Disparity of Primary and Secondary Language Outcomes in Bilingual Patients Undergoing Resection of Glioma of the Speech-Related Regions

BACKGROUND

The existing data about language recovery in bilingual patients come from few studies on acute lesional deficits like stroke or traumatic injury. Still, little is known about the neuroplasticity potential of bilingual patients who undergo resection of gliomas affecting language-eloquent brain regions. In this study, we prospectively evaluated the pre- and postoperative language functions among bilinguals with eloquent region gliomas.

METHODS

We have prospectively collected the preoperative, 3-month and 6-month postoperative data from patients with tumors infiltrating the dominant hemisphere language areas during a 15-month period. Validated Persian/Turkish version of Western Aphasia Battery test and Addenbrooke Cognitive Examination were assessed for main language (L1) and second acquired languages (L2) in each visit.

RESULTS

Twenty-two right-handed bilingual patients were enrolled, and language proficiencies were assessed using mixed model analysis. On baseline and postoperative points, L1 had higher scores in all Addenbrooke Cognitive Examination and Western Aphasia Battery subdomains than L2. Both languages had deterioration at 3-month visit; however, L2 was significantly more deteriorated in all domains. At 6-month visit, both L1 and L2 showed recovery; however, L2 recovered to a less extent than L1. The single most parameter affecting the ultimate language outcome in this study was the preoperative functional level of L1.

CONCLUSIONS

This study shows L1 is less vulnerable to operative insults and L2 may be damaged even when L1 is preserved. We would suggest the more sensitive L2 be used as the screening tool and L1 be used for confirmation of positive responses during language mapping.

Spontaneous Intraparenchymal Hemorrhage in Patients with COVID-19: A Prospective Study and Literature Review

Introduction Coronavirus disease 2019 (COVID-19) is a devastating pandemic that may also affect the nervous system. One of its neurological manifestations is intracerebral hemorrhage (ICH). Data about pure spontaneous intraparenchymal hemorrhage related to COVID-19 is scarce. In this study, we present some patients with COVID-19 disease who also had spontaneous intraparenchymal hemorrhage along with a review of the literature.

Methods This single-center prospective study was done among 2,862 patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) between March 1 and November 1, 2020. Out of 2,862 patients with SARS-CoV-2, 14 patients with neurological manifestations were assessed with a noncontrast brain computed tomography scan. Seven patients with spontaneous intraparenchymal hemorrhage were enrolled.

Results All seven patients were male, with a mean age of 60.8 years old. Six patients (85.7%) only had minimal symptoms of COVID-19 without significant respiratory distress. The level of consciousness in two patients (28.5%) was less than eight, according to the Glasgow Coma Scale (GCS). Hypertension (71.4%) was the most common risk factor in their past medical history. The mean volume of hematoma was 41cc. Four patients died during hospitalization, and the others were discharged with a mean hospital stay of 42.6 days. All patients with GCS less than 11 died.

Conclusion It concluded that ICH patients with COVID-19 are related to higher blood volume, cortical and subcortical location of hemorrhage, higher fatality rate, and younger age that is different to spontaneous ICH in general population. We recommend more specific neuroimaging in patients with COVID 19 such as brain magnetic resonance imaging concomitant with vascular studies in future. The impact of COVID-19 on mortality rate is not clear because of limited epidemiologic studies, but identifying the causal relationship between COVID-19 and ICH requires further clinical and laboratory studies.

Severe acute respiratory syndrome coronavirus 2 and seizure: An insight into the pathophysiologic mechanisms

Based on previous studies, seizure has been reported to accompany coronavirus disease 2019 (COVID-19). Underlying mechanisms are those leading to the direct central nervous system (CNS) invasion through hematogenous spread or trans-synaptic retrograde invasion, causing meningoencephalitis. On the other hand, there are pathophysiologic mechanisms that seizure would be one of their early consequences, such as cytokine storm, hypoxemia, metabolic derangement, and structural brain lesions. Herein, we focused on available evidence to provide an insight into the pathophysiologic mechanisms that link seizure and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, as a better understanding of pathophysiology would lead to better diagnosis and treatment.

A Prospective Randomized Study Comparing Mini-surgical Percutaneous Dilatational Tracheostomy With Surgical and Classical Percutaneous Tracheostomy: A New Method Beyond Contraindications

Although percutaneous dilatational tracheostomy (PDT) is more accessible and less time-demanding compared with surgical tracheostomy (ST), it has its own limitations. We introduced a modified PDT technique and brought some surgical knowledge to the bedside to overcome some standard percutaneous dilatational tracheostomy relative contraindications. PDT uses a blind route of tracheal access that usually requires perioperational imaging guidance to protect accidental injuries. Moreover, there are contraindications in certain cases, limiting widespread PDT application. Different PDT modifications and devices have been represented to address the problem; however, these approaches are not generally popular among professionals due to limited accessibility and/or other reasons.We prospectively analyzed the double-blinded trial, patient and nurse head evaluating the complications, and collected data from 360 patients who underwent PDT, ST, or our modified mini-surgical PDT (msPDT, Hashemian method). These patients were divided into 2 groups-contraindicated to PDT-and randomization was done for msPDT or PDT in PDT-indicated group and msPDT or ST for PDT-contraindicated patients. The cases were compared in terms of pre and postoperational complications.Data analysis demonstrated that the mean value of procedural time was significantly lower in the msPDT group, either compared with the standard PDT or the ST group. Paratracheal insertion, intraprocedural hypoxemia, and bleeding were also significantly lower in the msPDT group compared with the standard PDT group. Other complications were not significantly different between msPDT and ST patients.The introduced msPDT represented a semiopen incision, other than blinded PDT route of tracheal access that allowed proceduralist to withdraw bronchoscopy and reduced the total time of procedure. Interestingly, the most important improvement was performing msPDT on PDT-contraindicated patients with the complication rate comparable to surgical procedure. Supplements citation missing in the text. Please check supplements video in original manuscript.

Complexity of Compensatory Effects in Nrf1 Knockdown: Linking Undeveloped Anxiety-Like Behavior to Prevented Mitochondrial Dysfunction and Oxidative Stress

Anxiety-related disorders are complex illnesses that underlying molecular mechanisms need to be understood. Mitochondria stand as an important link between energy metabolism, oxidative stress, and anxiety. The nuclear factor, erythroid-derived 2,-like 1(Nrf1) is a member of the cap "n" collar subfamily of basic region leucine zipper transcription factors and plays the major role in regulating the adaptive response to oxidants and electrophiles within the cell. Here, we injected small interfering RNA (siRNA) targeting Nrf1 in dorsal third ventricle of adult male albino Wistar rats and subsequently examined the effect of this silencing on anxiety-related behavior. We also evaluated apoptotic markers and mitochondrial biogenesis factors, along with electron transport chain activity in three brain regions: hippocampus, amygdala, and prefrontal cortex. Our data revealed that in the group that received Nrf1-siRNA, anxiety-related behavior did not show any significant changes compared to the control group. Caspase-3 did not increase in Nrf1-siRNA-injected rats even though Bax/Bcl2 ratio markedly elevated in Nrf1-knockdown rats in all three mentioned regions compared to control rats. Also, Nrf1 silencing of complex I and II-III did not alter, generally. In addition, Nrf1-knockdown affected mitochondrial biogenesis markers. The level of peroxisome proliferator-activated receptor gamma coactivator-1α and cytochrome-c increased, which indicates a possible role for mitochondrial biogenesis in anxiety.

Collaboration of geldanamycin-activated P70S6K and Hsp70 against beta-amyloid-induced hippocampal apoptosis: an approach to long-term memory and learning

One of the neuropathological hallmarks of Alzheimer's disease (AD) is the accumulation of beta-amyloid peptides (Aβ) in senile plaques. Aβ-induced oxidative stress is believed to be responsible for degeneration and apoptosis of neurons and consequent cognitive and memory deficits. Here, we investigated the possible neuroprotective effect of the heat shock protein 90 (Hsp90) inhibitor geldanamycin (GA) against amyloid pathogenesis in adult male Wistar rats. GA or vehicle was injected into the lateral cerebral ventricles of rats 24 h before injection of Aβ (1-42) in CA1 area of hippocampus. The learning and memory of the rats were assessed 7 days after injection of Aβ using passive avoidance (PA) task. As potential contributing factors in Aβ-induced memory decline, we evaluated apoptotic markers and also used terminal-transferase UTP nick end labeling (TUNEL) technique to detect apoptosis in the hippocampus of Aβ-injected rats. Our behavioral data suggest that GA pretreatment can significantly suppress memory deficits in Aβ-injected rats. There was also not only a marked increase in Hsp70 level but also upregulated 70 kDa ribosomal protein S6 kinase (p70S6K) in the hippocampus of GA-treated groups with a reduction in apoptotic factors including caspase-3, poly (ADP-ribose) polymerase, Bax/Bcl-2 ratio, and TUNEL-positive cells as well. Thus, we conclude that GA exerts its protective effects against Aβ (1-42) toxicity and memory deficits, at least in part, by upregulating of Hsp70 and P70S6K.

Encapsulated Choroid Plexus Epithelial Cells Actively Protect Against Intrahippocampal Aβ-induced Long-Term Memory Dysfunction; Upregulation of Effective Neurogenesis with the Abrogated Apoptosis and Neuroinflammation

Choroid plexus epithelial cells (CPECs) as a secretory epithelium are responsible for the secretion of cerebrospinal fluid (CSF). Beyond this classical tenet, CPECs also synthesize and release many neurotrophic factors such as antioxidants into the CSF, participating in brain homeostasis. In this study, CPECs were isolated from rat's brain and encapsulated in alginate microcapsules. Firstly, functional properties of alginate microcapsules and encapsulated CPECs were examined in vitro. Following, micro-encapsulated CPECs were grafted into rats' brains that were pretreated with Aβ. The in vivo studies include western blotting against Caspase-3 and Terminal-Transferase dUTP Nick End Labeling test that were performed to detect apoptosis in brain tissues. The in vivo part also included immunohistochemistry against Iba-1, glial fibrillary acidic protein, and Brdu to detect microglial migration, gliosis, and neurogenesis, respectively. Moreover, the activity of superoxide dismutase enzyme in hippocampi also was measured, and the memory was assessed by shuttle box apparatus. Our data suggest that transplantation of encapsulated CPECs resulted in a significant decrease in apoptosis, reduced migration microglia, diminished gliosis, increased neurogenesis, and improved long-term memory as well as upregulated antioxidant activity. Since microencapsulated CPECs do not need immunosuppression following implantation, and also we showed their neuroprotective effects against Aβ toxicity and oxidative stress, this may be a suitable candidate for cell therapy in neurological disorders.

Silencing of Hsp70 intensifies 6-OHDA-induced apoptosis and Hsp90 upregulation in PC12 cells

By the current study, we tried to find out the interactive mechanisms enrolled by Hsp70 and Hsp90 following the 6-hydroxydopamine (6-OHDA)-induced oxidative stress. Of heat shock protein (Hsp) family, we have previously evaluated the effects of Hsp90 gene silencing on in vitro model of Parkinson's disease and its influence on controlling the mechanisms of cell survival. Here, we extended our study to Hsp70 silencing short interfering RNA (siRNA) oligonucleotides, transfected into Pheochromocytoma (PC12) cells with/without exposure to 6-OHDA stress. In order to determine the probable effects of Hsp70 silencing on apoptotic factors, we assessed Bcl2/Bax ratio, nuclear level of PARP, and cleavage of caspase-3 under 6-OHDA stress condition. The results showed deteriorated effect of Hsp70 siRNA on apoptosis in cells exposed to only 6-OHDA. This is, at least in part, in consequence of upregulation of Hsp90, both at messenger RNA (mRNA) and protein levels. These data highlight the critical role of Hsp70 for cell survival under 6-OHDA stress condition. It could be a suggestive issue for supervision of caspase cascades by survival roles of Hsps as Hsp70 silencing resulted in apoptosis phenomenon. Convergence of Hsp70 anti-apoptotic and 6-OHDA pro-apoptotic pathways may explain intensified apoptosis following Hsp70 silencing. In addition, nuclear factor erythroid-2-related factor 2 (Nrf2), a transcription factor, has been previously studied in detoxification of oxidative stress. For this issue, we tried to elucidate Hsp70 silencing impact on Nrf2, which has been shown to regulate the transcription of Hsp70, unspecifically. Besides, our investigations revealed that Hsp70 siRNA did not affect the level of Nrf2 during 6-OHDA exposure. But, it is still a dealing question and other investigations are needed to have a comprehensive perception of Hsp family signaling functions.

Involvement of Nrf2 in development of anxiety-like behavior by linking Bcl2 to oxidative phosphorylation: estimation in rat hippocampus, amygdala, and prefrontal cortex

Anxiety-related disorders are complex illnesses that underlying molecular mechanisms of these complicated emotional disorders are poorly understood. Nuclear factor erythroid 2-related factor 2 (Nrf2) is the most important regulator of the antioxidant defense system. Its protective actions are not only limited to antioxidative transactivation, but also plays important roles in encountering various physiological and pathological stresses. In this study, we evaluated whether silencing of Nrf2 plays a role in development of anxiety-related behavior. In this regard, we exerted small interfering RNA (siRNA) targeting Nrf2 in dorsal third ventricle and subsequently examined the effect of this silencing on anxiety-related behavior along with supposed molecular mechanisms. Therefore, we evaluated apoptotic markers and mitochondrial electron transport chain (ETC) activity in three brain regions: hippocampus, amygdala, and prefrontal cortex. Based on our result, Nrf2-silenced rats exhibited greater anxiety-like behavior compared to control group. Furthermore, Nrf2 silencing increased activity of ETC complexes. Also, Bax/Bcl2 ratio of all mentioned areas of the brain and cleavage of caspase-3 in hippocampus increased in Nrf2 silenced group, however, with a distinct pattern.

Nrf2 and Nrf1 signaling and ER stress crosstalk: implication for proteasomal degradation and autophagy

The endoplasmic reticulum (ER) lumen is chemically complex and crowded with polypeptides in different stages of assembly. ER quality control monitors chaperone-assisted protein folding, stochastic errors and off-pathway intermediates. In acute conditions, potentially toxic polypeptides overflow the capacity of the chaperone system and lead to ER stress. Activation of the unfolded protein response (UPR) following ER stress buys time for non-native polypeptides to refold or be eliminated; otherwise cell death occurs. The clearance routes for deleterious proteins are endoplasmic reticulum-associated degradation (ERAD) and ER stress-activated autophagy. The ERAD pathway is a chaperone and proteasome-mediated polypeptide degradation, while autophagy applies to wider range of substances. ER stress signal transduction recruits diverse molecules and pathways upon UPR induction to compensate stress condition. NF-E2-related factor 1 (Nrf1) and Nrf2 are two transcription factors mostly known by their induction through an antioxidant response; they can also be activated by UPR machinery. Discovery of diverse molecules downstream of Nrf1 and Nrf2 has expanded our understanding of the biological impacts of these transcription factors beyond classic antioxidant activation. In this review, we summarize our current understanding of mutual relationships between Nrf1, Nrf2, and ER stress clearance mechanisms and highlight the crosstalk of specific molecules mediating these correlations.