Valle Camacho

DMSA study performed during febrile urinary tract infection: a predictor of patient outcome?

Technetium-99m dimercaptosuccinic acid (DMSA) study has been advocated as a method for the assessment of renal sequelae after acute febrile urinary tract infection (UTI). However, it is not known whether DMSA scintigraphy performed during acute UTI has any prognostic value for outcome assessment. The objective of this study was to evaluate the usefulness of DMSA scintigraphy performed during UTI as a predictor of patient outcome, to identify children at risk of events [vesico-ureteral reflux (VUR) or recurrent UTI] that may lead to the development of progressive renal damage. One hundred and fifty-two children (including 78 girls) with a mean age of 20 months (range 1 month to 12 years) with first febrile UTI were evaluated by DMSA scintigraphy during acute UTI. After acute UTI, children were explored by voiding cysto-urethrography. Children who presented an abnormal DMSA study, or a normal DMSA study but VUR or recurrent UTI, underwent a DMSA control study 6 months after UTI. Children with VUR were followed up by direct radionuclide cystography. DMSA scintigraphy performed during acute UTI was normal in 112 children (74%). In 95 of these children, follow-up DMSA scintigraphy was not performed owing to a good clinical outcome. In the remaining 17 children, follow-up scintigraphy was normal. Forty children (26%) presented abnormal DMSA study during acute UTI. Twenty-five of them presented a normal follow-up DMSA, and 15 presented cortical lesions. Children with abnormal DMSA had a higher frequency of VUR than children with normal DMSA (48% vs 12%). It is concluded that children with normal DMSA during acute UTI have a low risk of renal damage. Children with normal follow-up DMSA and low-grade VUR have more frequent spontaneous resolution of VUR.

Use of electrical impedance tomography (EIT) for the assessment of unilateral pulmonary function

We describe a fully automatable quantification process for the assessment of unilateral pulmonary function (UPF) by means of EIT and propose a measurement protocol for its clinical implementation. Measurements were performed at the fourth and sixth intercostal levels on a first group of ten healthy subjects (5M, 5F, ages 26-48 years) to define the proper protocol by evaluating the most common postures and ventilation modes. Several off-line processing tools were also evaluated, including the use of digital filters to extract the respiratory components from EIT time series. Comparative measures were then carried out on a second group consisting of five preoperatory patients with lung cancer (4M, IF, ages 25-77 years) scheduled for radionuclide scanning. Results show that measurements were best performed with the subject sitting down, holding his arms up and breathing spontaneously. As regards data processing, it is best to extract Fourier respiratory components. The mean of the healthy subject group leads to a left-right division of lung ventilation consistent with literature values (47% left lung, 53% right lung). The comparative study indicates a good correlation (r = 0.96) between the two techniques, with a mean difference of (-0.4+/-5.4)%, suggesting that the elimination of cardiac components from the thoracic transimpedance signal leads to a better estimation of UPF.

APOE -by-sex interactions on brain structure and metabolism in healthy elderly controls

Background The APOE effect on Alzheimer Disease (AD) risk is stronger in women than in men but its mechanisms have not been established. We assessed the APOE-by-sex interaction on core CSF biomarkers, brain metabolism and structure in healthy elderly control individuals (HC). Methods Cross-sectional study. HC from the Alzheimer’s Disease Neuroimaging Initiative with available CSF (n = 274) and/or 3T-MRI (n = 168) and/or a FDG-PET analyses (n = 328) were selected. CSF amyloid-β1–42 (Aβ1–42), total-tau (t-tau) and phospho-tau (p-tau181p) levels were measured by Luminex assays. We analyzed the APOE-by-sex interaction on the CSF biomarkers in an analysis of covariance (ANCOVA). FDG uptake was analyzed by SPM8 and cortical thickness (CTh) was measured by FreeSurfer. FDG and CTh difference maps were derived from interaction and group analyses. Results APOE4 carriers had lower CSF Aβ1–42 and higher CSF p-tau181p values than non-carriers, but there was no APOE-by-sex interaction on CSF biomarkers. The APOE-by-sex interaction on brain metabolism and brain structure was significant. Sex stratification showed that female APOE4 carriers presented widespread brain hypometabolism and cortical thinning compared to female non-carriers whereas male APOE4 carriers showed only a small cluster of hypometabolism and regions of cortical thickening compared to male non-carriers. Conclusions The impact of APOE4 on brain metabolism and structure is modified by sex. Female APOE4 carriers show greater hypometabolism and atrophy than male carriers. This APOE-by-sex interaction should be considered in clinical trials in preclinical AD where APOE4 status is a selection criterion.

Cannabis use and striatal D2 receptor density in untreated first-episode psychosis: An in vivo SPECT study

The biological basis of the association between cannabis-induced dopamine dysregulation and psychosis remains poorly understood. This (123)I-IBZM SPECT study assessed striatal dopamine D2 receptor (D2R) binding in 37 untreated first-episode psychosis (FEP) subjects, and 18 healthy controls. The aim was to examine if there were differences between FEP subjects with (n=14) and without (n=23) cannabis use in uptake ratios in the D2R. Striatal/Frontal cortex (S/F) uptake ratios were obtained. Healthy controls showed the lowest D2R binding ratios. No differences were found in S/F ratios between users and non-users, suggesting similar dopaminergic mechanisms underlying psychotic symptoms in both groups.

Individual renal function based on 99mTc dimercaptosuccinic acid uptake corrected for renal size.

BackgroundDecreased relative 99mTc dimercaptosuccinic acid (99mTc-DMSA) uptake can be a consequence of abnormal kidney size, associated with normal or impaired function. When there is a small kidney, relative 99mTc-DMSA uptake is decreased, and it is sometimes difficult to distinguish a small, normal kidney from a hypofunctioning kidney. Here, relative renal function was studied by quantifying the relative 99mTc-DMSA uptake corrected for renal size (RCU). MethodsFive hundred and fifty-five consecutive patients (184 adults) aged 1 month to 82 years (mean, 14.8 years) underwent a 99mTc-DMSA study for various renal diseases. Results were compared with the relative 99mTc-DMSA uptake without size correction (RUU). Visual evaluation of images was also performed. ResultsIn 288 patients (52%) the relative 99mTc-DMSA uptake was normal, either uncorrected or corrected, for renal size; in 184 (33%) it was abnormal by both quantification methods; and in 83 (15%) it was abnormal only by one method. Two hundred and fifty-seven patients (46%) presented with decreased RUU in one kidney, associated with a small kidney in 73 patients (13%). RCU was normal in all of these 73 patients (100%, P<0.0001). The sensitivity and specificity of RCU for evaluating renal function in relation to small renal size and with respect to RUU were 72% and 97%, with positive and negative predictive values of 95% and 80%, and an accuracy of 85%. Visual analysis of the 73 studies with decreased RUU and normal RCU showed a small, normal kidney on 55 occasions (75%), cortical scars in eight (11%), and impaired bilateral function in 10 (14%). Visual analysis of 10 studies with normal RUU and decreased RCU showed dilated pyelocalyceal system in seven occasions (70%) and normal kidneys in three (P<0.0001). ConclusionIt is concluded that relative 99mTc-DMSA uptake corrected for renal size is a more accurate method for assessing individual renal function. When there is a small kidney, relative 99mTc-DMSA uptake corrected for renal size can distinguish between a normal and a hypofunctioning kidney.

Evaluación de la respuesta terapéutica y PET-TAC: ¿realmente sólo importa el tamaño?

El criterio de evaluación de la respuesta al tratamiento de las neoplasias sólidas continúa siendo un tema controvertido. Desde los primeros intentos de estandarización de Moertel y sus colaboradores basados en la exploración fı́sica y la radiologı́a simple, se han ido proponiendo diversos modelos influidos principalmente por los avances tecnológicos en el diagnóstico por la imagen. En 1981 la Organización Mundial de la Salud (OMS) publicó los primeros criterios de respuesta tumoral principalmente dirigidos a ensayos clı́nicos. Se introdujeron conceptos de evaluación global del crecimiento tumoral tales como la comparación de la suma de medidas bidimensionales de las lesiones con respecto a estudios basales y la categorización de la respuesta como completa, parcial, enfermedad estable y progresión (tabla 1). Posteriormente diversos grupos de trabajo y laboratorios farmacéuticos modificaron estos criterios para acomodarlos a las nuevas tecnologı́as. Los Response Evaluation Criteria in Solid Tumors (RECIST) fueron publicados en el año 2000 en respuesta a las limitaciones de los de la OMS. Estos criterios ya se basaban en el TAC y la RM, especificando el número de lesiones que habı́a que valorar, diferenciando entre )lesiones diana* y )no diana*, implementando la medida unidimensional del diámetro máximo del tumor y diferenciando entre lesiones )medibles* y )no medibles*. Redefinı́an asimismo las categorı́as de respuesta al tratamiento. Cabe destacar la prácticamente nula referencia a conceptos de respuesta no morfológica basada en el PET. De manera prácticamente paralela al RECIST se propusieron los criterios de respuesta terapéutica de la European Organization for Research and Treatment of Cancer (EORTC), muy dirigidos a la radioterapia. En ellos ya se reconocı́a que la respuesta metabólica subclı́nica observada precozmente por PET (con o sin correlación morfológica) podı́a ser importante. Los tumores podı́an progresar no sólo por aumento de tamño, sino también por incrementos en los valores de standarized uptake value (SUV). Para valorar esta respuesta, no obstante, era esencial una metodologı́a estricta y reproducible en cuanto a la práctica e interpretación de los estudios.

99mTc-depreotide scintigraphy of bone lesions in patients with lung cancer

PurposeScintigraphy with 99mTc-depreotide, a somatostatin analogue–technetium ligand, has been used for evaluation of various malignant neoplasms, including lung cancer. The diagnosis of bone metastases in patients with lung cancer is not always definitive with current imaging methods. Visualisation of somatostatin receptors (SSTRs) in bone lesions, when the primary tumour exhibits such receptors, could be helpful in characterising them as metastatic. The aim of this study was to assess the value of 99mTc-depreotide in differentiating between benign and malignant bone lesions in patients with lung cancer.MethodsThe study population comprised 20 patients (17 males and three females, mean age 63 years) with proven lung cancer in whom bone lesions had been detected by conventional imaging methods. All patients underwent 99mTc-hydroxydiethylene diphosphonate and 99mTc-depreotide scintigraphy within 2 weeks. Bone lesions were classified as benign or malignant on the basis of clinical, imaging and/or histological criteria.Results99mTc-depreotide uptake in the primary tumour was seen in 19 of the 20 patients. Conventional imaging methods detected 55 bone lesions, 31 of which were classified as malignant. Twenty-eight (90%) of these lesions showed 99mTc-depreotide uptake, suggesting bone metastases, while three did not. Twenty-four bone lesions were classified as benign by conventional imaging methods, and none of them showed 99mTc-depreotide uptake. In addition, 99mTc-depreotide demonstrated extra-osseous lesions in six patients.Conclusion In patients with lung cancer and bone lesions, 99mTc-depreotide scintigraphy uptake in the bone lesions supports the diagnosis of malignancy, in particular if the primary lung tumour also exhibits SSTRs. Furthermore, whole-body 99mTc-depreotide scintigraphy may disclose extra-osseous disease.

Visualisation of sodium-iodide symporter.

A 60-year-old man with an 11-year history of mucinous adenocarcinoma of the salivary gland and a 4-year history of pulmonary metastases underwent pertechnetate (TcO4 ) scintigraphy of the thyroid gland. As abnormal pulmonary TcO4 − uptake was observed, whole-body (a) and thoracic SPECT-CT (b) studies were performed, which showed images of focal pulmonary tracer uptake matching radiological images of pulmonary metastases. At the time of these studies, tumour marker levels were: CA 19-9, 2,761 kU/l; CA-125, 1,170 kU/l; CA 15-3, 172 kU/l. The sodium-iodide symporter (NIS) is an integral plasma membrane glycoprotein involved in the active transport of iodide into the thyroid follicular cells [1, 2]. In addition to the thyroid gland, NIS is expressed in non-thyroid tissues, including salivary glands, stomach, thymus and breast [2, 3]. Recently, NIS has been proposed as a target for non-thyroid malignancies that express the symporter [4, 5]. Since the transport of pertechnetate, like that of iodide, is NISmediated, pertechnetate could have a role in the assessment of tumours derived from organs expressing NIS and their metastases.

Effect of REST on brain metabolism in the Alzheimer disease continuum

Effect of REST on Brain Metabolism in the Alzheimer Disease Continuum Oriol Dols-Icardo, MSc, Eduard Vilaplana, MSc, Frederic Sampedro, MSc, Daniel Alcolea, MD, Olivia Belbin, PhD, Valle Camacho, MD, Rafael Blesa, MD, PhD, Alberto Lle o, MD, PhD, Jordi Clarim on, PhD, and Juan Fortea, MD, PhD, for the Alzheimer’s Disease Neuroimaging Initiative Recently, Nho and colleagues showed that the minor allele of rs3796529, a nonsynonymous polymorphism in the REST gene, was protective against medial temporal lobe (MTL) atrophy in APOE e3/e3 individuals across the Alzheimer disease (AD) continuum and, specifically, in patients with mild cognitive impairment (MCI). However, the possible protective effect

The impact of bilingualism on brain structure and function in Huntington's disease

INTRODUCTION Bilingualism exerts neuroprotective effects against neurodegeneration. In Huntingtons disease (HD), the systems involved in bilingual control show early compromise, but the effect of bilingualism on the course of HD is unknown. METHODS We addressed the impact of livelong use of bilingualism on the clinical features, brain structure and function in 30 early-mild stage HD patients. Using voxel-wise regression analysis, we explored the effect of levels of use of bilingualism on grey-matter volume (GMV) and 18F-FDG metabolism. RESULTS Higher use of bilingualism was associated with better performance in inhibitory control and set-shifting independently of age and education and with higher GMV in the inferior frontal gyrus. 18F-FDG data revealed a significant effect on multiple fronto-temporal regions, specifically, in the dorsal anterior cingulate cortex, the anterior insula, the ventromedial orbital prefrontal cortex and the inferior frontal gyrus. These changes contributed to better inhibitory control and set-shifting and to more preserved motor and functional capacity. CONCLUSION In HD, lifelong use of bilingualism is associated with structural and metabolic brain changes that have an impact on cognition, movement and functionality. These findings highlight the importance of stimulating cognitive and brain reserve in HD and in other neurodegenerative conditions.