Impact of left atrial appendage closure on cardiac functional and structural remodeling: A difference-in-difference analysis of propensity score matched samples

Background: Although the safety and efficacy of left atrial (LA) appendage (LAA) closure (LAAC) in nonvalvular atrial fibrillation (NVAF) patients have been well documented in randomized controlled trials and real-world experience, there are limited data in the literature about the impact of LAAC on cardiac remodeling. The aim of the study was to examine the impact of LAAC on cardiac functional and structural remodeling in NVAF patients. Methods: Between March 2014 and November 2016, 47 NVAF patients who underwent LAAC were included in this study (LAAC group). A control group (non-LAAC group) was formed from 141 NVAF patients without LAAC using propensity score matching. The difference-in-difference analysis was used to evaluate the difference in cardiac remodeling between the two groups at baseline and follow-up evaluations. Results: The LAAC group had a larger increase in LA dimension, volume and volume index than the non-LAAC group (+3.9 mm, p = 0.001; +9.7 mL, p = 0.006 and +5.9 mL/m2, p = 0.011, respectively). Besides, a significant increase in E and E/e’ ratio was also observed in the LAAC group (+14.6 cm/s, p = 0.002 and +2.3, p = 0.028, respectively). Compared with the non-LAAC group, left ventricular (LV) ejection fraction and fractional shortening decreased in LAAC patients, but were statistically insignificant (–3.5%, p = 0.109 and –2.0%, p = 0.167, respectively). Conclusions: There were significant increases in LA size and LV filling pressure among NVAF patients after LAAC. These impacts of LAAC on cardiac functional and structural remodeling may have some clinical implications that need to be addressed in future studies

A Micromachined Silicon Depth Probe for Multichannel Neural Recording

Aprocess of making a new type of silicon depth-probe microelectrode array is described using a combination of plasma and wet etch. The plasma etch, which is done using a low temperature oxide (LTO) mask, enables probe thickness to be controlled over a range from 5 to 90 . Bending tests show that the probes mechanical strength depends largely on shank thickness. More force can be applied to thicker shanks while thinner shanks are more flexible. One can then choose a thickness and corresponding mechanical strength using the process developed. The entire probe shaping process is performed only at low temperature, and thus is consistent with the standard CMOS fabrication. Using the probe in recording from rats somatosensory cortex, we obtained four channel simultaneous recordings which showed clear independence among channels with a signal-to-noise ratio performance comparable with that obtained using other devices.This paper was supported by the Nano Bioelectronics & System Center, Basic Research program of Korea Science and Engineering Foundation (KOSEF) under Grant 971- 0913-076-2, by the Korea Research Foundation (NDRF) under Grant 1996-012- E0529, by Ministry Health andWelfare, Korea under Grant HMP-98-E-1-0006, by the Korea Electronic Technology Institute (KETI) MEMS, and by the Research Products Sharing Program of Inter-university Semiconductor Research Center (ISRC) at Seoul National University

Toxic leukoencephalopathy with axonal spheroids caused by chemotherapeutic drugs other than methotrexate

Background The objective of this report is to share the clinicopathological features of chemotherapy-induced toxic leukoencephalopathy, which is a rare and under-recognized disease, clinically characterized by rapidly progressive cognitive loss that often leads to sudden death. Case presentation A 64-year-old woman and a 63-year-old man, who had both suffered from a rapid deterioration of consciousness, were autopsied under the clinical impressions of either the central nervous system graft versus host disease (CNS-GVHD), infectious encephalitis, or autoimmune encephalitis. Both patients had been treated with multiple chemotherapy regimens, including adriamycin, cytarabine arabinoside, daunorubicin, fludarabine, azacitidine, and allogeneic peripheral blood stem cell transplantation to treat hematological malignancies (acute myelogenous leukemia and myelodysplastic syndrome). Neuropathological findings at autopsy revealed rarefaction and vacuolar changes of the white matter with axonal spheroids, reactive gliosis, and foamy macrophage infiltration, predominantly in the visual pathways of the occipital and temporal lobes. Damaged axons exhibited immunoreactivity to beta-amyloid, consistent with axonopathy. However, there was no lymphocyte infiltration that suggested CNS-GVHD or any type of encephalitis. Conclusion The neuropathology found in the presented cases had the characteristic features of toxic leukoencephalopathy (chemobrain). Our cases showed that toxic leukoencephalopathy can also be caused by chemotherapy drugs other than methotrexate.This research was supported by a fund (2021-ER1001-01) by the Research of Korea Disease Control and Prevention Agency. The role of the funder is financial support for the operation of the brain bank of Seoul National University Hospital and the operation of the brain donation program for the research

Active contour configuration model for estimating the posterior ablative margin in image fusion of real-time ultrasound and 3D ultrasound or magnetic resonance images for radiofrequency ablation: an experimental study

Purpose The purpose of this study was to evaluate the accuracy of an active contour model for estimating the posterior ablative margin in images obtained by the fusion of real-time ultrasonography (US) and 3-dimensional (3D) US or magnetic resonance (MR) images of an experimental tumor model for radiofrequency ablation. Methods Chickpeas (n=12) and bovine rump meat (n=12) were used as an experimental tumor model. Grayscale 3D US and T1-weighted MR images were pre-acquired for use as reference datasets. US and MR/3D US fusion was performed for one group (n=4), and US and 3D US fusion only (n=8) was performed for the other group. Half of the models in each group were completely ablated, while the other half were incompletely ablated. Hyperechoic ablation areas were extracted using an active contour model from real-time US images, and the posterior margin of the ablation zone was estimated from the anterior margin. After the experiments, the ablated pieces of bovine rump meat were cut along the electrode path and the cut planes were photographed. The US images with the estimated posterior margin were compared with the photographs and post-ablation MR images. The extracted contours of the ablation zones from 12 US fusion videos and post-ablation MR images were also matched. Results In the four models fused under real-time US with MR/3D US, compression from the transducer and the insertion of an electrode resulted in misregistration between the real-time US and MR images, making the estimation of the ablation zones less accurate than was achieved through fusion between real-time US and 3D US. Eight of the 12 post-ablation 3D US images were graded as good when compared with the sectioned specimens, and 10 of the 12 were graded as good in a comparison with nicotinamide adenine dinucleotide staining and histopathologic results. Conclusion Estimating the posterior ablative margin using an active contour model is a feasible way of predicting the ablation area, and US/3D US fusion was more accurate than US/MR fusion

Clinical implications of neoadjuvant chemotherapy in advanced endometrial cancer: a multi-center retrospective cohort study

Background : The mainstay of endometrial cancer treatment is surgical resection of tumors and postoperative adjuvant treatment is recommended if necessary. However, there is no consensus on the management of unresectable metastatic endometrial cancer. This study aimed to assess the feasibility and effectiveness of neoadjuvant chemotherapy followed by interval debulking surgery (NAC-IDS) in unresectable, metastatic endometrial cancer. Methods : From the endometrial cancer cohorts of four institutions in Korea, we identified patients with International Federation of Gynecology and Obstetrics stages IIIC–IVB endometrial cancer who received NAC-IDS between January 2008 and December 2020. Through a medical record review, we collected patients’ clinicopathological data. Progression-free survival (PFS), overall survival (OS), and the factors affecting survival outcomes were analyzed. Results : Overall, 32 patients were included with endometrioid (n = 18), serous (n = 5), carcinosarcoma (n = 6), and other histological types (n = 3). Among them, 28 (87.5%) patients had stage IVB disease. The most common neoadjuvant chemotherapy (NAC) regimen was paclitaxel-carboplatin (n = 25, 78.1%), which was administered for a median of six cycles. While 26 (81.3%) patients showed an objective response, two (6.3%) progressed despite NAC. At the time of interval debulking surgery (IDS), 23 (71.9%) patients achieved complete cytoreduction. During 31.0 months of the median follow-up, there were 23 recurrences and 11 deaths, corresponding to a median PFS of 19.7 months and a 3-year OS rate of 69.7%. In multivariate analyses, non-endometrioid histology and residual tumor after IDS were identified as independent poor prognostic factors for PFS (adjusted hazard ratio [HR], 7.322; P < 0.001 and 5.934; P = 0.001, respectively). Multivariate analysis for OS could not be conducted because of the small number of events, although non-endometrioid histology was the only factor associated with worse OS in univariate analysis (adjusted HR, 4.523; P = 0.032). Conclusions : NAC-IDS may be a treatment option for unresectable metastatic endometrial cancer. Tumor histology and the possibility of complete cytoreduction are the primary considerations for NAC-IDS