Estimation of brain network ictogenicity predicts outcome from epilepsy surgery

Surgery is a valuable option for pharmacologically intractable epilepsy. However, significant post-operative improvements are not always attained. This is due in part to our incomplete understanding of the seizure generating (ictogenic) capabilities of brain networks. Here we introduce an in silico, model-based framework to study the effects of surgery within ictogenic brain networks. We find that factors conventionally determining the region of tissue to resect, such as the location of focal brain lesions or the presence of epileptiform rhythms, do not necessarily predict the best resection strategy. We validate our framework by analysing electrocorticogram (ECoG) recordings from patients who have undergone epilepsy surgery. We find that when post-operative outcome is good, model predictions for optimal strategies align better with the actual surgery undertaken than when post-operative outcome is poor. Crucially, this allows the prediction of optimal surgical strategies and the provision of quantitative prognoses for patients undergoing epilepsy surgery.

SEMANTIC SEGMENTATION OF AERIAL IMAGES WITH AN ENSEMBLE OF CNNS

This paper describes a deep learning approach to semantic segmentation of very high resolution (aerial) images. Deep neural architectures hold the promise of end-to-end learning from raw images, making heuristic feature design obsolete. Over the last decade this idea has seen a revival, and in recent years deep convolutional neural networks (CNNs) have emerged as the method of choice for a range of image interpretation tasks like visual recognition and object detection. Still, standard CNNs do not lend themselves to per-pixel semantic segmentation, mainly because one of their fundamental principles is to gradually aggregate information over larger and larger image regions, making it hard to disentangle contributions from different pixels. Very recently two extensions of the CNN framework have made it possible to trace the semantic information back to a precise pixel position: deconvolutional network layers undo the spatial downsampling, and Fully Convolution Networks (FCNs) modify the fully connected classification layers of the network in such a way that the location of individual activations remains explicit. We design a FCN which takes as input intensity and range data and, with the help of aggressive deconvolution and recycling of early network layers, converts them into a pixelwise classification at full resolution. We discuss design choices and intricacies of such a network, and demonstrate that an ensemble of several networks achieves excellent results on challenging data such as the <i>ISPRS semantic labeling benchmark</i>, using only the raw data as input.

Association Between Nutritional Status and Quality of Life in (Pre) Frail Community-Dwelling Older Persons

BACKGROUND: For developed countries, healthy aging is one of the challenges and the number of healthy life years and especially the quality of life (QoL) are important. OBJECTIVE: This study aimed to assess the association between nutritional status and different domains of QoL in (pre)frail community-dwelling elders. DESIGN: Baseline data from persons, who participated in a 12-week nutritional and physical training intervention program, conducted from September 2013 - July 2015. Setting: (Pre)frail community-dwelling elders living in Vienna, Austria. PARTICIPANTS: A total of 83 older persons living at home, 12 men and 71 women (86%) aged 65 to 98 years. Measurements: Structured interviews were conducted at participants’ homes. Mini Nutritional Assessment® long-form (MNA®-LF) was used to investigate the nutritional status. The QoL domains were assessed with the World Health Organization Quality of Life questionnaires. Simple and multiple linear regression analyses were performed to evaluate the association between nutritional status and QoL domains, adjusted for possible confounders. RESULTS: 45% of the participants were at risk of malnutrition and 3% were malnourished. Compared to normal nourished people, persons who had an impaired nutritional status, significantly differed in the QoL domain ‘autonomy’ with mean (SD) scores of 50.0 (14.9) vs. 57.3 (13.7); p=0.022 and in the QoL domain ‘social participation’ with scores of 40.1 (13.6) vs. 47.0 (11.2); p=0.014, respectively. According to linear regression analyses, the MNA®-LF score was significantly associated with ‘overall QoL’ (β=0.26; p=0.016) and the QoL domains ‘physical health’ (β=0.23; p=0.036), ‘autonomy’ (β=0.27; p=0.015), and ‘social participation’ (β=0.28; p=0.013).CONCLUSIONS: There was a significant association between nutritional status and QoL in elderly (pre)frail community-dwelling people, in particular for the QoL domains ‘autonomy’ and ‘social participation’. However, it remains unclear whether malnutrition was the cause or the consequence, or it was mediated through a third possible factor e.g. the functional status.

Toxicities of the anti-PD-1 and anti-PD-L1 immune checkpoint antibodies

Immune checkpoint antibodies that augment the programmed cell death protein 1 (PD-1)/PD-L1 pathway have demonstrated antitumor activity across multiple malignancies, and gained recent regulatory approval as single-agent therapy for the treatment of metastatic malignant melanoma and nonsmall-cell lung cancer. Knowledge of toxicities associated with PD-1/PD-L1 blockade, as well as effective management algorithms for these toxicities, is pivotal in order to optimize clinical efficacy and safety. In this article, we review selected published and presented clinical studies investigating single-agent anti-PD-1/PD-L1 therapy and trials of combination approaches with other standard anticancer therapies, in multiple tumor types. We summarize the key adverse events reported in these studies and their management algorithms.

Inverse relationship between body mass index and mortality in older nursing home residents: a meta-analysis of 19,538 elderly subjects

Body mass index (BMI) and mortality in old adults from the general population have been related in a U-shaped or J-shaped curve. However, limited information is available for elderly nursing home populations, particularly about specific cause of death. A systematic PubMed/EMBASE/CINAHL/SCOPUS search until 31 May 2014 without language restrictions was conducted. As no published study reported mortality in standard BMI groups (<18.5, 18.5-24.9, 25-29.9, ≥30 kg/m(2)), the most adjusted hazard ratios (HRs) according to a pre-defined list of covariates were obtained from authors and pooled by random-effect model across each BMI category. Out of 342 hits, 20 studies including 19,538 older nursing home residents with 5,223 deaths during a median of 2 years of follow-up were meta-analysed. Compared with normal weight, all-cause mortality HRs were 1.41 (95% CI = 1.26-1.58) for underweight, 0.85 (95% CI = 0.73-0.99) for overweight and 0.74 (95% CI = 0.57-0.96) for obesity. Underweight was a risk factor for higher mortality caused by infections (HR = 1.65 [95% CI = 1.13-2.40]). RR results corroborated primary HR results, with additionally lower infection-related mortality in overweight and obese than in normal-weight individuals. Like in the general population, underweight is a risk factor for mortality in old nursing home residents. However, uniquely, not only overweight but also obesity is protective, which has relevant nutritional goal implications in this population/setting.

PureEEG: automatic EEG artifact removal for epilepsy monitoring

AIM OF THE STUDY

A novel method for removal of artifacts from long-term EEGs was developed and evaluated. The method targets most types of artifacts and works without user interaction.

MATERIALS AND METHODS

The method is based on a neurophysiological model and utilizes an iterative Bayesian estimation scheme. The performance was evaluated by two independent reviewers. From 48 consecutive epilepsy patients, 102 twenty-second seizure onset EEGs were used to evaluate artifacts before and after artifact removal and regarding the erroneous attenuation of true EEG patterns.

RESULTS

The two reviewers found "major improvements" in 59% and 49% of the EEG epochs respectively, and "minor improvements" in 38% and 47% of the epochs, respectively. The answer "similar or worse" was chosen only in 0% and 4%, respectively. Neither of the reviewers found "major attenuations", i.e., a significant attenuation of significant EEG patterns. Most EEG epochs were found to be either "mostly preserved" or "all preserved". A "minor attenuation" was found only in 0% and 17%, respectively.

CONCLUSIONS

The proposed artifact removal algorithm effectively removes artifacts from EEGs and improves the readability of EEGs impaired by artifacts. Only in rare cases did the algorithm slightly attenuate EEG patterns, but the clear visibility of significant patterns was preserved in all cases of this study. Current artifact removal methods work either semi-automatically or with insufficient reliability for clinical use, whereas the "PureEEG" method works fully automatically and leaves true EEG patterns unchanged with a high reliability.

Weight loss and weight regain-5-year follow-up for circular- vs. linear-stapled gastrojejunostomy in laparoscopic Roux-en-Y gastric bypass

BACKGROUND

Weight regain (WR) occurs in some patients after laparoscopic Roux-en-Y gastric bypass (LRYGBP). Loss of restriction due to dilation of the gastrojejunostomy (GJS) or the gastric pouch might be the main cause for WR. With different techniques available for the establishment of the GJS, the surgical technique might influence long-term success.

METHODS

We present a 5-year follow-up for weight loss and WR of a matched-pair study comparing circular stapled (CSA) to linear stapled (LSA) GJS in a series of 150 patients who underwent primary antecolic antegastric LRYGBP. Complete 5-year follow-up was obtained for 79 % of the patients.

RESULTS

Excess BMI loss (EBL) at 3 months was better with the CSA (p = 0.02) and comparable thereafter. The 5-year %EBL was 67.3 ± 23.2 vs. 73.3 ± 24.3 % (CSA vs. LSA, p = 0.19) WR of > 10 kg from nadir was found in 24 patients (16 %) with higher incidence in CSA than in LSA patients (20 % vs. 12 %). The %WR was comparable for both groups, 16 ± 13 vs. 15 ± 19 % (CSA vs. LSA, p = 0.345). Eleven patients underwent surgical re-intervention for WR by placement of a non-adjustable band (n = 2), adjustable band (n = 7) and conversion to distal gastric bypass (n = 2).

CONCLUSIONS

CSA and LSA lead to comparable weight loss in this 5-year follow-up. More patients in the CSA group had WR. Weight regain of more than 10 kg was found in one out of seven patients within 5 years postoperatively.

Gastric stimulation in the digestive period modifies length and contractility of the inter-digestive period in obese non-diabetic and diabetic subjects

BACKGROUND

The association between phase II of the motor migratory complex (MMC) and hunger remains poorly understood, which may be important in non-diabetic and diabetic obese subjects where gastric inter-digestive motility has been often reported as impaired. We characterize phase II of the MMC and its predictive power on food intake, weight loss, and glycemia in non-diabetic (OB) and diabetic (DM) obese subjects treated with gastric stimulation for 6 months.

METHODS

Twelve OB and 12 DM subjects were implanted with bipolar electrodes connected to a gastric stimulator capable of recording antrum electromechanical activity.

RESULTS

The phase II mean interval size and duration increased from 156 ± 121 to 230 ± 228 s and from 98 ± 33 to 130 ± 35 min (p < 0.05) in OB and from 158 ± 158 to 180 ± 112 s and from 77 ± 26 to 109 ± 18 min (p < 0.05) in DM after 6 months. There was a significant trend of meals to interrupt the late rather than the early phase II. Nonlinear regression analysis demonstrated that weight loss in OB was significantly associated with the change in interval size of the late phase II and with phase II duration. In the DM group, weight loss and glycemia were also significantly associated with the change in the interval size of the early phase II.

CONCLUSIONS

Gastric stimulation delivered in the digestive period can modify the length of the MMC and the contractility in its longest component, phase II. The duration and contractility of the MMC can determine to some extent future intake and, thus, influence energy balance.

Pretherapeutic laboratory findings, extent of metastasis and choice of treatment as prognostic markers in ocular melanoma- a single centre experience

BACKGROUND

Uveal melanoma is the most common intraocular neoplasm with a high tendency to metastasize predominantly to the liver. Prognostic parameters for progression and overall survival are not well defined. The aim of this study was to assess the value of pretherapeutic serum levels of C-reactive protein (CRP), lactate dehydrogenase, albumin and fibrinogen in patients with uveal melanoma and to evaluate their significance as prognostic parameters for survival.

METHODS

Forty-nine patients with metastatic uveal melanoma treated between 2000 and 2010 were retrospectively analysed. The potential influence of levels of CRP, lactate dehydrogenase, fibrinogen and albumin as well as other commonly known prognostic variables on progression-free and overall survival were investigated.

RESULTS

Patients' age and treatment with systemic chemotherapy were the only variables to show significant influences on progression-free and overall survival in a univariate analysis. Multivariate analysis confirmed the influence of these variables on progression-free survival, presence of metastasis, pretherapeutic CRP levels and treatment with systemic chemotherapy were associated with overall survival.

CONCLUSION

In this patient cohort elevated pretherapeutic CRP and extent of metastasis are independent prognostic factors for decreased overall survival, whereas treatment with systemic chemotherapy showed a significant association with improved overall survival.