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1.
Gesundheitswesen ; 79(8-09): 638-644, 2017 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-25985221

RESUMEN

Our mixed methods (narrative interviews; group discussions; quantitative online survey) study examines the motivation of physicians in training as specialists in general practice to open their own practice. In addition, we wondered how motivations change during the vocational training. In a synchronic perspective motivations are highly differentiated on the one hand, on the other hand they are clearly gender-specific. In a diachronic perspective, the decision for or against their own GP surgery is uncertain for a long time during vocational training.


Asunto(s)
Selección de Profesión , Medicina Familiar y Comunitaria/educación , Medicina General/educación , Motivación , Pautas de la Práctica en Medicina , Práctica Privada , Especialización , Adulto , Femenino , Alemania , Necesidades y Demandas de Servicios de Salud/tendencias , Humanos , Masculino , Factores Sexuales , Recursos Humanos
2.
Pilot Feasibility Stud ; 8(1): 12, 2022 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-35063040

RESUMEN

BACKGROUND: Although the benefits of physical activity (PA) on health are recognised, prostate cancer patients do not follow PA recommendations. The barriers to PA, whether physical, environmental or organisational, are known. Furthermore, even when such barriers are overcome, this achievement is not systematically accompanied by a change in lifestyle habits. The proposal of a programme enabling the integration of PA in the patient's everyday life represents a new challenge in the personalized management of cancer patients. Peer-mentoring interventions have demonstrated their effectiveness in increasing adherence to PA by patients. This study aimed (1) to assess the feasibility of a peer-mentoring intervention: the Acti-Pair program in a local context and (2) to assess the effectiveness of the intervention in this context. METHODS AND ANALYSIS: A pre-post  design pilot study will be used to evaluate feasibility, potential effectiveness and implementation outcomes overs in prostate cancer patients. We performed a mixed quantitative and qualitative prospective study to assess means and process indicators and the implementation of the Acti-Pair program. This study will be performed in cancer centres of Loire district and will be comprised of three successive stages (1) diagnosis of the target population, (2) recruitment and training of peers, and (3) implementation of this intervention in the Loire department. DISCUSSION: This study will allow us to extend the peer-mentoring intervention to other contexts and assess the effectiveness of this intervention and its generalisability.

3.
Langmuir ; 27(13): 8396-403, 2011 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-21630652

RESUMEN

Coatings based on sol-gel technology with different types of nanoparticles embedded into the sol-gel matrix were fabricated, and the resulting properties were investigated. Pyrogenic silica nanoparticles were added to the sol before coating. The silica particles varied in primary particle size and agglomerate size, and in their surface modification. The particles were wetted in ethanol and dispersed to certain finenesses. The difference in agglomerate size was partly caused by varying particle types, but also by the dispersing processes that were applied to the particles. The resulting coatings were examined by visual appearance and SEM microscopy. Furthermore, their micromechanical properties were determined by nanoindentation. The results show an important influence from the added nanoparticles and their properties on the visual appearance as well as the micromechanical behavior of the sol-gel coatings. It is shown that, in fact, the particle size distribution can have a major impact on the coating properties as well as the surface modification.

4.
AIMS Public Health ; 7(2): 319-335, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32617359

RESUMEN

BACKGROUND: The purpose of this study was to determine the prevalence of Burnout syndrome (BOS), risk factors and the effect of physical activity in six professions in Cameroon. METHODS: 2012 participants completed questionnaires related to socio-demographic conditions and work perception. Appropriate Maslach Burnout Inventory (MBI) psychometers were used for specific professions. Level of physical activity and sports practice was determined using the Ricci and Gagnon scale. RESULTS: The overall prevalence of burnout was 67.9%; with 5.3% high; 34.3% moderate; and 60.4% low degree. 42.2% of victims of BOS were in high loss of personal achievement, 39.9% in high depersonalization of and 38.2% in high emotional exhaustion. Higher prevalence of BOS was found in Army (85.3%) and educational sectors (78.5% in secondary school teachers (SET) and 68% in university teaching staff (UTS)). BOS was significantly associated (p < 0.05) with distance from home to workplace, number of children per participant, number of hospitals attended, number of guards per month, labour hours per day, conflicts with the hierarchy, conflicts with colleagues, poor working conditions, unsatisfactory salary, part time teaching in private university institutions, job seniority, sedentariness. Apart from UTS, no association was observed between the level of physical activity and occurrence of BOS. CONCLUSION: Burnout is a reality in occupational environments in Cameroon.

5.
Cell Death Differ ; 15(10): 1553-63, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18535584

RESUMEN

Mitochondrial dysfunction and release of pro-apoptotic factors such as cytochrome c or apoptosis-inducing factor (AIF) from mitochondria are key features of neuronal cell death. The precise mechanisms of how these proteins are released from mitochondria and their particular role in neuronal cell death signaling are however largely unknown. Here, we demonstrate by fluorescence video microscopy that 8-10 h after induction of glutamate toxicity, AIF rapidly translocates from mitochondria to the nucleus and induces nuclear fragmentation and cell death within only a few minutes. This markedly fast translocation of AIF to the nucleus is preceded by increasing translocation of the pro-apoptotic bcl-2 family member Bid (BH3-interacting domain death agonist) to mitochondria, perinuclear accumulation of Bid-loaded mitochondria, and loss of mitochondrial membrane integrity. A small molecule Bid inhibitor preserved mitochondrial membrane potential, prevented nuclear translocation of AIF, and abrogated glutamate-induced neuronal cell death, as shown by experiments using Bid small interfering RNA (siRNA). Cell death induced by truncated Bid was inhibited by AIF siRNA, indicating that caspase-independent AIF signaling is the main pathway through which Bid mediates cell death. This was further supported by experiments showing that although caspase-3 was activated, specific caspase-3 inhibition did not protect neuronal cells against glutamate toxicity. In conclusion, Bid-mediated mitochondrial release of AIF followed by rapid nuclear translocation is a major mechanism of glutamate-induced neuronal death.


Asunto(s)
Factor Inductor de la Apoptosis/metabolismo , Proteína Proapoptótica que Interacciona Mediante Dominios BH3/metabolismo , Muerte Celular/fisiología , Mitocondrias/metabolismo , Neuronas/fisiología , Animales , Factor Inductor de la Apoptosis/genética , Proteína Proapoptótica que Interacciona Mediante Dominios BH3/antagonistas & inhibidores , Proteína Proapoptótica que Interacciona Mediante Dominios BH3/genética , Caspasas/metabolismo , Activación Enzimática , Silenciador del Gen , Ácido Glutámico/toxicidad , Humanos , Ratones , Microscopía Fluorescente , Microscopía por Video , Neuronas/citología , Neuronas/efectos de los fármacos , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo
6.
Methods Inf Med ; 45(4): 419-23, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16964359

RESUMEN

OBJECTIVES: The extreme sib-pair approach has been shown to be a powerful strategy to identify susceptibility loci linked to quantitative traits. The body mass index is the usually assessed trait in genetic studies on human obesity. Environmental factors clearly play an important role for this trait. We hypothesized that the low weight of most sibs who were seemingly discordant to the obese index proband was influenced by other environmental and/or genetic factors like restrained eating or psychiatric disorders. METHODS: A screening questionnaire was sent to parents of all consecutively admitted patients three weeks prior to referral of index probands for inpatient treatment of obesity. The first 320 families were further investigated. Twenty-seven seemingly extremely discordant sib-pairs (ED) were identified and examined in detail. RESULTS: The low weight of most sibs who were seemingly discordant to the obese index proband was influenced by factors like restrained eating or psychiatric disorders. Only 20% of the interviewed ED could be considered as genuine ED. CONCLUSION: We conclude that extensive medical evaluation is necessary if the aim is to guarantee genuine ED in family studies for human obesity. Non-paternity deserves specific attention in ED studies.


Asunto(s)
Índice de Masa Corporal , Frecuencia de los Genes , Obesidad/genética , Sitios de Carácter Cuantitativo , Hermanos , Adolescente , Niño , Factores de Confusión Epidemiológicos , Conducta Alimentaria , Femenino , Genotipo , Alemania/epidemiología , Humanos , Masculino , Tamizaje Masivo , Obesidad/epidemiología , Obesidad/terapia , Medición de Riesgo , Factores de Riesgo , Medio Social , Encuestas y Cuestionarios
7.
J Natl Cancer Inst ; 82(16): 1345-9, 1990 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-2199682

RESUMEN

We evaluated adoptive cellular therapy with recombinant interleukin-2 (rIL-2) plus lymphokine-activated killer (LAK) cells alternating with sequential dacarbazine chemotherapy in 27 patients with metastatic melanoma. rIL-2 was given to the patients as a 5-day continuous-infusion priming cycle followed by 1 day of rest, 4 days of leukapheresis for in vitro LAK cell expansion, and then 4 1/2 days of continuous rIL-2 infusion in conjunction with reinfusion of LAK cells during the first 3 days of the continuous infusion. Two weeks later, patients received dacarbazine (1,200 mg/m2) chemotherapy. Two patients achieved complete remission, and five achieved a partial remission for a response rate of 26% (95% confidence interval = 12%-47%). Three patients had mixed responses. The partial and mixed responses were brief, ranging from 1 month to 6 months, whereas the two complete responses have been sustained for 13+ and 24+ months. There were no additive toxic effects except for thrombocytopenia, which delayed treatment in two patients. Alternating adoptive immunotherapy and dacarbazine chemotherapy appear to be reasonably tolerated by patients, but the response rate is not clearly better than that achieved with other rIL-2 regimens or with chemotherapy alone.


Asunto(s)
Dacarbazina/uso terapéutico , Inmunización Pasiva , Interleucina-2/uso terapéutico , Células Asesinas Activadas por Linfocinas/inmunología , Melanoma/terapia , Adulto , Anciano , Terapia Combinada , Dacarbazina/administración & dosificación , Dacarbazina/efectos adversos , Femenino , Humanos , Interleucina-2/administración & dosificación , Interleucina-2/efectos adversos , Masculino , Melanoma/tratamiento farmacológico , Melanoma/secundario , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/efectos adversos , Proteínas Recombinantes/uso terapéutico
8.
MMW Fortschr Med ; 148(24): 32-5, 2006 Jun 15.
Artículo en Alemán | MEDLINE | ID: mdl-16850805

RESUMEN

Physical maltreatment, neglect and sexual abuse have manifold consequences for the young victims. Depending on subsequent life circumstances, they may develop not only physical problems, but also anxiety disorders, depression, personality disorders, eating disorders, and other problems. A lack of self-esteem, exaggerated aggressiveness and bonding problems can result in long-term psychosocial consequences that may persist into adulthood.


Asunto(s)
Abuso Sexual Infantil/psicología , Maltrato a los Niños/psicología , Discapacidades del Desarrollo/etiología , Trastornos Mentales/etiología , Adaptación Psicológica , Adolescente , Adopción/psicología , Factores de Edad , Niño , Preescolar , Emociones , Estudios de Seguimiento , Humanos , Lactante , Factores de Riesgo , Factores de Tiempo
9.
J Clin Oncol ; 9(7): 1233-40, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2045864

RESUMEN

We conducted a multicenter, phase II trial of continuous-infusion recombinant interleukin-2 (rIL-2) and lymphokine-activated killer (LAK) cells. Patients had advanced cancer, measurable disease, and a good performance level. Treatment included a 5-day continuous infusion of 18 x 10(6) IU/m2/d of rIL-2 followed by 1 day of rest, 4 days of leukapheresis to collect cells for in vitro augmentation of cellular cytotoxicity, and 5 more days of rIL-2 infusion with reinfusion of LAK cells for 3 successive days. Therapy was repeated after 2 weeks. There were 117 patients enrolled: 63% were males, with a median age of 51 years. Eighty-two percent were managed in oncology units, and 18% were in intensive care units. Six patients died within 1 month of initiating therapy. In renal cell carcinoma, the response rate was one of 31 patients (3%), with a median survival of 10.7 months. In melanoma, the response rate was four of 33 patients (12%), with a median survival of 6.1 months. For all other histologies, response rate was three of 53 patients (5%), with a median survival of 7.4 months. All responders were asymptomatic when therapy was initiated. This trial confirms the feasibility of administering continuous rIL-2 and LAK cells outside the intensive care unit environment. Antitumor activity in melanoma was similar to that seen in multicenter trials of bolus rIL-2 and LAK cells. Activity in renal cell cancer was disappointing.


Asunto(s)
Interleucina-2/uso terapéutico , Células Asesinas Activadas por Linfocinas , Neoplasias/terapia , Adolescente , Adulto , Anciano , Terapia Combinada , Femenino , Humanos , Infusiones Intravenosas , Interleucina-2/administración & dosificación , Interleucina-2/efectos adversos , Masculino , Persona de Mediana Edad , Neoplasias/mortalidad , Neoplasias/patología , Proteínas Recombinantes/uso terapéutico , Tasa de Supervivencia
11.
J Clin Endocrinol Metab ; 85(6): 2287-92, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10852465

RESUMEN

Leydig cells and Sertoli cells of the testes produce hormones that cause male differentiation, if receptors are present. The Y chromosomal SRY gene (sex determining Region Y gene) acts as TDF and is required for regular male sex determination. SRY represents a transcription factor belonging to the superfamily of genes sharing the HMG-box motif(high-mobility group-box), which acts as DNA binding region. Here, we describe a nonmosaic XY sex-reversed female with pure gonadal dysgenesis (46,XY karyotype, completely female external genitalia, normal Müllerian ducts, absence of Wolffian ducts, streak gonads) who harbored a yolk-sac tumor and was referred for the assessment of primary amenorrhea. Using genomic PCR analysis, a 423-bp PCR product, encompassing the HMG-box of the SRY gene, was amplified from the proposita, her father, and her three brothers, whereas no band was visible in the patient's mother and her three sisters. The PCR products were sequenced for mutations subsequently. A new de novo missense mutation within the HMG-box of the SRY gene was discovered in the proposita. A G is replaced by an A in codon 95 at position +284, resulting in the replacement of the nonpolar aminoacid glycine by the polar amino acid glutamate. The glycine at codon 95 is highly conserved between the family of HMG-box proteins and between species. This point mutation has not been described earlier and brings the total number of SRY mutations described so far to 36, each mutation being unique. This mutation was not detected in the patient's father and her male siblings. The present data provide further evidence to support the functional importance of the putative DNA binding activity of the SRY HMG-box domain.


Asunto(s)
Proteínas de Unión al ADN/genética , Tumor del Seno Endodérmico/genética , Ácido Glutámico , Glicina , Disgenesia Gonadal/genética , Mutación Missense , Proteínas Nucleares , Procesos de Determinación del Sexo , Factores de Transcripción , Cromosoma Y , Adulto , Secuencia de Aminoácidos , Codón , Secuencia Conservada , Proteínas de Unión al ADN/química , Tumor del Seno Endodérmico/patología , Femenino , Disgenesia Gonadal/patología , Humanos , Cariotipificación , Masculino , Datos de Secuencia Molecular , Fenotipo , Estructura Secundaria de Proteína , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Proteína de la Región Y Determinante del Sexo , Cromosoma X
12.
Crit Rev Oncol Hematol ; 39(1-2): 115-23, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11418308

RESUMEN

We established short-term cell lines for 108/170 (64%) patients with metastatic melanoma. Tumor cell numbers were expanded to 10(8), then cells were irradiated, aliquoted, and cryopreserved for clinical use. Vaccines have been used to treat 69 patients with clinical follow up for 33 who had measurable metastatic disease at the time vaccine therapy was initiated (METS), and 33 who had no evidence of disease (NED) at the time of vaccine therapy following surgical resection of metastases. The protocol called for a baseline test of delayed tumor hypersensitivity (DTH), three weekly injections, a repeat of the DTH test, then monthly injections for an additional 5 months. Objective tumor responses were noted in 3/26 (12%) patients who received a minimum of three vaccinations, one complete, and two partial, with survivals of 36, 46+, and 78+ months. Only 6/64 (9.4%) had a positive DTH (>10 mm) at baseline, including three METS, all of whom progressed within 4 months and died within a year, and three who are still NED after more than 5 years. Conversion of DTH from negative to positive was documented in 18/44 (41%) patients who were tested at week 0 and 4. At a median follow up of greater than 5 years, the median overall survival (OS) was 40 months for "NED" with a 5-year survival rate of 39%, and 8.6 months with a 5-year survival rate of 10% for "METS" The 18 patients who had conversion of their DTH had a median event-free survival (EFS) of 15.8 months and 5-year EFS of 32% compared to 4.2 months and 9% for the 26 non-converters (P=0.012, two-tailed, log-rank test). Among patients who were NED when treatment started, the 12 patients whose DTH converted had a median overall survival of 61.4 months with 5-year survival of 63% compared to 9.7 months and 0% for the 13 non-converters (P=0.0026). This treatment approach is feasible, produces minimal toxicity, and is associated with long-term survival in a significant subset of patients.


Asunto(s)
Vacunas contra el Cáncer/administración & dosificación , Inmunoterapia/métodos , Melanoma/terapia , Células Tumorales Cultivadas/inmunología , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Masculino , Melanoma/mortalidad , Melanoma/secundario , Persona de Mediana Edad , Tasa de Supervivencia , Resultado del Tratamiento
13.
Neuro Oncol ; 3(1): 35-41, 2001 01.
Artículo en Inglés | MEDLINE | ID: mdl-11305415

RESUMEN

Interferon-alpha (IFN-alpha) has been safely given concurrently with radiation therapy (RT) in treating gliomas. As single agents, both IFN-alpha and cis-retinoic acid (CRA) have produced objective tumor regressions in patients with recurrent gliomas. In vitro, IFN-alpha2a and CRA enhance radiation therapy effects on glioblastoma cells more than either agent alone. This trial was conducted to determine the clinical effects of IFN-alpha2a and CRA when given concurrently with radiation therapy to patients with high-grade glioma. Newly diagnosed patients with high-grade glioma received IFN-alpha2a at a dosage of 3 to 6 million IU s.c. 4 times a day for 3 days per week and 1 mg/kg CRA by mouth 4 times a day for 5 days per week during the delivery of partial brain radiation therapy at 180 cGy x 33 fractions for 5 days per week for a total of 59.4 Gy during the 7-week period. Use of the antiepileptic phenytoin was prohibited after observing that the combination of IFN-alpha2a, CRA, and phenytoin was associated with a high rate of dermatologic toxicity not seen in a previous study with concurrent IFN-alpha2a and radiation therapy. Forty patients (26 men and 14 women) with a median age of 60 (range, 19 to 81 years) were enrolled between August 1996 and October 1998. Histopathologic diagnoses were glioblastoma multiforme or grade 4 anaplastic astrocytoma in 36 patients, and grade 3 anaplastic astrocytoma in 4 patients. Only 4 patients (10%) underwent a gross total resection of tumor prior to this therapy; 50% were asymptomatic when treatment was initiated. The planned 7-week course of concurrent therapy was completed by 75% of patients; 30% completed the 16-week course of IFN-alpha and CRA alone. At a median follow-up of 36 months, there were 37 deaths, with a median overall survival of 9.3 months and a 1-year survival rate of 42%. There was no improvement in survival compared with a similar group of 19 patients treated with concurrent IFN-alpha2a and radiation therapy in a previous trial. In the high-risk group of patients in the present study, concurrent treatment with IFN-alpha2a, CRA, and RT was feasible, but was not associated with a better outcome compared with a similar patient population treated with radiation therapy and IFN-alpha2a, or compared with radiation therapy alone in other trials.


Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Glioblastoma/tratamiento farmacológico , Factores Inmunológicos/uso terapéutico , Interferón-alfa/uso terapéutico , Isotretinoína/uso terapéutico , Teleterapia por Radioisótopo , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirugía , Quimioterapia Adyuvante , Terapia Combinada , Contraindicaciones , Craneotomía , Erupciones por Medicamentos/etiología , Femenino , Glioblastoma/mortalidad , Glioblastoma/radioterapia , Glioblastoma/cirugía , Humanos , Hipertrigliceridemia/inducido químicamente , Interferón alfa-2 , Isotretinoína/efectos adversos , Tablas de Vida , Masculino , Persona de Mediana Edad , Fenitoína/efectos adversos , Traumatismos por Radiación/etiología , Teleterapia por Radioisótopo/efectos adversos , Proteínas Recombinantes , Análisis de Supervivencia , Insuficiencia del Tratamiento
14.
Int J Radiat Oncol Biol Phys ; 18(2): 425-31, 1990 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2303369

RESUMEN

The mathematical formalism associated with a 2-dimensional inverse problem in radiation therapy treatment and planning is discussed. The formalism is extended to convex phantoms of arbitrary cross-section. Relations necessary to produce circularly symmetric dose distributions about any point within the phantom are obtained. The general case for a particularly simple class of ideal dose distributions within 2-dimensional convex phantoms of arbitrary shape is solved. The relationship between treatment beans with and without negative fluences, and their associated dose distributions, is discussed.


Asunto(s)
Planificación de la Radioterapia Asistida por Computador , Radioterapia Asistida por Computador , Humanos , Matemática , Modelos Estructurales , Dosificación Radioterapéutica
15.
Int J Radiat Oncol Biol Phys ; 18(2): 433-9, 1990 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2303370

RESUMEN

The inverse problem in radiation therapy presents a solution for a fluence distribution based on the specification of a region of dose in a patient. We show results for one such solution based on the inversion of an integral over a function of the fluence profile of a rotating beam. We use Monte Carlo methods and numerical integrations to evaluate dose distributions obtained with the inverse method and show the limitations of this theoretical approach. Our results show that dose to a single circular region at an arbitrary position in a 2-dimensional volume can be calculated. Uniform dose to arbitrarily shaped regions cannot be calculated with this formalism, although practical solutions can still be obtained.


Asunto(s)
Planificación de la Radioterapia Asistida por Computador , Radioterapia Asistida por Computador , Humanos , Matemática , Dosificación Radioterapéutica
16.
Int J Radiat Oncol Biol Phys ; 13(8): 1241-6, 1987 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-3301760

RESUMEN

We report on a useful clinical method for precisely locating intracranial targets. Utilizing the BRW system, the technique is currently used in stereotaxic irradiation of arteriovenous malformations. An intracranial localizer box, with four radio-opaque markers on each face, surrounds the patient's head and is attached to the BRW Head Ring. Two localization films are required. One film includes the target and the eight anterior and posterior markers, whereas the other film includes the target and the eight right and left markers. There are no constraints that the films be orthogonal or parallel to the box faces, only that the target and radio-opaque markers appear on the films. In addition, knowledge of the source-image and source-target distances are not required. Analysis of the projected target and radio-opaque markers gives both the target location and magnification. Simulation with the BRW Phantom Base demonstrates that point targets can be located with respect to the BRW system to within 0.3 mm and magnification determined to within 0.5%.


Asunto(s)
Angiografía Cerebral/métodos , Técnicas Estereotáxicas , Humanos
17.
Int J Radiat Oncol Biol Phys ; 15(2): 441-7, 1988 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-3042719

RESUMEN

We have recently initiated a program for irradiating small, unresectable arteriovenous malformations (AVM's) in the brain. The treatments are delivered using a modified and carefully calibrated 6 MV linac. We are using high, single doses (15 to 25 Gy) with a goal of sclerosing the vessels and preventing hemorrhages. This technique, radiosurgery, is somewhat controversial in the radiotherapy community. Since the treatment is given in a single sitting, rather than in the more conventional pattern of multiple small daily fractions, there is some concern about late radiation damage to the normal brain tissue. However an extensive review of the literature leads us to the conclusion that if a technique is used that keeps the volume irradiated to high dose small, radiosurgery is a safe and efficacious treatment for small (less than 2.5 cm) AVM's. To decrease the risk of necrosis of normal brain tissue, it is important to confine the high dose region as tightly as possible to the target volume. Precise target localization and patient immobilization is achieved using a stereotactic head frame which is used during angiography, CT scanning, and during the radiation treatment. This minimizes the margin of safety that must be added to the target volume for errors in localization and set-up. The treatment is delivered using multiple noncoplanar arcs, with small, sharp edged X ray beams, and with the center of the AVM at isocenter. This produces a rapid dropoff of dose beyond the target volume. Early results in our first few patients are encouraging.


Asunto(s)
Malformaciones Arteriovenosas Intracraneales/radioterapia , Humanos , Aceleradores de Partículas , Técnicas Estereotáxicas
18.
Clin Pharmacokinet ; 1(6): 444-52, 1976.
Artículo en Inglés | MEDLINE | ID: mdl-1024769

RESUMEN

Plasma protein binding of phenytoin (diphenylhydantoin) in 63 epileptic patients was investigated with an ultrafiltration technique at room temperature using 14C-labelled phenytoin. A strong correlation was found between the total and the unbound drug concentration (r = 0.97, p less than 0.001). The unbound phenytoin fraction was 7.1 +/- 1.0% with a range of 4.9 to 10.2%. This variation is considerably less than that reported recently by different authors. Individual phenytoin binding was reproducible when the determination was repeated several weeks later. Salivary phenytoin concentrations in 33 epileptic patients were significantly correlated to the unbound (r = 0.83) and total concentrations (r = 0.82) of phenytoin in plasma. This study confirms that the clinical practice of monitoring total phenytoin plasma concentrations is sufficient, since the unbound phenytoin fraction has only a 2-fold interindividual variation in epileptic patients, provided that they do not suffer from renal or hepatic disease.


Asunto(s)
Proteínas Sanguíneas/metabolismo , Epilepsia/sangre , Fenitoína/sangre , Adulto , Anciano , Femenino , Humanos , Masculino , Métodos , Persona de Mediana Edad , Fenitoína/análisis , Unión Proteica , Saliva/análisis
19.
Naunyn Schmiedebergs Arch Pharmacol ; 288(2-3): 215-31, 1975.
Artículo en Inglés | MEDLINE | ID: mdl-1161046

RESUMEN

1. Isolated rabbit hearts were perfused with a modified Tyrode solution containing noradrenaline in concentrations increasing stepwise from 5.9 nM to 5.9 muM at 5 min intervals. This dose regime was applied twice before and once 20 min after starting perfusion with one of 9 tricyclic drugs. Ventricular rate and right atrial and ventricular tensions were recorded using the transverse method. 2. Infusions of noradrenaline evoked ventricular arrhythmias in hearts perfused with amitriptyline 4.8 muM, chlorpromazine 5.0 muM, desipramine 5.0 muM, dibenzepine 34.7 muM, doxepin 4.7 muM, imipramine 4.7 muM, noxiptiline 9.1 muM and opipramole 9.2 muM. The incidence of arrhythmias increased with the concentration of noradrenaline applied and the dose of tricyclic drug administered. Whenever arrhythmias had started they continued as long as noradrenaline was infused. Noradrenaline failed to produce arrhythmias in hearts not exposed to drugs and after iprindole 4.7 muM or cocaine 2.9-18 muM. 3. Propranolol 0.1 muM inhibited the incidence of arrhythmias after doxepin 4.7 muM plus noradrenaline 5.9-190 nM. 4. Neuronal uptake of exogenous noradrenaline in the rabbit heart was inhibited by the tricyclic drugs in the following order of declining p potency: doxepin, noxiptiline, amitriptyline, desipramine, chlorpromazine, imipramine, dibenzepine, opipramole and iprindole. 5. Among tricyclic drugs the potency to inhibit amine uptake is related to the incidence of arrhythmias evoked by a submaximal concentration of noradrenaline. It appears, however, that these two parameters are not causally linked. 6. The isolated rabbit heart perfused with noradrenaline might be used as a model for testing the arrhythmogenic actions of tricyclic drugs and the treatment of such arrhythmias.


Asunto(s)
Antidepresivos Tricíclicos/farmacología , Arritmias Cardíacas/inducido químicamente , Clorpromazina/farmacología , Miocardio/metabolismo , Norepinefrina/metabolismo , Animales , Cocaína/farmacología , Circulación Coronaria/efectos de los fármacos , Depresión Química , Femenino , Técnicas In Vitro , Masculino , Norepinefrina/farmacología , Perfusión , Propranolol/farmacología , Conejos
20.
Life Sci ; 61(1): PL9-16, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9200673

RESUMEN

Serotonin is a neurotransmitter involved in a large number of psychophysiological processes including the regulation of mood, arousal, aggression, sleep, learning, nociceptions, nerve growth and importantly, appetitive functions. Alterations of 5-HT receptor activity have been shown to occur in many psychiatric diseases including depression, anxiety, eating disorders, schizophrenia etc. Hence, genetic variation in genes coding for serotonin receptor proteins might well be involved in the genetic predisposition to these diseases and therefore are of great pharmacogenetic relevance. Knockout mice deficient of a functional 5-HT2C receptor have implicated a potential role of this receptor subtype in the serotonergic control of appetite. A Cys23Ser mutation in the human 5-HT2C receptor gene discovered recently prompted us to investigate this mutation with regard to the development of human obesity. We have evaluated this mutation in 241 obese children and adolescents (mean BMI > or = 97th percentile), 80 normal weight children (BMI 5th-85th percentile) and 92 underweight probands (BMI < or = 15th percentile) for a possible association with obesity. The frequencies of the mutant allele in all three weight groups (obese subjects: 0.1597; normal weight: 0.168; underweight: 0.1575) were very similar. Association as well as linkage studies were negative. Therefore it is unlikely that this receptor mutation plays a direct role in the development of human obesity.


Asunto(s)
Peso Corporal/fisiología , Mutación/genética , Obesidad/genética , Receptores de Serotonina/genética , Adolescente , Adulto , Alelos , Niño , Femenino , Humanos , Masculino
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