Controlled Cardiac Computed Tomography

Cardiac computed tomography (CT) has been a hot topic for years because of the clinical importance of cardiac diseases and the rapid evolution of CT systems. In this paper, we propose a novel strategy for controlled cardiac CT that may effectively reduce image artifacts due to cardiac and respiratory motions. Our approach is radically different from existing ones and is based on controlling the X-ray source rotation velocity and powering status in reference to the cardiac motion. We theoretically show that by such a control-based intervention the data acquisition process can be optimized for cardiac CT in the cases of periodic and quasiperiodic cardiac motions. Specifically, we formulate the corresponding coordination/control schemes for either exact or approximate matches between the ideal and actual source positions, and report representative simulation results that support our analytic findings

Self-driven Hybrid Atomic Spin Oscillator

A self-driven hybrid atomic spin oscillator is demonstrated in theory and experiment with a vapor Rb-Xe dual-spin system. The raw signal of Rb spin oscillation is amplified, phase-shifted and sent back to drive the Xe spins coherently. By fine tuning the driving field strength and phase, a self-sustaining spin oscillation signal with zero frequency shift is obtained. The effective coherence time is infinitely prolonged beyond the intrinsic coherence time of Xe spins, forming a hybrid atomic spin oscillator. Spectral analysis indicates that a frequency resolution of 13.1 nHz is achieved, enhancing the detection sensitivity for magnetic field. Allan deviation analysis shows that the spin oscillator can operate in continuous wave mode like a spin maser. The prototype spin oscillator can be easily implanted into other hybrid spin systems and enhance the detection sensitivity of alkali metal-noble gas comagnetometers.Comment: 6 pages,5 figure

Activating mu-opioid receptors in the spinal cord mediates the cardioprotective effect of remote preconditioning of trauma

Background: Remote precoditioning of trauma (RPCT) confers cardioprotective effects against myocardial ischemia/reperfusion injury, which are mediated by spinal opioid receptors. The aim of this study was to identify the roles of opioid receptor subtypes in the cardioprotective effect of RPCT and possible mechanisms. Methods: In this study, 192 Sprague-Dawley rats were allocated to 12 groups. Except for the sham group, rats in all groups were subjected to myocardial ischemia reperfusion. Rats in the ischemia precondition (IPC) group were treated with IPC. In the RPCT groups, an abdominal incision was made 15 min before inducing ischemia. The selective delta-, kappa-, and mu-opioid receptor antagonists were administered to groups of animals receiving RPCT, respectively. Data were collected for myocardial infarct size, intercellular adhesion molecule 1 (ICAM-1), plasma cardiac troponin I (cTnI) concentrations, activation of protein kinase C epsilon (PKCe) in myocardial cell membranes, and adenosine release in the spinal cord. Results: Compared with the control groups, infarct size, plasma concentrations of cTnI, and myocardial ICAM-1 expression were significantly lower, while adenosine release and PKCe activation were enhanced in the IPC and RPCT groups. Compared with the RPCT group, infarct size, plasma cTnI concentration, and myocardial ICAM-1 expression were greater and adenosine release and PKCe activation were reduced in the mu-opioid receptor antagonist plus RPCT group. Conclusions: The spinal mu-opioid receptor mediated the cardiac protective effect of RPCT. The mechanism may be enhanced by adenosine release in the spinal cord and PKCe activation in the myo­cardium, thereby inhibiting inflammation induced by ischemia/reperfusion injury

Microvesicles secreted by macrophages shuttle invasion-potentiating microRNAs into breast cancer cells

<p>Abstract</p> <p>Background</p> <p>Tumor-associated macrophages (TAMs) are alternatively activated cells induced by interleukin-4 (IL-4)-releasing CD4⁺T cells. TAMs promote breast cancer invasion and metastasis; however, the mechanisms underlying these interactions between macrophages and tumor cells that lead to cancer metastasis remain elusive. Previous studies have found microRNAs (miRNAs) circulating in the peripheral blood and have identified microvesicles, or exosomes, as mediators of cell-cell communication. Therefore, one alternative mechanism for the promotion of breast cancer cell invasion by TAMs may be through macrophage-secreted exosomes, which would deliver invasion-potentiating miRNAs to breast cancer cells.</p> <p>Results</p> <p>We utilized a co-culture system with IL-4-activated macrophages and breast cancer cells to verify that miRNAs are transported from macrophages to breast cancer cells. The shuttling of fluorescently-labeled exogenous miRNAs from IL-4-activated macrophages to co-cultivated breast cancer cells without direct cell-cell contact was observed. miR-223, a miRNA specific for IL-4-activated macrophages, was detected within the exosomes released by macrophages and was significantly elevated in the co-cultivated SKBR3 and MDA-MB-231 cells. The invasiveness of the co-cultivated breast cancer cells decreased when the IL-4-activated macrophages were treated with a miR-223 antisense oligonucleotide (ASO) that would inhibit miR-223 expression. Furthermore, results from a functional assay revealed that miR-223 promoted the invasion of breast cancer cells via the Mef2c-β-catenin pathway.</p> <p>Conclusions</p> <p>We conclude that macrophages regulate the invasiveness of breast cancer cells through exosome-mediated delivery of oncogenic miRNAs. Our data provide insight into the mechanisms underlying the metastasis-promoting interactions between macrophages and breast cancer cells.</p

Hey factors at the crossroad of tumorigenesis and clinical therapeutic modulation of Hey for anticancer treatment

Hairy and Enhancer-of-split related with YRPW motif (Hey) transcription factors are important regulators of stem cell embryogenesis. Clinical relevance shows that they are also highly expressed in malignant carcinoma. Recent studies have highlighted functions for the Hey factors in tumor metastasis, the maintenance of cancer cell self-renewal, as well as proliferation and the promotion of tumor angiogenesis. Pathways that regulate Hey gene expression, such as Notch and TGFβ signaling, are frequently aberrant in numerous cancers. In addition, Hey factors control downstream targets via recruitment of histone deacetylases (HDAC). Targeting these signaling pathways or HDACs may reverse tumor progression and provide clinical benefit for cancer patients. Thus, some small molecular inhibitors or monoclonal antibodies of each of these signaling pathways have been studied in clinical trials. This review focuses on the involvement of Hey proteins in malignant carcinoma progression and provides valuable therapeutic information for anticancer treatment

Altered spontaneous brain activity during dobutamine challenge in healthy young adults: A resting-state functional magnetic resonance imaging study

IntroductionThere is a growing interest in exploring brain-heart interactions. However, few studies have investigated the brain-heart interactions in healthy populations, especially in healthy young adults. The aim of this study was to explore the association between cardiovascular and spontaneous brain activities during dobutamine infusion in healthy young adults.MethodsForty-eight right-handed healthy participants (43 males and 5 females, range: 22–34 years) underwent vital signs monitoring, cognitive function assessment and brain MRI scans. Cardiovascular function was evaluated using blood pressure and heart rate, while two resting-state functional magnetic resonance imaging (rs-fMRI) methods—regional homogeneity (ReHo) and amplitude of low-frequency fluctuation (ALFF)—were used together to reflect the local neural activity of the brain. Logistic regression was used to model the association between brain and heart.ResultsResults showed that blood pressure and heart rate significantly increased after dobutamine infusion, and the performance in brain functional activity was the decrease in ReHo in the left gyrus rectus and in ALFF in the left frontal superior orbital. The results of logistic regression showed that the difference of diastolic blood pressure (DBP) had significant positive relationship with the degree of change of ReHo, while the difference of systolic blood pressure (SBP) had significant negative impact on the degree of change in ALFF.DiscussionThese findings suggest that the brain-heart interactions exist in healthy young adults under acute cardiovascular alterations, and more attention should be paid to blood pressure changes in young adults and assessment of frontal lobe function to provide them with more effective health protection management

Small molecular inhibitors reverse cancer metastasis by blockading oncogenic PITPNM3

Most cancer‐related deaths are a result of metastasis. The development of small molecular inhibitors reversing cancer metastasis represents a promising therapeutic opportunity for cancer patients. This pan‐cancer analysis identifies oncogenic roles of membrane‐associated phosphatidylinositol transfer protein 3 (PITPNM3), which is crucial for cancer metastasis. Small molecules targeting PITPNM3 must be explored further. Here, PITPNM3‐selective small molecular inhibitors are reported. These compounds exhibit target‐specific inhibition of PITPNM3 signaling, thereby reducing metastasis of breast cancer cells. Besides, by using nanoparticle‐based delivery systems, these PITPNM3‐selective compounds loaded nanoparticles significantly repress metastasis of breast cancer in mouse xenograft models and organoid models. Notably, the results establish an important metastatic‐promoting role for PITPNM3 and offer PITPNM3 inhibition as a therapeutic strategy in metastatic breast cancer