Involvement of fast-spiking cells in ictal sequences during spontaneous seizures in rats with chronic temporal lobe epilepsy

Epileptic seizures represent altered neuronal network dynamics, but the temporal evolution and cellular substrates of the neuronal activity patterns associated with spontaneous seizures are not fully understood. We used simultaneous recordings from multiple neurons in the hippocampus and neocortex of rats with chronic temporal lobe epilepsy to demonstrate that subsets of cells discharge in a highly stereotypical sequential pattern during ictal events, and that these stereotypical patterns were reproducible across consecutive seizures. In contrast to the canonical view that principal cell discharges dominate ictal events, the ictal sequences were predominantly composed of fast-spiking, putative inhibitory neurons, which displayed unusually strong coupling to local field potential even before seizures. The temporal evolution of activity was characterized by unique dynamics where the most correlated neuronal pairs before seizure onset displayed the largest increases in correlation strength during the seizures. These results demonstrate the selective involvement of fast spiking interneurons in structured temporal sequences during spontaneous ictal events in hippocampal and neocortical circuits in experimental models of chronic temporal lobe epilepsy

Second Virtual International Symposium on Cellular and Organismal Stress Responses, September 8–9, 2022 [Meeting Review]

The Second International Symposium on Cellular and Organismal Stress Responses took place virtually on September 8–9, 2022. This meeting was supported by the Cell Stress Society International (CSSI) and organized by Patricija Van Oosten-Hawle and Andrew Truman (University of North Carolina at Charlotte, USA) and Mehdi Mollapour (SUNY Upstate Medical University, USA). The goal of this symposium was to continue the theme from the initial meeting in 2020 by providing a platform for established researchers, new investigators, postdoctoral fellows, and students to present and exchange ideas on various topics on cellular stress and chaperones. We will summarize the highlights of the meeting here and recognize those that received recognition from the CSSI

Susceptibility and Antibody Response of the Laboratory Model Zebra Finch (Taeniopygia guttata) to West Nile Virus

Since the introduction of West Nile virus (WNV) into North America in 1999 a number of passerine bird species have been found to play a role in the amplification of the virus. Arbovirus surveillance, observational studies and experimental studies have implicated passerine birds (songbirds, e.g., crows, American robins, house sparrows, and house finches) as significant reservoirs of WNV in North America, yet we lack a tractable passerine animal model for controlled studies of the virus. The zebra finch (Taeniopygia guttata) serves as a model system across a diversity of fields, and here we develop the zebra finch a songbird model for WNV. Like many natural hosts of WNV, we found that zebra finches developed sufficient viremia to serve as a competent host, yet in general resisted mortality from infection. In the Australian zebra finch (AZF) T. g. castanotis, we detected WNV in the majority of sampled tissues by 4 days post injection (dpi). However, WNV was not detected in tissues of sacrificed birds at 14 dpi, shortly after the development of detectable anti-WNV antibodies in the majority of birds indicating successful viral clearance. We compared susceptibility between the two zebra finch subspecies AZF and Timor zebra finch (TZF) T. g. guttata. Compared to AZF, WNV RNA was detected in a larger proportion of challenged TZF and molecular detection of virus in the serum of TZF was significantly higher than in AZF. Given the observed moderate host competence and disease susceptibility, we suggest that zebra finches are appropriate as models for the study of WNV and although underutilized in this respect, may be ideal models for the study of the many diseases carried and transmitted by songbirds

Health outcomes and the transition experience of HIV-infected adolescents after transfer to adult care in Québec, Canada.

BACKGROUND: Little is known on outcomes after transition to adult care among adolescents with perinatal HIV infection. Though there is data from other chronic pediatric diseases suggesting increased morbidity and mortality following transfer to adult care, this has not well been studied among the first wave of survivors of perinatal HIV infection. The primary objective of this study was to determine outcomes after transition to adult care among a cohort of HIV-infected adolescents in Québec, Canada. Secondary objectives were to document participant experiences with the transition process, identify barriers to successful transition, and potential changes to improve the transition process. METHODS: Clinic records were reviewed to identify all perinatally-infected youth who transitioned from the Centre Maternel et Infantile sur le Sida pediatric HIV clinic (Montreal) at age 18 to an adult care provider between 1999 and 2012. Transitioned patients were contacted using last available patient or parental listed phone number on hospital record, internet based telephone directory, or social media. A standardized questionnaire was administered by telephone or in-person interview, and copies of current medical records obtained from treating physicians. RESULTS: Forty-five patients were transferred between 1999 and 2012, among whom 25 consented to the study, eight were lost to follow-up, eight refused participation, and four were deceased. Overall 76 % of patients remained engaged in care, defined by at least one physician visit within 6 months of the interview. Over 50 % reported difficulty with adherence to their current drug regimens. At one-year post-transfer, there was a decrease in the proportion of patients with CD4 count >500 cells/mm(3) from 64 to 29 %, and a statistically significant decrease in absolute CD4 count (mean 370 vs 524 cells/mm(3), p = 0.04.). The majority (92 %) of participants felt that 18 was too young an age to transfer to adult care, and provided suggestions for improving the transition process. CONCLUSIONS: This group of perinatally-infected youth remained engaged in care after transition, however difficulties with adherence and assuming responsibility for their own care were identified as issues in their post-transition care. The high rate of mortality among them and the changes to their health status post-transition suggest that further work is necessary to document the health outcomes of this group in larger, more diverse cohort settings

MOESM1 of Interference between surgical magnetic drapes and pacemakers: an observational study comparing commercially available devices and a new magnetically isolated drape

Additional file 1. Patent for the LT10GTM drape from Menodys: US patent 9,232,976. Dated January 12th, 2016. http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=9232976.PN.&OS=PN/9232976&RS=PN/9232976

Epithelial lacrimal gland tumors: pathologic classification and current understanding

OBJECTIVE: To apply the updated epithelial salivary gland classification scheme to a large cohort of lacrimal gland tumors so as to provide an updated lacrimal gland tumor classification scheme. METHODS: A retrospective multicenter cohort study of 118 cases of epithelial neoplasia was undertaken. Main outcome measures included pathologic analysis, subtyping, and survival. RESULTS: Of 118 cases, 17 (14%) were reclassified using the proposed expanded classification scheme based on the current World Health Organization classification of salivary gland tumors. The most frequent neoplasms were pleomorphic adenoma and adenoid cystic carcinoma, of which we highlight more unusual histologic features. Three tumors were found to be unclassifiable with the updated scheme, with 2 having histologically malignant features. Deficiencies and variations in pathologic assessment were noted. Variation in the histologic findings of pleomorphic adenoma and assessment of the extent of invasion of carcinoma ex pleomorphic adenoma were highlighted. CONCLUSIONS: The use of the more histologically diverse classification of salivary gland tumors can be successfully applied to the epithelial lacrimal gland neoplasms. This expanded classification system led to reclassifying 14% of cases. Currently, there are no consistent pathologic standards for processing and evaluating these lesion

Involvement of fast-spiking cells in ictal sequences during spontaneous seizures in rats with chronic temporal lobe epilepsy

See Lenck-Santini (doi:10.1093/awx205) for a scientific commentary on this article. Epileptic seizures represent altered neuronal network dynamics, but the temporal evolution and cellular substrates of the neuronal activity patterns associated with spontaneous seizures are not fully understood. We used simultaneous recordings from multiple neurons in the hippocampus and neocortex of rats with chronic temporal lobe epilepsy to demonstrate that subsets of cells discharge in a highly stereotypical sequential pattern during ictal events, and that these stereotypical patterns were reproducible across consecutive seizures. In contrast to the canonical view that principal cell discharges dominate ictal events, the ictal sequences were predominantly composed of fast-spiking, putative inhibitory neurons, which displayed unusually strong coupling to local field potential even before seizures. The temporal evolution of activity was characterized by unique dynamics where the most correlated neuronal pairs before seizure onset displayed the largest increases in correlation strength during the seizures. These results demonstrate the selective involvement of fast spiking interneurons in structured temporal sequences during spontaneous ictal events in hippocampal and neocortical circuits in experimental models of chronic temporal lobe epilepsy.status: publishe