Diagnostic delay and outcome in immunocompetent patients with primary central nervous system lymphoma in Spain: a multicentric study.

INTRODUCTION: To assess the management of immunocompetent patients with primary central nervous system lymphomas (PCNSL) in Spain. METHODS: Retrospective analysis of 327 immunocompetent patients with histologically confirmed PCNSL diagnosed between 2005 and 2014 in 27 Spanish hospitals. RESULTS: Median age was 64 years (range: 19-84; 33% ≥ 70 years), 54% were men, and 59% had a performance status (PS) ≥ 2 at diagnosis. Median delay to diagnosis was 47 days (IQR 24-81). Diagnostic delay > 47 days was associated with PS ≥ 2 (OR 1.99; 95% CI 1.13-3.50; p = 0.016) and treatment with corticosteroids (OR 2.47; 95% CI 1.14-5.40; p = 0.023), and it did not improve over the years. Patients treated with corticosteroids (62%) had a higher risk of additional biopsies (11.7% vs 4.0%, p = 0.04) but corticosteroids withdrawal before surgery did not reduce this risk and increased the diagnostic delay (64 vs 40 days, p = 0.04). Median overall survival (OS) was 8.9 months [95% CI 5.9-11.7] for the whole series, including 52 (16%) patients that were not treated, and 14.1 months (95%CI 7.7-20.5) for the 240 (73.4%) patients that received high-dose methotrexate (HD-MTX)-based chemotherapy. Median OS was shorter in patients ≥ 70 years (4.1 vs. 13.4 months; p < 0.0001). Multivariate analysis identified age ≥ 65 years, PS ≥ 2, no treatment, and cognitive/psychiatric symptoms at diagnosis as independent predictors of short survival. CONCLUSIONS: Corticosteroids withdrawal before surgery does not decrease the risk of a negative biopsy but delays diagnosis. In this community-based study, only 73.4% of patients could receive HD-MTX-based chemotherapy and OS remains poor, particularly in elderly patients ≥ 70 years.

Orphan Formulations in Pediatric Schistosomiasis Treatment: Development and Characterization of Praziquantel Nanoparticle-Loaded Powders for Reconstitution.

Praziquantel is a broad spectrum antihelmintic agent and represents the drug of choice for the treatment of schistosomiasis. However, its low aqueous solubility and strong bitter taste highly affect the bioavailability and compliance in pediatric patients. Thus, the purpose of this study was to develop a dry nanosuspension, by a combination of high-pressure homogenization and spray drying, intended for redispersion in a pleasant taste vehicle for extemporaneous use. Three formulations, varying stabilizers to drug ratio, were developed and characterized in terms of particle size distribution, crystallinity, morphology, in vitro dissolution, and sedimentation-redispersibility behavior. A significant reduction in particle size was achieved after the high-pressure homogenization process, and the nanoparticles were further microencapsulated by spray drying technique. The redispersed dried powders exhibited a conserved particle size distribution (in the nanometric range) and certain crystallinity extent, with satisfactory redispersion ability. Besides, the enhancement of the dissolution performance obtained after comminution was conserved, even after drying and redispersion of the extemporaneous powdered formulation. In conclusion, the developed nanoparticle-loaded powders comprise an interesting tool for the administration of praziquantel to preschool-age children.

The structure of schizotypal personality traits: a cross-national study.

BACKGROUND: Schizotypal traits are considered a phenotypic-indicator of schizotypy, a latent personality organization reflecting a putative liability for psychosis. To date, no previous study has examined the comparability of factorial structures across samples originating from different countries and cultures. The main goal was to evaluate the factorial structure and reliability of the Schizotypal Personality Questionnaire (SPQ) scores by amalgamating data from studies conducted in 12 countries and across 21 sites. METHOD: The overall sample consisted of 27 001 participants (37.5% males, n = 4251 drawn from the general population). The mean age was 22.12 years (s.d. = 6.28, range 16-55 years). The SPQ was used. Confirmatory factor analysis (CFA) and Multilevel CFA (ML-CFA) were used to evaluate the factor structure underlying the SPQ scores. RESULTS: At the SPQ item level, the nine factor and second-order factor models showed adequate goodness-of-fit. At the SPQ subscale level, three- and four-factor models displayed better goodness-of-fit indices than other CFA models. ML-CFA showed that the intraclass correlation coefficients values were lower than 0.106. The three-factor model showed adequate goodness of fit indices in multilevel analysis. The ordinal α coefficients were high, ranging from 0.73 to 0.94 across individual samples, and from 0.84 to 0.91 for the combined sample. CONCLUSIONS: The results are consistent with the conceptual notion that schizotypal personality is a multifaceted construct and support the validity and utility of SPQ in cross-cultural research. We discuss theoretical and clinical implications of our results for diagnostic systems, psychosis models and cross-national mental health strategies.

Seizure-susceptible brain regions in glioblastoma: identification of patients at risk.

BACKGROUND AND PURPOSE: The main aim of this study was to identify which patients with glioblastoma multiforme (GBM) have a higher risk of presenting seizures during follow-up. METHODS: Patients with newly diagnosed GBM were reviewed (n = 306) and classified as patients with (Group 1) and without (Group 2) seizures at onset. Group 2 was split into patients with seizures during follow-up (Group 2A) and patients who never had seizures (Group 2B). The anatomical location of GBM was identified and compared by voxel-based lesion symptom mapping (discovery set). Seizure-susceptible brain regions obtained were assessed visually and automatically in external GBM validation series (n = 85). RESULTS: In patients with GBM who had no seizures at onset, an increased risk of presenting seizures during follow-up was identified in the superior frontal and inferior occipital lobe, as well as in inferoposterior regions of the temporal lobe. Conversely, those patients with GBM located in medial and inferoanterior temporal areas had a significantly lower risk of suffering from seizures during follow-up. Additionally, the seizure-susceptible brain region maps obtained classified patients in the validation set with high positive and negative predictive values. CONCLUSIONS: Tumor location is a useful marker to identify patients with GBM who are at risk of suffering from seizures during follow-up. These results may help to support the use of antiepileptic prophylaxis in a selected GBM population and to improve stratification in antiepileptic clinical trials.

The role of stress-regulation genes in moderating the association of stress and daily-life psychotic experiences.

OBJECTIVE: The interaction of single nucleotide polymorphisms with both distal and proximal environmental factors across the extended psychosis phenotype is understudied. This study examined (i) the interaction of relevant SNPs with both early-life adversity and proximal (momentary) stress on psychotic experiences (PEs) in an extended psychosis sample; and (ii) differences between early-psychosis and non-clinical groups for these interactions. METHODS: Two hundred and forty-two non-clinical and 96 early-psychosis participants were prompted randomly eight times daily for 1 week to complete assessments of current experiences, including PEs and stress. Participants also reported on childhood trauma and were genotyped for 10 SNPs on COMT, RGS4, BDNF, FKBP5, and OXTR genes. RESULTS: Unlike genetic variants, distal and proximal stressors were associated with PEs in both samples and were more strongly associated with PEs in the early-psychosis than in the non-clinical group. The RGS4 TA and FKBP5 CATT haplotypes interacted with distal stress, whereas the A allele of OXTR (rs2254298) interacted with proximal stress, increasing momentary levels of PEs in the early-psychosis group. No interactions emerged with COMT or BDNF variants. CONCLUSION: Individual differences in relevant stress-regulation systems interact with both distal and proximal psychosocial stressors in shaping the daily-life manifestation of PEs across the psychosis continuum.

Fluorimetric screening assay for protein carbonyl evaluation in biological samples.

Many assays are available for the detection of protein carbonyls (PCs). Currently, the measurement of PC groups after their derivatization with 2,4-dinitrophenol hydrazine (DNPH) is widely used for measuring protein oxidation in biological samples. However, this method includes several washing steps. In this context, we have developed a rapid, sensitive, and accurate fluorimetric method adapted to 96-well microplates for the convenient assessment of protein carbonyl level in biological samples. The method reported here is based on the reaction of carbonyl content in proteins with 7-hydrazino-4-nitrobenzo-2,1,3-oxadiazole (NBDH) to form highly fluorescent derivatives via hydrazone formation. PCs were determined using the DNPH and NBDH assays in fully reduced bovine serum albumin (BSA) and plasma and liver homogenates obtained from healthy control rats up the addition of various amounts of HOCl-oxidized BSA (OxBSA). Using the NBDH assay, PC concentrations as low as 0.2 nmol/mg were detected with precision as low as 5%. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectroscopy was used to successfully identify the formation of the NBDH adducts after derivatization with standard oxidized peptides. Finally, the two methods were further used for PC determination in plasma and liver samples from diabetic and normal rats, showing that the NBDH assay can be reliably used in biological experiments.

Copper clusters as novel fluorescent probes for the detection and photocatalytic elimination of lead ions.

A new homogeneous assay for a fast, selective and sensitive detection and elimination of lead ions has been developed using copper clusters as novel fluorescent probes in aqueous solutions. At the same time, their elimination is achieved using the efficient photocatalytic activity of such clusters. Both effects are explained in terms of an efficient electron transfer due to the LUMO energy of the cluster overlapping with the ion redox potential. The mechanism, which allows the explanation of previously reported results for different types of metal clusters, is further confirmed using smaller and larger Cu clusters displaying non-selective and non-quenching luminescence in the presence of different cations.

Management of patients with localized prostate cancer and biochemical recurrence in Spain: A medical survey.

INTRODUCTION: The management of patients with prostate cancer (PCa) is established in clinical practice guidelines, which are based on randomized studies according to the level of evidence. In Spain, the degree of compliance with these guidelines in clinical practice is unknown. OBJECTIVES: To describe the profiles of PCa patients at the time of diagnosis and the management of patients with localized PCa and those with BCR in Spain. MATERIALS & METHODS: A medical survey was conducted in specialized care (85 urologists [UROs], 64 radiation oncologists [ROs], and 21 medical oncologists [MOs]). Three questionnaires were developed for this study with 22 (UROs and ROs) or 21 questions (MOs). RESULTS: The annual incidence of PCa was 24,057 in participating hospitals (N = 131). The extrapolated annual incidence in Spain is 40,531 cases. The estimated prevalence of PCa in Spain is 221,689. Of note, 79% and 80% of patients seen by UROs and ROs, respectively had localized PCa at diagnosis. Biopsy was the most used diagnostic test among the three specialties, followed by abdominopelvic computer tomography. More than 90% of patients with BCR underwent standard tests. Next generation imaging tests and PET-choline/PSMA are still used residually. Most patients with localized PCa are currently treated with either surgery or radiotherapy, while for BCR patients, UROs and ROs prefer radiotherapy and MOs androgen deprivation therapy alone or in combination. CONCLUSION: This study describes patient profiles at the time of diagnosis and provides an overview of the current therapeutic management of localized PCa and BCR in clinical practice in Spain.

Visual and semi-quantitative analysis of 6-[18F]FDOPA PET/CT in patients with brain tumors and suspected tumor recurrence versus radionecrosis.

INTRODUCTION: Amino acid PET is a tool recommended by the main neuroimaging societies in the differential diagnosis between radionecrosis (RNC) and umour recurrence (TR) in brain tumours, but its use in our country is still limited. The aim of this work is to present our experience with 6-[18F]FDOPA PET/CT (FDOPA) in brain tumours (primary and M1), comparing these results with other published results. MATERIAL AND METHODS: Retrospective study of 62 patients with suspected tumour recurrence (TR): 42 brain metastases (M1) and 20 primary, who underwent FDOPA. Images were analysed visually and semi-quantitatively, obtaining SUVmax and SUVmaxlesion/SUVmaxstriatum (L/S) and SUVmaxlesion/SUVmaxcortex (L/C) ratios. The diagnostic validity of PET was analysed and the best performing cut-off points were calculated. PET results were compared with clinical-radiological follow-up and/or histopathology. RESULTS: TR was identified in 49% of M1 and 76% of brain primaries. The best performing FDOPA interpretation was visual and semi-quantitative, with a sensitivity and specificity in primaries of 94% and 80% and in M1s of 96% and 72% respectively. The cut-off points with the best diagnostic performance were L/C1.44 in M1 and L/C1.55 in primaries. There are discrepant results with other published results. CONCLUSION: FDOPA PET/CT is a useful tool in the differential diagnosis between recurrence and RNC in brain tumours. It is needed a standardization to contribute to homogenise FDOPA results a inter-centre level.

A derivative of ascorbic acid modulates cAMP production.

We reported, in previous experiments, that AA is a global regulator of cAMP pools. In this study, we demonstrate that K873, an analog of AA we synthesized and presenting antiproliferative properties, has also an impact on cAMP production. However, K873 has no antioxidant activity, at the contrary of AA. It definitively demonstrates that action of AA on the cAMP production is not linked to antioxidant activity. These data suggest that AA, and derivatives of this molecule, could be promising drug acting on biological processes that are under the control of cAMP dependent pathway.

Imaging of Lymphomas Involving the CNS: An Update-Review of the Full Spectrum of Disease with an Emphasis on the World Health Organization Classifications of CNS Tumors 2021 and Hematolymphoid Tumors 2022.

Lymphomas of the CNS are the second most frequent primary brain malignancy in adults after gliomas. Presurgical suspicion of lymphoma greatly impacts patient management. The radiologic features of this tumor have been widely covered in the literature for decades, but under current classifications, mainly corresponding to the most common presentations of the most frequent type: primary diffuse large B-cell lymphoma of the CNS. Nevertheless, rarer presentations of this specific lymphoma and of other World Health Organization lymphoma subtypes with different imaging features are rarely treated. Moreover, important advances in imaging techniques, changing epidemiologic factors with relevant impact on these tumors (eg, immunodeficiency/dysregulation), and recent updates of the World Health Organization Classification of CNS Tumors 2021 and Hematolymphoid Tumors 2022 may have rendered some accepted concepts outdated. In this article, the authors aim to fulfill a critical need by providing a complete update-review, emphasizing the latest clinical-radiologic features of the full spectrum of lymphomas involving the CNS.

Association between Hashimoto's thyroiditis and melanoma: a retrospective matched cohort study.

An inflammatory microenvironment has been shown to increase risk for malignant melanoma, suggesting that melanoma may be related to a pro-inflammatory state. Though Hashimoto's thyroiditis is one of the most common autoimmune diseases, there are no investigations of its relationship with melanoma. We aim to determine if Hashimoto's increases risk of developing melanoma. A retrospective, validated cohort of patients with a diagnosis of Hashimoto's between 2005 and 2020 were identified using the Olmsted County database. Patients were age and sex matched to controls without a Hashimoto's diagnosis. The primary outcomes were development of melanoma and time to first melanoma diagnosis. 4805 patients were included in the study, with 1726 (36%) having a diagnosis of Hashimoto's. Hashimoto's patients had no significant difference in risk of melanoma (relative risk 0.96, 95% CI 0.78-1.17) or nonmelanoma skin cancer (relative risk 0.95, 95% CI 0.86-1.06) compared with matched controls. This suggests that the local proinflammatory environment present in Hashimoto's does not contribute significantly to melanoma risk. Larger studies may be needed to further characterize the relationship between these diseases.

Comparative analysis of anticholinergic burden scales to explain iatrogenic cognitive impairment and self-reported side effects in the euthymic phase of bipolar disorders: Results from the FACE-BD cohort.

Bipolar disorders (BD) are characterized by cognitive impairment during the euthymic phase, to which treatments can contribute. The anticholinergic properties of medications, i.e., the ability of a treatment to inhibit cholinergic receptors, are associated with cognitive impairment in elderly patients and people with schizophrenia but this association has not been well characterized in individuals with remitted BD. Moreover, the validity of only one anticholinergic burden scale designed to assess the anticholinergic load of medications has been tested in BD. In a literature review, we identified 31 existing scales. We first measured the associations between 27 out of the 31 scales and objective cognitive impairment in bivariable regressions. We then adjusted the bivariable models with covariates: the scales significantly associated with cognitive impairment in bivariable and multiple logistic regressions were defined as having good concurrent validity to assess cognitive impairment. In a sample of 2,031 individuals with euthymic BD evaluated with a neuropsychological battery, two scales had good concurrent validity to assess cognitive impairment, whereas chlorpromazine equivalents, lorazepam equivalents, the number of antipsychotics, or the number of treatments had not. Finally, similar analyses with subjective anticholinergic side-effects as outcome variables reported 14 scales with good concurrent validity to assess self-reported peripheral anticholinergic side-effects and 13 to assess self-reported central anticholinergic side-effects. Thus, we identified valid scales to monitor the anticholinergic burden in BD, which may be useful in estimating iatrogenic cognitive impairment in studies investigating cognition in BD.

The expression of positive and negative schizotypy in daily life: an experience sampling study.

BACKGROUND: Psychometrically identified positive schizotypy and negative schizotypy are differentially related to psychopathology, personality and social functioning. However, little is known about the experience and expression of schizotypy in daily life and the psychological mechanisms that trigger psychotic-like experiences. METHOD: The present study employed experience sampling methodology (ESM) to assess positive and negative schizotypy in daily life in a non-clinical sample of 412 young adults. ESM is a structured diary technique in which participants are prompted at random times during the day to complete assessments of their current experiences. RESULTS: As hypothesized, positive schizotypy was associated with increased negative affect, thought impairment, suspiciousness, negative beliefs about current activities and feelings of rejection, but not with social disinterest or decreased positive affect. Negative schizotypy, on the other hand, was associated with decreased positive affect and pleasure in daily life, increased negative affect, and decreases in social contact and interest. Both positive schizotypy and negative schizotypy were associated with the desire to be alone when with others. However, this was moderated by anxiety in positive schizotypy and by diminished positive affect in negative schizotypy. CONCLUSIONS: The results support the construct validity of a multidimensional model of schizotypy and the ecological validity of the positive and negative schizotypy dimensions. ESM appears to be a promising method for examining the daily life experiences of schizotypic individuals.

Cellular lipids and protein alteration during biodegradation of expanded polystyrene by mealworm larvae under different feeding conditions.

The present study reports the biodegradation of polystyrene (PS) by mealworm (Tenebrio molitor) following different feeding regimes. Changes in lipids and protein were studied to evaluate possible differences in the growth and metabolic pathways of the insects depending on the diets. Thermo-gravimetric analysis of the excretions (frass) revealed a decrease in the molecular mass of the PS polymers. The insects' biomass contained less protein when PS was part of the diet, suggesting that the insects undergo a certain level of stress compared to control diets. The frass also contained lower amount of nitrogen content compared to that from insects fed a control diet. NH4+ and other cations involved in biochemical processes were also measured in insects' frass, including potassium, sodium, magnesium, and calcium, combined with a small pH change. The decrease in the mineral content of the frass was attributed to increased cellular activity in PS-fed insects. A higher amount of ceramides and cardiolipins, biomarkers of apoptosis, were also found in association with PS consumption. It was concluded that the insects could metabolize PS, but this caused an increase in its stress levels.

Diffuse Large B-Cell Epstein-Barr Virus-Positive Primary CNS Lymphoma in Non-AIDS Patients: High Diagnostic Accuracy of DSC Perfusion Metrics.

BACKGROUND AND PURPOSE: Immunodeficiency-associated CNS lymphoma may occur in different clinical scenarios beyond AIDS. This subtype of CNS lymphoma is diffuse large B-cell and Epstein-Barr virus-positive. Its accurate presurgical diagnosis is often unfeasible because it appears as ring-enhancing lesions mimicking glioblastoma or metastasis. In this article, we describe clinicoradiologic features and test the performance of DSC-PWI metrics for presurgical identification. MATERIALS AND METHODS: Patients without AIDS with histologically confirmed diffuse large B-cell Epstein-Barr virus-positive primary CNS lymphoma (December 2010 to January 2022) and diagnostic MR imaging without onco-specific treatment were retrospectively studied. Clinical, demographic, and conventional imaging data were reviewed. Previously published DSC-PWI time-intensity curve analysis methodology, to presurgically identify primary CNS lymphoma, was used in this particular lymphoma subtype and compared with a prior cohort of 33 patients with Epstein-Barr virus-negative CNS lymphoma, 35 with glioblastoma, and 36 with metastasis data. Normalized curves were analyzed and compared on a point-by-point basis, and previously published classifiers were tested. The standard percentage of signal recovery and CBV values were also evaluated. RESULTS: Seven patients with Epstein-Barr virus-positive primary CNS lymphoma were included in the study. DSC-PWI normalized time-intensity curve analysis performed the best for presurgical identification of Epstein-Barr virus-positive CNS lymphoma (area under the receiver operating characteristic curve of 0.984 for glioblastoma and 0.898 for metastasis), followed by the percentage of signal recovery (0.833 and 0.873) and CBV (0.855 and 0.687). CONCLUSIONS: When a necrotic tumor is found in a potentially immunocompromised host, neuroradiologists should consider Epstein-Barr virus-positive CNS lymphoma. DSC-PWI could be very useful for presurgical characterization, with especially strong performance of normalized time-intensity curves.

Regeneration of transgenic plants by Agrobacterium-mediated transformation of somatic embryos of juvenile and mature Quercus robur.

A protocol was developed for genetic transformation of somatic embryos derived from juvenile and mature Quercus robur trees. Optimal transformation conditions were evaluated on the basis of the results of transient GUS expression assays with five oak embryogenic lines and a strain of Agrobacterium tumefaciens (EHA105) harbouring a p35SGUSINT plasmid containing a nptII and a uidA (GUS) genes. For stable transformation, embryo clumps at globular/torpedo stages (4-10 mg) were inoculated with EHA105:p35SGUSINT bacterial cultures, cocultivated for 4 days and selected in proliferation medium with 75 mg/l of kanamycin. Putatively transformed masses appeared after 20-30 weeks of serial transfers to selective medium. Histochemical and molecular analysis (PCR and Southern blot) confirmed the presence of nptII and uidA genes in the plant genomes. Transformation efficiencies ranged from up to 2% in an embryogenic line derived from a 300-year-old tree, to 6% in a juvenile genotype. Twelve independent transgenic lines were obtained from these oak genotypes, and transgenic plantlets were recovered and acclimatized into the soil. This is the first demonstration of the production of transformed somatic embryos and regenerated plants from juvenile and mature trees of Q. robur and suggests the possibility of introducing other genetic constructions to develop trees that are tolerant/resistant to pathogens and/or biotic stresses.

Shoot apex explants for induction of somatic embryogenesis in mature Quercus robur L. trees.

A procedure for inducing somatic embryos in shoot apex explants (2 mm) excised from shoot proliferation cultures established from adult oak trees (Quercus robur) was investigated. Embryogenesis was induced in shoot tip as well as leaf explants in three out of the five genotypes evaluated. Somatic embryos were formed by culture in induction medium supplemented with 21.48 muM naphthalene acetic acid and 2.22 muM benzyladenine for 8 weeks, and successive transfer of explants to expression media with a low concentration of growth regulators and without them. Both types of explants formed callus tissue from which somatic embryos developed, indicating indirect embryogenesis. Although the embryogenic frequencies were lower than 12%, it did not prevent the establishment of clonal embryogenic lines maintained by repetitive embryogenesis. Histological study confirmed an indirect somatic embryogenesis process from shoot tip explants, in which leaf primordia and the corresponding axial zones were involved in generating callus, whereas the apical meristem itself did not proliferate. The origin of embryogenic cells appeared to be associated with dedifferentiation of certain parenchymal cells in callus regions after transfer of explants to expression media without auxin. Division of embryogenic cells gave rise to proembryo aggregates of unicellular origin, although a multicellular origin from bulging embryogenic areas would also seem possible. Further development led to the formation of cotyledonary-stage somatic embryos and nodular embryogenic structures that may be considered as anomalous embryos with no clear bipolarity. Inducement of somatic embryos from explants isolated from shoot cultures ensures plant material all year round, thus providing a significant advantage over the use of leaf explants from field-grown trees.

Adaptation of the wisconsin scales of psychosis proneness to Spanish.

INTRODUCTION: Nowadays the study of vulnerability to psychosis and early intervention is an area of great clinical impact and research. The aim of this study was to adapt the Wisconsin Scales of Vulnerability to Psychosis from English to Spanish. A set of five scales (Magical Ideation, Perceptual Aberration, Physical Anhedonia, Revised Social Anhedonia and Ambivalence) assess schizotypal traits in the general population and the possible risk of developing disorders embedded in the psychotic spectrum. Additionally, this tool contains a scale of Hypomaniac Personality to detect risk of affective spectrum psychosis. METHODOLOGY: The Wisconsin Scales of Vulnerability to Psychosis have been adapted following the back-translation method. The scales were translated to an original Spanish version, which was then translated again into English in order to assess the conceptual and semantic overlap with the original items. RESULTS: All the items were back-translated and evaluated in respect to the original ones by an expert in the scales, and all of them were rated with a perfect equivalence (Type A) or satisfactory (Type B). CONCLUSIONS: The Spanish version of the Wisconsin Scales of Vulnerability to Psychosis shows good equivalence with the English one, thus allowing to measure affective and schizotypal traits in samples of Spanish-speaking individuals properly. Future studies should test the reliability and validity of these scales in our environment.

Presurgical Identification of Primary Central Nervous System Lymphoma with Normalized Time-Intensity Curve: A Pilot Study of a New Method to Analyze DSC-PWI.

BACKGROUND AND PURPOSE: DSC-PWI has demonstrated promising results in the presurgical diagnosis of brain tumors. While most studies analyze specific parameters derived from time-intensity curves, very few have directly analyzed the whole curves. The aims of this study were the following: 1) to design a new method of postprocessing time-intensity curves, which renders normalized curves, and 2) to test its feasibility and performance on the diagnosis of primary central nervous system lymphoma. MATERIALS AND METHODS: Diagnostic MR imaging of patients with histologically confirmed primary central nervous system lymphoma were retrospectively reviewed. Correlative cases of glioblastoma, anaplastic astrocytoma, metastasis, and meningioma, matched by date and number, were retrieved for comparison. Time-intensity curves of enhancing tumor and normal-appearing white matter were obtained for each case. Enhancing tumor curves were normalized relative to normal-appearing white matter. We performed pair-wise comparisons for primary central nervous system lymphoma against the other tumor type. The best discriminatory time points of the curves were obtained through a stepwise selection. Logistic binary regression was applied to obtain prediction models. The generated algorithms were applied in a test subset. RESULTS: A total of 233 patients were included in the study: 47 primary central nervous system lymphomas, 48 glioblastomas, 39 anaplastic astrocytomas, 49 metastases, and 50 meningiomas. The classifiers satisfactorily performed all bilateral comparisons in the test subset (primary central nervous system lymphoma versus glioblastoma, area under the curve = 0.96 and accuracy = 93%; versus anaplastic astrocytoma, 0.83 and 71%; versus metastases, 0.95 and 93%; versus meningioma, 0.93 and 96%). CONCLUSIONS: The proposed method for DSC-PWI time-intensity curve normalization renders comparable curves beyond technical and patient variability. Normalized time-intensity curves performed satisfactorily for the presurgical identification of primary central nervous system lymphoma.