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1.
BMC Palliat Care ; 18(1): 96, 2019 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-31694715

RESUMEN

BACKGROUND: In the Netherlands, general practitioners (GPs) and community nurses play a central role in the palliative care for home-dwelling patients with advanced cancer and their relatives. To optimize the palliative care provision at home, it is important to have insight in the elements that patients and relatives consider essential for high-quality palliative care, and whether these essentials are present in the actual care they receive. METHODS: Qualitative semi-structured interviews were conducted with 13 patients with advanced cancer and 14 relatives. The participants discussed their experiences with the care and support they received from the GP and community nurses, and their views on met and unmet needs. Interview data were analysed according to the principles of thematic analysis. RESULTS: Patients as well as relatives considered it important that their GP and community nursing staff are medically proficient, available, person-focused and proactive. Also, proper information transfer between care professionals and clear procedures when asking for certain resources or services were considered essential for good palliative care at home. Most interviewees indicated that these essential elements were generally present in the care they received. However, the requirements of 'proper information transfer between professionals' and 'clear and rapid procedures' were mentioned as more difficult to meet in actual practice. Patients and relatives also emphasized that an alert and assertive attitude on their own part was vital in ensuring they received the care they need. They expressed worries about other people who are less vigilant regarding the care they receive, or who have no family to support them in this. CONCLUSIONS: Medical proficiency, availability, a focus on the person, proper information transfer between professionals, clear procedures and proactivity on the part of GPs and community nursing staff are considered essential for good palliative care at home. Improvements are particularly warranted with regard to collaboration and information transfer between professionals, and current bureaucratic procedures. It is important for care professionals to ensure that the identified essential elements for high-quality palliative care at home are met, particularly for patients and relatives who are not so alert and assertive.


Asunto(s)
Médicos Generales , Servicios de Atención de Salud a Domicilio/organización & administración , Neoplasias/terapia , Enfermeros de Salud Comunitaria/organización & administración , Cuidados Paliativos/organización & administración , Calidad de la Atención de Salud/organización & administración , Anciano , Anciano de 80 o más Años , Competencia Clínica , Comunicación , Femenino , Servicios de Atención de Salud a Domicilio/normas , Humanos , Relaciones Interprofesionales , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Países Bajos , Rol de la Enfermera , Cuidados Paliativos/normas , Atención Dirigida al Paciente/normas , Rol del Médico , Investigación Cualitativa , Calidad de la Atención de Salud/normas , Cuidado Terminal/organización & administración , Factores de Tiempo
2.
Psychooncology ; 25(5): 559-66, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26403320

RESUMEN

OBJECTIVE: Cancer and its treatment often have a profound impact on patients, leading to increased health care use in the years after diagnosis. Social support is an important determinant of health care use. Partners of cancer patients may not always be able to provide all support patients need and patients may then revert to professional health care. We examined whether partners' health and the support they provide affect the use of general practitioner (GP) care in cancer patients. METHODS: Cancer patients aged ≥18, diagnosed <20 years ago with a cancer type with a 5-year survival rate >20% and no distant metastases were sent a questionnaire, along with their partners. Patients' self-reported recent use of GP care, i.e. whether they had discussed health problems with the GP in the past year, was assessed. Partner support as perceived by the patient was measured on three scales: Active engagement, protective buffering and overprotection. RESULTS: We included 219 patients and partners. Many patients discussed physical and emotional problems with their GP (60% and 28% of patients, respectively). Patients were less likely to discuss physical problems when they experienced active engagement and protective buffering, the latter only for females. CONCLUSION: Partner support affects use of GP care in cancer patients. GPs should therefore pay attention to the support style of the partner. GPs could ask about the support provided by the partner and inform both patients and partners about support groups where they can share experiences.


Asunto(s)
Médicos Generales/estadística & datos numéricos , Neoplasias/psicología , Parejas Sexuales/psicología , Apoyo Social , Esposos/psicología , Estrés Psicológico/etiología , Adolescente , Adulto , Anciano , Femenino , Encuestas de Atención de la Salud , Estado de Salud , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/diagnóstico , Percepción , Calidad de Vida , Encuestas y Cuestionarios , Adulto Joven
3.
J Intellect Disabil Res ; 55(1): 4-18, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21029235

RESUMEN

BACKGROUND: Community participation has been defined as performing daytime activities by people while interacting with others. Previous studies on community participation among people with intellectual disability (ID) have mainly focused on the domestic life aspect. This study investigates the variation in community participation in the domains work, social contacts and leisure activities among people with ID in the Netherlands. A number of categories of people with ID were distinguished by: (1) gender; (2) age; (3) type of education; (4) severity of ID; and (5) accommodation type. METHODS: Data were gathered on 653 people with mild or moderate ID, of whom 513 by oral interviews and 140 by structured questionnaires filled in by representatives of those who could not be interviewed. Pearson chi-square tests were used to test differences between categories of people with ID in the distributions of the participation variables. Additional logistic regression analyses were conducted to correct for differences between the categories in other variables. RESULTS: Most people with mild or moderate ID in the Netherlands have work or other daytime activities, have social contacts and have leisure activities. However, people aged 50 years and over and people with moderate ID participate less in these domains than those under 50 years and people with mild ID. Moreover, people with ID hardly participate in activities with people without ID. CONCLUSION: High participation among people with a mild or moderate ID within the domains of work, social contact and leisure activities does not necessarily indicate a high level of interaction with the community, because the majority hardly interact with people without ID. Furthermore, older people with ID and people with a more severe level of ID seem to be more at risk for social exclusion.


Asunto(s)
Discapacidad Intelectual/psicología , Discapacidad Intelectual/rehabilitación , Inteligencia , Relaciones Interpersonales , Actividades Recreativas , Rehabilitación Vocacional , Actividades Cotidianas/clasificación , Actividades Cotidianas/psicología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Evaluación de la Discapacidad , Femenino , Humanos , Entrevista Psicológica , Masculino , Persona de Mediana Edad , Países Bajos , Medio Social , Encuestas y Cuestionarios , Adulto Joven
4.
Appl Magn Reson ; 38(3): 349-360, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20502507

RESUMEN

The objective of this study is to assess whether ultrasmall superparamagnetic iron oxide (USPIO)-induced changes of the water proton longitudinal relaxation rate (R(1)) provide a means to assess blood hemodynamics of tumors. Two types of murine colon tumors (C26a and C38) were investigated prior to and following administration of USPIO blood-pool contrast agent with fast R(1) measurements. In a subpopulation of mice, R(1) was measured following administration of hydralazine, a well-known blood hemodynamic modifier. USPIO-induced R(1) increase in C38 tumors (DeltaR(1) = 0.072 +/- 0.0081 s(-1)) was significantly larger than in C26a tumors (DeltaR(1) = 0.032 +/- 0.0018 s(-1), N = 9, t test, P < 0.001). This was in agreement with the immunohistochemical data that showed higher values of relative vascular area (RVA) in C38 tumors than in C26a tumors (RVA = 0.059 +/- 0.015 vs. 0.020 +/- 0.011; P < 0.05). Following administration of hydralazine, a decrease in R(1) value was observed. This was consistent with the vasoconstriction induced by the steal effect mechanism. In conclusion, R(1) changes induced by USPIO are sensitive to tumor vascular morphology and to blood hemodynamics. Thus, R(1) measurements following USPIO administration can give novel insight into the effects of blood hemodynamic modifiers, non-invasively and with a high temporal resolution.

5.
BMC Public Health ; 6: 188, 2006 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-16848897

RESUMEN

BACKGROUND: People's trust in health care and health care professionals is essential for the effectiveness of health care, especially for chronically ill people, since chronic diseases are by definition (partly) incurable. Therefore, it may be understandable that chronically ill people turn to complementary and alternative medicine (CAM), often in addition to regular care. Chronically ill people use CAM two to five times more often than non-chronically ill people. The trust of chronically ill people in health care and health care professionals and the relationship of this with CAM use have not been reported until now. In this study, we examine the influence of chronically ill people's trust in health care and health care professionals on CAM use. METHODS: The present sample comprises respondents of the 'Panel of Patients with Chronic Diseases' (PPCD). Patients (>or=25 years) were selected by GPs. A total of 1,625 chronically ill people were included. Trust and CAM use was measured by a written questionnaire. Statistical analyses were t tests for independent samples, Chi-square and one-way analysis of variance, and logistic regression analysis. RESULTS: Chronically ill people have a relatively low level of trust in future health care. They trust certified alternative practitioners less than regular health care professionals, and non-certified alternative practitioners less still. The less trust patients have in future health care, the more they will be inclined to use CAM, when controlling for socio-demographic and disease characteristics. CONCLUSION: Trust in future health care is a significant predictor of CAM use. Chronically ill people's use of CAM may increase in the near future. Health policy makers should, therefore, be alert to the quality of practising alternative practitioners, for example by insisting on professional certification. Equally, good quality may increase people's trust in public health care.


Asunto(s)
Enfermedad Crónica/psicología , Terapias Complementarias/estadística & datos numéricos , Personas con Discapacidad/psicología , Aceptación de la Atención de Salud/estadística & datos numéricos , Relaciones Médico-Paciente , Confianza , Adulto , Anciano , Femenino , Humanos , Masculino , Medicina/normas , Persona de Mediana Edad , Países Bajos , Médicos de Familia/normas , Especialización , Encuestas y Cuestionarios
6.
Cancer Epidemiol ; 39(1): 109-14, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25560973

RESUMEN

AIM: More than two-thirds of cancer patients have one or more chronic diseases besides cancer. The purpose of this study was to get detailed insight into the combined effect of cancer and chronic diseases on general practitioner (GP) consultation rates. METHODS: From the NIVEL Primary Care Database we identified cancer patients with diabetes mellitus (n=629), osteoarthritis (n=425), coronary artery disease (n=466), COPD (n=383) or without a chronic disease (n=1507), diagnosed with cancer between 2002 and 2010. They were matched on sex, age, practice and chronic disease to 6645 non-cancer controls. RESULTS: 2-5 years after diagnosis, cancer patients without a chronic disease had on average 6.5 GP contacts per year, those with a comorbid disease almost twice as many (ranging from 10 for osteoarthritis to 12.4 for COPD). A similar difference was seen in non-cancer controls. The number of GP contacts for chronic diseases did not differ between cancer patients and controls. The increase in the number of GP consultations with age and number of chronic diseases was similar in cancer patients and controls. Consultation rates were similar in cancer patients and controls if they were stratified by number of chronic diseases while counting cancer as a chronic disease. CONCLUSIONS: Two to five years after diagnosis, cancer leads to an increase in GP contacts that is similar to having a chronic disease. This increase does not differ between those with and without a chronic disease and cancer does not seem to increase the impact of having a chronic disease.


Asunto(s)
Médicos Generales/estadística & datos numéricos , Neoplasias/terapia , Atención Primaria de Salud/estadística & datos numéricos , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Bases de Datos Factuales , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/epidemiología
7.
J Cereb Blood Flow Metab ; 20(5): 861-70, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10826537

RESUMEN

Pathophysiologic parameters of the functional neovasculature and the blood-brain barrier of 9L-glioma in rat brain were measured noninvasively by dynamic 1H magnetic resonance imaging studies of gadolinium (Gd)-DTPA uptake. Changes of apparent [Gd-DTPA] uptake in time (CT[t]) were analyzed in a slice through the center of 10 9L-gliomas using fast T1 measurements. The distribution of the contrast agent was spatially correlated with the distribution of perfused microvessels as determined by immunohistochemical analysis. This method permits a distinction between perfused and nonperfused microvessels with a disrupted blood-brain barrier. In transverse slices of the whole tumor, a spatial correlation was observed between CT maps and the two-dimensional distribution of perfused microvessels. In the next step, Gd-DTPA uptake rates were spatially related to the perfused microvessel density (Np) or vascular surface area (Sp). In tumor voxels with perfused microvessels, a linear correlation was found between Gd-DTPA uptake rate constants (k values) and Np or Sp. No correlation was observed between k values and the total microvessel density. These are the first data that show a relation between Gd-DTPA uptake rates and parameters of the functional neovasculature in 9L-glioma growing in rat brain. Now that Gd-DTPA uptake studies can be related to parameters of the functional neovasculature, they may be used more efficiently as a prognostic tool before or during therapy.


Asunto(s)
Neoplasias Encefálicas/irrigación sanguínea , Medios de Contraste , Gadolinio DTPA , Glioma/irrigación sanguínea , Imagen por Resonancia Magnética , Neovascularización Patológica/diagnóstico , Animales , Neoplasias Encefálicas/metabolismo , Medios de Contraste/farmacocinética , Gadolinio DTPA/farmacocinética , Glioma/metabolismo , Inmunohistoquímica , Protones , Ratas , Ratas Endogámicas F344
8.
FEBS Lett ; 453(3): 278-82, 1999 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-10405160

RESUMEN

A ratio-fluorescence assay was developed for on-line localization and quantification of lipid oxidation in living cells. The assay explores the oxidative sensitivity of C11-BODIPY(581/591). Upon oxidation, the fluorescence of this fluorophore shifts from red to green. The probe incorporates readily into cellular membranes and is about twice as sensitive to oxidation as arachidonic acid. Using confocal microscopy, the cumene hydroperoxide-induced oxidation of C11-BODIPY(581/591) was visualized at the sub-cellular level in rat-1 fibroblasts. Preloading of the cells with tocopherol retarded this oxidation. The data demonstrate that C11-BODIPY(581/591) is a valuable tool to quantify lipid oxidation and anti-oxidant efficacy in single cells.


Asunto(s)
Colorantes Fluorescentes , Peroxidación de Lípido , Microscopía Fluorescente/métodos , Sondas Moleculares , Animales , Antioxidantes/farmacología , Ácido Araquidónico/metabolismo , Derivados del Benceno/metabolismo , Células Cultivadas , Fibroblastos/citología , Miocardio/citología , Ratas , Espectrometría de Fluorescencia , Vitamina E/farmacología
9.
Int J Radiat Oncol Biol Phys ; 44(3): 649-58, 1999 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-10348296

RESUMEN

PURPOSE: The aim of this study was to characterize and to validate noninvasive 19F-magnetic resonance relaxometry for the measurement of oxygen tensions in human glioma xenografts in nude mice. The following three questions were addressed: 1. When perfluorocarbon compounds (PFCs) are administrated intravenously, which tumor regions are assessed by 19F-MR relaxometry? 2. Are oxygen tension as detected by 19F-MR relaxometry (pO2/relaxo) comparable to Eppendorf O2-electrode measurements (pO2/electrode)? 3. Can 19F-MR relaxometry be used to detect oxygen tension changes in tumor tissue during carbogen breathing? METHODS AND MATERIALS: Slice-selective 19F-MR relaxometry was carried out with perfluoro-15-crown-5-ether as oxygen sensor. The PFC was injected i.v. 3 days before the 19F-MR experiments. Two datasets were acquired before and two after the start of carbogen breathing. The distribution of PFCs and necrotic areas were analyzed in 19F-Spin Echo (SE) density MR images and T2-weighted 1H-SE MR images, respectively. One day after the MR investigations, oxygen tensions were measured by oxygen electrodes in the same slice along two perpendicular tracks. These measurements were followed by (immuno)histochemical analysis of the 2D distribution of perfused microvessels, hypoxic cells, necrotic areas, and macrophages. RESULTS: The PFCs mainly became sequestered in perfused regions at the tumor periphery; thus, 19F-MR relaxometry probed mean oxygen tensions in these regions throughout the selected MR slice. In perfused regions of the tumor, mean PO2/relaxo values were comparable to mean PO2/electrode values, and varied from 0.03 to 9 mmHg. Median pO2/electrode values of both tracks were lower than mean pO2/relaxo values, because low pO2 electrode values that originate from hypoxic and necrotic areas were also included in calculations of median pO2/electrode values. After 8-min carbogen breathing, the average PO2/relaxo increase was 3.3 +/- 0.8 (SEM) mmHg and 2.1 +/- 0.6 (SEM) after 14 min breathing. CONCLUSIONS: We have demonstrated that PFCs mainly became sequestered in perfused regions of the tumor. Here, mean PO2/relaxo values were comparable to mean PO2electrode values. In these areas, carbogen breathing was found to increase the PO2/relaxo values significantly.


Asunto(s)
Glioma/fisiopatología , Consumo de Oxígeno , Oxígeno/metabolismo , Animales , Flúor , Humanos , Espectroscopía de Resonancia Magnética , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Presión Parcial , Polarografía , Radiobiología , Trasplante Heterólogo
10.
Int J Radiat Oncol Biol Phys ; 48(5): 1529-38, 2000 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-11121659

RESUMEN

PURPOSE: Development of a double hypoxic cell marker assay, using the bioreductive nitroimidazole derivatives CCI-103F and pimonidazole, to study changes in tumor hypoxia after treatments that modify tumor oxygenation. METHODS AND MATERIALS: Both hypoxic markers were visualized by immunohistochemical techniques to detect changes in hypoxic fraction induced by carbogen breathing (95% O(2) and 5% CO(2)) or hydralazine injection. The protocol was tested in a human laryngeal squamous cell carcinoma xenograft line. Quantitative measurements were derived from consecutive tissue sections that were analyzed by a semiautomatic image analysis system. Qualitative analysis was obtained by double staining of the two hypoxic markers on the same tissue section. RESULTS: A significant correlation between the hypoxic fractions for the two markers, CCI-103F and pimonidazole, was found in air breathing animals. After carbogen breathing, the hypoxic fraction decreased significantly from 0.07 to 0.03, and after hydralazine treatment, the hypoxic fraction increased significantly. Reduction of hypoxia after carbogen breathing was most pronounced close to well-perfused tumor regions. CONCLUSIONS: With this method, employing two consecutively injected bioreductive markers, changes in tumor hypoxia can be studied. A significant reduction in hypoxia after carbogen breathing and a significant increase in hypoxia after hydralazine administration was demonstrated.


Asunto(s)
Hipoxia de la Célula/fisiología , Nitroimidazoles/metabolismo , Animales , Bencimidazoles/metabolismo , Biomarcadores , Dióxido de Carbono/administración & dosificación , Carcinoma de Células Escamosas/irrigación sanguínea , Carcinoma de Células Escamosas/metabolismo , Hipoxia de la Célula/efectos de los fármacos , Endotelio Vascular/metabolismo , Colorantes Fluorescentes/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Oxígeno/administración & dosificación , Oxígeno/metabolismo , Fármacos Sensibilizantes a Radiaciones/metabolismo , Células Tumorales Cultivadas
11.
Int J Radiat Oncol Biol Phys ; 48(2): 571-82, 2000 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-10974478

RESUMEN

PURPOSE: To quantitatively study the spatial distribution of tumor hypoxia in relation to the perfused vasculature. METHODS AND MATERIALS: Using a human glioma xenograft model, nude mice were administered two different hypoxia markers (NITP or pimonidazole) and the perfusion marker Hoechst 33342. Frozen tumor sections were sequentially scanned for perfusion, hypoxia, and vasculature, respectively, to quantitate perfusion, vasculature, and hypoxia parameters in the same section. RESULTS: All tumors showed incomplete perfusion. Both NITP and pimonidazole stained the same hypoxic tumor areas. No statistically significant differences between the two markers were observed. The density of the perfused vessels was inversely related to the hypoxic fraction. At critical distances from perfused vessels, hypoxia occurred. These data suggest that predominantly diffusion-limited hypoxia was detected, based on the spatial distribution of nearby vessels. Also, the proportion of hypoxia distributed over arbitrary zones of 50 microm around perfused vessels was calculated. The largest proportion of hypoxia was found at distances beyond 100 microm from perfused vessels. CONCLUSION: With the multiple staining and functional microscopic imaging technique described here, the spatial relationship between perfused vessels and hypoxia was quantified in whole tumor cross-sections. The usefulness of this histologically-based method to quantitate morphological and physiological aspects of the tumor microenvironment was evaluated.


Asunto(s)
Hipoxia de la Célula , Glioma/irrigación sanguínea , Glioma/fisiopatología , Teofilina/análogos & derivados , Animales , Bencimidazoles , Colorantes Fluorescentes , Humanos , Inmunohistoquímica , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Nitroimidazoles , Fármacos Sensibilizantes a Radiaciones , Flujo Sanguíneo Regional , Trasplante Heterólogo
12.
Radiother Oncol ; 50(2): 173-84, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10368041

RESUMEN

BACKGROUND AND PURPOSE: A better understanding of the vascular architecture and the microenvironmental parameters (VAMP) will allow the identification of tumours that can be more effectively treated by intensified fractionated radiotherapy or modifiers of blood flow and oxygenation or combinations of these approaches. MATERIALS AND METHODS: Proliferation (BrdUrd), vascular architecture (endothelial marker), perfusion (Hoechst 33342) and oxygenation (NITP) were studied in two human laryngeal squamous cell carcinoma tumour lines grown as xenografts in nude mice. The effects of carbogen and nicotinamide on these parameters were evaluated. RESULTS: Carbogen treatment resulted in a decrease of the number of perfused blood vessels from 66% to 55% in one of the two tumour lines. In this tumour line nicotinamide prevented this reduction of tumour blood flow by carbogen. In both tumour lines the labelling index (LI) decreased after treatment with carbogen for 1 h, from 11-13% to 5-7%. Both tumour lines showed a drastic reduction of hypoxia by carbogen alone or by carbogen plus nicotinamide. CONCLUSIONS: In both laryngeal squamous cell carcinoma xenograft tumour lines carbogen was very effective in reducing diffusion limited hypoxia. Only in one of the two tested tumour lines carbogen also caused a reduction of tumour blood perfusion, which could be compensated for by nicotinamide. In addition, carbogen reduced tumour cell proliferation. The fact that differences in response to nicotinamide and carbogen were observed and that they can be studied in vivo provides a basis for further development of a 'predictive profile' which will guide the clinician to select the optimal treatment for individual patients or groups of patients.


Asunto(s)
Vasos Sanguíneos/patología , Dióxido de Carbono/farmacología , Carcinoma de Células Escamosas/irrigación sanguínea , Neoplasias Laríngeas/irrigación sanguínea , Niacinamida/farmacología , Oxígeno/farmacología , Fármacos Sensibilizantes a Radiaciones/farmacología , Animales , Bencimidazoles/farmacología , Vasos Sanguíneos/efectos de los fármacos , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/patología , División Celular/efectos de los fármacos , Endotelio Vascular/ultraestructura , Humanos , Hipoxia/prevención & control , Neoplasias Laríngeas/tratamiento farmacológico , Neoplasias Laríngeas/patología , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Nitroimidazoles/farmacología , Teofilina/análogos & derivados , Teofilina/farmacología , Trasplante Heterólogo , Células Tumorales Cultivadas/trasplante
13.
Radiat Res ; 157(6): 626-32, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12005540

RESUMEN

Tissue oxygenation influences the radiation response of tumors. To further investigate the underlying mechanisms of tumor hypoxia, the spatial distribution of hypoxic cells in relation to the vasculature was studied. In a panel of three human glioma xenograft lines (E2, E102, E106) with different growth characteristics, tumor line-specific patterns of hypoxia (pimonidazole) and (functional) vasculature (Hoechst 33342) were observed. Two of the three glioma lines showed a more homogeneous distribution of perfused vessels (E102 and E106) than the third glioma line (E2). Although all tumors showed hypoxia, the distance at which the steepest part of the gradient of the hypoxia marker was found varied significantly among the different glioma lines. The faster-growing E102 tumors had the longest distance (>300 microm). These results indicate that tumor line-specific factors, rather than vascular geometry alone, may determine the oxygenation status of a tumor. As a consequence, vascular density cannot be used as a surrogate parameter for tumor hypoxia when comparing different tumors. Additional hypoxia and perfusion markers will further improve our understanding of changes in tumor physiology at the microregional level explaining the relationship between the low oxygen levels and the response of tumors to treatment.


Asunto(s)
Glioma/irrigación sanguínea , Glioma/patología , Hipoxia/sangre , Hipoxia/patología , Animales , Humanos , Inmunohistoquímica , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Nitroimidazoles/metabolismo , Perfusión , Trasplante Heterólogo , Células Tumorales Cultivadas
14.
Radiat Res ; 153(4): 398-404, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10760999

RESUMEN

The effect of irradiation depends on the oxygenation status of the tissue, while irradiation itself also changes the oxygenation and perfusion status of tissues. A better understanding of the changes in tumor oxygenation and perfusion over time after irradiation will allow a better planning of fractionated radiotherapy in combination with modifiers of blood flow and oxygenation. Vascular architecture (endothelial marker), perfusion (Hoechst 33342) and oxygenation (pimonidazole) were studied in a human laryngeal squamous cell carcinoma tumor line grown as xenografts in nude mice. The effect of a single dose of 10 Gy X rays on these parameters was evaluated from 2 h to 11 days after irradiation. Shortly after irradiation, there was an 8% increase in perfused blood vessels (from 57% to 65%) followed by a significant decrease, with a minimum value of 42% at 26 h after irradiation, and a subsequent increase to control levels at 7 to 11 days after irradiation. The hypoxic fraction showed a decrease at 7 h after treatment from 13% to 5% with an increase to 19% at 11 days after irradiation. These experiments show that irradiation causes rapid changes in oxygenation and perfusion which may have consequences for the optimal timing of radiotherapy schedules employing multiple fractions per day and the introduction of oxygenation- and perfusion-modifying drugs.


Asunto(s)
Carcinoma de Células Escamosas/sangre , Carcinoma de Células Escamosas/patología , Hipoxia de la Célula/efectos de la radiación , Neoplasias Laríngeas/sangre , Neoplasias Laríngeas/patología , Humanos , Procesamiento de Imagen Asistido por Computador , Inmunohistoquímica , Células Tumorales Cultivadas
15.
Neurosurgery ; 43(3): 570-5; discussion 575-6, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9733312

RESUMEN

OBJECTIVE: The purpose of this study was to examine the delayed effects of antivascular endothelial growth factor treatment on tumor growth and vascularity in a subcutaneous mouse tumor model of human glioblastoma. METHODS: Antivascular endothelial growth factor antibody treatment was administered for a period of 6 weeks, to suppress tumor growth. To detect late vascular effects, tumor vascular parameters for treated tumors and control tumors were analyzed 4 weeks thereafter. By that time, tumors had grown to adequate sizes (diameter, 8-10 mm) for comparison with untreated control tumors. Vascular parameters were quantified by using an image-analysis system. RESULTS: Vascular density was significantly lower in antivascular endothelial growth factor antibody-treated tumors, compared with control tumors of similar size. The vascular architecture of treated tumors was also distinctly different, compared with control tumors, showing larger but sparser vessel structures. CONCLUSION: These findings suggest that antiangiogenic therapy may have a prolonged effect on the vascular architecture of certain tumors, resulting in enduring changes in the tumor vessels. Because tumor vasculature plays an important role in the sensitivity to various treatment modalities, these changes are likely to influence the responses of these tumors to further therapy.


Asunto(s)
Anticuerpos/uso terapéutico , Factores de Crecimiento Endotelial/inmunología , Glioma/irrigación sanguínea , Glioma/tratamiento farmacológico , Linfocinas/inmunología , Neovascularización Patológica/prevención & control , Adulto , Animales , Vasos Sanguíneos/efectos de los fármacos , Vasos Sanguíneos/patología , División Celular/efectos de los fármacos , Factores de Crecimiento Endotelial/metabolismo , Glioma/metabolismo , Glioma/patología , Humanos , Procesamiento de Imagen Asistido por Computador , Linfocinas/metabolismo , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Factores de Tiempo , Trasplante Heterólogo , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial Vascular
16.
J Neurosurg ; 93(3): 449-54, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10969943

RESUMEN

OBJECT: The development of hypoxia in human gliomas is closely related to functional vasculature and the presence of hypoxia has important biological and therapeutic consequences. Assessment of hypoxia is necessary to understand its role in treatment response and to evaluate treatment strategies to improve tumor oxygenation. In this study, the authors report findings of their analysis of the degree of hypoxia in relation to other vascular parameters in a human intracerebral glioma xenograft. METHODS: In sections of tumor, hypoxic regions were identified immunohistochemically by using the hypoxic marker pimonidazole. The S-phase marker bromodeoxyuridine was used to detect cell proliferation, and the perfusion marker Hoechst 33342 was used to delineate perfused vessels. Vascular structures were stained with an endothelial marker. Hypoxic tumor regions were clearly present in this human intracerebral glioma model. Hypoxic areas were usually found in nonperfused regions, whereas tumor cell proliferation was especially marked in perfused tumor areas. Furthermore, by using in situ hybridization the authors identified infiltrating tumor cells in the normal brain. This feature is often observed in gliomas in patients. CONCLUSIONS: This model is a representative human glioma model that provides the researcher with the opportunity to analyze the relationship between the degree of hypoxia and vascular parameters, as well as to examine the effects of treatments aimed at modification of the oxygenation status of a tumor.


Asunto(s)
Neoplasias Encefálicas/fisiopatología , Glioma/fisiopatología , Hipoxia/fisiopatología , Animales , Neoplasias Encefálicas/irrigación sanguínea , Neoplasias Encefálicas/patología , División Celular , Modelos Animales de Enfermedad , Glioma/irrigación sanguínea , Glioma/patología , Ratones , Ratones Endogámicos BALB C , Microcirculación , Nitroimidazoles/análisis , Fármacos Sensibilizantes a Radiaciones/análisis
17.
Food Chem Toxicol ; 40(6): 801-8, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11983275

RESUMEN

Although there is much epidemiological evidence for an interaction between diet and colorectal cancer risk, the mechanisms by which diet might protect against colorectal cancer are still unclear. Here we report the significant up-regulation of carcinogen-induced apoptosis in the colon of rats fed a diet containing low-risk factors for colon cancer, namely low fat content, high calcium and high non-digestible carbohydrate. The dose-dependent induction of apoptosis in colonic crypts by the carcinogen 1,2-dimethylhydrazine (DMH) was significantly greater in rats receiving the low-risk compared with a high-risk (high fat, low calcium, low non-digestible carbohydrate) diet (P<0.001). There were also significant interactions of colon region with DMH dose and region by diet, with the greatest increases in apoptosis occurring in the mid and distal regions of the colon compared with the proximal region. Since we have previously shown the low-risk diet to be non-toxic, these new results suggest a diet-induced up-regulation of apoptosis, which may represent a mechanism of protection against the early stages of carcinogenesis in the colon.


Asunto(s)
Apoptosis/fisiología , Colon/citología , Colon/patología , Neoplasias del Colon/patología , Dieta , Animales , Peso Corporal/fisiología , Neoplasias del Colon/epidemiología , ADN/química , Ratas , Ratas Sprague-Dawley , Factores de Riesgo
18.
Drugs Exp Clin Res ; 30(5-6): 207-12, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15700748

RESUMEN

Olive oil phenolic compounds are generally believed to have beneficial antioxidant effects, but little is known about characteristics of their postprandial bioavailability in natural olive oil at real-life doses. The aim of the present study was to determine the concentrations of olive oil phenolic compounds in urine collected over 24 h (24-h urine) after a bolus ingestion of 25 ml of olive oil with different phenolic content, and to demonstrate the effect of this real-life olive oil dose on postprandial levels of blood lipids and oxidative stress biomarkers, as well as to examine the beneficial effects of olive oil phenols. Oral fat loads of 25 ml olive oil with high, moderate, and low phenolic content were administered to 12 healthy male volunteers in a randomized, controlled, crossover trial. Tyrosol and hydroxytyrosol were absorbed in a dose-dependent manner according to the phenolic content of the olive oil administered. The administered dose of 25 ml, which is close to that used daily in Mediterranean countries, did not induce significant postprandial lipemia nor did it promote an increase of in vivo oxidation markers. With regard to plasma antioxidant enzymes, glutathione peroxidase activity decreased postprandially after low phenolic content olive oil ingestion; however this was not observed after intake of moderate and high phenolic content olive oils. The phenolic content of the olive oils administered may account for the protection of the endogenous antioxidant defenses at postprandial state after ingestion of moderate and high phenolic content olive oils.


Asunto(s)
Antioxidantes/administración & dosificación , Fenoles/administración & dosificación , Aceites de Plantas/administración & dosificación , Periodo Posprandial/efectos de los fármacos , Adulto , Antioxidantes/metabolismo , Disponibilidad Biológica , Estudios Cruzados , Método Doble Ciego , Humanos , Masculino , Aceite de Oliva , Oxidantes/metabolismo , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Fenoles/metabolismo , Aceites de Plantas/metabolismo , Periodo Posprandial/fisiología
19.
Disabil Rehabil ; 20(9): 330-6, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9664191

RESUMEN

PURPOSE: Patients with diabetes mellitus frequently suffer from foot pain. This pain seems to be a neglected area in studies on the diabetic foot. The purpose of this study was to identify clinical variables associated with foot pain in diabetic patients. In addition, the relationships between foot pain and several functional impairments and disabilities were explored. METHOD: The research group consisted of 29 diabetic patients with any symptoms possibly associated with a diabetic foot, who were referred to podiatry. The relationships between several clinical measures and foot pain were analysed by means of Mann-Whitney U-tests. In addition, Spearman rank correlations coefficients were computed to assess the relationships between foot pain and measures of functional health. RESULTS: Diabetic patients suffering from sensory neuropathy experience more severe foot pain. Furthermore, patients with more severe foot pain experience more fatigue, more disabilities in walking and a lower level of affective well-being. CONCLUSION: Based on these findings this paper concludes that foot pain in diabetic patients is an important impairment which deserves further scientific attention.


Asunto(s)
Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 2/complicaciones , Pie Diabético/etiología , Dolor/etiología , Calidad de Vida , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Pie Diabético/diagnóstico , Pie Diabético/rehabilitación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor/fisiopatología , Dolor/rehabilitación , Dimensión del Dolor , Muestreo , Índice de Severidad de la Enfermedad , Estadísticas no Paramétricas , Encuestas y Cuestionarios
20.
Adv Space Res ; 12(1): 145-52, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-11536950

RESUMEN

Epidermal growth factor (EGF) activates a well characterized signal transduction cascade in human A431 epidermoid carcinoma cells. The influence of gravity on EGF-induced EGF-receptor clustering and early gene expression as well as on actin polymerization and actin organization have been investigated. Different signalling pathways induced by the agents TPA, forskolin and A23187 that activate gene expression were tested for sensitivity to gravity. EGF-induced c-fos and c-jun expression were decreased in microgravity. However, constitutive beta-2 microglobulin expression remained unaltered. Under simulated weightlessness conditions EGF- and TPA-induced c-fos expression was decreased, while forskolin- and A23187-induced c-fos expression was independent of the gravity conditions. These results suggest that gravity affects specific signalling pathways. Preliminary results indicate the EGF-induced EGF-receptor clustering remained unaltered irrespective of the gravity conditions. Furthermore, the relative filamentous actin content of steady state A431 cells was enhanced under microgravity conditions and actin filament organization was altered. Under simulated weightlessness actin filament organization in steady state cells as well as in EGF-treated cells was altered as compared to the 1 G reference experiment. Interestingly the microtubule and keratin organization in untreated cells showed no difference with the normal gravity samples. This indicates that gravity may affect specific components of the signal transduction circuitry.


Asunto(s)
Carcinoma de Células Escamosas/genética , Gravitación , Rotación , Transducción de Señal/fisiología , Vuelo Espacial , Ingravidez , Calcimicina/farmacología , Carcinógenos/farmacología , Carcinoma de Células Escamosas/química , Carcinoma de Células Escamosas/patología , Colforsina/farmacología , Factor de Crecimiento Epidérmico/fisiología , Regulación Neoplásica de la Expresión Génica , Humanos , Ionóforos/farmacología , Proteínas Proto-Oncogénicas c-fos/análisis , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas Proto-Oncogénicas c-jun/análisis , Proteínas Proto-Oncogénicas c-jun/genética , Proteínas Proto-Oncogénicas c-jun/metabolismo , Transducción de Señal/efectos de los fármacos , Acetato de Tetradecanoilforbol/farmacología , Células Tumorales Cultivadas , Simulación de Ingravidez
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