T2-weighted, apparent diffusion coefficient and 18F-FDG PET histogram analysis of rectal cancer after preoperative chemoradiotherapy.

BACKGROUND: The aim of our study was to investigate the correlation among T2-weighted (T2w) images, apparent diffusion coefficient (ADC) maps, 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) images, histogram analysis and the pathological response in locally advanced rectal cancer (LARC) after preoperative chemoradiotherapy (pCRT). METHODS: Patients with LARC were prospectively enrolled between February 2015 and August 2018 and underwent PET/magnetic resonance imaging (MRI). MRI included T2w and diffusion-weighted imaging (DWI)-sequences. ADC maps and PET images were matched to the T2w images. Voxel-based standardized uptake values (SUVs,) ADC and T2w-signal-intensity values were collected from the volumes of interest (VOIs) and mean, skewness and kurtosis were calculated. Spearman's correlation coefficient was applied to evaluate the correlation among the variables and tumor regression grade (TRG), T stage, N stage and fibrosis. RESULTS: Twenty-two patients with biopsy-proven LARC in the low or mid rectum were enrolled [17 males, mean age was 69 years (range 49-85 years)]. Seven patients experienced complete regression (TRG1). A significant positive correlation was found between SUV mean values (ρ = 0.480; p = 0.037) and TRG. No other significant correlations were found. CONCLUSIONS: Histogram analysis of SUV values is a predictor of TRG in LARC.

Sleep-dependent consolidation of motor skills in patients with narcolepsy-cataplexy.

BACKGROUND AND OBJECTIVES: This study investigated whether the altered organization of post-training sleep in patients with narcolepsy-cataplexy (NC) is associated with a lower off-line improvement in the consolidation of motor skills compared with normal subjects. STUDY DESIGN: Fourteen drug-naive NC patients, fulfilling the international clinical and polysomnographic diagnostic criteria, and 14 individually-matched controls underwent training at a sequential finger tapping task (FTT) and were re-tested on the next morning (after a night with polysomnographic recording) and after another six nights (spent at home). SETTING: Training and retrieval sessions were performed in a controlled laboratory setting. RESULTS: FTT performance was worse in NC patients than controls at training and at both retrieval sessions and showed a fairly different time course (slower than in controls) of consolidation. Several sleep indices (lower values of stage-2 NREM sleep and SWS) were compatible with a lower effectiveness of sleep for consolidation of motor skills in NC patients, although no statistically significant relationship was found between such indices and improvement rate. CONCLUSION: The consolidation process of motor skills results less effective in NC patients since training and slower than in normal subjects over the week following training. The wider variations in performance scores and sleep parameters of post.-training night in NC patients relative to controls suggest that a) the lower initial consolidation may be due to a less effective encoding consequent to altered prior sleep, and b) the consolidation process over the 24 h following training is negatively influenced not only by the altered characteristics of post-training sleep, but also by the daytime sleepiness following training.

Learning via variably scaled kernels.

We investigate the use of the so-called variably scaled kernels (VSKs) for learning tasks, with a particular focus on support vector machine (SVM) classifiers and kernel regression networks (KRNs). Concerning the kernels used to train the models, under appropriate assumptions, the VSKs turn out to be more expressive and more stable than the standard ones. Numerical experiments and applications to breast cancer and coronavirus disease 2019 (COVID-19) data support our claims. For the practical implementation of the VSK setting, we need to select a suitable scaling function. To this aim, we propose different choices, including for SVMs a probabilistic approach based on the naive Bayes (NB) classifier. For the classification task, we also numerically show that the VSKs inspire an alternative scheme to the sometimes computationally demanding feature extraction procedures.

Radiomics: a new tool to differentiate adrenocortical adenoma from carcinoma.

BACKGROUND: The main challenge in the management of indeterminate incidentally discovered adrenal tumours is to differentiate benign from malignant lesions. In the absence of clear signs of invasion or metastases, imaging techniques do not always precisely define the nature of the mass. The present pilot study aimed to determine whether radiomics may predict malignancy in adrenocortical tumours. METHODS: CT images in unenhanced, arterial, and venous phases from 19 patients who had undergone resection of adrenocortical tumours and a cohort who had undergone surveillance for at least 5 years for incidentalomas were reviewed. A volume of interest was drawn for each lesion using dedicated software, and, for each phase, first-order (histogram) and second-order (grey-level colour matrix and run-length matrix) radiological features were extracted. Data were revised by an unsupervised machine learning approach using the K-means clustering technique. RESULTS: Of operated patients, nine had non-functional adenoma and 10 carcinoma. There were 11 patients in the surveillance group. Two first-order features in unenhanced CT and one in arterial CT, and 14 second-order parameters in unenhanced and venous CT and 10 second-order features in arterial CT, were able to differentiate adrenocortical carcinoma from adenoma (P < 0.050). After excluding two malignant outliers, the unsupervised machine learning approach correctly predicted malignancy in seven of eight adrenocortical carcinomas in all phases. CONCLUSION: Radiomics with CT texture analysis was able to discriminate malignant from benign adrenocortical tumours, even by an unsupervised machine learning approach, in nearly all patients.

Patterns of cerebral activation during lexical and phonological reading in Portuguese.

According to the concepts of cognitive neuropsychology, there are two principal routes of reading processing: a lexical route, in which global reading of words occurs and a phonological route, responsible for the conversion of the graphemes into their respective phonemes. In the present study, functional magnetic resonance imaging (fMRI) was used to investigate the patterns of cerebral activation in lexical and phonological reading by 13 healthy women with a formal educational level greater than 11 years. Participants were submitted to a silent reading task containing three types of stimuli: real words (irregular and foreign words), nonwords and illegitimate graphic stimuli. An increased number of activated voxels were identified by fMRI in the word reading (lexical processing) than in the nonword reading (phonological processing) task. In word reading, activation was greater than for nonwords in the following areas: superior, middle and inferior frontal gyri, and bilateral superior temporal gyrus, right cerebellum and the left precentral gyrus, as indicated by fMRI. In the reading of nonwords, the activation was predominant in the right cerebellum and in the left superior temporal gyrus. The results of the present study suggest the existence of differences in the patterns of cerebral activation during lexical and phonological reading, with greater involvement of the right hemisphere in reading words than nonwords.

Effects of highly selective kappa-opioid agonists on EEG power spectra and behavioural correlates in conscious rats.

The present study compares the electroencephalographic (EEG) and behavioural effects of highly selective kappa-opioid agonists, spiradoline (U62066), enadoline (CI-977), BRL 52656, and BRL 53001, after SC administration to conscious rats. All compounds caused a distinctive dose- and time-related EEG effect and behavioural profile. The EEG power spectra (PS) of treated animals were characterised by power reduction indicative of CNS activation and an unusual spectral peak at 4-7 Hz, compared to controls. Behaviourally, however, the animals appeared to be sedated, with a reduction of locomotor activity, loss of postural tone, ataxia, and unusual hyperreactivity. The compounds differed in their liability to produce these CNS effects, with kappa-opioid analgesics such as enadoline and BRL 53001 showing a reduced propensity at equivalent antinociceptive doses. Where tested, these effects were inhibited by the nonselective opioid antagonist naloxone. The non-brain penetrating kappa-opioid agonist, BRL 52974, failed to produce alterations in EEG PS or behaviour, up to a dose of 10 mg/kg, indicating that the effects depend on activation of centrally located kappa-receptors.

Highly Automated Dipole EStimation (HADES).

Automatic estimation of current dipoles from biomagnetic data is still a problematic task. This is due not only to the ill-posedness of the inverse problem but also to two intrinsic difficulties introduced by the dipolar model: the unknown number of sources and the nonlinear relationship between the source locations and the data. Recently, we have developed a new Bayesian approach, particle filtering, based on dynamical tracking of the dipole constellation. Contrary to many dipole-based methods, particle filtering does not assume stationarity of the source configuration: the number of dipoles and their positions are estimated and updated dynamically during the course of the MEG sequence. We have now developed a Matlab-based graphical user interface, which allows nonexpert users to do automatic dipole estimation from MEG data with particle filtering. In the present paper, we describe the main features of the software and show the analysis of both a synthetic data set and an experimental dataset.

Breast cancer: implications of tumor cell kinetics on clinical outcome.

The relevance of tumor proliferative activity as an indicator of biologic aggressiveness was analyzed on a series of 506 patients with primary breast cancer. In 258 patients with operable tumors without nodal and distant metastases, none of whom was subjected to postoperative irradiation or systemic adjuvant therapy, proliferative activity was significantly correlated with prognosis; 6-year relapse-free survival (RFS) and overall survival (OS) were higher for patients with slowly proliferating tumors for patient with fast-proliferating tumors (RFS: 80.5% vs 59.6%, p = 0.00004; OS: 90.8% vs 74.4%, p = 0.002). On a series of 196 patients with node-positive operable tumors, subjected to 6 or 12 cycles of cyclophosphamide, methotrexate and 5-fluorouracil, a trend in favor of longer 6-year RFS was observed for patients with slowly proliferating tumors than for patients with fast-proliferating tumors (62.5% vs 48.3%, p = 0.08), whereas proliferative activity did not influence OS. In 52 patients with locally advanced disease treated with a multimodality approach, including chemotherapy (adriamycin and vincristine), surgery or radiotherapy, tumor proliferative activity was a strong indicator of biologic aggressivity, since women with slowly proliferating cancers had a higher 4-year probability of OS than women with fast-proliferating tumors (68.1% vs 36.7%, p = 0.02).

Cell kinetics of human epithelial ovarian cancers.

Tumor cellular proliferative activity was evaluated by 3H-thymidine labeling index (LI) determination in 73 lesions from 62 patients with ovarian cancers. The median LI value for the overall series was 5.8% and places this tumor type in a position of intermediate proliferative activity. In this case series, the relationship between proliferative activity and different morphologic and pathologic characteristics of the disease was analyzed. Similar median LI values were found for ascitic effusions and solid tumors and, among these, between primary tumors and metastases. No significant relation was observed between proliferative activity and histologic type, whereas a definite direct correlation was found between the kinetic variable and prognostic features such as pathologic stage and histologic grading. In fact median LI was higher for stage IV for stage I and for grade 3 than for grade 1 tumors. The strong association between tumor proliferative rate and conventional prognostic factors suggests that also on this tumor type the kinetic variable could play a role as a prognostic indicator and modulator of aggressiveness.

Patterns of cerebral activation during lexical and phonological reading in Portuguese

According to the concepts of cognitive neuropsychology, there are two principal routes of reading processing: a lexical route, in which global reading of words occurs and a phonological route, responsible for the conversion of the graphemes into their respective phonemes. In the present study, functional magnetic resonance imaging (fMRI) was used to investigate the patterns of cerebral activation in lexical and phonological reading by 13 healthy women with a formal educational level greater than 11 years. Participants were submitted to a silent reading task containing three types of stimuli: real words (irregular and foreign words), nonwords and illegitimate graphic stimuli. An increased number of activated voxels were identified by fMRI in the word reading (lexical processing) than in the nonword reading (phonological processing) task. In word reading, activation was greater than for nonwords in the following areas: superior, middle and inferior frontal gyri, and bilateral superior temporal gyrus, right cerebellum and the left precentral gyrus, as indicated by fMRI. In the reading of nonwords, the activation was predominant in the right cerebellum and in the left superior temporal gyrus. The results of the present study suggest the existence of differences in the patterns of cerebral activation during lexical and phonological reading, with greater involvement of the right hemisphere in reading words than nonwords.

Loss of A, B, and H antigens in oral cancer

Los antígenos ABH, productos de la interacción de dos sistemas genéticos Hh y ABO, están sujetos a leyes de herencia y pueden estar localizados no sólo en los eritrocitos sino también en la mayoría de las células humanas. El objetivo del este trabajo fue investigar la expresión de antígenos ABH en pacientes con lesiones orales pre-malignas y malignasorales. Se trabajó con muestras incluidas en tacos de parafina de pacientes con lesiones orales. Los pacientes fueron clasificados en 2 grupos: a) Pacientes con lesiones premalignas y malignas diagnosticadas clí-nica y anatopatológicamente y b) pacientes con lesiones benignas. Sei nvestigaron los antígenos ABH por la técnica de inmunoadherencia específica modificada. Se utilizó la adherencia al tejido vascular como control positivo y al tejido adiposo como control negativo. Los resultados fueron valorados de forma semicuantitativa desde adherencia fuertemente positiva a negativa. Hemos encontrado una significativa relación entre la expresión antigénica ABH y el grado de malignidad de las lesiones analizadas (P Yates= 0.005). Una pérdida de reactividad ABH en los sitios de mayor invasividad tumoral se correlaciona con el grado del desarrollo del tumor, el grado histológico y su malignidad (AU)

In most human carcinomas, including oral carcinoma, a significant event is decreased expression of histo-blood-group antigens A,B and H. The mechanisms of aberrant expression of blood-group antigens are not clear in all cases. The aim of this work was to investigate the association of ABO blood groups with oral cancer. We studied the expression of ABH antigen in tissues of premalignant lesions and in diagnosed malignant tumors. In total, 132 patients were examined, half of whom suffered from oral pre-cancerous and cancerous lesions, while the other half were the control group (benign lesions).All tumors were histologically confirmed. We found a significant relationship between antigen expression and the malignancy of the lesions analyzed (P Yates= 0.005). A loss of ABH reactivity within the most invasive sites of the tumors correlated significantly with the stage of tumor development and histological grade of malignancy. These findings support the view that features regarding the cells of deeper parts of the carcinomas are very important for the clinical behavior of the tumors and that loss of ABH-antigen expression is linked to the stage of the tumor and invasion of carcinoma cells (AU)