Differentiation of viable and nonviable myocardium by the use of three-dimensional tagged MRI in 2-day-old reperfused canine infarcts

BACKGROUND: To limit ischemic myocardial injury, it is important to differentiate viable from infarcted myocardium. Three dimensional (3D) tagged MRI has the ability to quantify myocardial 3D deformation and strain (noninvasively and precisely), and can achieve a true comparison of contraction not only from region to region, but also at different levels of function. In this study, we investigated whether regional strain mapping obtained by 3D-tagged MRI can differentiate between viable but stunned myocardium and nonviable myocardium. METHODS AND RESULTS: We examined 7 dogs 2 days after a 90-minute closed-chest left anterior descending coronary artery occlusion followed by 48 hours of reperfusion. 3D-tagged MR images spanning the entire left ventricle were acquired both at rest and during dobutamine infusion (5 microg. kg-1. min-1 IV). Regional blood flow was measured with radioactive microspheres and used to define risk regions. Infarcted regions were defined as 2,3,5 triphenyltetrazolium chloride negative regions. Strains in infarcted regions were greatly impaired compared with remote regions (P<0.001) and remained unchanged during dobutamine stress. Risk regions showed a dysfunction at rest, with improved function during dobutamine infusion. Receiver operating characteristics analysis showed that radial strain was more accurate for identifying viable regions. CONCLUSIONS: When coupled with a stress test, 3D strain mapping by the use of tagged MRI is a sensitive and noninvasive method for characterizing ischemic injury. Regional strain can be used to differentiate between viable but stunned and nonviable myocardium within the postischemic injured myocardium.     

Identification and characterization of a differentiation-specific antigen on normal and malignant murine erythroid cells

Rauscher murine erythroleukemia cells grow continuously in vitro and undergo terminal differentiation in response to the physiological inducer erythropoietin. In the course of this developmental process they express many erythroid-specific markers. In order to investigate the expression of cell surface determinants during Rauscher cell differentiation we generated monoclonal antibodies to uninduced cells. Using an anti-Rauscher cell monoclonal antibody, we have identified a cell surface determinant, designated ERY-1, that is present on normal murine erythroid cells. This determinant is apparently absent from the early progenitor BFU-E, but is present on the more mature progenitors CFU-E and CFC-E. It disappears during erythroid maturation and is absent from the mature erythrocyte. This pattern of ERY-1 expression is exhibited with remarkable fidelity during the erythropoietin-induced differentiation of Rauscher cells. Such differentiation-specific expression of the ERY-1 determinant suggests that it may play a functional role in erythropoiesis.     

Southern blot patterns, frequencies, and junctional diversity of T-cell receptor-delta gene rearrangements in acute lymphoblastic leukemia

Southern blot analysis of T-cell receptor (TCR)-delta gene rearrangements is useful for diagnostic studies on the clonality of lymphoproliferative diseases. We have developed 18 new TCR-delta gene probes by use of the polymerase chain reaction (PCR) techniques. Application of these probes for detailed analysis of the TCR-delta genes in normal control samples, 138 T-cell acute lymphoblastic leukemias (T-ALL), and 91 precursor B-ALL allowed us to determine the TCR-delta gene restriction map for five restriction enzymes, as well as the Southern blot restriction enzyme patterns of all theoretically possible TCR-delta gene rearrangements. Based on this information, it appeared that 97% of all 213 detected TCR-delta gene rearrangements in our series of ALL could be detected by use of the TCRDJ1 probe and that the majority (76%) of the 213 rearrangements could be identified precisely. In T-ALL, we found a strong preference for the complete rearrangements V delta 1-J delta 1 (33%), V delta 2-J delta 1 (10%), and V delta 3-J delta 1 (7%) and the incomplete rearrangement D delta 2- J delta 1 (11%). In precursor B-ALL, the majority of rearrangements consisted of V delta 2-D delta 3 (72%) and D delta 2-D delta 3 (10%). The junctional diversity of these 6 preferential TCR-delta rearrangements was analyzed and showed an extensive junctional insertion (approximately 30 nucleotides) for complete V delta-J delta rearrangements, whereas incomplete rearrangements had correspondingly smaller junctional regions. The detailed TCR-delta gene restriction map and probes presented here, in combination with the Southern blot patterns of TCR-delta gene rearrangements, are important for TCR-delta gene studies in ALL; all TCR-delta gene rearrangements can be detected and the majority can be identified precisely. Identification of rearrangements is a prerequisite for subsequent PCR analysis of TCR- delta gene junctional regions, eg, for detection of minimal residual disease during follow-up of ALL patients.     

失功能高密度脂蛋白与心血管疾病研究进展

高密度脂蛋白胆固醇被认为是心血管疾病的重要保护因素,它在血清中的水平与心血管疾病风险呈负相关。然而在心血管疾病中,高密度脂蛋白的蛋白质、脂质或microRNAs等发生变化,使其转变为失功能高密度脂蛋白,失功能高密度脂蛋白具有促进动脉粥样硬化、促氧化、促炎等特性。本文对失功能高密度脂蛋白的结构和功能改变进行概括。     

Lutein/zeaxanthin isomers regulate neurotrophic factors and synaptic plasticity in trained rats

Background/aim This study was conducted to elucidate the effects of lutein/zeaxanthin isomers (L/Zi) on lipid metabolism, oxidative stress, NF-κB/Nrf2 pathways, and synaptic plasticity proteins in trained rats.Materials and methods Wistar rats were distributed into four groups: 1) control, 2) L/Zi: rats received L/Zi at the dose of 100 mg/kg by oral gavage, 3) exercise, 4) exercise+L/Zi: rats exercised and received L/Zi (100 mg/kg) by oral gavage. The duration of the study was eight weeks. Results Exercise combined with L/Zi reduced lipid peroxidation and improved antioxidant enzyme activities of muscle and cerebral cortex in rats (p < 0.001). In the Exercise + L/Zi group, muscle and cerebral cortex Nrf2 and HO-1 levels increased, while NF-κB levels decreased (p <0.001). Also, L/Zi improved BDNF, synapsin I, SYP, and GAP-43 levels of the cerebral cortex of trained rats (p < 0.001). The highest levels of BDNF, synapsin SYP, and GAP-43 in the cerebral cortex were determined in the Exercise+L/Zi group.Conclusion These results suggested that exercise combined with L/Zi supplementation might be effective to reduce neurodegeneration via improving neurotrophic factors and synaptic proteins, and oxidative capacity in the cerebral cortex.     

Evaluation of systemic involvement of Coronavirus disease 2019 through spleen; size and texture analysis

Background/aimTo investigate the changes in the spleen size, parenchymal heterogeneity, and computed tomography (CT) texture analysis features of patients diagnosed with Coronavirus disease 2019 (COVID-19)Materials and methodsThe size and parenchymal structure of the spleen in 91 patients who underwent thoracic CT examination due to COVID-19 were evaluated. For the evaluation of parenchymal heterogeneity, CT texture analysis was performed using dedicated software (Olea Medical, France). The texture analysis of each case consisted of 15 first-order intensity-based features, 17 gray level co-occurrence matrix-based features, and 9 gray level run length matrix-based features.ResultsA total of 91 patients (45 males, 46 females) with a mean age of 54.31 ± 16.33 years (range: 18–81) were included in the study. A statistically significant decrease in spleen size was seen in the follow-up CT examinations (p < 0.001) whereas no statistically significant difference was found between the Hounsfield unit (HU) values. The radiomics consisted of first-order intensity-based features such as 90th percentile, maximum, interquartile range, range, mean absolute deviation, standard deviation, and variance, all of which showed statistically significant differences (p - values: < 0.001, < 0.001, 0.001, 0.003, 0.001, 0.001, and 0.004, respectively). “Correlation” as a gray level co-occurrence matrix-based feature and “gray level nonuniformity” as a gray level run length matrix-based feature showed statistically differences (p-values: 0.033 and < 0.001, respectively).ConclusionsAlthough COVID-19 manifests with lung involvement in the early stage, it can also cause systemic involvement, and the spleen may be one of its target organs. A decrease in the spleen size and parenchymal microstructure changes can be observed in the short follow-up time. It is hoped that the changes in the parenchymal microstructure will be demonstrated by a noninvasive method: texture analysis.