Influence of the head model on EEG and MEG source connectivity analysis

The results of brain connectivity analysis using reconstructed source time courses derived from EEG and MEG data depend on a number of algorithmic choices. While previous studies have investigated the influence of the choice of source estimation method or connectivity measure, the effects of the head modeling errors or simplifications have not been studied sufficiently. In the present simulation study, we investigated the influence of particular properties of the head model on the reconstructed source time courses as well as on source connectivity analysis in EEG and MEG. Therefore, we constructed a realistic head model and applied the finite element method to solve the EEG and MEG forward problem. We considered the distinction between white and gray matter, the distinction between compact and spongy bone, the inclusion of a cerebrospinal fluid (CSF) compartment, and the reduction to a simple 3-layer model comprising only skin, skull, and brain. Source time courses were reconstructed using a beamforming approach and the source connectivity was estimated by the imaginary coherence (ICoh) and the generalized partial directed coherence (GPDC). Our results show that in both EEG and MEG, neglecting the white and gray matter distinction or the CSF causes considerable errors in reconstructed source time courses and connectivity analysis, while the distinction between spongy and compact bone is just of minor relevance, provided that an adequate skull conductivity value is used. Large inverse and connectivity errors are found in the same regions that show large topography errors in the forward solution. Moreover, we demonstrate that the very conservative ICoh is relatively safe from the crosstalk effects caused by imperfect head models, as opposed to the GPDC

Lymph node metastases are more frequent in paediatric appendiceal NET ≥1.5 cm but without impact on outcome – data from the German MET studies

Background Paediatric appendiceal neuroendocrine tumours (appNET) are very rare tumours, mostly detected incidentally by histopathological evaluation after appendectomy. Treatment recommendations are based on adult data considering high-risk NET as defined by European Neuroendocrine Tumour Society (ENETS) guidelines for completion right-sided hemicolectomy (RHC). Recent data suggest that less aggressive therapy may be justified. Procedure Analysis of children and adolescents with appNET prospectively registered with the German Malignant Endocrine Tumour (MET) studies between 1997 and 2022. Results By December 2022, 662 patients (64.7% females, 35.3% male) had been reported. Median age was 13.3 years [4.5–17.9], median duration of follow-up 2.2 years [0–10.9]. No distant metastases were reported. Tumour size was 2 cm in 3.2% of patients. WHO grade 1 and 2 tumours were diagnosed in 76.9% and 23.1% of patients, respectively. Lymphovascular invasion and lymph node metastases were associated with tumour size ≥1.5 cm. 27.0% of patients presented with high-risk NET according to ENETS criteria. Of those, only 55.9% underwent secondary oncological right hemicolectomy. Neither distant metastases, nor recurrences or disease-related deaths occurred in patients with appendectomy only as well as in patients with completion RHC. Overall and event-free survival were both 100%. Conclusions Internationally harmonized consensus recommendations on treatment of children and adolescents with appendiceal NET are urgently needed to avoid completion RHC in high-risk patients

Adrenocortical tumors and pheochromocytoma/paraganglioma initially mistaken as neuroblastoma — experiences from the GPOH-MET registry

In children and adolescents, neuroblastoma (NBL), pheochromocytoma (PCC), and adrenocortical tumors (ACT) can arise from the adrenal gland. It may be difficult to distinguish between these three entities including associated extra-adrenal tumors (paraganglioma, PGL). Precise discrimination, however, is of crucial importance for management. Biopsy in ACT or PCC is potentially harmful and should be avoided whenever possible. We herein report data on 10 children and adolescents with ACT and five with PCC/PGL, previously mistaken as NBL. Two patients with adrenocortical carcinoma died due to disease progression. Two (2/9, missing data in one patient) patients with a final diagnosis of ACT clearly presented with obvious clinical signs and symptoms of steroid hormone excess, while seven patients did not. Blood analyses indicated increased levels of steroid hormones in one additional patient; however, urinary steroid metabolome analysis was not performed in any patient. Two (2/10) patients underwent tumor biopsy, and in two others tumor rupture occurred intraoperatively. In 6/10 patients, ACT diagnosis was only established by a reference pediatric pathology laboratory. Four (4/5) patients with a final diagnosis of PCC/PGL presented with clinical signs and symptoms of catecholamine excess. Urine tests indicated possible catecholamine excess in two patients, while no testing was carried out in three patients. Measurements of plasma metanephrines were not performed in any patient. None of the five patients with PCC/PGL received adrenergic blockers before surgery. In four patients, PCC/PGL diagnosis was established by a local pathologist, and in one patient diagnosis was revised to PGL by a pediatric reference pathologist. Genetic testing, performed in three out of five patients with PCC/PGL, indicated pathogenic variants of PCC/PGL susceptibility genes. The differential diagnosis of adrenal neoplasias and associated extra-adrenal tumors in children and adolescents may be challenging, necessitating interdisciplinary and multidisciplinary efforts. In ambiguous and/or hormonally inactive cases through comprehensive biochemical testing, microscopical complete tumor resection by an experienced surgeon is vital to preventing poor outcome in children and adolescents with ACT and/or PCC/PGL. Finally, specimens need to be assessed by an experienced pediatric pathologist to establish diagnosis

Locally advanced adrenocortical carcinoma in children and adolescents — enigmatic and challenging cases

Background: Locally advanced tumors account for approximately 50% of children and adolescents with adrenocortical carcinoma (ACC), and of these, up to 50% relapse. We explored the five-item microscopic score and the pS-GRAS score for guiding management. Methods: Data from children and adolescents with COG stage II and III ACC registered in the MET studies were included. The five-item and pS-GRAS score were retrospectively calculated. Results: By December 2021, 55 patients with stage II and III (stage II n = 18, stage III n = 37) had been reported. Median age was 4.3 years [0.1–17.8], median duration of follow-up 6.0 years [0–16.7]. 3-year event-free survival (EFS) rate was 76.5% and 49.8% (p = 0.088), respectively. In stage II tumors, neither the five-item score (p = 0.872) nor pS-GRAS grouping (p = 0.218) had any effect as prognostic factors. In stage III patients, EFS was impaired in tumors with unfavorable histology according to the five-item score (100% vs. 30.8%, p = 0.018). No difference was observed for pS-GRAS groups (p = 0.798). Conclusions: In patients with COG stage III, but not stage II, the five-item score affected EFS. Further studies are needed to identify patients at risk in COG stage II

Migration of superior vena cava stent

There has been a recent increase in the use of endovascular prostheses resulting in complex surgical and interventional complications not previously recognised. We report a case of Superior vena cava stenosis treated with a wallstent which migrated to the right atrium, necessitating a combined radiological and surgical approach to retrieve it

MicroRNAs targeting oncogenes are down-regulated in pancreatic malignant transformation from benign tumors

BACKGROUND MicroRNA (miRNA) expression profiles have been described in pancreatic ductal adenocarcinoma (PDAC), but these have not been compared with pre-malignant pancreatic tumors. We wished to compare the miRNA expression signatures in pancreatic benign cystic tumors (BCT) of low and high malignant potential with PDAC, in order to identify miRNAs deregulated during PDAC development. The mechanistic consequences of miRNA dysregulation were further evaluated. METHODS Tissue samples were obtained at a tertiary pancreatic unit from individuals with BCT and PDAC. MiRNA profiling was performed using a custom microarray and results were validated using RT-qPCR prior to evaluation of miRNA targets. RESULTS Widespread miRNA down-regulation was observed in PDAC compared to low malignant potential BCT. We show that amongst those miRNAs down-regulated, miR-16, miR-126 and let-7d regulate known PDAC oncogenes (targeting BCL2, CRK and KRAS respectively). Notably, miR-126 also directly targets the KRAS transcript at a "seedless" binding site within its 3'UTR. In clinical specimens, miR-126 was strongly down-regulated in PDAC tissues, with an associated elevation in KRAS and CRK proteins. Furthermore, miR-21, a known oncogenic miRNA in pancreatic and other cancers, was not elevated in PDAC compared to serous microcystic adenoma (SMCA), but in both groups it was up-regulated compared to normal pancreas, implicating early up-regulation during malignant change. CONCLUSIONS Expression profiling revealed 21 miRNAs down-regulated in PDAC compared to SMCA, the most benign lesion that rarely progresses to invasive carcinoma. It appears that miR-21 up-regulation is an early event in the transformation from normal pancreatic tissue. MiRNA expression has the potential to distinguish PDAC from normal pancreas and BCT. Mechanistically the down-regulation of miR-16, miR-126 and let-7d promotes PDAC transformation by post-transcriptional up-regulation of crucial PDAC oncogenes. We show that miR-126 is able to directly target KRAS; re-expression has the potential as a therapeutic strategy against PDAC and other KRAS-driven cancers

Outcome for pediatric adreno-cortical tumors is best predicted by the COG stage and five-item microscopic score — report from the German MET studies

Background: Adrenocortical tumors (ACTs) encompassing the adrenocortical adenoma (ACA), carcinoma (ACC), and tumors of undetermined malignant potential (ACx) are rare endocrine neoplasms with a poor prognosis. We report on pediatric ACT patients registered with the Malignant Endocrine Tumor studies and explore the EXPeRT recommendations for management. Patients: Data from the ACT patients (<18 years) were analyzed. For the risk prediction, the patients were retrospectively assigned to the COG stages and the five-item score. Results: By December 2021, 161 patients with ACT (ACA n = 51, ACx n = 19, and ACC n = 91) had been reported (the median age at the diagnosis was 4.3 years with a range of 0.1–17.8), with lymph node and distant metastases in 10.7% and 18.9% of the patients with ACC/ACx. The mean follow-up was 4.5 years (with a range of 0–16.7). The three-year overall (OS) and event-free survival (EFS) rates were 65.5% and 50.6%. In the univariate analyses, the OS was impaired for patients aged ≥ 4 years (p = 0.001) with the initial biopsy (p = 0.016), tumor spillage (p = 0.028), incomplete tumor resection (p < 0.001), unfavorable histology (p = 0.047), and COG stages III/IV (p = 0.002). Multivariate analysis revealed COG stages III/IV and an unfavorable five-item score as independent negative prognostic factors for the EFS and OS. Conclusions: Age defines the clinical presentation and prognosis in pediatric ACTs. The outcome is best predicted by the COG stage and five-item score

Модернизация технологического процесса на газораспределительной станции Барабинского линейного производственного управления

Выпускная квалификационная работа содержит 160 страницы машинописного текста, 29 таблиц, 27 рисунков, 1 список использованных источников из 18 наименований, 9 приложений. Объектом исследования является газораспределительная станция. Цель работы – разработка автоматизированной системы управления ГРС с использованием ПЛК, на основе выбранной SCADA-системы. В данном отчете описан производственный процесс на газораспределительной станции Барабинского ЛПУМГ, а также выявлены производственные проблемы и даны рекомендации для совершенствования системы контроля и управления этого процесса.Final qualifying work contains 160 pages of typewritten text, 29 tables, 27 figures, 1 list of references from 18 names, 9 applications. The object of research is a gas distribution station. The purpose of work - development of automated gas distribution station control system using PLC, based on the selected SCADA-system. This report describes a manufacturing process at a gas distribution station Baraba LPUMG and identified production problems and recommendations for improving the monitoring and management of this process

Refractory and relapsed paediatric ACC in the MET studies – a challenging situation necessitating novel diagnostic and therapeutic concepts

Background Paediatric adrenocortical carcinomas (ACC) are highly aggressive malignancies with a dismal prognosis in advanced and metastatic disease. Little is known about outcome of patients with refractory and relapsed (r/r) disease. Procedure National retrospective multicentre study including r/r ACC diagnosed in patients aged <18 years registered in the MET studies between January 1997 and December 2021 Results A total of 16 patients (5 male; median age 12.9 years) with refractory disease were included. Median time to progression was 0.6 years [0.0-1.3]. Site of progression was locoregional (n=1), distant (n=3), and combined (n=12). 3-year overall (OS) and progression-free (PFS) survival were both 0%. Thirty patients with relapse (11 male; median age 7.3 years) were identified. Median time to relapse was 0.7 years [0.1-3.2]. Site of relapse was locoregional (n=8), distant (n=15), and combined (n=7). At last follow-up, 20 patients had died of disease or complications or were alive with disease, 10 patients were in second complete remission (median follow-up: 6.8 years [0-10.5]). 3-year OS and PFS following relapse were 39.1% and 31.9%. Survival was superior in patients with distant relapse (59.6%) compared to locoregional (28.6%) and combined (14.3%) (p=0.028) and in patients with complete surgical resection of all sites of recurrence (70.0%) compared to incomplete (21.4%) and no surgery (0%) (p=0.003). Conclusions For patients nonresponsive to first-line therapy or who experience relapse, prognosis is dismal and options are scarce. Site of relapse and resectability define prognosis. Novel therapeutic concepts are needed to improve the outcome of paediatric patients with r/r ACC