponin elevation in this analysis were associated, to varying degrees, with increased risk of death and disability.


Asunto(s)
Anestésicos por Inhalación/efectos adversos , Cardiopatías/epidemiología , Óxido Nitroso/efectos adversos , Procedimientos Quirúrgicos Operativos/efectos adversos , Administración por Inhalación , Anciano , Anestésicos por Inhalación/administración & dosificación , Biomarcadores/sangre , Evaluación de la Discapacidad , Femenino , Estado de Salud , Cardiopatías/diagnóstico , Cardiopatías/mortalidad , Cardiopatías/terapia , Humanos , Masculino , Persona de Mediana Edad , Óxido Nitroso/administración & dosificación , Medición de Riesgo , Factores de Riesgo , Procedimientos Quirúrgicos Operativos/mortalidad , Factores de Tiempo , Resultado del Tratamiento , Troponina/sangre , Regulación hacia Arriba
10.
Diagn Interv Imaging ; 98(3): 191-202, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27614585

RESUMEN

Pancreatic serous cystadenoma can be categorized into microcystic, honeycomb, oligocystic, and solid patterns based on imaging appearance. The presence of typical computed tomography (CT) features helps to differentiate serous cystadenomas from other cystic and solid pancreatic masses. Cases with atypical features present a diagnostic challenge as they can mimic malignant neoplasms. This article reviews pathophysiology, prevalence, CT features, mimickers and recommendations for management of pancreatic serous cystadenoma.


Asunto(s)
Cistadenoma Seroso/diagnóstico por imagen , Cistadenoma Seroso/patología , Neoplasias Pancreáticas/diagnóstico por imagen , Neoplasias Pancreáticas/patología , Adenocarcinoma/diagnóstico por imagen , Adenocarcinoma Mucinoso/diagnóstico por imagen , Carcinoma Papilar/diagnóstico por imagen , Diagnóstico Diferencial , Humanos , Metástasis de la Neoplasia/diagnóstico por imagen , Tumores Neuroendocrinos/diagnóstico por imagen , Seudoquiste Pancreático/diagnóstico por imagen , Enfermedad de von Hippel-Lindau/diagnóstico por imagen
11.
Br J Anaesth ; 112(1): 47-56, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24172055

RESUMEN

BACKGROUND: Myocardial injury after non-cardiac surgery (MINS) is a common complication with associated serious morbidity and mortality. Endothelial dysfunction might play an important role in MINS, and its rapid assessment could provide a novel method of risk stratification before surgery. METHODS: We studied 238 subjects scheduled to undergo intermediate or high-risk surgery in a two-centre prospective study to determine whether preoperative endothelial dysfunction identified by a reactive hyperaemia-peripheral arterial tonometry (RH-PAT) index could provide effective risk stratification for MINS, defined as serum troponin ≥0.04 µg litre(-1), within 3 postoperative days. RESULTS: The primary outcome occurred in 35 subjects (14.7%). Endothelial dysfunction was defined as an RH-PAT index of ≤1.22. Adjusted for age, Lee index and a composite measure of the extent of surgery, endothelial dysfunction was associated with MINS [odds ratio 10.1, 95% confidence interval (CI) 3.3-30.9, P=0.001] and increased time to discharge from hospital after surgery (hazard ratio 0.39, 95% CI 0.23-0.65, P=0.001). Endothelial dysfunction identified MINS with a sensitivity of 31%, a specificity of 96%, and a positive diagnostic likelihood ratio of 8.0. Risk classification for MINS was improved by the addition of RH-PAT-defined endothelial dysfunction to the Lee index (c-statistic increased from 0.69 to 0.77; integrated discrimination improvement 0.11, P=0.003). However, prognostic utility varied widely between sites. CONCLUSIONS: For patients undergoing non-cardiac surgery, non-invasive assessment of endothelial function might enhance preoperative risk stratification for perioperative myocardial injury. However, unexplained large inter-site variation in prognostic utility could limit widespread application and needs to be further understood.


Asunto(s)
Cardiomiopatías/etiología , Endotelio Vascular/fisiopatología , Cuidados Intraoperatorios , Complicaciones Posoperatorias/etiología , Automatización , Humanos , Periodo Perioperatorio , Estudios Prospectivos , Curva ROC , Riesgo
12.
Br J Anaesth ; 106(5): 699-705, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21441243

RESUMEN

BACKGROUND: Gabapentin is an anticonvulsant and adjuvant analgesic. It is effective in several pain studies. Neuropathic pain is the most difficult type of pain to treat. In this study, we examined if intrathecal gabapentin could prevent nerve injury-induced pain. METHODS: Under isoflurane anaesthesia, male Sprague-Dawley rats (200-250 g) underwent right L5/6 spinal nerve ligation and placement of an intrathecal catheter connected to an infusion pump. After surgery, intrathecal saline or gabapentin (20 µg h(-1)) was given for 7 days (n=8 per group). The right hind paw withdrawal threshold to von Frey filament stimuli and withdrawal latency to radiant heat were determined before (baseline) and once daily for 7 days after surgery. Haematoxylin and eosin and toluidine blue staining were used to evaluate the neurotoxicity of gabapentin (40 µg h(-1)). RESULTS: Seven days after nerve ligation, the affected paw withdrawal threshold and latency of saline-treated rats decreased from the baseline 11.7 (11.7-22.2) [median (inter-quartile range)] to 1.6 (0.9-3.2) g and 10.8 (10.5-11.2) to 4.3 (4.2-7) s, respectively. Rats receiving gabapentin (20 µg h(-1)) had higher withdrawal threshold [9.9 (9.9-19.3) g] and latency [11.5 (9.7-11.9) s] on day 7 after ligation. No obvious histopathological change or growth retardation was detected after intrathecal gabapentin (40 µg h(-1)) infusion. CONCLUSIONS: We showed a preventative effect of intrathecal gabapentin on the development of nerve injury-induced mechanical allodynia and thermal hyperalgesia. Our data suggest that continuous intrathecal gabapentin may be considered as an alternative for the prevention of nerve injury-induced pain.


Asunto(s)
Aminas/administración & dosificación , Analgésicos no Narcóticos/administración & dosificación , Ácidos Ciclohexanocarboxílicos/administración & dosificación , Hiperalgesia/prevención & control , Ácido gamma-Aminobutírico/administración & dosificación , Aminas/uso terapéutico , Analgésicos no Narcóticos/uso terapéutico , Animales , Cauda Equina/efectos de los fármacos , Cauda Equina/patología , Ácidos Ciclohexanocarboxílicos/uso terapéutico , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Evaluación Preclínica de Medicamentos/métodos , Gabapentina , Hiperalgesia/etiología , Infusiones Parenterales , Ligadura/efectos adversos , Masculino , Dimensión del Dolor/métodos , Desempeño Psicomotor/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Médula Espinal/efectos de los fármacos , Médula Espinal/patología , Nervios Espinales/lesiones , Aumento de Peso/efectos de los fármacos , Ácido gamma-Aminobutírico/uso terapéutico
13.
Hong Kong Med J ; 11(5): 391-6, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16219959

RESUMEN

From 1 August 2001 to 31 July 2004, 137 patients were referred from the Association Concerning Sexual Violence Against Women to the Accident and Emergency Department at the Kwong Wah Hospital for alleged rape. Approximately half of the patients presented within 3 days of the alleged assault. Fifty-one patients were prescribed emergency contraception: one patient remained pregnant despite treatment and was referred with a further six patients to the Gynaecology Department for termination of pregnancy. Thirty-two patients received hepatitis B immunoglobulin injection. One patient had a positive result for rapid plasma reagin 3 months following the assault and was referred to the Social Hygiene Clinic. All tests for antibody to human immunodeficiency virus were negative. Antimicrobial therapy was prescribed for women who had an endocervical and/or high vaginal swab positive for Chlamydia trachomatis (n=9), Trichomonas vaginalis (n=1), and gonococcus (n=1).


Asunto(s)
Evaluación de Resultado en la Atención de Salud , Violación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticonceptivos Poscoito/uso terapéutico , Servicio de Urgencia en Hospital , Femenino , Hong Kong , Humanos , Persona de Mediana Edad , Embarazo , Enfermedades de Transmisión Sexual/prevención & control , Enfermedades de Transmisión Sexual/transmisión
14.
J Submicrosc Cytol Pathol ; 28(1): 81-5, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8929629

RESUMEN

A comparison of the collagen network in three dimensions was conducted in 8 hypertrophic cardiomyopathy (HCM)-affected and 8 normal hearts. All these hearts were obtained from male and age-matched pigs of the same breeding farm under identical feeding conditions. The selection of HCM-affected heart was based on the abnormal histologic features such as marked disorientation of muscle cells, thickening of the intramural coronary arterial wall with a narrowed lumen, endocardial fibrosis, and myocardial fibrosis. Mean values of heart weight and ratio of heart to body weight of HCM group were significantly (p < 0.01) increased by 36% and 47%, respectively, but not the body weight, as compared to those of the normal group. The scanning electron microscopic (SEM) investigation demonstrated that collagen weave, struts, and strands appeared more numerous in HCM-affected myocardium than in normals. Moreover, the tendons of collagen in HCM-affected myocardium showed increases in both numbers and thickness.


Asunto(s)
Cardiomiopatía Hipertrófica/veterinaria , Colágeno/ultraestructura , Miocardio/ultraestructura , Enfermedades de los Porcinos/patología , Animales , Peso Corporal , Cardiomiopatía Hipertrófica/metabolismo , Cardiomiopatía Hipertrófica/patología , Colágeno/análisis , Vasos Coronarios/metabolismo , Vasos Coronarios/ultraestructura , Modelos Animales de Enfermedad , Masculino , Microscopía Electrónica de Rastreo , Miocardio/química , Tamaño de los Órganos , Especificidad de la Especie , Porcinos , Enfermedades de los Porcinos/metabolismo
15.
Zhonghua Yi Xue Za Zhi (Taipei) ; 56(2): 125-8, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7553420

RESUMEN

From 1981 to 1993, 40 cases of acute type A viral hepatitis were reviewed and 2 cases (5%) of relapsing hepatitis were reported here. One case relapsed two weeks after remission and the other relapsed three weeks after remission, both had benign courses and recovered within four months. They were negative for serum hepatitis B surface antigen and hepatitis B core IgM antibodies. The serum autoantibodies, hepatitis C antibodies and hepatitis E antibodies were all negative during relapse. In summary, relapsing hepatitis A is rare in Taiwan and it is not related to multiple viral infections.


Asunto(s)
Hepatitis A/etiología , Enfermedad Aguda , Adulto , Femenino , Humanos , Masculino , Recurrencia
16.
J Pers Soc Psychol ; 62(1): 88-97, 1992 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1538316

RESUMEN

That observers tend to agree in their ratings of a target even if they have never interacted with that target has been called consensus at zero acquaintance. The basic finding that consensus is highest for judgments concerning a target's degree of extraversion (EV) and somewhat weaker for judgments of conscientiousness is replicated. Several potential observable cues that might be used by judges when rating targets are examined. The finding that ratings of physical attractiveness correlate with judgments of EV is replicated. In Study 1, rapid body movements and smiling were also found to correlate with EV judgments. The level of consensus declined when initially unacquainted Ss interacted one-on-one (Study 2), but did not decline--and even increased--when Ss interacted in a group (Study 3). Ss judged as extraverted at zero acquaintance were also seen as extraverted after interacting with others.


Asunto(s)
Extraversión Psicológica , Relaciones Interpersonales , Personalidad , Medio Social , Percepción Social , Adulto , Femenino , Humanos , Masculino
17.
Angiology ; 35(9): 545-52, 1984 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-6435484

RESUMEN

This double-blind cross-over study evaluates in 12 male volunteers the time course of nitroglycerin concentration in plasma with use of the TTS-nitroglycerin, a controlled-release transdermal dosage form for nitroglycerin, and compares the bioavailability of nitroglycerin delivered from the transdermal system with that from three successive applications of 0.5 inch of 2% nitroglycerin ointment placed at 8 hr intervals over 10 cm2 of skin. The mean amounts of nitroglycerin available when subjects wore the TTS-nitroglycerin or received successive applications of ointment were 15.8 mg +/- 1.8 (SE) and 9.8 mg +/- 0.8, respectively. Mean plasma concentrations for both treatments ranged from 10-18 pg/ml-cm2. The normalized areas under the curves--353 and 410 pg/hr/ml-cm2, respectively--did not differ significantly. The ratio of clearance from the two dosage forms was 0.98 +/- 0.12. All subjects experienced mild-to-moderate side effects of nitrate therapy with both dosage forms and also decrease in blood pressure and increase in heart rate.


Asunto(s)
Nitroglicerina/administración & dosificación , Administración Tópica , Adulto , Disponibilidad Biológica , Preparaciones de Acción Retardada , Humanos , Masculino , Nitroglicerina/sangre , Pomadas
18.
Eur J Clin Pharmacol ; 22(6): 473-80, 1982.
Artículo en Inglés | MEDLINE | ID: mdl-6813125

RESUMEN

A new transdermal therapeutic system (TTS) for the administration of nitroglycerin (NTG) was tested in human pharmacological studies in 26 healthy volunteers. Plasma concentrations and haemodynamic responses were determined after the application of the system in different dosages. The concentrations of NTG reached in the plasma were uniform and dose-related, i.e. dependent on the drug-release area, and showed only minor inter-individual variation. They remained almost constant as long as the system was in contact with the skin. Renewal of the system caused no appreciable change in the plasma concentration. The haemodynamic effects, like those of all nitrates, were not clearly related to the dose administered, and were not always dependent on the plasma concentration. Upon repeated application, NTG-TTS was well tolerated locally and systemically and led to no alteration in blood chemistry or haematological parameters. The typical nitrate headaches disappeared after a few days. The presence of the system on the skin caused no discomfort or inconvenience.


Asunto(s)
Nitroglicerina/administración & dosificación , Administración Tópica , Adulto , Presión Sanguínea/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Frecuencia Cardíaca/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Humanos , Persona de Mediana Edad , Nitroglicerina/efectos adversos , Nitroglicerina/farmacología
19.
Eur J Clin Pharmacol ; 23(2): 99-106, 1982.
Artículo en Inglés | MEDLINE | ID: mdl-6814928

RESUMEN

The effects of nitroglycerin, infused intravenously at 3.4 and 7.5 micrograms/min over 30 min, on haemodynamic parameters were determined in the morning and the afternoon in a randomized, placebo-controlled study in 5 healthy volunteers. The mean steady-state concentrations of nitroglycerin reached in the plasma during the infusions of 3.4 and 7.5 micrograms/min were 0.35 +/- 0.06 ng/ml and 0.64 +/- 0.22 ng/ml, respectively. Wide inter-individual variation was noted. The nitroglycerin-induced increase in the orthostatic rise in heart rate and the change in digital-pulse-wave morphology roughly paralleled the plasma concentration, whereas the reduction in systolic blood pressure in the upright position was still evident 15 mins after the infusion, i.e. when nitroglycerin was no longer measurable in plasma. No significant diurnal variation in vascular sensitivity to the vasodilative action of nitroglycerin was demonstrable. The change in pulse-wave morphology resulting from the reduction in peripheral resistance (shift of the dicrotic wave in the descending limb towards the base-line) proved to be the most sensitive haemodynamic parameter.


Asunto(s)
Hemodinámica/efectos de los fármacos , Nitroglicerina/sangre , Adulto , Presión Sanguínea/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Infusiones Parenterales , Masculino , Nitroglicerina/administración & dosificación , Nitroglicerina/farmacología , Pulso Arterial/efectos de los fármacos , Factores de Tiempo
20.
Clin Pharmacol Ther ; 30(6): 729-34, 1981 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7307423

RESUMEN

Analysis of sequential plasma samples in 14 hypertensive subjects receiving their usual oral dose of clonidine (0.1 to 0.6 mg twice daily) indicated that clonidine plasma concentration increased for the first 2 hr and then decreased and stabilized over the next 12 hr. Percent fall in diastolic blood pressure, but not side effects, correlated well with plasma concentration. Our study indicates a potential role for plasma clonidine determination in the treatment of patients with hypertension. It also demonstrates that clonidine can probably be given at 12-hr intervals and be effective.


Asunto(s)
Clonidina/sangre , Hipertensión/tratamiento farmacológico , Adulto , Presión Sanguínea/efectos de los fármacos , Clonidina/uso terapéutico , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Tiempo
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