SARS‑CoV‑2 Omicron variant causes brain infection with lymphoid depletion in a mouse COVID‑19 model / 한국실험동물학회지

Background@#The Omicron variant has become the most prevalent SARS-CoV-2 variant. Omicron is known to induce milder lesions compared to the original Wuhan strain. Fatal infection of the Wuhan strain into the brain has been well documented in COVID-19 mouse models and human COVID-19 cases, but apparent infections into the brain by Omicron have not been reported in human adult cases or animal models. In this study, we investigated whether Omicron could spread to the brain using K18-hACE2 mice susceptible to SARS-CoV-2 infection. @*Results@#K18-hACE2 mice were intranasally infected with 1 × 105 PFU of the original Wuhan strain and the Omicron variant of SARS-CoV-2. A follow-up was conducted 7 days post infection. All Wuhan-infected mice showed > 20% body weight loss, defined as the lethal condition, whereas two out of five Omicron-infected mice (40%) lost > 20% body weight. Histopathological analysis based on H&E staining revealed inflammatory responses in the brains of these two Omicron-infected mice. Immunostaining analysis of viral nucleocapsid protein revealed severe infection of neuron cells in the brains of these two Omicron-infected mice. Lymphoid depletion and apoptosis were observed in the spleen of Omicron-infected mice with brain infection. @*Conclusion@#Lethal conditions, such as severe body weight loss and encephalopathy, can occur in Omicron-infected K18-hACE2 mice. Our study reports, for the first time, that Omicron can induce brain infection with lymphoid depletion in the mouse COVID-19 model.

Association between High Diffusion-Weighted Imaging-Derived Functional Tumor Burden of Peritoneal Carcinomatosis and Overall Survival in Patients with Advanced Ovarian Carcinoma

Objective@#To investigate the association between functional tumor burden of peritoneal carcinomatosis (PC) derived from diffusion-weighted imaging (DWI) and overall survival in patients with advanced ovarian carcinoma (OC). @*Materials and Methods@#This prospective study was approved by the local research ethics committee, and informed consent was obtained. Fifty patients (mean age ± standard deviation, 57 ± 12 years) with stage III–IV OC scheduled for primary or interval debulking surgery (IDS) were recruited between June 2016 and December 2021. DWI (b values: 0, 400, and 800 s/mm2 ) was acquired with a 16-channel phased-array torso coil. The functional PC burden on DWI was derived based on K-means clustering to discard fat, air, and normal tissue. A score similar to the surgical peritoneal cancer index was assigned to each abdominopelvic region, with additional scores assigned to the involvement of critical sites, denoted as the functional peritoneal cancer index (fPCI). The apparent diffusion coefficient (ADC) of the largest lesion was calculated. Patients were dichotomized by immediate surgical outcome into high- and low-risk groups (with and without residual disease, respectively) with subsequent survival analysis using the Kaplan-Meier curve and log-rank test. Multivariable Cox proportional hazards regression was used to evaluate the association between DWI-derived results and overall survival. @*Results@#Fifteen (30.0%) patients underwent primary debulking surgery, and 35 (70.0%) patients received neoadjuvant chemotherapy followed by IDS. Complete tumor debulking was achieved in 32 patients. Patients with residual disease after debulking surgery had reduced overall survival (p = 0.043). The fPCI/ADC was negatively associated with overall survival when accounted for clinicopathological information with a hazard ratio of 1.254 for high fPCI/ADC (95% confidence interval, 1.007–1.560; p = 0.043). @*Conclusion@#A high DWI-derived functional tumor burden was associated with decreased overall survival in patients with advanced OC.

Cloning of LVA Ca 2＋ channel and its primary structure features / 细胞与分子免疫学杂志

Aim To clone LVA calcium channel (also known as T-type calcium channel) from INS-1 cell line derived from rat pancreatic β cells. Methods RT-PCR, 3′ -RACE and 5′ -RACE were used to clone coding sequence of the whole gene. DNA sequencing and genomic DNA walking were used to identify the primary structure features and exons. Results The cloned gene, named as α 1 G-INS, was composed of 6 864 bp, encoding 2 288 amino acids, which shares 96.3％ identity to α 1G, the neuronal T-type calcium channel. Compared to α 1G, the amino acids in membrane-spanning regions of four transmembrane domains and intracellular loop LI-II of α 1G-INS were highly conserved, but there are three distinct regions. This discrepancy was due to alternative mRNA splicing. Scattering on other regions of the molecule there were 10 single amino acid substitutions, which could be explained as site-mutations of the gene. Conclusion A new isoform,α 1G-INS, of T-type calcium channel is successfully cloned from rat insulin-secreting cell line INS-1, which is significant to further understanding many Ca2＋ -involved biologically essential processes.