Unwrapping of transient responses from high rate overlapping pattern electroretinograms by deconvolution

Objective

Due to overlapping, temporal information is mostly lost in high rate steady-state pattern electroretinograms (PERG_SS). This study develops a deconvolution method and a display/recording system to “unwrap” PERG_SS and obtain a transient, “per stimulus” response (PERG_tr) regardless of reversal rate.

Methods

Processing and instrumentation, including high temporal resolution display and acquisition were developed for deconvolving PERGs acquired at high rates by slight jittering of reversal onsets at a given mean rate.

Results

The system was successfully tested at eight rates from 2.2 to 78.1 rps. At medium rates (17.4–41.2 rps) recordings with conventional morphology (N35–P50–N95) but earlier peaks and higher amplitudes were extracted up to 40 rps. At higher rates, smaller triphasic responses were obtained, exhibiting similar peak latencies, but reversed polarity. Oscillating potentials (OPs) were also recorded at all rates after deconvolution.

Conclusions

Transient PERGs and OPs can be extracted from quasi steady-state PERG recordings obtained at high rates with a deconvolution algorithm using high temporal resolution display and acquisition systems.

Significance

The methodology to extract transient and oscillatory responses from steady-state PERGs could be useful in understanding high rate responses and diagnosis of various retinal diseases by revealing temporal information on waveform components which cannot be normally observed.     

MANIA—A Pattern Classification Toolbox for Neuroimaging Data

Conventional univariate statistics are common and widespread in neuroimaging research. However, functional and structural MRI data reveal a multivariate nature, since neighboring voxels are highly correlated and different localized brain regions activate interdependently. Multivariate pattern classification techniques are capable of overcoming shortcomings of univariate statistics. A rising interest in such approaches on neuroimaging data leads to an increasing demand of appropriate software and tools in this field. Here, we introduce and release MANIA—Machine learning Application for NeuroImaging Analyses. MANIA is a Matlab based software toolbox enabling easy pattern classification of neuroimaging data and offering a broad assortment of machine learning algorithms and feature selection methods. Between groups classifications are the main scope of this software, for instance the differentiation between patients and controls. A special emphasis was placed on an intuitive and easy to use graphical user interface allowing quick implementation and guidance also for clinically oriented researchers. MANIA is free and open source, published under GPL3 license. This work will give an overview regarding the functionality and the modular software architecture as well as a comparison between other software packages.     

Mapping the brain pathways of declarative verbal memory: Evidence from white matter lesions in the living human brain

Understanding the contribution of the brain white matter pathways to declarative verbal memory processes has been hindered by the lack of an adequate model in humans. An attractive and underexplored approach to study white matter region functionality in the living human brain is through the use of non-aprioristic models which specifically search disrupted white matter pathways. For this purpose, we employed voxel-based lesion–function mapping to correlate white matter lesions on the magnetic resonance images of 46 multiple sclerosis patients with their performance on declarative verbal memory storage and retrieval. White matter correlating with storage was in the temporal lobe–particularly lateral to the hippocampus and in the anterior temporal stem–, in the thalamic region and in the anterior limb of the internal capsule, all on the left hemisphere, and also in the right anterior temporal stem. The same volumes were relevant for retrieval, but to them were added temporo-parieto-frontal paramedian bundles, particularly the cingulum and the fronto-occipital fasciculus. These 3D maps indicate the white matter regions most critically involved in declarative verbal memory in humans.     

Percutaneous biliary drainage in acute suppurative cholangitis

One hundred and sixteen percutaneous drainage procedures of the biliary system were performed in a 2-year period. Eight of 9 acutely ill patients with the diagnosis of acute suppurative cholangitis were successfully treated nonoperatively. They represented 26% of all patients with benign or postsurgical obstruction referred for biliary decompression. Conversely, acute suppurative cholangitis only occurred in 2.3% of patients with underlying malignant disease. These observations are considered most relevant in predicting the purulent nature of the disease, with further implications for patient management. Early recognition and prompt decompression of the biliary system are mandatory, along with the appropriate antibiotic coverage. Our experience compares favorably with surgical results and the procedure is proposed as the method of choice for the initial treatment of acute suppurative cholangitis.     

Do patient and ward-related characteristics influence the use of coercive measures? Results from the EUNOMIA international study

Purpose

This study aims to identify whether selected patient and ward-related factors are associated with the use of coercive measures. Data were collected as part of the EUNOMIA international collaborative study on the use of coercive measures in ten European countries.

Methods

Involuntarily admitted patients (N = 2,027) were divided into two groups. The first group (N = 770) included patients that had been subject to at least one of these coercive measures during hospitalization: restraint, and/or seclusion, and/or forced medication; the other group (N = 1,257) included patients who had not received any coercive measure during hospitalization. To identify predictors of use of coercive measures, both patients’ sociodemographic and clinical characteristics and centre-related characteristics were tested in a multivariate logistic regression model, controlled for countries’ effect.

Results

The frequency of the use of coercive measures varied significantly across countries, being higher in Poland, Italy and Greece. Patients who received coercive measures were more frequently male and with a diagnosis of psychotic disorder (F20–F29). According to the regression model, patients with higher levels of psychotic and hostility symptoms, and of perceived coercion had a higher risk to be coerced at admission. Controlling for countries’ effect, the risk of being coerced was higher in Poland. Patients’ sociodemographic characteristics and ward-related factors were not identifying as possible predictors because they did not enter the model.

Conclusions

The use of coercive measures varied significantly in the participating countries. Clinical factors, such as high levels of psychotic symptoms and high levels of perceived coercion at admission were associated with the use of coercive measures, when controlling for countries’ effect. These factors should be taken into consideration by programs aimed at reducing the use of coercive measures in psychiatric wards.     

The Brazilian Founder Mutation TP53 p.R337H is Uncommon in Portuguese Women Diagnosed with Breast Cancer

Since the first studies reporting the TP53 p.R337H mutation as founder mutation in Southern and Southeastern Brazil, there has been controversy on its origin. Preliminary analysis of a small subset of Brazilian mutation carriers revealed that the haplotype incided on a Caucasian background. The vast majority of carriers identified today reside in Brazil or, if identified in other countries, are Brazilian immigrants. To our knowledge, the only two exceptions of carriers without a recognizable link with Brazil are two European families, from Portugal and Germany. Haplotype analysis in the Portuguese family revealed the same haplotype identified in Brazilian individuals, but in the German family, a distinct haplotype was found. Knowing that a significant proportion of women with breast cancer (BC) in Southern Brazil are p.R337H carriers, we analyzed p.R337H in a Portuguese cohort of women diagnosed with this disease. Median age at diagnosis among the first 573 patients tested was 60 years and 100 (17.4%) patients had been diagnosed at or under the age of 45 years. Mutation screening failed to identify the mutation in the 573 patients tested. These results are in contrast with the mutation frequency observed in a study including 815 BC‐affected women from Brazil, in which carrier frequencies of 12.1 and 5.1% in pre‐ and postmenopausal women were observed, respectively. These findings suggest that the Brazilian founder mutation p.R337H, the most frequent germline TP53 mutation reported to date, is not a common germline alteration in Portuguese women diagnosed with BC.