Sodium current of neurosecretory cells in the eyestalk from the shrimp Penaeus japonicus

The properties of the inward current of medulla terminalis-X-organ (MTXO) cells isolated from the Penaeus japonicus eyestalk were studied with the whole-cell clamp technique in the presence of Ca2+ and K+ channel blockers. The inward currents had a threshold at about -50 mV and peaked at -10 mV. The reversed potential (V-rev) was very close to V-Na, the theoretical Nernst equilibrium potential for Na+. V-rev followed V-Na when the external Na+ concentration was varied and the currents were entirely suppressed by 30 nM tetrodotoxin (TTX), indicating that it was carried by Na+. The smooth line of concentration-dependent inhibition of sodium currents by TTX represented the best. t with the Hill equation, yielding an IC50 of 2.1 +/- 0.1 nM. The values of the half-maximal activation voltage V-h were -20.6 +/- 0.5 and -19.3 +/- 0.5 mV, respectively, in the absence and presence of 2 nM TTX. TTX had no significant effect on the voltage dependence of steady-state activation and inactivation of I-Na. Taken together, the results suggest that the inward current recorded under our experimental conditions was carried by sodium ions. owing through fast voltage-dependent Na+ channels. (C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved.National Natural Science Foundation of China [30300269]; Technical Innovation Project of Fujian [2003J018

Superoxide dismutase alterations in COVID-19: implications for disease severity and mortality prediction in the context of omicron variant infection

BackgroundIn the few reports to date, the changes in superoxide dismutase (SOD), a key factor in cellular protection against superoxide, in COVID-19 have been very inconsistent and contradictory. There is also a lack of data on COVID-19 induced by Omicron variant. Further investigation is warranted to figure out SOD alterations in COVID-19, particularly within the context of ongoing Omicron variant infection, which may provide clues to its role within COVID-19 pathogenesis and open up new avenues for COVID-19 treatment.MethodsSOD activity in 109 COVID-19 patients (including 46 severe cases and 63 mild to moderate cases) and 30 matched healthy controls were quantified. Demographic data, blood cell counts, biochemical indicators, coagulation indicators, and inflammatory markers were also recorded.ResultsSOD, an important key node, experienced a significant decrease in COVID-19, with the severe patients exhibiting lower activity compared to the mild to moderate patients and control healthy. Notably, severe patients who deceased had the lowest SOD activity. Correlation analysis revealed significant correlations between SOD and inflammatory markers, organ injury markers, coagulation dysfunction indicators, nutritional markers, and lymphocytes counts. The ROC curve also showed good performance for the differentiation of severe cases and the prediction of death.ConclusionSOD activity was significantly decreased in COVID-19 infected with Omicron variant and significantly correlated with systemic changes, and could be used as a biomarker to assess disease severity and predict mortality in COVID-19 clinical pathway management. Additionally, this finding will contribute to exploring new potential direction for the treatment of severe COVID-19 patients

MUC5AC upstream complex repetitive region length polymorphisms are associated with susceptibility and clinical stage of gastric cancer.

MUC5AC was deemed to be involved in gastric carcinogenesis since aberrant MUC5AC expression has been repeatedly detected in patients with gastric cancer (GC). In this study, length polymorphisms in a complicated repetitive region adjacent to MUC5AC promoter were assessed in 230 patients with GC and 328 cancer-free controls. Alleles of 1.4 and 1.8 kb were significantly more prevalent in GC group than in controls. In contrast, 2.3 and 2.8 kb alleles occurred at significantly lower frequencies in patients than in controls. Alleles were then classified into susceptible (S; 1.4 and 1.8 kb), protective (P; 2.3 and 2.8 kb) and null (N; all other alleles) categories with respect to their linkage with the susceptibility to GC. Individuals with genotype SS had a 2.7-fold increased risk of GC occurrence, but PN genotype was associated with a significantly reduced risk of this cancer. Moreover, homozygous or heterozygous individuals with one or two copies of 1.4 kb allele showed an earlier age of onset and more advanced metastasis stage compared with patients without this allele (Bonferroni corrected p = 1.35×10(-4) and 6.60×10(-4) accordingly), whereas homozygous patients with two copies of 1.8 kb allele were linked to less advanced GC TNM stage. Our results suggest that certain genetic variations in MUC5AC upstream repetitive region are associated with the susceptibility and progression of GC

Rotation axis calibration of a 3D scanning system based on dual-turntable angle cancellation

Rotation axis calibration is crucial for high-precision automatic point cloud stitching in turntable-based 3D scanning systems. To achieve a 360◦ sampling with a 2D calibrator in rotation axis calibration, this paper proposes a dual-turntable angle cancellation (DTAC) method. DTAC introduces an auxiliary turntable to keep a proper relative angle between the 3D sensor and the calibrator during the calibration process. The auxiliary turntable rotates at the same and opposite angle as the main turntable and cancels the increment of the relative angle. By projecting the feature points on the planar calibrator from real-world space to virtual calibration space, the projected points all share the same rotation axis of the main turntable. Further, a layered circle center extraction (LCCE) algorithm is applied to deal with outlier data points. The algorithm uses a two-step robust estimation strategy combining RANSAC circle fitting with a median noise filter for circle center selection. The standard ball reconstruction experiment shows that the 3D system calibrated by the method achieves a mean absolute error of 0.022 mm and root mean square error of 0.025 mm within the measurement distance of 60–70 cm. Point cloud stitching experiments of different types of objects show that our method outperforms other state-of-the-art methods in stitching accuracy. The DTAC method and LCCE algorithm can improve turntable-based 3D scanning systems

Atp6v1c1 may regulate filament actin arrangement in breast cancer cells.

Previous studies have shown that the rate of breast cancer metastasis correlates with the expression of vacuolar H(+)-ATPases (V-ATPases). However, how V-ATPase is involved in breast cancer metastasis remains unknown. Our previous study showed that Atp6v1c1-depleted osteoclasts did not form organized actin rings and that Atp6v1c1 co-localizes with F-actin. In this study, we found that the normal arrangement of filamentous actin is disrupted in Atp6v1c1-depleted 4T1 mouse breast cancer cells and in the ATP6V1C1-depleted human breast cancer cell lines MDA-MB-231 and MDA-MB-435s. We further found that Atp6v1c1 co-localizes with F-actin in 4T1 cells. The results of our study suggest that high expression of Atp6v1c1 affects the actin structure of cancer cells such that it facilitates breast cancer metastasis. The findings also indicate that Atp6v1c1 could be a novel target for breast cancer metastasis therapy

Distribution of <i>MUC5AC-u</i> repetitive region alleles among cases and controls.

<p>pc, p value corrected using the Bonferroni correction for multiple comparisons. 31 statistical tests were totally conducted in the whole study, and pc = p×31.</p