Age-Related Thymic Atrophy: Mechanisms and Outcomes

Age-related thymic atrophy or involution, a hallmark of thymic aging, takes place both in humans and animals. In this chapter, we will discuss age-related thymic atrophy, outlining the underlying cellular and molecular mechanisms of its occurrence. We will also address the downstream influences on the aged T cell immune system, not only regarding insufficiency against pathogens, but also hyper-reactivity to self. Particularly, we will focus on how thymic atrophy disrupts efficient establishment of central T cell immune tolerance primarily via impairment of thymocyte negative selection, resulting in an increased number of self-reactive conventional T cells, and on thymic-derived regulatory T cell generation. Finally, we will provide a framework for understanding the significant role that the atrophied thymus plays in shaping inflammaging: a chronic, low-grade, systemic inflammatory phenotype observed in aged individuals in the absence of acute infection. The involvement of T cell adaptive immunity in mediating inflammaging plays a crucial role in the progression of many age-related neurological and cardiovascular diseases

Stage-specific changes in fetal thymocyte proliferation during the CD4(-)8(-) to CD4(+)8(+) transition in wild type, Rag1(-/-), and Hoxa3,Pax1 mutant mice

BACKGROUND: The function of the thymic microenvironment is to promote thymocyte maturation, in part via regulation of thymocyte proliferation and cell death. Defects in fetal thymic epithelial cell (TEC) development and function, and therefore in the formation of a functional microenvironment, can be caused either directly by TEC differentiation defects or indirectly by defective thymocyte maturation. In this paper we studied fetal thymocyte proliferation during the early transition from the CD3(-)4(-)8(-) (triple negative, TN) to CD4(+)8(+) (double positive, DP) stages. We compared wild type mice with Rag1(-/-) mice and with Hoxa3(+/-)Pax1(-/-) compound mutant mice, which have blocks at different stages of thymocyte development. RESULTS: Wild type fetal and adult thymus showed stage-specific differences in the proliferation profiles of developing thymocytes, with fetal stages showing generally higher levels of proliferation. The proliferation profile of fetal thymocytes from Rag1(-/-) mutants also had stage-specific increases in proliferation compared to wild type fetal thymocytes, in contrast to the lower proliferation previously reported for thymocytes from adult Rag1(-/-) mutants. We have previously shown that Hoxa3(+/-)Pax1(-/-) mice have abnormal fetal TEC development, resulting in increased apoptosis at the TN to DP transition and decreased DP cell numbers. Fetal thymocytes from Hoxa3(+/-)Pax1(-/-) compound mutants had increased proliferation, but fewer proliferating cells, at the DP stage. We also observed a decrease in the level of the cytokines IL-7 and SCF produced by Hoxa3(+/-)Pax1(-/-)TECs. CONCLUSION: Our results indicate complex and stage-specific effects of abnormal TEC development on thymocyte proliferation

Tie-dye technique and pattern features

Relationship between tie-dye technique and image pattern has been studied. Based on digital image processing, average value of HSV (hue, saturation, value) tri-component of valid tie-dye area, proportion of incompletely dyed area in HSV color space and the Tamura first three texture features of digital tie-dye image have been extracted. Then, the repeated tests and analysis of variance (ANOVA) of rotation speed and concentration have been done. The results show the obvious impact of concentration and rotation speed on the color and texture feature of tie-dye pattern. Furthermore, back propagation neutral network is developed and partial pattern features with low correlation is used to forecast the tie-dye concentration and rotation speed. The experiment results show the 100% rate of forecast, which proves that pattern features can effectively achieve the technique forecast

Beneficial Effects of Anisodamine in Shock Involved Cholinergic Anti-Inflammatory Pathway

Anisodamine, an antagonist of muscarinic receptor, has been used therapeutically to improve blood flow in circulatory disorders such as septic shock in China since 1965. The main mechanism of anisodamine for anti-shock proposed in Pharmacology for Chinese medical students is to improve blood flow in the microcirculation. Here, we suggest a new mechanism for its anti-shock effect. That is, anisodamine, by blocking muscarinic receptor, results in rerouting of acetylcholine to α7 nicotinic acetylcholine receptor (α7nAChR) bringing about increased acetylcholine-mediated activation of α7nAChR and the cholinergic anti-inflammatory pathway

An adaptive acoustoelectric signal decoding algorithm based on Fourier fitting for brain function imaging

Acousticelectric brain imaging (ABI), which is based on the acoustoelectric (AE) effect, is a potential brain function imaging method for mapping brain electrical activity with high temporal and spatial resolution. To further enhance the quality of the decoded signal and the resolution of the ABI, the decoding accuracy of the AE signal is essential. An adaptive decoding algorithm based on Fourier fitting (aDAF) is suggested to increase the AE signal decoding precision. The envelope of the AE signal is first split into a number of harmonics by Fourier fitting in the suggested aDAF. The least square method is then utilized to adaptively select the greatest harmonic component. Several phantom experiments are implemented to assess the performance of the aDAF, including 1-source with various frequencies, multiple-source with various frequencies and amplitudes, and multiple-source with various distributions. Imaging resolution and decoded signal quality are quantitatively evaluated. According to the results of the decoding experiments, the decoded signal amplitude accuracy has risen by 11.39% when compared to the decoding algorithm with envelope (DAE). The correlation coefficient between the source signal and the decoded timing signal of aDAF is, on average, 34.76% better than it was for DAE. Finally, the results of the imaging experiment show that aDAF has superior imaging quality than DAE, with signal-to noise ratio (SNR) improved by 23.32% and spatial resolution increased by 50%. According to the experiments, the proposed aDAF increased AE signal decoding accuracy, which is vital for future research and applications related to ABI

Interleukin-10 Genotype Correlated to Deficiency Syndrome in Hepatitis B Cirrhosis

Traditional Chinese medicine (TCM) syndrome is an important basis for TCM diagnosis and treatment. As Child-Pugh classification as well as compensation and decompensation phase in liver cirrhosis, it is also an underlying clinical classification. In this paper, we investigated the correlation between single nucleotide polymorphisms (SNPs) of Interleukin-10 (IL-10) and TCM syndromes in patients with hepatitis B cirrhosis (HBC). Samples were obtained from 343 HBC patients in China. Three SNPs of IL-10 (−592A/C, −819C/T, and −1082A/G) were detected with polymerase chain-reaction-ligase detection reaction (PCR-LDR). The result showed the SNP-819C/T was significantly correlated with Deficiency syndrome (P = 0.031), but none of the 3 loci showed correlation either with Child-Pugh classification and phase in HBC patients. The logistic regression analysis showed that the Excess syndrome was associated with dizzy and spider nevus, and the Deficiency syndrome was associated with dry eyes, aversion to cold, IL-10-819C/T loci, and IL-10-1082A/G loci. The odds ratio (OR) value at IL-10-819C/T was 4.022. The research results suggested that IL-10-819C/T locus (TC plus CC genotype) is probably a risk factor in the occurrence of Deficiency syndrome in HBC patients