104 research outputs found

    HIV seroprevalence and exposure categories among adolescents tested at a sexually transmitted clinic diseases. Madrid, 1986-2000

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    [ES] Objetivos Describir los cambios en los tipos de exposición y en la prevalencia del VIH en adolescentes que se hicieron la prueba voluntaria entre 1986 y 2000. Métodos Se incluyó a todos los adolescentes de 13 a 19 años que se hicieron por primera vez la prueba del VIH en una clínica de enfermedades de transmisión sexual de Madrid. Se determinaron anticuerpos en suero mediante ELISA y se confirmaron con Western blot. Se analizaron los cambios en los tipos de exposición y en la seroprevalencia del VIH. Resultados De los 1.327 adolescentes analizados (un 52% de mujeres) el 22% eran menores de 18 años. El número de adolescentes analizados anualmente se mantuvo, aunque descendieron los usuarios de drogas por vía parenteral (UDVP) y las parejas de UDVP, y aumentaron las mujeres que ejercen la prostitución. Se diagnosticaron 108 infecciones, el 71% en UDVP. La seroprevalencia fue del 8,1%, alcanzando el 31,3% en UDVP. Descendió desde 18,2% en 1986 al 1,5% en 1995, manteniéndose desde entonces por debajo del 4%. En varias categorías de exposición se observaron descensos, que alcanzaron significación estadística en varones homo/bisexuales y en mujeres que ejercen la prostitución. El análisis de regresión logística evidenció una reducción anual de la seroprevalencia (odds ratio [OR] = 0,87; intervalo de confianza [IC] del 95%: 0,81-0,94) tras ajustar por los cambios en las categorías de exposición. Conclusiones La prevalencia del VIH ha descendido debido a la disminución de nuevos UDVP y de la prevalencia en varias categorías de exposición. Siguen produciéndose conductas de riesgo e infecciones por el VIH en adolescentes. [EN] Objective To describe the time-trend in exposure categories and HIV seroprevalence among adolescents who underwent to voluntary testing in the period 1986-2000. Methods This study covered all adolescents, aged 13 to 19 years, at their first test for HIV in a sexually transmitted disease clinic in Madrid. Gender, age and HIV risk behaviours were collected. HIV diagnosis relies on ELISA test and Western blot confirmation. Time trends in HIV seroprevalence and exposure categories were analysed. Results A total of 1327 adolescents, 52% women and 22% under 18 years, were studied. The annual number of adolescents remained through the time, but injecting drug users (IDU) and IDU partners declined and female sex workers rose. 108 adolescents were diagnosed with HIV infection –71% were IDU–. HIV seroprevalence was 8.1% –31.3% in IDU–. It declined from 18.2% in 1986 to 1.5% in 1995, and after then it held steady under 4%. This decline involved several risk categories and was statistically significant in homo/bisexual men and female sex workers. The logistic regression analysis, adjusting for changes in exposure categories, showed an annual reduction in HIV seroprevalence (OR = 0.87; 95% CI, 0.81- 0.94). Conclusions HIV seroprevalence has decreased due to the fall of new young IDU and the decrease of seroprevalence within several exposure categories. HIV infections and risk behaviours continue happened among adolescents.Este trabajo ha sido financiado por proyectos FIS (99/0195) y FIPSE (3076/99). Ricardo Gómez Lázaro ha sido beneficiario de una beca del Instituto de Salud Carlos III (00/0073).S

    Clinical and epidemiological characterization of a lymphogranuloma venereum outbreak in Madrid, Spain: co-circulation of two variants

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    AbstractThe lymphogranuloma venereum (LGV) outbreak described in the Netherlands in 2003, increased the interest in the genotyping of Chlamydia trachomatis. Although international surveillance programmes were implemented, these studies slowly decreased in the following years. Now data have revealed a new accumulation of LGV cases in those European countries with extended surveillance programmes. Between March 2009 and November 2011, a study was carried out to detect LGV cases in Madrid. The study was based on screening of C. trachomatis using commercial kits, followed by real-time pmpH-PCR discriminating LGV strains, and finally ompA gene was sequenced for phylogenetic reconstruction. Ninety-four LGV infections were identified. The number of cases increased from 10 to 30 and then to 54 during 2009–2011. Incidence of LGV was strongly associated with men who have sex with men; but in 2011, LGV cases were described in women and heterosexual men. Sixty-nine patients were also human immunodeficiency virus (HIV) positive, with detectable viral loads at the moment of LGV diagnosis, suggesting a high-risk of co-transmission. In fact, in four patients the diagnosis of HIV was simultaneous with LGV infection. The conventional treatment with doxycycline was prescribed in 75 patients, although in three patients the treatment failed. The sequencing of the ompA gene permitted identification of two independent transmission nodes. One constituted by 25 sequences identical to the L2b variant, and a second node including 37 sequences identical to L2. This epidemiological situation characterized by the co-circulation of two LGV variants has not been previously described, reinforcing the need for screening and genotyping of LGV strains

    FDG uptake, a surrogate of tumour hypoxia?

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    Introduction Tumour hyperglycolysis is driven by activation of hypoxia-inducible factor-1 (HIF-1) through tumour hypoxia. Accordingly, the degree of 2-fluro-2-deoxy-D-glucose (FDG) uptake by tumours might indirectly reflect the level of hypoxia, obviating the need for more specific radiopharmaceuticals for hypoxia imaging. Discussion In this paper, available data on the relationship between hypoxia and FDG uptake by tumour tissue in vitro and in vivo are reviewed. In pre-clinical in vitro studies, acute hypoxia was consistently shown to increase FDG uptake by normal and tumour cells within a couple of hours after onset with mobilisation or modification of glucose transporters optimising glucose uptake, followed by a delayed response with increased rates of transcription of GLUT mRNA. In pre-clinical imaging studies on chronic hypoxia that compared FDG uptake by tumours grown in rat or mice to uptake by FMISO, the pattern of normoxic and hypoxic regions within the human tumour xenografts, as imaged by FMISO, largely correlated with glucose metabolism although minor locoregional differences could not be excluded. In the clinical setting, data are limited and discordant. Conclusion Further evaluation of FDG uptake by various tumour types in relation to intrinsic and bioreductive markers of hypoxia and response to radiotherapy or hypoxia-dependent drugs is needed to fully assess its application as a marker of hypoxia in the clinical setting

    Dose escalation to high-risk sub-volumes based on non-invasive imaging of hypoxia and glycolytic activity in canine solid tumors:a feasibility study

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    INTRODUCTION: Glycolytic activity and hypoxia are associated with poor prognosis and radiation resistance. Including both the tumor uptake of 2-deoxy-2-[(18) F]-fluorodeoxyglucose (FDG) and the proposed hypoxia tracer copper(II)diacetyl-bis(N(4))-methylsemithio-carbazone (Cu-ATSM) in targeted therapy planning may therefore lead to improved tumor control. In this study we analyzed the overlap between sub-volumes of FDG and hypoxia assessed by the uptake of (64)Cu-ATSM in canine solid tumors, and evaluated the possibilities for dose redistribution within the gross tumor volume (GTV). MATERIALS AND METHODS: Positron emission tomography/computed tomography (PET/CT) scans of five spontaneous canine solid tumors were included. FDG-PET/CT was obtained at day 1, (64)Cu-ATSM at day 2 and 3 (3 and 24 h pi.). GTV was delineated and CT images were co-registered. Sub-volumes for 3 h and 24 h (64)Cu-ATSM (Cu3 and Cu24) were defined by a threshold based method. FDG sub-volumes were delineated at 40% (FDG40) and 50% (FDG50) of SUV(max). The size of sub-volumes, intersection and biological target volume (BTV) were measured in a treatment planning software. By varying the average dose prescription to the tumor from 66 to 85 Gy, the possible dose boost (D( B )) was calculated for the three scenarios that the optimal target for the boost was one, the union or the intersection of the FDG and (64)Cu-ATSM sub-volumes. RESULTS: The potential boost volumes represented a fairly large fraction of the total GTV: Cu3 49.8% (26.8-72.5%), Cu24 28.1% (2.4-54.3%), FDG40 45.2% (10.1-75.2%), and FDG50 32.5% (2.6-68.1%). A BTV including the union (∪) of Cu3 and FDG would involve boosting to a larger fraction of the GTV, in the case of Cu3∪FDG40 63.5% (51.8-83.8) and Cu3∪FDG50 48.1% (43.7-80.8). The union allowed only a very limited D( B ) whereas the intersection allowed a substantial dose escalation. CONCLUSIONS: FDG and (64)Cu-ATSM sub-volumes were only partly overlapping, suggesting that the tracers offer complementing information on tumor physiology. Targeting the combined PET positive volume (BTV) for dose escalation within the GTV results in a limited D( B ). This suggests a more refined dose redistribution based on a weighted combination of the PET tracers in order to obtain an improved tumor control

    pO polarography, contrast enhanced color duplex sonography (CDS), [18F] fluoromisonidazole and [18F] fluorodeoxyglucose positron emission tomography: validated methods for the evaluation of therapy-relevant tumor oxygenation or only bricks in the puzzle of tumor hypoxia?

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    <p>Abstract</p> <p>Background</p> <p>The present study was conducted to analyze the value of ([<sup>18</sup>F] fluoromisonidazole (FMISO) and [<sup>18</sup>F]-2-fluoro-2'-deoxyglucose (FDG) PET as well as color pixel density (CPD) and tumor perfusion (TP) assessed by color duplex sonography (CDS) for determination of therapeutic relevant hypoxia. As a standard for measuring tissue oxygenation in human tumors, the invasive, computerized polarographic needle electrode system (pO<sub>2 </sub>histography) was used for comparing the different non invasive measurements.</p> <p>Methods</p> <p>Until now a total of 38 Patients with malignancies of the head and neck were examined. Tumor tissue pO<sub>2 </sub>was measured using a pO<sub>2</sub>-histograph. The needle electrode was placed CT-controlled in the tumor without general or local anesthesia. To assess the biological and clinical relevance of oxygenation measurement, the relative frequency of pO<sub>2 </sub>readings, with values ≤ 2.5, ≤ 5.0 and ≤ 10.0 mmHg, as well as mean and median pO<sub>2 </sub>were stated. FMISO PET consisted of one static scan of the relevant region, performed 120 min after intravenous administration. FMISO tumor to muscle ratios (FMISO<sub>T/M</sub>) and tumor to blood ratios (FMISO<sub>T/B</sub>) were calculated. FDG PET of the lymph node metastases was performed 71 ± 17 min after intravenous administration. To visualize as many vessels as possible by CDS, a contrast enhancer (Levovist<sup>®</sup>, Schering Corp., Germany) was administered. Color pixel density (CPD) was defined as the ratio of colored to grey pixels in a region of interest. From CDS signals two parameters were extracted: color hue – defining velocity (v) and color area – defining perfused area (A). Signal intensity as a measure of tissue perfusion (TP) was quantified as follows: TP = v<sub>mean </sub>× A<sub>mean</sub>.</p> <p>Results</p> <p>In order to investigate the degree of linear association, we calculated the Pearson correlation coefficient. Slight (|r| > 0.4) to moderate (|r| > 0.6) correlation was found between the parameters of pO<sub>2 </sub>polarography (pO<sub>2 </sub>readings with values ≤ 2.5, ≤ 5.0 and ≤ 10.0 mmHg, as well as median pO<sub>2</sub>), CPD and FMISO<sub>T/M</sub>. Only a slight correlation between TP and the fraction of pO<sub>2 </sub>values ≤ 10.0 mmHg, median and mean pO<sub>2 </sub>could be detected. After exclusion of four outliers the absolute values of the Pearson correlation coefficients increased clearly. There was no relevant association between mean or maximum FDG uptake and the different polarographic- as well as the CDS parameters.</p> <p>Conclusion</p> <p>CDS and FMISO PET represent different approaches for estimation of therapy relevant tumor hypoxia. Each of these approaches is methodologically limited, making evaluation of clinical potential in prospective studies necessary.</p

    Focal dose escalation using FDG-PET-guided intensity-modulated radiation therapy boost for postoperative local recurrent rectal cancer: a planning study with comparison of DVH and NTCP

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    <p>Abstract</p> <p>Background</p> <p>To evaluate the safety of focal dose escalation to regions with standardized uptake value (SUV) >2.0 using intensity-modulated radiation therapy (IMRT) by comparison of radiotherapy plans using dose-volume histograms (DVHs) and normal tissue complication probability (NTCP) for postoperative local recurrent rectal cancer</p> <p>Methods</p> <p>First, we performed conventional radiotherapy with 40 Gy/20 fr. (CRT 40 Gy) for 12 patients with postoperative local recurrent rectal cancer, and then we performed FDG-PET/CT radiotherapy planning for those patients. We defined the regions with SUV > 2.0 as biological target volume (BTV) and made three boost plans for each patient: 1) CRT boost plan, 2) IMRT without dose-painting boost plan, and 3) IMRT with dose-painting boost plan. The total boost dose was 20 Gy. In IMRT with dose-painting boost plan, we increased the dose for BTV+5 mm by 30% of the prescribed dose. We added CRT boost plan to CRT 40 Gy (<it>summed plan 1</it>), IMRT without dose-painting boost plan to CRT 40 Gy (<it>summed plan 2</it>) and IMRT with dose-painting boost plan to CRT 40 Gy (<it>summed plan 3</it>), and we compared those plans using DVHs and NTCP.</p> <p>Results</p> <p>D<sub>mean </sub>of PTV-PET and that of PTV-CT were 26.5 Gy and 21.3 Gy, respectively. V<sub>50 </sub>of small bowel PRV in <it>summed plan 1 </it>was significantly higher than those in other plans ((<it>summed plan 1 </it>vs. <it>summed plan 2 </it>vs. <it>summed plan 3</it>: 47.11 ± 45.33 cm<sup>3 </sup>vs. 40.63 ± 39.13 cm<sup>3 </sup>vs. 41.25 ± 39.96 cm<sup>3</sup>(p < 0.01, respectively)). There were no significant differences in V<sub>30</sub>, V<sub>40</sub>, V<sub>60</sub>, D<sub>mean </sub>or NTCP of small bowel PRV.</p> <p>Conclusions</p> <p>FDG-PET-guided IMRT can facilitate focal dose-escalation to regions with SUV above 2.0 for postoperative local recurrent rectal cancer.</p

    Epidemiología y características del ictus isquémico en el adulto joven en Aragón

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    Introducción Alrededor de 15 millones de personas sufren un ictus cada año, de los que un 10-15% ocurre en menores de 50 años (ictus en el adulto joven). La prevalencia de los distintos factores de riesgo vascular y las estrategias sanitarias para el manejo del ictus varían a nivel mundial, siendo interesante conocer la epidemiología y las características específicas de cada región. El objetivo de este estudio fue determinar la prevalencia de los diferentes factores de riesgo vascular, la etiología y las características de los ictus isquémicos en el adulto joven en la comunidad autónoma de Aragón. Métodos Estudio multicéntrico, de corte transversal, realizado por los Servicios de Neurología de todos los hospitales del Servicio Aragonés de Salud (SALUD). Se identificó a todos los pacientes entre 18 y 50 años que ingresaron en cualquiera de estos hospitales con el diagnóstico de ictus isquémico o AIT entre enero del 2005 y diciembre del 2015. Se recogieron variables demográficas, factores de riesgo vascular y tipo de ictus isquémico entre otras. Resultados En el periodo de estudio, 786 pacientes entre 18 y 50 años ingresaron con el diagnóstico de ictus isquémico o AIT en algún hospital del SALUD, con una tasa anual promedio de 12, 3 por 100.000 habitantes. La mediana de su edad fue de 45 años (RIQ: 40-48 años). El factor de riesgo vascular más prevalente fue el tabaquismo, 404 (51, 4%). La mayoría fue de causa indeterminada (36, 2%), seguida por «otras causas» (26, 5%). La mediana de puntuación en la escala NIHSS fue de 3, 5 (RIQ: 2, 07, 0). En total, 211 (26, 8%) de los ingresos fueron por AIT. De los pacientes que ingresaron con el diagnóstico de ictus isquémico, 59 (10, 3%) se fibrinolizaron. Conclusiones El ictus isquémico en el adulto joven no es infrecuente en Aragón y en un importante número de casos es de etiología indeterminada, por lo que es necesario implementar medidas que nos permitan mejorar su estudio, disminuir su incidencia y prevenir su recurrencia. Introduction: Stroke affects around 15 million people per year, with 10%-15% occurring in individuals under 50 years old (stroke in young adults). The prevalence of different vascular risk factors and healthcare strategies for stroke management vary worldwide, making the epidemiology and specific characteristics of stroke in each region an important area of research. This study aimed to determine the prevalence of different vascular risk factors and the aetiology and characteristics of ischaemic stroke in young adults in the autonomous community of Aragon, Spain. Methods: A cross-sectional, multi-centre study was conducted by the neurology departments of all hospitals in the Aragonese Health Service. We identified all patients aged between 18 and 50 years who were admitted to any of these hospitals with a diagnosis of ischaemic stroke or TIA between January 2005 and December 2015. Data were collected on demographic variables, vascular risk factors, and type of stroke, among other variables. Results: During the study period, 786 patients between 18 and 50 years old were admitted with a diagnosis of ischaemic stroke or TIA to any hospital of Aragon, at a mean annual rate of 12.3 per 100 000 population. The median age was 45 years (IQR: 40-48 years). The most prevalent vascular risk factor was tobacco use, in 404 patients (51.4%). The majority of strokes were of undetermined cause (36.2%), followed by other causes (26.5%). The median NIHSS score was 3.5 (IQR: 2.0-7.0). In total, 211 patients (26.8%) presented TIA. Fifty-nine per cent of the patients admitted with a diagnosis of ischaemic stroke (10.3%) were treated with fibrinolysis. Conclusions: Ischaemic stroke in young adults is not uncommon in Aragon, and is of undetermined aetiology in a considerable number of cases; it is therefore necessary to implement measures to improve study of the condition, to reduce its incidence, and to prevent its recurrence

    Molecular imaging of hypoxia with radiolabelled agents

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    Tissue hypoxia results from an inadequate supply of oxygen (O2) that compromises biological functions. Structural and functional abnormalities of the tumour vasculature together with altered diffusion conditions inside the tumour seem to be the main causes of tumour hypoxia. Evidence from experimental and clinical studies points to a role for tumour hypoxia in tumour propagation, resistance to therapy and malignant progression. This has led to the development of assays for the detection of hypoxia in patients in order to predict outcome and identify patients with a worse prognosis and/or patients that would benefit from appropriate treatments. A variety of invasive and non-invasive approaches have been developed to measure tumour oxygenation including oxygen-sensitive electrodes and hypoxia marker techniques using various labels that can be detected by different methods such as positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), autoradiography and immunohistochemistry. This review aims to give a detailed overview of non-invasive molecular imaging modalities with radiolabelled PET and SPECT tracers that are available to measure tumour hypoxia
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