Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine | July 6, 2022 | Volume: 236 | Issue: 8 | Pages: 1232-1237
Heart disease has a higher fatality rate than any other disease. Increased Atrial fat on the left atrium has been discovered to cause Atrial Fibrillation (AF) in most patients. AF can put one’s life at risk and eventually lead to death. AF might worsen over time; therefore, it is crucial to have an early diagnosis and treatment. To evaluate the left atrium fat tissue pattern using Radon descriptor-based machine learning. This study developed a bridge between the Radon transform framework and machine learning to distinguish two distinct patterns. Motivated by a Radon descriptor-based machine learning approach, the patches of eight patients from CT images of the heart were used and categorized into “epicardial fat tissue” and “nonfat tissue” groups. The 10 feature vectors are extracted from each big patch using Radon descriptors and then fed into a traditional machine learning model. The results show that the proposed methodology discriminates between fat tissues and nonfat tissues clearly. KNN has shown the best performance with 96.77% specificity, 98.28% sensitivity, and 97.50% accuracy. To our knowledge, this study is the first attempt to provide a Radon transform-based machine learning method to distinguish between fat tissue and nonfat tissue on the left atrium. Our proposed research method could be potentially used in advanced interventions.
Upregulation of airway smooth muscle calcium-sensing receptor by low-molecular-weight hyaluronan
We investigated the mechanisms involved in the development of airway hyperresponsiveness (AHR) following exposure of mice to halogens. Male mice (C57BL/6; 20–25 g) exposed to either bromine (Br2) or Cl2(600 or 400 ppm, respectively, for 30 min) developed AHR 24 h after exposure. Nifedipine (5 mg/kg body wt; an L-type calcium channel blocker), administered subcutaneously after Br2or Cl2exposure, produced higher AHR compared with Br2or Cl2alone. In contrast, diltiazem (5 mg/kg body wt; a nondihydropyridine L-type calcium channel blocker) decreased AHR to control (air) values. Exposure of immortalized human airway smooth muscle cells (hASMC) to Br2resulted in membrane potential depolarization ( VmAir: 62 ± 3 mV; 3 h post Br2:−45 ± 5 mV; means ± 1 SE; P < 0.001), increased intracellular [Ca2+]i, and increased expression of the calcium-sensing receptor (Ca-SR) protein. Treatment of hASMC with a siRNA against Ca-SR significantly inhibited the Br2and nifedipine-induced Vmdepolarization and [Ca2+]iincrease. Intranasal administration of an antagonist to Ca-SR in mice postexposure to Br2reversed the effects of Br2and nifedipine on AHR. Incubation of hASMC with low-molecular-weight hyaluronan (LMW-HA), generated by exposing high-molecular-weight hyaluronan (HMW-HA) to Br2, caused Vmdepolarization, [Ca2+]iincrease, and Ca-SR expression to a similar extent as exposure to Br2and Cl2. The addition of HMW-HA to cells or mice exposed to Br2, Cl2, or LMW-HA reversed these effects in vitro and improved AHR in vivo. We conclude that detrimental effects of halogen exposure on AHR are mediated via activation of the Ca-SR by LMW-HA.
Granular cell astrocytoma: an aggressive IDH‐wildtype diffuse glioma with molecular genetic features of primary glioblastoma
AbstractGranular cell astrocytoma (GCA) is a rare adult infiltrating glioma subtype. We studied a series of 39 GCAs. Median age of presentation was 57.8 years and most cases developed in the frontal or temporal lobes. Tumors included grade II (n = 14), grade III (n = 11), and grade IV (n = 14) by WHO criteria. Granular cell morphology was diffuse in 31 (79%) cases and partial in eight (21%). Immunohistochemistry showed frequent positivity for GFAP (28 of 31), OLIG2 (16 of 16), and CD68 (27 of 30), but HAM56, CD163, and IBA‐1 histiocytic markers were all negative (22 of 22). IDH1(R132H) was negative in all the cases tested (16 of 16), while ATRX expression was retained (12 of 12). Cytogenetics demonstrated monosomy 10 (6 of 6) cases, +7 in 4 (of 6), −13q in 4 of 6, and −14 in 4 of 6. Next‐generation sequencing demonstrated mutations in PTEN/PIK3 genes in 6/13 (46%), NF1 in 3 of 10 (30%), TP53 in 3 of 13 (23%), PALB2 in 3 of 10 (30%), STAG2 in 3 of 10 (30%), EGFR mutation/amplification in 3 of 13 (23%), and AR in 2 of 10 (20%). CDKN2A/B deletion was identified in 5 of 13 (30%) cases (homozygous deletion in 4). The TERT C228T mutation was identified in 9 of 13 (69%). No mutations were encountered in IDH1, IDH2, CIC, FUBP1, H3F3A, BRAF or ATRX genes. The mean overall survival was 11.3 months. Patients >60 years old at diagnosis had a worse survival than patients <60 years (P = 0.001). There were no statistically significant differences in survival by WHO grade, extent of granular cell change, sex or MIB‐1 (P > 0.05). GCA is a variant of IDH‐wildtype diffuse glioma with aggressive behavior irrespective of grade and extent of granular cell morphology, and with molecular genetic features corresponding to primary glioblastoma.
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