Biomedical subjects

Francisco Lomeña

Publications and source records attributed to Francisco Lomeña.

17 recordsLinked to original sources

PubMed2006

Dopamine transporter (DAT) genotype (VNTR) and phenotype in extrapyramidal symptoms induced by antipsychotics.

INTRODUCTION: Impaired dopamine transporter (DAT) function may be involved in antipsychotic (AP)-induced extrapyramidal symptoms (EPS). A polymorphism involving a variable number of tandem repeats (VNTR) has been described in the DAT gene (SLC6A3). OBJECTIVE: We studied whether the SLC6A3 VNTR polymorphism is a risk or protection factor for AP-induced EPS. We also investigated the relationship between the polymorphism and DAT availability in the schizophrenic patient's brain. METHODS: Sixty-one patients receiving AP therapy participated in the EPS study. Of these, thirty-two cases presented EPS (Simpson-Angus >3) and twenty-nine without EPS (Simpson-Angus < or =3). The DAT expression was studied in fifteen AP-naive patients by [(123)I] FP-CIT SPECT. RESULTS: No significant differences were observed for the more common alleles ((*)9R and (*)10R) or for genotype frequencies between patients with EPS and those without EPS. The frequency of the (*)9R and (*)10R alleles was similar to that described in other European populations. There were no significant differences in striatal DAT binding among the three major VNTR genotype groups. CONCLUSIONS: Our results suggest that the VNTR polymorphism did not influence AP-induced EPS and did not affect DAT gene expression or protein function.

Adult↗

PubMed2006

Lower striatal dopamine transporter binding in neuroleptic-naive schizophrenic patients is not related to antipsychotic treatment but it suggests an illness trait.

INTRODUCTION: Drug induced parkinsonism (DIP) is directly related to dopamine D2 receptor blockade. However, there are many references describing parkinsonian signs (PS) in naive-patients. In our previous study, we observed lower DAT binding in a group of first-episode schizophrenic patients after short-term treatment with risperidone, compared with age-matched healthy controls. AIM: To clarify if DAT decrease could be an illness trait, excluding the effect of antipsychotics on DAT availability, and to determine whether DAT availability before treatment with antipsychotics may predict subsequent development of PS. MATERIALS AND METHODS: A new series of 20 neuroleptic-naive schizophrenic patients and 15 healthy subjects was recruited. SPECT with [(123)I] FP-CIT (DaTSCAN(R)) was performed before starting antipsychotics and after 4 weeks of treatment. PS and psychopathological status were assessed by the Simpson-Angus (SAS), CGI and PANSS scales. Quantitative analyses of SPECTs were performed using ROIs placed in the caudate, putamen and occipital cortex. RESULTS: Schizophrenic patients showed lower DAT binding compared with the healthy subjects at baseline (p<0.001) and after a 4-week-treatment period (p=0.001). Six out of eight schizophrenic patients of the DIP group were symptomatic for PS at baseline, in comparison to two out of 12 in the NoDIP group. Nonetheless, no differences were observed on DAT between DIP and NoDIP, neither at baseline (p=0.360) nor at endpoint (p=0.984). Finally, no differences between baseline-endpoint DAT binding were observed, neither in the DIP group (p=0.767) nor in the NoDIP group (p=0.093). CONCLUSION: Our new series of first-episode naive-schizophrenic patients (1) points out DAT dysfunction as an illness trait due to the significantly lower DAT binding in schizophrenic patients in comparison to healthy subjects; (2) supports the results of other authors who describe PS in never-treated patients; (3) confirms that [(123)I] FP-CIT does not allow us to predict which patients will develop parkinsonism due to the lack of differences between DIP and NoDIP patients; and (4) confirms a null effect of antipsychotics on DAT due to the lack of differences in [(123)I] FP-CIT before and after a 4-week-treatment period.

Adult↗

PubMed2006

Usefulness of 18-fluorodeoxyglucose positron emission tomography in the evaluation of tumor cardiac thrombus from renal cell carcinoma.

PURPOSE: Retrospectively analysed our experience in Renal Cell carcinoma (RCC) patients studied with 18-Fluorodeoxyglucose Positron Emission Tomography (FDG PET) to rule out the incidence and clinical impact of heart metastases. MATERIAL AND METHODS: In two years, 37 patients with RCC were studied with FDG PET. 10 were studied for initial staging and 27 patients were evaluated for suspected recurrence or re-staging. RESULTS: In two patients (5%), PET scan showed pathological focal uptake in myocardium. On the bases of this finding, MRI was performed visualizing a myocardial mass in both lesions and confirmed by histology in one of them. The hypothesis of prolepses of the tumour by thrombus in RCC patients justified the surgery. CONCLUSION: Whole-body FDG PET in RCC patients could help to diagnose cardiac metastasis, and allows the possibility of therapeutic surgery, due to the thrombus significance of heart involvement.

Carcinoma, Renal Cell↗

PubMed2006

Relation of left ventricular hypertrophy to regional cerebral blood flow: single photon emission computed tomography abnormalities in essential hypertension.

Several reports have shown that left ventricular hypertrophy (LVH) is an independent predictor of acute cerebrovascular events. The aim of the present study was to investigate the relationship between LVH and cerebral blood flow in middle-aged patients with essential hypertension. Forty never-treated hypertensive patients (24 men, 16 women, aged 50-60 years) without clinical evidence of target organ damage were studied. Regional cerebral blood flow was measured by means of single photon emission computed tomography of the brain. Twenty-nine patients showed echocardiographic criteria of LVH; 11 patients did not show this feature. No differences were found in regional cerebral blood flow ratio of all brain areas studied between hypertensives with or without LVH except for the striatum area. The regional cerebral blood flow ratio was significantly reduced in the striatum region of hypertensive patients with LVH, compared with patients without LVH (91.5+/-7.4 vs 98.1+/-8.3; P=.023). This relationship remained significant after adjusting for blood pressure. The authors conclude that the presence of LVH in middle-aged patients with essential hypertension is associated with a reduction of regional cerebral blood flow in the striatum area.

Blood Pressure↗

PubMed2006

Intravenous furosemide injection during 18F-FDG PET acquisition.

UNLABELLED: Urinary-system elimination of (18)F-FDG can be mistaken for pathologic uptake. Furosemide helps eliminate this artifact. Unnecessary administration should be avoided. Our approach obviates furosemide administration and other invasive procedures in many cases. METHODS: Thirty-seven cancer patients referred for PET to evaluate treatment response or suspected recurrence were prospectively studied using whole-body scanning, with (18)F-FDG injected via dorsal hand catheter beforehand. The catheter was left in place to enable injection of furosemide while the patient was inside the scanner. After abdominopelvic scanning, physicians evaluated the need to inject furosemide. Thirty minutes after furosemide injection, another abdominopelvic scan was obtained to detect postinjection urinary tract changes. RESULTS: Postfurosemide images showed effects due to physiologic elimination in 24 patients (64.9%), of whom 11 patients (45.8%) had more than one inconclusive prefurosemide finding. In 13 patients (35.1%), delayed images confirmed persistent lymph node uptake, including 3 patients (23.1%) with 1 lesion. CONCLUSION: Furosemide injection during scanning reduces artifacts, shortens examinations, and helps avoid invasive procedures.

Abdominal Neoplasms↗

PubMed2005

Decreased striatal dopamine transporter binding assessed with [123I] FP-CIT in first-episode schizophrenic patients with and without short-term antipsychotic-induced parkinsonism.

RATIONALE: Drug-induced parkinsonism (DIP) is one of the main causes of treatment drop-out in schizophrenic patients causing a high incidence of relapse that leads patients to a bad clinical prognosis. The dopaminergic nigrostriatal pathway is involved in the movement control, so the study of the dopamine transporter (DAT) could be of great value to determine its implication in the appearance of DIP. OBJECTIVE: The goal of the study is to determine the striatal DAT binding assessed with [(123)I] FP-CIT SPECT in first-episode neuroleptic-naive schizophrenic in-patients with DIP after short-term antipsychotic treatment. METHOD: The [(123)I] FP-CIT binding ratios of ten schizophrenic in-patients who developed DIP during the first 4-week period of risperidone treatment (6+/-2 mg/day) were compared with ten schizophrenic in-patients treated with the same doses of risperidone and who do not developed DIP and with ten age-matched healthy subjects. Quantitative analyses of SPECTs were performed using regions of interest located in caudate, putamen and occipital cortex. Parkinsonism was assessed by the Simpson-Angus Scale and the psychopathological status by the Clinical General Impression and Positive and Negative Syndrome Scales. RESULTS: Whole striatal [(123)I] FP-CIT binding ratios were significantly lower in patients with and without DIP than in healthy subjects (p<0.001). This was also observed in whole putamen (p<0.001) and caudate nucleus (p<0.001). Females showed higher whole striatal [(123)I] FP-CIT binding ratios than males (p<0.05). No differences in psychopathological scales were observed between patients with and without DIP. CONCLUSION: Our first-episode schizophrenic patients with and without DIP after short-term risperidone treatment have a decreased striatal DAT binding assessed with [(123)I] FP-CIT. This alteration could be related to the schizophrenic disease or may be secondary to the antipsychotic treatment.

Adult↗

PubMed2005

Therapeutic immunization with dendritic cells loaded with heat-inactivated autologous HIV-1 in patients with chronic HIV-1 infection.

Therapeutic immunization with autologous monocyte-derived dendritic cells (DCs) loaded with heat-inactivated autologous human immunodeficiency virus type 1 (HIV-1) in 12 patients with chronic HIV-1 infection who were receiving highly active antiretroviral therapy (HAART) was feasible, safe, and well tolerated. Virus was obtained during an initial interruption of HAART (hereafter, "stop 1") so that DCs could be pulsed. After immunization and a second interruption of HAART (hereafter, "stop 2"), set-point plasma viral load (PVL; 24 weeks after stop 2) decreased > or =0.5 log(10) copies/mL relative to baseline PVL in 4 of 12 patients. We observed a significant lengthening in mean doubling time of PVL rebound and significant decreases in the area under the curve and the mean peak of PVL rebound after stop 2, compared with those after stop 1. This response was associated with changes in HIV-1-specific CD4(+) lymphoproliferative and CD8(+) T cell responses. These changes were not observed in a group of nonimmunized control patients.

AIDS Vaccines↗

PubMed2005

Neuropsychological disturbances and cerebral blood flow in bipolar disorder.

OBJECTIVE: To determine and correlate alterations in neuropsychological function and cerebral blood flow in bipolar patients. METHOD: Assessments included the Positive and Negative Symptom Scale, Global Assessment Functioning, Wechsler Adult Intelligence Scale (WAIS), Wisconsin Card Sorting Test (WCST), Stroop test, Trail Making Test (TMT), California Verbal Learning Test (CVLT), Wechsler Memory Scale (WMS) and phonetic verbal fluency/controlled oral word association tests. Single photon emission computed tomography (SPECT) was carried out with the administration of 99mTc-HMPAO. Forty-three outpatients out of 85 fulfilling RDC diagnostic criteria for bipolar disorder and six healthy subjects were included in the study. SPECT and neuropsychological assessments were performed in 30 patients in manic (n = 7), hypomanic (n = 8), depressed (n = 12) or euthymic (n = 3) states. All assessments were carried out before starting treatment. RESULT: Several corrected correlations between neuropsychological function and cerebral blood flow (CBF) were identified: executive function (WCST) and striatal, frontal, temporal, cerebellum, parietal and cingulate CBF; memory (WMS, WAIS-Digits) and striatal, frontal, temporal and parietal CBF; attentional tasks (Stroop) and striatal, temporo-medial and parietal CBF; verbal learning (CVLT) and frontal, posterior temporal, cingulate and occipital CBF; psychomotor disturbances (TMT) and anterior temporal CBF; poorer intelligence performance scores (WAIS-Vocabulary) and cerebellum and parietal CBF. CONCLUSIONS: This study confirms the presence of functional disturbances in fronto-subcortical structures, the cerebellum and limbic system in bipolar patients.

Adult↗

PubMed2005

Absolute quantification in dopaminergic neurotransmission SPECT using a Monte Carlo-based scatter correction and fully 3-dimensional reconstruction.

UNLABELLED: Dopamine transporter (DAT) ligands have been developed for in vivo imaging of the dopaminergic system in SPECT. Although the visual analysis of SPECT images is, in general, suitable for clinical assessment, the accurate quantification of the striatal uptake might increase the sensitivity of the technique and help in the early diagnosis, follow-up, and eventual treatment response of Parkinson's disease (PD). This work is focused on assessment of the quantification of specific uptake of (99m)Tc-DAT ligands when compensation for all degrading phenomena is performed. METHODS: The SimSET Monte Carlo (MC) code was used to generate a set of SPECT projections of a numeric striatal phantom with different specific uptake ratios (SURs). An absolute quantification method (AQM), which performs a MC-based scatter compensation and a fully 3-dimensional (3D) reconstruction, was implemented. The scatter estimate was included in the reconstruction algorithm. RESULTS: The use of attenuation, point-spread-function (PSF), and scatter corrections resulted in an improvement in the value of the SUR of 37% on average with respect to the reconstruction without corrections. The magnitude of each improvement corresponded to 7% for the attenuation correction, 12% for the PSF correction using a 2-dimensional reconstruction algorithm and a further 11% for the PSF correction using a 3D reconstruction algorithm, and 7% for the scatter correction. CONCLUSION: Our findings indicate that the PSF correction plays a major role in the quantification of striatal uptake in comparison with the attenuation correction and the scatter correction. The implemented method also provides an absolute quantification procedure based on MC methods that do not depend on empiric approximations. The relative quantification results using the proposed AQM accounted for 96%-97% of the nominal SUR, whereas the limit achieved using only primary photons attained 98%-99%. The volumetric activity values obtained using the AQM converged toward the nominal values.

Algorithms↗

PubMed2004

Clinical value of 99mTc-HMPAO SPECT in depressed bipolar I patients.

Regional cerebral blood flow was studied in 17 bipolar I depressed patients (DSM-IV criteria) with single photon emission computed tomography (SPECT). Visual analysis of images revealed no abnormality in eight patients and abnormal findings in nine patients. In the nine patients with abnormal findings, all showed regional decreases of the uptake of (99m)Tc-D,L-hexamethylpropylene amine oxime (HMPAO, four in the frontal region, two in the basal ganglia, and three in both the frontal region and the basal ganglia). The patients with visible SPECT abnormalities had significantly higher scores on the Hamilton Rating Scale for Depression (HDRS).

Adult↗

PubMed2004

Lack of sex differences in striatal dopamine D2 receptor binding in drug-naive schizophrenic patients: an IBZM-SPECT study.

Differences in antipsychotic treatment response, clinical course and outcome of schizophrenia could be related to gender-related cerebral differences in anatomy and function. The aim of the study was to assess sex differences in the striatal dopamine D2 receptor binding in 15 drug-naive schizophrenic patients (seven males, eight females) using (123)I-IBZM single photon emission computed tomography. Basal ganglia/frontal cortex (BG/FC) uptake ratios were obtained. No significant differences were found in global, left and right BG/FC ratios or laterality indices between males and females. No correlation was found between BG/FC ratios and age, duration of illness or scores on symptom rating scales. Our data indicate a lack of sex differences in striatal D2 receptor binding in drug-naive schizophrenic patients and do not support previous reports of left lateralized striatal asymmetry in male schizophrenic patients.

Adult↗

PubMed2004

Prognostic value of frontal functional neuroimaging in late-onset severe major depression.

BACKGROUND: There is growing evidence of a relationship between frontal neuroimaging and neuropsychological abnormalities and the physiopathology and course of late-onset major depression. AIMS: To assess acute antidepressant response in late-onset major depression in relation to baseline frontal perfusion ratios. METHOD: A 99mTc HMPAO single photon emission computed tomographic brain scan was performed in medication-free patients with late-onset major depression, who were then included in a 12-week antidepressant treatment regimen. Logistic regression was used to define a predictive model of non-remission. RESULTS: A total of 47 patients completed the study, 34 of whom were classed as remitters and 13 as non-remitters. The variable left anterior fronto-cerebellar perfusion ratio had a global predictive power of 87%. Analysing this variable together with the baseline variables age of onset and duration of index episode, the predictive power of the model rose to 94%. CONCLUSIONS: Our study suggests that a specific frontal functioning could predict the acute antidepressant response in late-onset severe major depression.

Age of Onset↗

PubMed2004

Frontal cerebral perfusion after antidepressant drug treatment versus ECT in elderly patients with major depression: a 12-month follow-up control study.

BACKGROUND: Little is known about the evolution of brain perfusion alterations in patients with major depression, and still less about the changes in functional neuroimage produced by different antidepressant biological treatments. METHOD: Between January 2001 and December 2003, long-term follow-up frontal brain perfusion was compared in 2 subgroups of elderly patients (>or= 60 years) treated for severe unipolar major depression (DSM-IV): one subgroup of 16 patients administered electroconvulsive therapy, and another of 26 patients receiving pharmacologic treatment. All patients were remitters. A medication-free brain single photon emission computed tomography was performed in baseline conditions and after a minimum period of 12 months of euthymia. Twenty-eight age- and sex-matched healthy controls were also assessed. RESULTS: No significant differences were found between the 2 subgroups in frontal uptake ratios after a 12-month follow-up period of euthymia. During the acute episode, patients presented significant anterior hypofrontality; 12 months later the hypofrontality had disappeared. CONCLUSION: The long-term evolution of frontal perfusion in elderly major depressives who respond to antidepressant biological treatment is essentially the same in those who receive electroconvulsive therapy and in those who receive medication.

Aged↗

PubMed2003

Striatal dopamine D2 receptor density in neuroleptic-naive and in neuroleptic-free schizophrenic patients: an 123I-IBZM-SPECT study.

Most post-mortem autoradiographic studies have described striatal dopamine D(2) receptor up-regulation due to chronic neuroleptic exposure. The aim of our study was to compare in-vivo striatal D(2) receptor density in neuroleptic-naive and neuroleptic-free schizophrenic patients. We included 28 young (mean age: 28+/-8 years) acute psychotic patients meeting DSM-IV criteria for schizophrenia or schizophreniform disorder. Enrolled patients were either first-episode neuroleptic-naive (n=12) or neuroleptic-free (n=16) after a minimum washout period of 7 days. All neuroleptic-free subjects had previously received neuroleptic treatment for a median period of 3.5 years. Both groups were evaluated using standard clinical scales. In-vivo striatal D(2) receptor binding was assessed by basal ganglia/frontal cortex ratios using (123)I-IBZM SPECT. No statistically significant differences were found in age or clinical assessment between neuroleptic-naive and neuroleptic-free schizophrenic patients. No differences were found in the basal ganglia/frontal cortex ratios of neuroleptic-naive (1.78+/-0.11) and neuroleptic-free (1.81+/-0.15) patients. No striatal uptake laterality was observed in either group. No correlation was demonstrated between BG/FC ratios and duration of illness, period of neuroleptic exposure or time of drug washout. We conclude that our neuroleptic-naive and neuroleptic-free schizophrenic patients did not show differences in striatal D(2) receptor binding, suggesting that IBZM-SPECT fails to detect D(2) receptor up-regulation induced by chronic exposure to neuroleptic drugs.

Adult↗

PubMed2003

Iterative reconstruction with correction of the spatially variant fan-beam collimator response in neurotransmission SPET imaging.

The dopamine transporter (DAT) has been shown to be a sensitive indicator of nigrostriatal dopamine function. Although visual inspection is often sufficient to assess DAT imaging, quantification could improve the diagnostic accuracy of single-photon emission tomography (SPET) studies of the dopaminergic system. The aim of this study was to assess the accuracy of quantification of the striatal/background uptake ratio when correction for attenuation, scatter and spatially variant fan-beam collimator response is performed in technetium-99m and iodine-123 SPET imaging. A numerical striatal phantom was implemented, and simulated projections of low-energy photons were obtained by using the SimSET Monte Carlo code. High-energy contamination in 123I studies was modelled from experimental measurements with 99mTc and 123I. The ordered subsets expectation maximisation (OSEM) algorithm was employed in reconstruction. Mean improvements of 8% and 16% were obtained in the calculated striatal/background uptake ratio in the putamen and the caudate, respectively, when the spatially variant point spread function was included in the transition matrix. Ideal scatter correction resulted in improvements in the putamen and caudate of 9% for 99mTc agents and 19% for 123I agents. Improvements averaged 31% in the putamen and 43% in the caudate when correction for attenuation, scatter and spatially variant collimator response was included in the reconstruction.

Algorithms↗

PubMed2002

Normalization of frontal cerebral perfusion in remitted elderly major depression: a 12-month follow-up SPECT study.

We examined global and regional cerebral blood flow abnormalities in a group of unmedicated nondemented elderly late-onset unipolar major depressed patients in acute depression and in remission (after a 12-month follow-up period). 35 somatic treatment remitter patients over the age of 60 years and 20 sex-, age-, and vascular risk factor-matched healthy controls were imaged with single photon emission computed tomography, using technetium-99m hexamethylpropylene amine oxime as a tracer. In depression, the depressed group had significantly lower uptake in the left anterior frontal region than the control group. In remission, the left frontal cerebral perfusion abnormalities disappeared, and there were no significant differences in uptake between controls and patients. No significant correlations were found between baseline clinical characteristics of patients and their regional cerebral perfusion at baseline or after a 12-month follow-up. These findings are consistent with the hypothesis that certain neuroanatomic regions of the central nervous system may be functionally and reversibly involved in unipolar major depression, particularly in the late-onset subgroup.

Aged↗

PubMedDate not supplied

[About PET-CT...].

Explore the source record for details and available documents.

Humans↗