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1.
Fisioterapia (Madr., Ed. impr.) ; 45(2): 74-83, mar.- abr. 2023. graf, tab
Artículo en Español | IBECS | ID: ibc-217334

RESUMEN

Introducción Durante el periodo inicial del confinamiento por la COVID-19 se tomaron una serie de medidas de restricción que modificaron el día a día de la población. En este estudio se buscó conocer el impacto de este periodo en la salud física y mental de niños y jóvenes con discapacidad originada en la infancia, y de sus familias, y describir los cambios que se produjeron en el acceso a la educación y a los servicios de salud. Material y métodos Se realizó un estudio analítico observacional y transversal. Los datos se obtuvieron mediante una encuesta electrónica a través de una plataforma online realizada por la Academia Europea de Discapacidad Infantil. La encuesta incluyó preguntas sobre cuatro bloques temáticos: características sociodemográficas y de salud, impacto del confinamiento en la salud y bienestar, acceso a la educación y a los servicios de salud. Resultados Se obtuvieron 145 respuestas. El 45,5% de los niños y jóvenes eran totalmente dependientes. Se percibió un impacto sobre su salud física (54,5%), mental (47,6%) y sobre ambas (32%), mayores niveles de estrés (68,3%) y problemas de sueño (41,4%), así como una sobrecarga muy elevada en el 84,8% de los progenitores, sobre todo en familias de niños con mayor nivel de dependencia (p<0,001). El 55% de los niños y jóvenes no recibieron ningún tratamiento durante este periodo, ni siquiera remoto. Conclusiones El confinamiento afectó en gran medida la salud física y mental, así como a los servicios recibidos por los niños y jóvenes con discapacidad y sus familias (AU)


Introduction During the initial period of COVID-19 lockdown, restriction measures modified the day-to-day life of the population. This study sought to know the impact of this period on the physical and mental health of children and young people with disabilities originating in childhood, and their families, and to describe the changes that occurred in access to education and health services. Material and methods An observational and cross-sectional analytical study was carried out. The data were obtained by means of an electronic survey through an online platform carried out by the European Academy of Childhood Disability. The survey included questions on four thematic blocks: sociodemographic and health characteristics, impact of lock down on health and well-being, and access to education and health services. Results One hundred and forty-five responses were obtained. 45.5% of the children and young people were totally dependent. There was an impact on their physical (54.5%), mental health (47.6%) and both (32%), higher levels of stress (68.3%), and sleep problems (41.4%), as well as a high burden in 84.8% of parents, especially in families of children with a higher level of dependency (P=.00). 55% of children and young people did not receive any treatment during this period, not even remotely. Conclusions COVID lock down period greatly affected physical and mental health, as well as the services for children and young people with disabilities and their families (AU)


Asunto(s)
Humanos , Masculino , Femenino , Recién Nacido , Lactante , Preescolar , Niño , Adolescente , Cuarentena , Infecciones por Coronavirus/prevención & control , Neumonía Viral/prevención & control , Pandemias , Servicios de Salud del Niño , Servicios de Salud para Personas con Discapacidad , Estudios Transversales , España
3.
Chem Phys Lipids ; 207(Pt B): 239-245, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28647339

RESUMEN

BACKGROUND: Changes in the microbiota composition have been implicated in the development of obesity and type 2 diabetes. However, not much is known on the involvement of gut microbiota in lipid and cholesterol metabolism. In addition, the gut microbiota might also be a potential source of plasma oxyphytosterol and oxycholesterol concentrations (oxidation products of plant sterols and cholesterol). Therefore, the aim of this study was to modulate the gut microbiota by antibiotic therapy to investigate effects on parameters reflecting cholesterol metabolism and oxyphytosterol concentrations. DESIGN: A randomized, double blind, placebo-controlled trial was performed in which 55 obese, pre-diabetic men received oral amoxicillin (broad-spectrum antibiotic), vancomycin (antibiotic directed against Gram-positive bacteria) or placebo (microcrystalline cellulose) capsules for 7days (1500mg/day). Plasma lipid and lipoprotein, non-cholesterol sterol, bile acid and oxy(phyto)sterol concentrations were determined at baseline and after 1-week intervention. RESULTS: Plasma secondary bile acids correlated negatively with cholestanol (marker for cholesterol absorption, r=-0.367; P<0.05) and positively with lathosterol concentrations (marker for cholesterol synthesis, r=0.430; P<0.05). Fasting plasma secondary bile acid concentrations were reduced after vancomycin treatment as compared to placebo treatment (-0.24±0.22µmol/L vs. -0.08±0.29µmol/L; P<0.01). Vancomycin and amoxicillin treatment did not affect markers for cholesterol metabolism, plasma TAG, total cholesterol, LDL-C or HDL-C concentrations as compared to placebo. In addition, both antibiotic treatments did not affect individual isoforms or total plasma oxyphytosterol or oxycholesterol concentrations. CONCLUSION: Despite strong correlations between plasma bile acid concentrations and cholesterol metabolism (synthesis and absorption), amoxicillin and vancomycin treatment for 7days did not affect plasma lipid and lipoprotein, plasma non-cholesterol sterol and oxy(phyto)sterol concentrations in obese, pre-diabetic men.


Asunto(s)
Amoxicilina/farmacología , Antibacterianos/farmacología , Colesterol/metabolismo , Vancomicina/farmacología , Administración Oral , Amoxicilina/administración & dosificación , Antibacterianos/administración & dosificación , Ácidos y Sales Biliares/sangre , Ácidos y Sales Biliares/metabolismo , Colesterol/sangre , Método Doble Ciego , Humanos , Masculino , Persona de Mediana Edad , Obesidad/sangre , Obesidad/metabolismo , Estado Prediabético/sangre , Estado Prediabético/metabolismo , Vancomicina/administración & dosificación
4.
Psychol Med ; 42(1): 149-59, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21676285

RESUMEN

BACKGROUND: There may be biological plausibility to the notion that cannabis use and childhood trauma or maltreatment synergistically increase the risk for later development of psychotic symptoms. To replicate and further investigate this issue, prospective data from two independent population-based studies, the Greek National Perinatal Study (n=1636) and The Netherlands Mental Health Survey and Incidence Study (NEMESIS) (n=4842), were analyzed. METHOD: Two different data sets on cannabis use and childhood maltreatment were used. In a large Greek population-based cohort study, data on cannabis use at age 19 years and childhood maltreatment at 7 years were assessed. In addition, psychotic symptoms were assessed using the Community Assessment of Psychic Experiences (CAPE). In NEMESIS, the Composite International Diagnostic Interview (CIDI) was used to assess psychotic symptoms at three different time points along with childhood maltreatment and lifetime cannabis use. RESULTS: A significant adjusted interaction between childhood maltreatment and later cannabis use was evident in both samples, indicating that the psychosis-inducing effects of cannabis were stronger in individuals exposed to earlier sexual or physical mistreatment [Greek National Perinatal Study: test for interaction F(2, 1627)=4.18, p=0.02; NEMESIS: test for interaction χ2(3)=8.08, p=0.04]. CONCLUSIONS: Cross-sensitivity between childhood maltreatment and cannabis use may exist in pathways that shape the risk for expression of positive psychotic symptoms.


Asunto(s)
Maltrato a los Niños/estadística & datos numéricos , Abuso de Marihuana/epidemiología , Trastornos Psicóticos/epidemiología , Adolescente , Adulto , Animales , Niño , Maltrato a los Niños/psicología , Relación Dosis-Respuesta a Droga , Métodos Epidemiológicos , Femenino , Grecia/epidemiología , Humanos , Masculino , Abuso de Marihuana/psicología , Persona de Mediana Edad , Países Bajos/epidemiología , Trastornos Psicóticos/psicología , Ratas , Estrés Psicológico/epidemiología , Estrés Psicológico/psicología , Encuestas y Cuestionarios , Adulto Joven
5.
Acta Psychiatr Scand ; 118(3): 209-13, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18452569

RESUMEN

OBJECTIVE: Cannabis use increases the risk for psychosis, but psychotogenic effects of cannabis may be restricted to exposure during early adolescence. METHOD: Four hundred and seventy-two participants (aged 12-23 years), randomly selected from the general population in Trinidad, completed questionnaires on past and current cannabis use and psychotic symptoms (using the Community Assessment of Psychic Experiences). RESULTS: Cannabis use increased the risk of experiencing psychotic symptoms and this effect was conditional on early exposure, defined around the mean age of onset of cannabis use. Thus, exposure before but not after the age of 14 years predicted psychotic symptoms (respectively beta: 0.71, 95% CI 0.22; 1.19, P = 0.004 and beta: -0.11, 95% CI -0.57; 0.36, P = 0.66). The developmental effect of cannabis use was independent of use of other drugs or current use of cannabis. CONCLUSION: Early adolescence may be a critical period with regard to the psychotogenic effect of cannabis across geographical settings and ethnic groups.


Asunto(s)
Conducta del Adolescente/psicología , Abuso de Marihuana/epidemiología , Abuso de Marihuana/psicología , Fumar Marihuana/efectos adversos , Trastornos Psicóticos/epidemiología , Adolescente , Adulto , Factores de Edad , Edad de Inicio , Niño , Comorbilidad , Estudios Transversales , Etnicidad/psicología , Etnicidad/estadística & datos numéricos , Femenino , Humanos , Masculino , Fumar Marihuana/epidemiología , Valor Predictivo de las Pruebas , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Factores de Riesgo , Autorrevelación , Encuestas y Cuestionarios , Trinidad y Tobago/epidemiología , Adulto Joven
6.
Int J Adolesc Med Health ; 18(2): 221-33, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16894861

RESUMEN

Notwithstanding the increase use of cannabis among adolescents in both developing and developed countries, few studies have looked at cannabis use and mood disorders. In a series of case studies, this research project seeks to investigate patterns of clinical presentations seen among cannabis users in psychiatric outpatients in Trinidad. Five clinical patterns of presentations are identified among cannabis users and abusers based on variables of dosing, age of initial use, duration of use, tolerance and reverse tolerance and poly-drug abuse. All patients in these case studies were standardized for method of use and potency of cannabis used. Patients were screened by urine tests to determine co-morbid use of other substances. Other variables such as environmental factors and genetic vulnerability were reviewed as far as possible from historical accounts of family members. The five patterns described are low, controlled use with mild euphoria and heightened awareness, moderate use with mixed depressive symptoms and suicidal behaviour, heavy, short term use with manic symptoms, long term incremental use with psychotic symptoms due to the trumping of depressive symptoms and cannabis mixed with other substances resulting in florid psychosis. Mood disorders appear to be a common finding among adolescents using cannabis. Sensitization to symptomatic presentation and early detection of cannabis use in young adolescents are necessary. Further research is needed on the effect of cannabinoids on emotions, behaviour and thinking and its relationship to mental disorders. This study is useful as a guideline for the implementation of public health strategies and legislation concerning the use of cannabis in youths.


Asunto(s)
Psiquiatría del Adolescente , Cannabis/toxicidad , Abuso de Marihuana/psicología , Trastornos del Humor/inducido químicamente , Adolescente , Adulto , Diagnóstico Dual (Psiquiatría) , Femenino , Humanos , Masculino , Abuso de Marihuana/complicaciones , Proyectos Piloto , Medición de Riesgo , Factores de Riesgo , Estudiantes/psicología , Trinidad y Tobago
7.
Acta Psychiatr Scand ; 114(1): 55-61, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16774662

RESUMEN

OBJECTIVE: General population longitudinal cohort studies have demonstrated the prognostic validity of self-reported psychotic experiences, but data on reliability and cross-validation with interview-based measures of these experiences are sparse. This study tested the reliability and validity of the Community Assessment of Psychic Experiences (CAPE42). METHOD: At baseline, the CAPE42 was used to measure the subclinical psychosis phenotype in a general population sample (n = 765). At follow-up (mean interval: 7.7 months), the Structured Interview for Schizotypy, Revised (SIS-R), the Brief Psychiatric Rating Scale (BPRS), and the CAPE42 were administered (n = 510). RESULTS: Baseline self-reported dimensions of psychosis were specifically and independently associated with their equivalent interview-based dimension at follow-up (standardized effect sizes of 0.4-0.5) and with their equivalent self-reported measure (standardized effect sizes of 0.6-0.8). CONCLUSION: The results indicate that self-reported dimensions of psychotic experiences in general population samples appear to be stable, reliable and valid.


Asunto(s)
Inventario de Personalidad/estadística & datos numéricos , Trastornos Psicóticos/diagnóstico , Trastorno de Personalidad Esquizoide/diagnóstico , Trastorno de la Personalidad Esquizotípica/diagnóstico , Adolescente , Adulto , Anciano , Escalas de Valoración Psiquiátrica Breve/estadística & datos numéricos , Estudios de Cohortes , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/epidemiología , Trastorno Depresivo/genética , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Países Bajos , Determinación de la Personalidad/estadística & datos numéricos , Vigilancia de la Población , Psicometría/estadística & datos numéricos , Trastornos Psicóticos/epidemiología , Trastornos Psicóticos/genética , Reproducibilidad de los Resultados , Factores de Riesgo , Trastorno de Personalidad Esquizoide/epidemiología , Trastorno de Personalidad Esquizoide/genética , Trastorno de la Personalidad Esquizotípica/epidemiología , Trastorno de la Personalidad Esquizotípica/genética
8.
Rev Environ Health ; 21(1): 69-79, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16700431

RESUMEN

UNLABELLED: This study investigated gender and ethnic differences in the rate of first contact outpatients with schizophrenia in the setting of a more-urban region (MUR) and a less-urban region (LUR) in Trinidad. In a prospective study, 134 first-contact patients with a diagnosis of schizophrenia were selected from two ecologically different regions. RESULTS: Of this population, 56.7% were of African origin and 32.1% were of Indian descent. Gender differences were significant, with males accounting for 66.4% (n=89) of patients with schizophrenia (chi2 = 14.45, d.f. = 1, p = 0.0001). Further analysis by age categories revealed a significant male predominance at ages 20-24 (p = 0.0001) and 25-29 (p = 0.002). Young African males (15-19 y, p = 0.049) predominated in MUR compared with LUR. The results showed a marked presence of Afro-Trinidadian males in both outpatient clinics (p < 0.05). We conclude that gender and ethnicity are important variables in the presentation of schizophrenia in Trinidad, whereas neither rural nor urban environments appeared to influence the expression of schizophrenia.


Asunto(s)
Servicios de Salud Mental/estadística & datos numéricos , Salud Rural/estadística & datos numéricos , Esquizofrenia/etnología , Salud Urbana/estadística & datos numéricos , Adolescente , Adulto , Factores de Edad , Áreas de Influencia de Salud , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Esquizofrenia/epidemiología , Factores Sexuales , Trinidad y Tobago/epidemiología
9.
Phys Med Biol ; 51(4): 891-902, 2006 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-16467585

RESUMEN

The purpose of this study is to develop and test a tapping device for needle insertion for prostate brachytherapy. This device will tap the needle into the prostate with a certain, well-defined, amount of momentum, instead of the currently used method of pushing the needle. Because of the high needle insertion velocity, we expect prostate motion and deformation to be less compared to current methods. We measured the momentum that is applied when manually tapping the needle into the prostate and found a mean momentum of 0.50 +/- 0.07 N s. The tapping device is pneumatically driven and we found that the delivered momentum increased linearly with the applied air pressure. The efficacy of the tapping device was tested on a piece of beef, placed on a freely moving and rotating platform. A significant correlation was found between the applied pressure and the rotation and displacement of the beef. Displacements and rotations were minimal for the highest pressure (4 bar) and amounted to only 2 mm and 6 degrees, respectively. Higher air pressures will further reduce displacements and rotations.


Asunto(s)
Braquiterapia/instrumentación , Agujas , Neoplasias de la Próstata/radioterapia , Implantación de Prótesis/instrumentación , Robótica/instrumentación , Transductores , Braquiterapia/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Masculino , Implantación de Prótesis/métodos , Robótica/métodos , Estrés Mecánico
10.
Reviews on environmental health ; 21(1): 69-79, 2006.
Artículo en Inglés | MedCarib | ID: med-17567

RESUMEN

This study investigated gender and ethnic differences in the rate of first contact outpatients with schizophrenia in the setting of a more-urban region (MUR) and a less-urban region (LUR) in Trinidad. In a prospective study, 134 first-contact patients with a diagnosis of schizophrenia were selected from two ecologically different regions. Results: Of this population, 56.7 per cent were of African origin and 32.1 per cent were of Indian descent. Gender differences were significant, with males accounting for 66.4 per cent (n=89) of patients with schizophrenia (X2 = 14.45, d.f. = 1, p = 0.0001). Further analysis by age categories revealed a significant male predominance at ages 20-24 (p= 0.0001) and 25-29 (p = 0.002). Young African males (15-19 y, p = 0.049) predominated in MUR compared with LUR. The results showed a marked presence of Afro-Trinidadian males in both outpatient clinics (p < 0.05). We conclude that gender and ethnicity are important variables in the presentation of schizophrenia in Trinidad, whereas neither rural nor urban environments appeared to influence the expression of schizophrenia.


Asunto(s)
Humanos , Esquizofrenia/etnología , Esquizofrenia/epidemiología , Esquizofrenia/fisiopatología , Trinidad y Tobago/epidemiología
12.
Med Biol Eng Comput ; 41(6): 689-700, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14686595

RESUMEN

Performing minimally invasive vascular interventions requires proper training, as a guide wire needs to be manipulated, by the tail, under fluoroscopic guidance. To provide a training environment, the motion of the guide wire inside the human vasculature can be simulated by computer. Such a simulation needs to be based on an algorithm that is both realistic and fast. To meet these two demands, an analytical solution to the problem of guide wire motion has been derived, using a new parametrisation of guide wire shape. The algorithm is highly generic, is entirely based on elementary physics and has good convergence properties (accuracy of 22 micron after two iterations). In an experimental validation of the algorithm in a planar model, the RMS of the spatial discrepancy between the real and simulated catheter positions was about 10% of the lumen size. Comparison of the simulated guide wire motion with 3D rotational angiography data of a real guide wire advanced in a plastic phantom of the cerebral vasculature showed that the new algorithm produced realistic results.


Asunto(s)
Algoritmos , Radiografía Intervencional/métodos , Enfermedades Vasculares/terapia , Cateterismo , Humanos , Modelos Cardiovasculares , Movimiento (Física) , Enfermedades Vasculares/diagnóstico por imagen
13.
J Magn Reson Imaging ; 13(1): 131-5, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11169815

RESUMEN

We developed a magnetic resonance (MR)-safe tracking catheter using an optical fiber with a light-diffusing tip segment to transport laser energy through the catheter. This energy is converted to a DC current running through a small coil at the catheter tip. Our method is inherently MR-safe since the use of long conducting wires is avoided. The intravoxel dephasing induced by the tip coil was clearly visible for laser powers between 250 mW and 750 mW for all angular positions of the catheter. J. Magn. Reson. Imaging 2001;13:131-135.


Asunto(s)
Cateterismo , Rayos Láser , Imagen por Resonancia Magnética , Diseño de Equipo , Tecnología de Fibra Óptica/instrumentación , Humanos , Fibras Ópticas , Seguridad
14.
Phys Med Biol ; 46(1): 245-59, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11197675

RESUMEN

There is a growing interest in performing intravascular interventions guided by MR imaging--a technique which offers the possibility of flow measurements during the intervention. For a reliable assessment of the haemodynamic significance of a stenosis, the flow and the pressure decay within the stenosis should both be measured. We have developed an optical, MR-compatible, pressure sensor (Annupres) that uses a novel annular element. Existing optical pressure sensors measure pressures unilaterally, thus giving rise to artefacts because of the dependence of the measurement on the angular orientation of the aperture. The annular element, however, measures blood pressure on all sides, and we show that by using circularly polarized light this pressure measurement is intrinsically insensitive to rotation of the sensor around its long axis. The Annupres sensor has been tested in an experimental set-up, and was able to measure pressures from 50 mmHg to 180 mmHg reliably with an accuracy of 1.5%.


Asunto(s)
Velocidad del Flujo Sanguíneo/efectos de la radiación , Imagen por Resonancia Magnética/instrumentación , Imagen por Resonancia Magnética/métodos , Radioterapia/instrumentación , Presión Sanguínea/efectos de la radiación , Hemodinámica/efectos de la radiación , Humanos , Cinética , Modelos Estadísticos , Presión , Factores de Tiempo
15.
J Magn Reson Imaging ; 12(1): 79-85, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10931567

RESUMEN

We examined the unwanted radiofrequency (RF) heating of an endovascular guidewire frequently used in interventional magnetic resonance imaging (MRI). A Terumo guidewire was partly immersed in an oblong saline bath to simulate an endovascular intervention. The temperature rise of the guidewire tip during an FFE sequence [average specific absorption rate (SAR) = 3.9 W/kg] was measured with a Luxtron fluoroscopic fiber. Starting from 26 degrees C, the guidewire tip reached temperatures up to 74 degrees C after 30 seconds of scanning. Touching the guidewire may cause sudden heating at the point of contact, which in one instance caused a skin burn. The excessive heating of a linear conductor like the guidewire can only be explained by resonating RF waves. The capricious dependencies of this resonance phenomenon on environmental factors have severe consequences for predictability and safety guidelines.


Asunto(s)
Cateterismo/instrumentación , Calor , Imagen por Resonancia Magnética/instrumentación , Ondas de Radio/efectos adversos , Vasos Sanguíneos/patología , Seguridad de Equipos , Humanos , Imagen por Resonancia Magnética/efectos adversos , Modelos Teóricos , Fantasmas de Imagen , Radiología Intervencionista , Factores de Riesgo , Sensibilidad y Especificidad
16.
Ned Tijdschr Geneeskd ; 143(24): 1265-8, 1999 Jun 12.
Artículo en Holandés | MEDLINE | ID: mdl-10396338

RESUMEN

OBJECTIVE: To assess the short and middle-long term results of outpatient treatment of internal haemorrhoids by rubber band ligation. DESIGN: Prospective. METHODS: The results and the complications of rubber band ligation were assessed in a group of consecutive patients treated for internal haemorrhoids by one surgeon in March 1995-September 1997 in the Laurentius Hospital Roermond, the Netherlands. Middle-long term results were assessed by an independent examiner who questioned the patients by phone. RESULTS: Ninety-four patients were treated: 43 women and 51 men, with a mean age of 51 years (range: 23-80). After 6-18 weeks 80 out of 90 accessible patients (89%) were symptom-free, 71 (79%) of them after one treatment. Serious complications were not reported. However, the days after treatment mild complaints of anal urgency and pain were present in 16 patients (20%). Twenty-three patients underwent sigmoidoscopy. In 10 patients (43%) adenomatous polyps (in 9 patients) or diverticulosis (in 1 patient) were found. After a mean of 18 months (range: 6-31) 32 patients (41%) (still) had anal complaints compatible with haemorrhoids. CONCLUSION: Rubber band ligation is an easy and safe outpatient treatment of internal haemorrhoids. Most patients become symptom-free, often after one treatment. However, about 40% of the patients have recurrent symptoms within a few years after initial treatment.


Asunto(s)
Hemorroides/cirugía , Procedimientos Quirúrgicos Menores/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Ligadura/efectos adversos , Ligadura/métodos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Recurrencia , Goma , Resultado del Tratamiento
17.
Phys Med Biol ; 43(5): 1049-57, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9623640

RESUMEN

Several types of intravascular ultrasound (IVUS) catheters are connected to a motor at their proximal end, in order to let the catheter rotate around its length axis. However, the rotation of the distal axis tip does not follow exactly the rotation of the motor, since the catheter axis is not completely torsion-free and friction forces cause the tip to rotate in a shockwise manner. In the case of the IVUS catheter, continuous information concerning the exact rotation of the crystal is essential for 3D image reconstruction. We developed a simple method of measuring the tip rotation continuously, the TOMCAT method, using only a single optical fibre glued in a fixed position inside the rotating axis of the IVUS catheter, or any rotating axis or catheter in general. Our method does not require external electromagnetic fields or the presence of a non-rotating guiding catheter. The rotation of the distal tip is related to that of the proximal part by transporting polarized light through the fibre. We performed in vitro experiments using various types of optical fibres to test the TOMCAT method, and conclude that using a specific step-index monomode cylinder-symmetrical optical fibre the TOMCAT approach yields accurate results.


Asunto(s)
Cateterismo , Ultrasonografía Intervencional/instrumentación , Diseño de Equipo , Humanos , Modelos Teóricos , Estrés Mecánico
18.
IEEE Trans Med Imaging ; 16(4): 439-46, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9263001

RESUMEN

Recent studies show that the presence of fatty lesions in the atherosclerotic vessel wall is a risk factor for acute occlusion of blood vessels. Although fat has a high electrical resistivity, existing impedance catheter systems cannot be used for detection of these lesions because artifacts owing to impedance variations in the extravascular surroundings have a major and irretraceable effect on the measurement. Standard algorithms used in attempt to compensate for these artifacts suffer from severe instability problems. We defined design guidelines to be met by a new impedance catheter system in order to make a robust reconstruction algorithm possible and have built an experimental in travascular impedance catheter (IIC) system according to these guidelines, using a normalized differential measurement procedure. With this IIC, we performed experiments on human iliac arteries from the section ward (fixed specimens), showing that plastic models of arterial fatty lesions (8 mm3) can be detected reliably.


Asunto(s)
Arteriosclerosis/diagnóstico , Cateterismo/instrumentación , Impedancia Eléctrica , Arteria Ilíaca/patología , Guías como Asunto , Humanos , Modelos Cardiovasculares
19.
Biopharm Drug Dispos ; 17(3): 209-21, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8983396

RESUMEN

The absorption of sulindac from two different 200 mg oral dosage forms, Pro-SorbTM liquid and Clinoril tablets, was compared following administration to eight healthy human volunteers. Subjects received both formulations according to a randomized crossover design and blood samples were collected at selected times during 24 h. Concentrations of both sulindac and its active sulphide metabolite were determined by HPLC and individual serum concentration versus time profiles were constructed. Maximal serum concentrations (Cmax) and area under the curve values (AUClast and AUC0-infinity) were compared for both sulindac and sulindac sulphide. The results indicate that the rate and extent of absorption of sulindac from Pro-SorbTM liquid are significantly greater than those from Clinoril tablets, a finding consistent with the observation that the liquid form produces less gastric irritation following oral administration.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacocinética , Profármacos/farmacocinética , Sulindac/farmacocinética , Absorción , Adulto , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/sangre , Disponibilidad Biológica , Química Farmacéutica , Estudios Cruzados , Formas de Dosificación , Humanos , Masculino , Persona de Mediana Edad , Profármacos/administración & dosificación , Método Simple Ciego , Sulindac/administración & dosificación , Sulindac/sangre
20.
Appl Radiat Isot ; 45(10): 997-107, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7994289

RESUMEN

Since the introduction of radioiodinated m-iodobenzylguanidine in 1980, much research has been performed, both in the chemical field as well as in medical sciences. This paper reviews the synthesis, radiolabelling and stability of radioiodinated m-iodobenzylguanidine. Regarding the many radiolabelling procedures for m-iodobenzylguanidine, the Cu(1+)-assisted nucleophilic exchange radioiodination can be considered as the method of first choice. Quality control of the radiopharmaceutical product is discussed and attention is paid to recent studies regarding the radiochemical stability of iodine-131 labelled m-iodobenzylguanidine.


Asunto(s)
Radioisótopos de Yodo , Yodobencenos/química , Yodobencenos/síntesis química , Simpaticolíticos/síntesis química , 3-Yodobencilguanidina , Cromatografía Líquida de Alta Presión , Cobre , Estabilidad de Medicamentos , Indicadores y Reactivos , Marcaje Isotópico/métodos , Simpaticolíticos/química
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