Nonlinear analysis and recognition of epileptic EEG signals in different stages.

It is a hot problem in epilepsy research to detect and predict seizures by EEG signals. Clinically, it is generally observed that there are only sudden abnormal signals during the ictal stage, but there is no significant difference in the EEG signal between the interictal and preictal stages. To solve the problem that preictal signals are difficult to recognize clinically, and then effectively improve the recognition efficiency of epileptic seizures, so, in this paper, some nonlinear methods are comprehensively used to extract the hidden information in the EEG signals in different stages, namely, phase space reconstruction (PSR), Poincaré section (PS), synchroextracting transform (SET) and machine learning for EEG signal analysis. Firstly, PSR based on C-C method is used, and the results show that there are different diffuse attractor trajectories of the signals in different stages. Secondly, the confidence ellipse (CE) is constructed by using the scatter diagram of the corresponding trajectory on PS, and the aspect ratio and area of the ellipse are calculated. The results show that there is an interesting transitional phenomenon in preictal stage. To recognize ictal and preictal signals, time-frequency (TF) spectrums which are processed by SET are fed into the convolutional neural networks (CNN) classifier. The accuracy of recognize ictal and preictal signals reaches 99.7% and 93.7% respectively. To summarize, our results based on nonlinear method provide new research ideas for seizures detection and prediction.

Corrigendum: Study on characteristic of epileptic multi-electroencephalograph base on Hilbert-Huang transform and brain network dynamics.

[This corrects the article DOI: 10.3389/fnins.2023.1117340.].

Study on characteristic of epileptic multi-electroencephalograph base on Hilbert-Huang transform and brain network dynamics.

Lots of studies have been carried out on characteristic of epileptic Electroencephalograph (EEG). However, traditional EEG characteristic research methods lack exploration of spatial information. To study the characteristics of epileptic EEG signals from the perspective of the whole brain，this paper proposed combination methods of multi-channel characteristics from time-frequency and spatial domains. This paper was from two aspects: Firstly, signals were converted into 2D Hilbert Spectrum (HS) images which reflected the time-frequency characteristics by Hilbert-Huang Transform (HHT). These images were identified by Convolutional Neural Network (CNN) model whose sensitivity was 99.8%, accuracy was 98.7%, specificity was 97.4%, F1-score was 98.7%, and AUC-ROC was 99.9%. Secondly, the multi-channel signals were converted into brain networks which reflected the spatial characteristics by Symbolic Transfer Entropy (STE) among different channels EEG. And the results show that there are different network properties between ictal and interictal phase and the signals during the ictal enter the synchronization state more quickly, which was verified by Kuramoto model. To summarize, our results show that there was different characteristics among channels for the ictal and interictal phase, which can provide effective physical non-invasive indicators for the identification and prediction of epileptic seizures.

The expression of podoplanin protein is a diagnostic marker to distinguish the early infiltration of esophageal squamous cell carcinoma.

The esophageal squamous cell carcinoma (ESCC) is usually develped from low-grade intraepithelial neoplasia (LGIEN) and high-grade intraepithelial neoplasia (HGIEN) to infiltrative squamous cell carcinoma. Till now, it remains hard to screen for infiltration at earlier stages, especially the differentiation between HGEIN and early infiltrative carcinoma. The purpose of this study is to determine a role of podoplanin in differentiating between HGEIN and early infiltrative squamous cell carcinoma. Totally 133 patients pathologically diagnosed with early ESCC and/or precancerous lesions were enrolled.The EnVision two-step IHC staining technique was applied using the monoclonal mouse anti-human Podoplanin antibody (clone number: D2-40). The expressions of PDPN protein on the basal layer of squamous epithelium lesions could be divided into three different patterns: complete type, incomplete (non-continuous) type, or missing type. A diagnosis of HGEIN can be made if the basal layer showed non-continuous or complete expression of PDPN and a diagnosis of early infiltration can be made if the expression of PDPN is completely missing. Our study confirmed that PDPN was a potential biomarker to identify the presence of early infiltrative squamous cell carcinoma.

[Discrepancies in pathologic evaluation of dyaplasia/early cancer in 60 gastric endoscopic submucosal dissection specimens].

OBJECTIVE: To study the reasons for the discrepancies in pathologic diagnosis of gastric dysplasia/early cancer in endoscopic submucosal dissection (ESD) specimens, and how to cope with the discrepancies. METHODS: The pathologic diagnoses in 60 cases of ESD specimens according to the three currently used classification systems (namely Western criteria, Japanese criteria and Vienna classification) were compared. The diagnostic discrepancies were analyzed. RESULTS: Fifteen of the 17 cases diagnosed as low-grade intraepithelial neoplasia according to the Western criteria were revised as adenoma by the Japanese criteria. Amongst the 43 cases of gastric intramucosal adenocarcinoma diagnosed according to the Japanese criteria, 23 cases had concordant diagnosis by the Western criteria. While the diagnosis of low-grade intraepithelial neoplasia/adenoma was basically similar irrespective of classification system used, there were significant differences in the interpretation of gastric early cancer. CONCLUSIONS: The diagnostic discrepancies in the gastric dysplasia/early cancer are mainly related to the morphologic criteria applied in different classifications. In order to facilitate clinical and pathologic communication, a consensus using Vienna/WHO classifications, supplemented with Japanese system, is desirable.

Effects of external stimuli on the pacemaker function of the sinoatrial node in sodium channel gene mutations models.

Loss of function and gain of function mutations of the sodium channel were investigated using an intact two-dimensional rabbit sinoatrial node (SAN) and atrial cell model. The effects of three external stimuli (acetylcholine secretion by the vagal nerve, acid-base concentration, and tissue temperature) on cardiac pacemaker function and conduction were studied. Our results show that these two groups of mutations have different effects on pacemaker function and conduction. Furthermore, we found that the negative effects of these mutations could be altered by external stimuli. The bradycardic effects of mutations were magnified by an increase in acetylcholine level. Changes in acid-base concentration and tissue temperature increased the ability of the SAN to recover its pacemaker function. The results of this study increase our understanding of sodium channel disorders, and help to advance research on the treatment of these conditions.

[Clinical and pathologic features of tubulocystic carcinoma of kidney].

OBJECTIVE: To investigate clinicopathological features and differential diagnosis of tubulocystic carcinoma of the kidney. METHODS: The clinical features, histological and immunohistochemical findings were analyzed in 3 cases of tubulocystic carcinoma of the kidney, along with review of the related literatures. RESULTS: Three patients were males with a mean age of 59 years old (range from 44 to 71 years). All presented with no symptom and their tumors were found during routine examination. The tumor size ranged from 1.5 to 5.0 cm in greatest dimension. The tumors were grossly well-circumscribed without capsules and exhibited a spongy cut surface. Microscopically, all three tumors were composed of tubules and cysts of varying sizes separated by thin fibrous septa. The epithelial lining cells were flat, cuboidal and columnar, with often a hobnail-like appearance characterized by abundant eosinophilic cytoplasm with prominent nucleoli. Two cases showed focal clear cytoplasm. One of the three cases coexisted with a papillary renal cell carcinoma. Immunohistochemically, all 3 cases showed positivity for pan-CK, vimentin, CK19, CD10, P504S, and focal positivity for 34ßE12. Two cases showed focal positivity for CK7. CONCLUSIONS: Tubulocystic carcinoma of the kidney is a rare kidney neoplasm and occurs predominantly in males. The tumor is characterized by gross spongy appearance and microscopic cysts and tubules often lined by hobnail-like cells and separated by thin fibrotic stroma. The differential diagnosis mainly includes other lesions of the kidney that have a multicystic growth pattern.

Mesenchymal cystic hamartoma of the lung.

Mesenchymal cystic hamartoma (MHC) of the lung is a very rare disease with an indolent clinical course and might be easily misdiagnosed as pleuropulmonary blastoma and other uncommon cystic lung lesions. We present a case of a 43-year-old woman who had sudden dyspnea resulting from a spontaneous right-sided pneumothorax. Computed tomography revealed multiple bilateral nodules and cysts of the right lung. Pathologically, the cysts and nodules were composed of primitive mesenchymal cells. The walls of the cysts were lined with normal respiratory epithelium and the nodules were permeated by scattered airways that were also lined with normal respiratory epithelium. Based on the combination of pathologic and clinical features, we made the diagnosis of MHC. One and one-half years after thoracotomy the patient is well without evidence of recurrence.

[Clinicopathologic study of juvenile granulosa cell tumor of ovary].

OBJECTIVE: To study the clinicopathologic features, diagnostic criteria and prognostic parameters of juvenile granulosa cell tumor of ovary. METHODS: The clinical and pathologic findings of 7 cases of juvenile granulosa cell tumor were retrospectively reviewed. Immunohistochemical study was carried out in 6 of these cases. The follow-up data were also analyzed. RESULTS: The mean age of the patients was 24 years (range=6 to 53 years). Four patients presented with hormonal disturbance, while 3 patients presented with abdominal pain or swelling. Six patients underwent unilateral salpingo-oophorectomy. Six cases were in stage IA and the remaining case in stage IC. Follow-up information was available in 6 patients and the duration of follow up ranged from 1 to 10 years (mean=4.3 years). Five patients remained healthy, with no evidence of tumor recurrence. One patient died of tumor metastasis one year after the diagnosis. Gross examination showed that the tumor masses ranged from 7 to 20 cm in the greatest dimension (average=13.4 cm). Four of the 7 tumors were mixed solid-cystic in appearance and 2 cases were unilocular cystic in nature. Microscopic examination showed diffuse atypical follicular structures formed by granulosa cells. The granulosa cells contained round hyperchromatic nuclei, without nuclear grooves or Call-Exner body formation (6/7). In one of the cases studied, minor foci resembling adult granulosa cell tumor were also demonstrated. The degree of cellular atypia varied (3 cases with severe atypia, 1 case with moderate atypia and 3 cases with mild atypia). The mitotic count ranged from 1 to more than 5 per 10 high-power fields. Immunohistochemical study showed diffuse positivity for vimentin (6/6). The staining for cytokeratin (AE1/AE3) and calretinin was negative. Four cases expressed CD99 and 1 case was positive for inhibin. CONCLUSIONS: Juvenile granulosa cell tumor is characterized by the presence of diffuse atypical follicular structures formed by small round cells, without nuclear grooves or Call-Exner bodies. Rare cases contain minor foci of adult granulosa cell tumor. They can be unilocular cystic in nature. The degree of nuclear atypia, mitotic activity and size of the tumor vary and do not correlate with the risk of recurrence and aggressive biologic behavior.