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1.
Br J Dermatol ; 178(6): 1331-1340, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29315488

RESUMEN

BACKGROUND: Incontinence-associated dermatitis (IAD) is a specific type of irritant contact dermatitis with different severity levels. An internationally accepted instrument to assess the severity of IAD in adults, with established diagnostic accuracy, agreement and reliability, is needed to support clinical practice and research. OBJECTIVES: To design the Ghent Global IAD Categorization Tool (GLOBIAD) and evaluate its psychometric properties. METHODS: The design was based on expert consultation using a three-round Delphi procedure with 34 experts from 13 countries. The instrument was tested using IAD photographs, which reflected different severity levels, in a sample of 823 healthcare professionals from 30 countries. Measures for diagnostic accuracy (sensitivity and specificity), agreement, interrater reliability (multirater Fleiss kappa) and intrarater reliability (Cohen's kappa) were assessed. RESULTS: The GLOBIAD consists of two categories based on the presence of persistent redness (category 1) and skin loss (category 2), both of which are subdivided based on the presence of clinical signs of infection. The agreement for differentiating between category 1 and category 2 was 0·86 [95% confidence interval (CI) 0·86-0·87], with a sensitivity of 90% and a specificity of 84%. The overall agreement was 0·55 (95% CI 0·55-0·56). The Fleiss kappa for differentiating between category 1 and category 2 was 0·65 (95% CI 0·65-0·65). The overall Fleiss kappa was 0·41 (95% CI 0·41-0·41). The Cohen's kappa for differentiating between category 1 and category 2 was 0·76 (95% CI 0·75-0·77). The overall Cohen's kappa was 0·61 (95% CI 0·59-0·62). CONCLUSIONS: The development of the GLOBIAD is a major step towards a better systematic assessment of IAD in clinical practice and research worldwide. However, further validation is needed.


Asunto(s)
Dermatitis Irritante/etiología , Lenguaje , Índice de Severidad de la Enfermedad , Incontinencia Urinaria/complicaciones , Adulto , Dermatitis Irritante/diagnóstico , Femenino , Humanos , Internacionalidad , Masculino , Variaciones Dependientes del Observador , Psicometría , Estándares de Referencia , Sensibilidad y Especificidad , Terminología como Asunto
2.
Lab Chip ; 16(2): 334-44, 2016 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-26660268

RESUMEN

The hanging droplet technique for three-dimensional tissue culture has been used for decades in biology labs, with the core technology remaining relatively unchanged. Recently microscale approaches have expanded the capabilities of the hanging droplet method, making it more user-friendly. We present a spontaneously driven, open hanging droplet culture platform to address many limitations of current platforms. Our platform makes use of two interconnected hanging droplet wells, a larger well where cells are cultured and a smaller well for user interface via a pipette. The two-well system results in lower shear stress in the culture well during fluid exchange, enabling shear sensitive or non-adherent cells to be cultured in a droplet. The ability to perform fluid exchanges in-droplet enables long-term culture, treatment, and characterization without disruption of the culture. The open well format of the platform was utilized to perform time-dependent coculture, enabling culture configurations with bone tissue scaffolds and cells grown in suspension. The open nature of the system allowed the direct addition or removal of tissue over the course of an experiment, manipulations that would be impractical in other microfluidic or hanging droplet culture platforms.


Asunto(s)
Técnicas de Cultivo de Célula/métodos , Técnicas Analíticas Microfluídicas/métodos , Técnicas de Cultivo de Célula/instrumentación , Células Cultivadas , Humanos , Técnicas Analíticas Microfluídicas/instrumentación , Tamaño de la Partícula , Tensión Superficial
3.
AJNR Am J Neuroradiol ; 27(7): 1432-7, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16908552

RESUMEN

BACKGROUND AND PURPOSE: [(11)C]Methionine (MET) PET imaging is a sensitive technique for visualizing primary brain tumors and recurrence/progression after therapy. The aim of this study was to evaluate the relationship between the uptake of MET and histopathologic grading and to investigate the prognostic value of the tracer, in both settings. METHODS: Cerebral uptake of MET was determined in 52 patients: in 26 patients for primary staging (group A) and 26 patients with suspected brain tumor recurrence/progression after therapy (group B). Semiquantitative methionine uptake indices (UI) defined by the tumor (maximum)-to-background ratio was correlated with tumor grade and final outcome. RESULTS: Overall median survival was 34.9 months. MET showed pathologically increased uptake in 41 of 52 scans. Although a weak linear correlation between MET uptake and grading was observed (R = 0.38, P = .028), analysis of variance showed no significant differences in MET UI between tumor grades for either group A or B. Benign and grade I lesions showed significant difference in MET uptake in comparison with higher grade lesions (P = .006). Using Kaplan-Meier survival analysis, no thresholds could be found at which MET was predictive for survival. Proportional hazard regression showed that only WHO grading class (low versus high) was predictive of survival (P = .015). CONCLUSION: Interindividual MET uptake variability does not allow noninvasive grading on an individual patient basis. Moreover, there is no significant prognostic value in studying maximal methionine UI in brain tumors. The clinical use of MET should therefore be primarily focused on questions such as detection of recurrence, biopsy guidance, and radiation therapy target volume delineation.


Asunto(s)
Neoplasias Encefálicas/diagnóstico por imagen , Radioisótopos de Carbono , Glioma/diagnóstico por imagen , Metionina , Recurrencia Local de Neoplasia/patología , Tomografía de Emisión de Positrones/métodos , Radiofármacos , Adolescente , Adulto , Anciano , Astrocitoma/diagnóstico por imagen , Astrocitoma/patología , Astrocitoma/terapia , Encéfalo/metabolismo , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/terapia , Niño , Preescolar , Progresión de la Enfermedad , Femenino , Predicción , Glioma/patología , Glioma/terapia , Humanos , Masculino , Metionina/metabolismo , Persona de Mediana Edad , Estadificación de Neoplasias , Oligodendroglioma/diagnóstico por imagen , Oligodendroglioma/patología , Oligodendroglioma/terapia , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia
4.
Health Phys ; 91(3): 200-10, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16891895

RESUMEN

The present study reports on results of a nation-wide survey on the natural radioactivity concentrations and Rn exhalation rates of the prevailing building materials in the Netherlands. In total 100 samples were taken and analyzed for the activity concentrations of Ra, Ra, Th, and K and for their Rn exhalation rate. The sampled materials consisted of gypsum products, aerated concrete, sand-lime and clay bricks, mortars and concrete, representing about 95% of the stony building materials used in the construction of Dutch homes. The laboratory analyses were performed according to two well-documented standard procedures, the interlaboratory reproducibility of which is found to be within 5% on average. The highest radionuclide concentrations were found in a porous inner wall brick to which fly ash was added. The second highest were clay bricks with average Ra and Ra levels around 40 Bq kg. Concrete and mortar show the highest exhalation rates with a fairly broad range of 1 to 13 microBq (kg s). Low natural radioactivity levels are associated with either natural gypsum (products) or gypsum from flue gas desulphurization units, and low exhalation rates with clay bricks. To evaluate the radiological impact the radioactivity concentrations in each sample were combined into a so-called dose factor, representing the absorbed dose rate in a room with a floor, walls and ceiling of 20 cm of the material in question. For that purpose, calculations with the computer codes MCNP, Marmer and MicroShield on the specific absorbed dose rates were incorporated in the paper. The results of these codes corresponded within 6% and average values were calculated at 0.90, 1.10, and 0.080 nGy h per Bq kg for the U series, the Th series, and K, respectively. Model calculations on the external dose rate, based on the incidence of the various building materials in 1,336 living rooms, are in accordance with measured data.


Asunto(s)
Contaminantes Radiactivos del Aire/análisis , Contaminación del Aire Interior/análisis , Materiales de Construcción , Modelos Teóricos , Radón/análisis , Países Bajos , Monitoreo de Radiación , Radioisótopos/análisis
5.
J Pharm Biomed Anal ; 32(4-5): 663-8, 2003 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-12899956

RESUMEN

99mTc-TRODAT-1 (technetium(V)-oxo-2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2-yl]methyl](2-mercaptoethyl)amino]ethyl]]amino]-ethanethiolato(3-)) and 99mTc-TRODAT-M, the 4-methylphenyl derivative of 99mTc-TRODAT-1, are at this moment being evaluated in clinical trials as imaging agents for the central nervous dopamine transporter system. Both compounds are formed as a mixture of two major diastereomers. As the tracer concentration in preparations for clinical investigations is very low (30-150 pmol/ml), identification of these 99mTc-complexes was, up to now, carried out indirectly using X-ray diffraction analysis of the corresponding rhenium complexes which can be synthesized in gram amounts. In this study, we developed a convenient and practical reversed phase HPLC-method for purification and isolation of the respective diastereomers of 99mTc-TRODAT-1 and three of its derivatives using mixtures of solvents which are compatible with biological studies, i.e. aqueous buffers and ethanol. Furthermore, direct identity confirmation of the 99mTc-complexes using radio-LC-MS was successfully elaborated.


Asunto(s)
Tecnecio/análisis , Tecnecio/química , Tecnología Farmacéutica/métodos , Tropanos/análisis , Tropanos/química , Cromatografía Líquida de Alta Presión/métodos , Estereoisomerismo
6.
Ann Oncol ; 13(9): 1356-63, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12196360

RESUMEN

BACKGROUND: Less than half of all patients with aggressive non-Hodgkin's lymphoma (NHL) are cured with standard chemotherapy. Therefore, it is important to distinguish between responders to standard treatment and non-responders who may benefit from an early change to a more effective therapy. This study was intended to assess the value of a midtreatment fluorine-18 fluorodeoxyglucose positron emission tomography ([(18)F]FDG-PET) scan to predict clinical outcome in patients with aggressive NHL. PATIENTS AND METHODS: Seventy newly diagnosed patients with aggressive NHL, who were treated with doxorubicin-containing chemotherapy, underwent a [(18)F]FDG-PET scan at midtreatment. Presence or absence of abnormal [(18)F]FDG uptake was related to progression-free survival (PFS) and overall survival (OS) using Kaplan-Meier survival analysis. Multivariate analysis was performed to evaluate the effect of the International Prognostic Index (IPI) and early [(18)F]FDG-PET findings on PFS and OS. RESULTS: At midtreatment, 33 patients showed persistent abnormal [(18)F]FDG uptake and none of these patients achieved a durable complete remission (CR), whereas 37 patients showed a negative scan; 31/37 remained in CR, with a median follow-up of 1107 days. Only 6/37 patients either achieved a partial response or relapsed. Comparison between groups indicated a statistically significant association between [(18)F]FDG-PET findings and PFS (P <1 x 10(-5)) and OS (P <1 x 10(-5)). In multivariate analysis, [(18)F]FDG-PET at midtreatment was a stronger prognostic factor for PFS (P <1 x 10(-7)) and OS (P <9 x 10(-6)) than the IPI (P <0.11 and P <0.03, respectively). CONCLUSIONS: Early restaging [(18)F]FDG-PET may be used to tailor induction chemotherapy in patients with aggressive NHL.


Asunto(s)
Fluorodesoxiglucosa F18 , Linfoma no Hodgkin/diagnóstico por imagen , Linfoma no Hodgkin/patología , Tomografía Computarizada de Emisión/métodos , Adolescente , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Niño , Preescolar , Ciclofosfamida/administración & dosificación , Doxorrubicina/administración & dosificación , Estudios de Evaluación como Asunto , Femenino , Humanos , Linfoma no Hodgkin/tratamiento farmacológico , Linfoma no Hodgkin/mortalidad , Masculino , Persona de Mediana Edad , Monitoreo Fisiológico/métodos , Análisis Multivariante , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Prednisolona/administración & dosificación , Probabilidad , Pronóstico , Estudios Prospectivos , Sensibilidad y Especificidad , Tasa de Supervivencia , Factores de Tiempo , Resultado del Tratamiento , Vincristina/administración & dosificación
7.
Ned Tijdschr Tandheelkd ; 108(11): 446-9, 2001 Nov.
Artículo en Holandés | MEDLINE | ID: mdl-11732136

RESUMEN

The aim of the present study was to investigate the occurrence of somatization-specific behaviour in the dental setting and its relationship with patients' report of both dental and psychological complaints. Somatization-specific behaviour was operationalized as an unexplained dental complaint, high dental attendance, a high treatment consumption or an unreasonable demand with regard to treatment. Of the 309 patients 8.7% fulfilled the criteria for somatization-specific behaviour, which was mainly expressed as a high frequency of attendance (6.8%). Women showed significantly more often (73%) somatization-specific behaviour than men (27%). Further, a relation between depression and somatization-specific behaviour was found. Particularly patients with a relatively high level of long-lasting dental complaints demonstrated somatization-specific behaviour.


Asunto(s)
Odontología General , Mal Uso de los Servicios de Salud/estadística & datos numéricos , Trastornos Somatomorfos/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Prevalencia , Muestreo , Distribución por Sexo , Trastornos Somatomorfos/psicología , Encuestas y Cuestionarios
8.
Amyloid ; 8(3): 202-14, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11676297

RESUMEN

To date, systemic amyloidosis is diagnosed histologically using Congo red staining or in vivo using iodine-123 labelled serum amyloid P component (123I-SAP) scintigraphy. We developed 99mTc-MAMA-CG, a 99mTc-labelled derivative of the lipophilic Congo red analogue chrysamine G (CG), as a possible alternative to 123I-SAP. In vivo 99mTc-MAMA-CG scintigraphy, performed in chickens with spontaneous joint amyloidosis, resulted as soon as 10 min after injection in scintigraphic images showing uptake of activity in amyloid-loaded organs (liver, joints). One of these chickens was studied also with 123I-SAP resulting in scintigraphic images revealing 123I-SAP binding to amyloid deposits in the liver. However, up to 11 h after injection no radioactivity was visible in the amyloid positive joints. In vitro autoradiography, performed on sections of chicken joints with Enterococcus faecalis induced amyloid arthropathy (chjAA), demonstrated the failure of 99mTc-MAMA-CG to bind significantly to amyloid deposits in the presence of 10 microM Congo red The specificity of 99mTc-MAMA-CG localisation was also established by the absence of 99mTc-MAMA-CG binding in non-amyloidotic organs in vitro and in vivo. 99mTc-MAMA-CG did not show any sign of acute toxicity. These findings establish the usefulness of 99mTc-MAMA-CG as a non-invasive in vivo diagnostic probe in chickens with amyloid arthropathy and suggest that it may also be applicable to human amyloidosis.


Asunto(s)
Amiloide/análisis , Amiloidosis/diagnóstico por imagen , Benzoatos , Radioisótopos de Yodo/química , Compuestos de Organotecnecio , Amiloidosis/diagnóstico , Amiloidosis/microbiología , Animales , Autorradiografía/métodos , Benzoatos/química , Pollos , Modelos Animales de Enfermedad , Enterococcus faecalis/patogenicidad , Estudios de Evaluación como Asunto , Femenino , Sondas Moleculares , Compuestos de Organotecnecio/química , Cintigrafía , Componente Amiloide P Sérico
9.
Nucl Med Commun ; 22(5): 553-8, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11388578

RESUMEN

To date, systemic amyloidosis is diagnosed histologically in vitro using Congo red staining or in vivo using iodine-123 serum amyloid P component (123I-SAP) scintigraphy. 99Tcm-labelled derivatives of chrysamine G (CG), a lipophilic analogue of Congo red, were synthesized as potential tracer agents for direct and quantitative scintigraphic evaluation of amyloid deposits. To determine the affinity of 99Tcm-MAMA-CG, 99Tcm-Me4MAMA-CG and 99Tcm-MAMA-CG diethyl ester for amyloid, in vitro autoradiography was performed on sections of human kidney biopsy cylinders from kidneys with amyloid deposits (types AA, Alambda and Akappa) or control kidney tissue after incubation with the respective tracer agents. The binding of 99Tcm-MAMA-CG and its tetramethyl derivative was higher to kidney biopsy material with amyloid deposits of the AA, Alambda or Akappa type compared with control kidney tissue. This higher binding was prevented by the presence of 10 microM Congo red in the incubation medium. The diethyl ester of 9Tcm-MAMA-CG did not demonstrate increased binding to Congo red-positive kidney tissue. In conclusion, 99Tcm-MAMA-CG and 99Tcm-Me4MAMA-CG localize specifically to amyloid deposits in human kidney tissue, suggesting that these tracer agents may be applicable as specific targeting agents for diagnostic purposes in clinical amyloidosis.


Asunto(s)
Amiloide/análisis , Amiloidosis/diagnóstico por imagen , Benzoatos , Enfermedades Renales/diagnóstico por imagen , Riñón/diagnóstico por imagen , Compuestos de Organotecnecio , Radiofármacos , Tecnecio , Adulto , Anciano , Autorradiografía , Niño , Femenino , Humanos , Riñón/patología , Masculino , Persona de Mediana Edad , Cintigrafía , Radiofármacos/síntesis química , Radiofármacos/farmacocinética , Valores de Referencia , Tecnecio/farmacocinética
10.
Eur J Nucl Med ; 28(4): 457-65, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11357495

RESUMEN

The aim of this study was to evaluate the relationship between flow/metabolism, histology and functional follow-up in a sheep model of subacute myocardial infarction. In eight juvenile sheep, a myocardial infarction was induced by intracoronary injection of macrobeads. Left ventricular function was evaluated using echocardiography. 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG)/nitrogen-13-labelled ammonia (13NH3) positron emission tomography (PET) was performed at 6 weeks and 16 weeks after embolization. In five sheep, a dynamic carbon-11 acetate study was performed. In each animal, two regions of interest were defined on the polar map, corresponding to the embolized and the non-embolized region. After the final measurements, the hearts were processed for histological evaluation. PET revealed a moderately decreased flow and oxidative metabolism in the embolized region at 6 weeks, without significant changes at follow-up. At 6 weeks, 18F-FDG uptake in the embolized area was more severely decreased as compared to the flow index in the embolized area (P < 0.05). At 16 weeks, 18F-FDG metabolism had significantly recovered (P < 0.05). Serial echocardiography showed a persistent decrease in global and regional left ventricular function. Histology revealed a mix of micro-infarcted and viable tissue in the embolized region. In this model of subacute myocardial infarction, a PET "reversed mismatch" pattern was observed, with partial recovery of 18F-FDG uptake at follow-up. The histological counterpart of this PET pattern appears to be patchy necrosis.


Asunto(s)
Infarto del Miocardio/diagnóstico por imagen , Enfermedad Aguda , Animales , Circulación Coronaria/fisiología , Ecocardiografía , Femenino , Fluorodesoxiglucosa F18 , Corazón/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador , Infarto del Miocardio/metabolismo , Infarto del Miocardio/fisiopatología , Miocardio/metabolismo , Radiofármacos , Ovinos , Tomografía Computarizada de Emisión , Función Ventricular Izquierda
11.
Eur J Nucl Med ; 26(11): 1392-9, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10552079

RESUMEN

Chrysamine G (CG), an analogue of Congo red, is known to bind in vitro to the beta-amyloid protein (Abeta 10-43) and to homogenates of several regions of the brain of Alzheimer's disease (AD) patients. We synthesised a conjugate of 2-(acetamido)-CG with a bis-S-trityl protected monoamide-monoaminedithiol (MAMA-Tr(2)) tetraligand, which was efficiently deprotected and labelled with a 75% yield with technetium-99m, to obtain (99m)Tc-MAMA-CG. In mice, (99m)Tc-MAMA-CG was cleared mainly by the hepatobiliary system, resulting in a fast blood clearance. Brain uptake of (99m)Tc-MAMA-CG was low. Co-injection with the blood pool tracer iodine-125 human serum albumin ((125)I-HSA) demonstrated a brain/blood activity ratio for (99m)Tc-MAMA-CG that was significantly higher than that for (125)I-HSA (t test for dependent samples, P<0.02), indicating the ability of (99m)Tc-MAMA-CG to cross the blood-brain barrier. In vitro autoradiography demonstrated pronounced binding of (99m)Tc-MAMA-CG to beta-amyloid deposits in autopsy sections of the parietal and occipital cortex of an AD patient as compared with controls. Adding 10 microM Congo red during incubation displaced the binding of (99m)Tc-MAMA-CG. Congo red staining and autoradiography identified the same lesions. (99m)Tc-MAMA-CG seems to bind selectively to beta-amyloid deposition in human brain parenchyma and blood vessels in vitro and thus might be a lead compound for further development of a useful tracer agent for the in vivo diagnosis of Alzheimer's disease.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico por imagen , Péptidos beta-Amiloides/análisis , Benzoatos , Encéfalo/diagnóstico por imagen , Compuestos de Organotecnecio , Adulto , Anciano , Anciano de 80 o más Años , Animales , Compuestos de Bifenilo , Encéfalo/metabolismo , Colorantes , Femenino , Humanos , Marcaje Isotópico , Masculino , Ratones , Ratones Endogámicos , Persona de Mediana Edad , Cintigrafía , Radiofármacos , Tecnecio , Distribución Tisular
12.
J Clin Microbiol ; 37(7): 2291-6, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10364600

RESUMEN

A panel (ENVA-1) of well-defined blinded samples containing wild-type and mutant human immunodeficiency virus type 1 (HIV-1) reverse transcriptase was analyzed by automated DNA sequencing in 23 laboratories worldwide. Drug resistance mutations at codons 41, 215, and 184 were present in the panel samples at different ratios to the wild type. The presence of mutant genotypes was determined qualitatively and quantitatively. All laboratories reported the presence of sequence heterogeneities at codons 41, 215, and 184 in one or more of the panel samples, though not all reported the correct codon genotypes. Two laboratories reported a mutant genotype in samples containing only the wild type, whereas two and three laboratories failed to detect the mutant genotypes at codons 41 and 215, respectively, in a completely mutant DNA population. Mutations present at relative concentrations of 25% of the total DNA population were successfully identified by 13 of 23, 10 of 23, and 16 of 23 labs for codons 41, 215, and 184Val, respectively. For more than 80% of those laboratories that qualitatively detected the presence of a mutation correctly, the estimated wild type/mutant ratio was less than 25% different from the input ratio in those samples containing 25 to 50% or 75% mutant input. This first multicenter study on the quality of DNA sequencing approaches for identifying HIV-1 drug resistance mutations revealed large interlaboratory differences in the quality of the results. The application of these procedures in their current state would in several cases lead to inaccurate or even incorrect diagnostic results. Therefore, proper quality control and standardization are urgently needed.


Asunto(s)
Transcriptasa Inversa del VIH/genética , VIH-1/enzimología , VIH-1/genética , Mutación Puntual , Codón , ADN Viral/química , ADN Viral/genética , Farmacorresistencia Microbiana , Europa (Continente) , Genotipo , Salud Global , Humanos , Reproducibilidad de los Resultados
13.
Antivir Ther ; 4(2): 101-7, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10682155

RESUMEN

The compound 9-(2-phosphonylmethoxyethyl)adenine (adefovir; PMEA) is a potent inhibitor of a number of viruses in vitro, such as human immunodeficiency virus (HIV) type 1 and 2, herpes simplex virus (HSV) type 1 and 2, human papillomavirus virus (HBV) and Epstein-Barr virus (EBV). Adefovir also proved to be effective in vivo against feline immunodeficiency virus (FIV) in cats and simian immunodeficiency virus (SIV) in rhesus monkeys. In an open, non-placebo-controlled trial the antiviral activity of weekly doses of adefovir in nine patients with AIDS or AIDS-related complex was studied for a period of 11 weeks. CD4 cell counts at baseline were between 10 and 450 cells/mm3, HIV-1 RNA levels at baseline were between 24,210 copies/ml and 406,197 copies/ml. The drug was administered intravenously at a dose of 1000 mg every week and plasma viral load was assessed at multiple points during the study. Administration of adefovir was tolerated well and no severe side effects were seen. The response to adefovir treatment differed widely between patients. The increase in CD4 cell count at end point ranged from -40 to 120 cell/mm3. The lowest HIV RNA levels were measured after 3-5 days, showing an increase thereafter. The nadir in viral load was achieved after 2 weeks, with a mean viral load decline of 0.7 from baseline. The decrease of the HIV RNA level at end point ranged from -0.3 log10 to 1.8 log10 with a mean decrease of 0.4 log10. Our results indicate that adefovir given intravenously once weekly has a short-lasting initial antiviral effect. The effect of more frequent dosing requires further evaluation. If adefovir is to be useful clinically, it needs to be combined with other antiviral agents.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Adenina/análogos & derivados , Antivirales/administración & dosificación , VIH-1/aislamiento & purificación , Organofosfonatos , ARN Viral/sangre , Síndrome de Inmunodeficiencia Adquirida/virología , Adenina/administración & dosificación , Adulto , Recuento de Linfocito CD4 , VIH-1/genética , Humanos , Masculino , Persona de Mediana Edad
14.
AIDS ; 12(10): 1169-76, 1998 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-9677166

RESUMEN

OBJECTIVE: To determine the effect of lamivudine (3TC) on syncytium-inducing (SI) and non-SI (NSI) HIV-1 populations in vivo. DESIGN: Responses in virus load and 3TC resistance in 40 3TC-treated subjects were analysed in relation to the presence or absence of SI HIV-1 variants. METHODS: Peripheral blood samples were collected at regular intervals from 40 HIV-1-infected subjects during 3TC treatment. Virus isolates obtained at the start of treatment were typed for SI-capacity by coculture with MT-2 cells. Changes in levels of viral RNA in plasma were determined by quantitative reverse transcriptase PCR. The relative amount of wild-type and mutant virus at codon 184, associated with HIV resistance to 3TC, was determined using a primer-guided nucleotide incorporation assay after amplification of part of the reverse transcriptase gene. In five subjects the frequency of productively infected CD4+ cells with SI or NSI variants was determined in relation to codon 184 genotype. RESULTS: Twenty-six subjects harboured only NSI variants at baseline, whereas 14 subjects also harboured SI variants. Although baseline plasma viral RNA load and CD4 cell counts were different between the two groups, no differences in the response to 3TC therapy were observed for these parameters. In-depth analysis of five subjects showed that the kinetics of virus load changes and emergence of 3TC resistance mutations were similar in plasma and cells, and comparable for the SI and NSI populations present in one individual. CONCLUSIONS: These data show that, in contrast to didanosine and zidovudine, the pressure exerted by 3TC is similar for SI and NSI M184 populations.


Asunto(s)
Fármacos Anti-VIH/inmunología , Células Gigantes/efectos de los fármacos , Infecciones por VIH/virología , VIH-1/efectos de los fármacos , Lamivudine/farmacología , Inhibidores de la Transcriptasa Inversa/inmunología , Recuento de Linfocito CD4 , Codón/genética , ADN Viral/genética , Farmacorresistencia Microbiana/genética , Células Gigantes/fisiología , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/inmunología , VIH-1/genética , VIH-1/fisiología , Humanos , Lamivudine/uso terapéutico , Mutación , Provirus/genética , ARN Viral/sangre , ARN Viral/genética , Carga Viral , Replicación Viral/efectos de los fármacos
15.
J Infect Dis ; 176(2): 398-405, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9237704

RESUMEN

Exposure of human immunodeficiency virus to the nucleoside analogue lamivudine (3TC) rapidly selects for resistant variants with a valine at codon 184 (M184V) in the catalytic site of reverse transcriptase. In vitro, 184V demonstrated increased enzyme fidelity and suppressed zidovudine resistance. Clinical trials demonstrated that 3TC-zidovudine combination therapy results in a strong and sustained antiviral response. To investigate the role of 184V on in vivo virus evolution, the effect of zidovudine addition in 3TC-pretreated patients harboring 184V was studied. In vivo, no significant change in fidelity was observed with 184V, shown by generation of the classical pattern of zidovudine mutations. Of interest, in contrast to zidovudine monotherapy, in which just one substitution is sufficient for in vivo development of significant zidovudine resistance, multiple substitutions are required for the same level of zidovudine resistance in strains harboring 184V. This need for multiple substitutions may be one of the mechanisms explaining the sustained antiretroviral response of the 3TC-zidovudine combination.


Asunto(s)
Fármacos Anti-VIH/farmacología , Resistencia a Múltiples Medicamentos/genética , Transcriptasa Inversa del VIH/genética , VIH-1/efectos de los fármacos , Lamivudine/farmacología , Zidovudina/farmacología , Secuencia de Aminoácidos , Fármacos Anti-VIH/uso terapéutico , Recuento de Linfocito CD4 , Análisis Mutacional de ADN , ADN Viral/genética , Farmacorresistencia Microbiana , Quimioterapia Combinada , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Transcriptasa Inversa del VIH/química , VIH-1/genética , Humanos , Lamivudine/uso terapéutico , Datos de Secuencia Molecular , Mutación/genética , ARN Viral/sangre , Zidovudina/uso terapéutico
16.
Nucl Med Biol ; 24(5): 461-4, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9290083

RESUMEN

A phenylene moiety in the chain of fatty acids was expected to impair metabolic degradation. Three phenoxy-containing [11C]carboxyl-labelled fatty acids were synthesized and evaluated in mice and an in vivo tissue distribution study. Of these three, 1[11C]-3-(p-dodecyloxyphenyl)propionic acid (C12C3) showed the most favourable uptake in the myocardium: 1.2% of the injected dose at 30 min p.i., vs. 0.6% for [11C]palmitate. The metabolic stability of C12C3 and [11C]palmitate was assessed by determining the amount of exhaled [11C]CO2 during a 30-min interval after injection. It was found that the phenoxy moiety in the gamma-position did not prevent the metabolic degradation of C12C3: After 30 min 20.7% of the injected dose was exhaled as [11C]CO2 vs. 12.7% for [11C]palmitate.


Asunto(s)
Radioisótopos de Carbono , Ácidos Grasos/metabolismo , Miocardio/metabolismo , Animales , Dióxido de Carbono/metabolismo , Masculino , Ratones , Tomografía Computarizada de Emisión
17.
Psychiatry Res ; 68(1): 11-22, 1996 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-9027929

RESUMEN

We used [18F]altanserin and positron emission tomography (PET) to image serotonin 5-HT2A receptors in humans. The highest [18F]altanserin uptake is found in the cerebral cortex, with specific-to-nonspecific binding ratios varying from 0.53 to 1.91 in humans between 24 and 48 years of age. In all neocortical regions studied, [18F]altanserin uptake correlates negatively with age. No correlations were found between age and uptake in the cerebellum, the regional cerebral blood flow, or the time course of metabolization of [18F]altanserin. The reduction in cerebral 5-HT2A receptor binding thus directly reflects the loss of specific 5-HT2A receptors with age.


Asunto(s)
Envejecimiento/fisiología , Encéfalo/diagnóstico por imagen , Ketanserina/análogos & derivados , Receptores de Serotonina/fisiología , Antagonistas de la Serotonina/farmacocinética , Tomografía Computarizada de Emisión , Adulto , Mapeo Encefálico , Corteza Cerebral/diagnóstico por imagen , Dominancia Cerebral/fisiología , Femenino , Radioisótopos de Flúor , Humanos , Ketanserina/farmacocinética , Masculino , Receptor de Serotonina 5-HT2A , Valores de Referencia
18.
Nucl Med Biol ; 23(2): 155-7, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8868288

RESUMEN

N-Isopropylnorephedrine (INE) and N-fluoroisopropylnorephedrine (FINE) were found to have a poor affinity for either beta-adrenoceptors and the norepinephrine carrier protein. The low affinity of both compounds for Uptake-1 is probably due to the introduction of a bulky substituent on the nitrogen atom. It is concluded that INE and FINE cannot be used for cardiac imaging with PET.


Asunto(s)
Corazón/diagnóstico por imagen , Miocardio/metabolismo , Fenilpropanolamina/análogos & derivados , 3-Yodobencilguanidina , Animales , Proteínas Portadoras/metabolismo , Humanos , Yodobencenos/metabolismo , Ligandos , Células PC12 , Fenilpropanolamina/farmacocinética , Ratas , Receptores Adrenérgicos alfa/metabolismo , Receptores Adrenérgicos beta/metabolismo , Tomografía Computarizada de Emisión , Células Tumorales Cultivadas
19.
Nucl Med Biol ; 23(2): 159-67, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8868289

RESUMEN

The beta-adrenoceptor antagonist carazolol has been labelled with fluorine-18 in the isopropyl group via a reductive alkylation by [18F]-fluoroacetone of the corresponding (S)-desisopropyl compound according to a known procedure. The introduction of fluorine in the isopropyl group creates a new stereogenic centre resulting in the formation of (S,S)- and (S,R)-1'-[18F]fluorocarazolol, which were separated by HPLC. Tissue distribution studies were performed in male Wistar rats. Both the (S,S)- and (S,R)-diastereomers (S.A. 500-2000 Ci/mmol; 18.5-74 TBq/mmol) showed high uptake in lung and heart, which could be blocked by pretreatment of the animals with (+/-)-propranolol. No significant differences were observed between the biodistribution of the two diastereomers. Metabolite analysis showed a rapid appearance of polar metabolites in plasma, while at 60 min postinjection 92% and 82% of the total radioactivity in lung and heart was unmetabolized 1'-[18F]fluorocarazolol. In a PET-study with male Wistar rats, the lungs were clearly visualized and the pulmonary uptake was decreased after pretreatment of the animals with (+/-)-propranolol. The heart could not be visualized. Similar results were obtained in PET-studies with lambs.


Asunto(s)
Antagonistas Adrenérgicos beta , Carbazoles/química , Pulmón/metabolismo , Propanolaminas/química , Receptores Adrenérgicos beta/metabolismo , Antagonistas Adrenérgicos beta/síntesis química , Antagonistas Adrenérgicos beta/farmacocinética , Animales , Biotransformación , Encéfalo/metabolismo , Carbazoles/farmacocinética , Eritrocitos/metabolismo , Radioisótopos de Flúor , Marcaje Isotópico , Ligandos , Masculino , Miocardio/metabolismo , Propanolaminas/farmacocinética , Ensayo de Unión Radioligante , Ratas , Ratas Wistar , Ovinos , Estereoisomerismo , Distribución Tisular , Tomografía Computarizada de Emisión
20.
Eur J Morphol ; 33(2): 154-7, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7488519

RESUMEN

A comparable study of microwave versus thermal heating is described for the N-[18F]-fluoroalkylation of noraporphines. As compared to thermal treatment, different products were obtained during microwave treatment. Thermal treatment resulted in the loss of the protection of the catechol functionality of the noraporphines (O-deacylation), whereas during microwave treatment N-[18F]-fluoroalkylation was observed. The results described in this report might suggest that the influence of microwaves on chemical transformations is not exclusively thermal.


Asunto(s)
Alquilación , Aporfinas/química , Radioisótopos de Flúor/química , Calor , Marcaje Isotópico/métodos , Microondas , Humanos , Temperatura , Tomografía Computarizada de Emisión
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