Research on an SICM Scanning Image Resolution Enhancement Algorithm.

Scanning ion conductance microscopy (SICM) enables the non-invasive three-dimensional imaging of live cells and other structures in physiological environments. However, when imaging complex samples, SICM faces challenges such as having a low temporal resolution during slow scanning and a reduced signal-to-noise ratio during fast scanning, making it difficult to simultaneously improve both temporal and spatial resolution. To address these issues, this paper proposes an algorithm for enhancing image resolution under high-speed scanning. Firstly, scanning images are preprocessed using a median filtering algorithm to remove the salt-and-pepper noise generated during high-speed scanning. Next, the Canny edge detection algorithm is employed to extract the edges of the image targets. To avoid blurring the edges, the new edge-directed interpolation (NEDI) algorithm is then used to fill the edges, while non-edge areas are filled using bilinear interpolation, thereby enhancing the image resolution. Finally, the peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM) are used to analyze the imaging of articular chondrocytes. The results show that under a scanning speed of 480 nm/ms, the proposed algorithm improves the temporal resolution of imaging by 60% compared to traditional 2× resolution imaging, increases the peak signal-to-noise ratio of the scanning images by 7 dB, and achieves a structural similarity of 0.97. Therefore, the proposed algorithm effectively removes noise during high-speed scanning and improves the SICM scanning imaging resolution, thereby avoiding the reduction in temporal resolution when scanning larger resolution samples and effectively enhancing the performance of SICM scanning imaging.

Vascular wall microenvironment: exosomes secreted by adventitial fibroblasts induced vascular calcification.

Vascular calcification often occurs in patients with chronic renal failure (CRF), which significantly increases the incidence of cardiovascular events in CRF patients. Our previous studies identified the crosstalk between the endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), and the paracrine effect of VSMCs, which regulate the calcification of VSMCs. Herein, we aim to investigate the effects of exosomes secreted by high phosphorus (HPi) -induced adventitial fibroblasts (AFs) on the calcification of VSMCs and the underlying mechanism, which will further elucidate the important role of AFs in high phosphorus vascular wall microenvironment. The conditioned medium of HPi-induced AFs promotes the calcification of VSMCs, which is partially abrogated by GW4869, a blocker of exosomes biogenesis or release. Exosomes secreted by high phosphorus-induced AFs (AFsHPi-Exos) show similar effects on VSMCs. miR-21-5p is enriched in AFsHPi-Exos, and miR-21-5p enhances osteoblast-like differentiation of VSMCs by downregulating cysteine-rich motor neuron 1 (Crim1) expression. AFsHPi-Exos and exosomes secreted by AFs with overexpression of miR-21-5p (AFsmiR21M-Exos) significantly accelerate vascular calcification in CRF mice. In general, AFsHPi-Exos promote the calcification of VSMCs and vascular calcification by delivering miR-21-5p to VSMCs and subsequently inhibiting the expression of Crim1. Combined with our previous studies, the present experiment supports the theory of vascular wall microenvironment.

Protective role of small extracellular vesicles derived from HUVECs treated with AGEs in diabetic vascular calcification.

The pathogenesis of vascular calcification in diabetic patients remains elusive. As an effective information transmitter, small extracellular vesicles (sEVs) carry abundant microRNAs (miRNAs) that regulate the physiological and pathological states of recipient cells. In the present study, significant up-regulation of miR-126-5p was observed in sEVs isolated from human umbilical vein endothelial cells (HUVECs) stimulated with advanced glycation end-products (A-EC/sEVs). Intriguingly, these sEVs suppressed the osteogenic differentiation of vascular smooth muscle cells (VSMCs) by targeting BMPR1B, which encodes the receptor for BMP, thereby blocking the smad1/5/9 signalling pathway. In addition, knocking down miR-126-5p in HUVECs significantly diminished the anti-calcification effect of A-EC/sEVs in a mouse model of type 2 diabetes. Overall, miR-126-5p is highly enriched in sEVs derived from AGEs stimulated HUVECs and can target BMPR1B to negatively regulate the trans-differentiation of VSMCs both in vitro and in vivo.

Scanning Electrochemical Cell Microscopy Platform with Local Electrochemical Impedance Spectroscopy.

Local electrochemical impedance spectroscopy (LEIS) has been a versatile technology for characterizing local complex electrochemical processes at heterogeneous surfaces. However, further application of this technology is restricted by its poor spatial resolution. In this work, high-spatial-resolution LEIS was realized using scanning electrochemical cell microscopy (SECCM-LEIS). The spatial resolution was proven to be ∼180 nm based on experimental and simulation results. The stability and reliability of this platform were further verified by long-term tests and Kramers-Kronig transformation. With this technology, larger electric double-layer capacitance (Cdl) and smaller interfacial resistance (Rt) were observed at the edges of N-doped reduced graphene oxide, as compared to those at the planar surface, which may be due to the high electrochemical activity at the edges. The established SECCM-LEIS provides a high-spatial approach for study of the interfacial electrochemical behavior of materials, which can contribute to the elucidation of the electrochemical reaction mechanism at material surfaces.

Study on a Rapid Imaging Method for Scanning Ion Conductance Microscopy Using a Double-Barreled Theta Pipette.

Scanning ion conductance microscopy (SICM) is a new noncontact, high-resolution scanning probe microscopy technique, which has become increasingly popular in recent years. The hopping mode-currently the most widely used scanning mode-can be used for imaging samples with complicated surface topographies. However, its slow scanning rate seriously restricts its broader application. This paper proposes a fast imaging control mode using a double-barreled theta pipette as the probe, which effectively increases the imaging rate. In this mode, sample surface height information is obtained when the double-barreled theta pipette approaches the sample in a two-step downward process. The ion current sum of two barrels and ion current of one barrel are used as feedback signals to approach the sample until the feedback signals decrease to the set threshold, respectively, thereby obtaining the height of the imaging point. First, this work used COMSOL to establish an SICM model and perform simulation analysis. The simulation results verified the proposed method's feasibility. Second, a scanning time mathematical model was established. The results revealed that the new method is superior to the traditional method in terms of imaging rate. Finally, experiments were performed on poly(dimethylsiloxane) (PDMS) samples using the two imaging modes described above. The results demonstrated that the new scanning mode could significantly improve the imaging rate of SICM without a loss in imaging quality and stability.

Melatonin alleviates vascular calcification and ageing through exosomal miR-204/miR-211 cluster in a paracrine manner.

In the elderly with atherosclerosis, hypertension and diabetes, vascular calcification and ageing are ubiquitous. Melatonin (MT) has been demonstrated to impact the cardiovascular system. In this study, we have shown that MT alleviates vascular calcification and ageing, and the underlying mechanism involved. We found that both osteogenic differentiation and senescence of vascular smooth muscle cells (VSMCs) were attenuated by MT in a MT membrane receptor-dependent manner. Moreover, exosomes isolated from VSMCs or calcifying vascular smooth muscle cells (CVSMCs) treated with MT could be uptaken by VSMCs and attenuated the osteogenic differentiation and senescence of VSMCs or CVSMCs, respectively. Moreover, we used conditional medium from MT-treated VSMCs and Transwell assay to confirm exosomes secreted by MT-treated VSMCs attenuated the osteogenic differentiation and senescence of VSMCs through paracrine mechanism. We also found exosomal miR-204/miR-211 mediated the paracrine effect of exosomes secreted by VSMCs. A potential target of these two miRs was revealed to be BMP2. Furthermore, treatment of MT alleviated vascular calcification and ageing in 5/6-nephrectomy plus high-phosphate diet-treated (5/6 NTP) mice, while these effects were partially reversed by GW4869. Exosomes derived from MT-treated VSMCs were internalised into mouse artery detected by in vivo fluorescence image, and these exosomes reduced vascular calcification and ageing of 5/6 NTP mice, but both effects were largely abolished by inhibition of exosomal miR-204 or miR-211. In summary, our present study revealed that exosomes from MT-treated VSMCs could attenuate vascular calcification and ageing in a paracrine manner through an exosomal miR-204/miR-211.

Percutaneous gallbladder drainage as a bridge to concomitant coronary artery bypass grafting and laparoscopic cholecystectomy.

A 74-year-old woman with left main and three-vessel coronary artery disease was scheduled for off-pump coronary artery bypass grafting and developed acute severe cholecystitis preoperatively. Percutaneous gallbladder drainage was placed to achieve gallbladder decompression and infection control. Two weeks later, CABG and laparoscopic cholecystectomy were successfully performed at the same time.

Mesenchymal stem cell-derived conditioned medium attenuate angiotensin II-induced aortic aneurysm growth by modulating macrophage polarization.

Mesenchymal stem cells (MSCs) exhibit therapeutic benefits on aortic aneurysm (AA); however, the molecular mechanisms are not fully understood. The current study aimed to investigate the therapeutic effects and potential mechanisms of murine bone marrow MSC (BM-MSCs)-derived conditioned medium (MSCs-CM) on angiotensin II (AngII)-induced AA in apolipoprotein E-deficient (apoE-/- ) mice. Murine BM-MSCs, MSCs-CM or control medium were intravenously administrated into AngII-induced AA in apoE-/- mice. Mice were sacrificed at 2 weeks after injection. BM-MSCs and MSCs-CM significantly attenuated matrix metalloproteinase (MMP)-2 and MMP-9 expression, aortic elastin degradation and AA growth at the site of AA. These treatments with BM-MSCs and MSCs-CM also decreased Ly6chigh monocytes in peripheral blood on day 7 and M1 macrophage infiltration in AA tissues on day 14, whereas they increased M2 macrophages. In addition, BM-MSCs and MSCs-CM reduced MCP-1, IL-1Ra and IL-6 expression and increased IL-10 expression in AA tissues. In vitro, peritoneal macrophages were co-cultured with BM-MSCs or fibroblasts as control in a transwell system. The mRNA and protein expression of M2 macrophage markers were evaluated. IL-6 and IL-1ß were reduced, while IL-10 was increased in the BM-MSC systems. The mRNA and protein expression of M2 markers were up-regulated in the BM-MSC systems. Furthermore, high concentration of IGF1, VEGF and TGF-ß1 was detected in MSCs-CM. Our results suggest that MSCs-CM could prevent AA growth potentially through regulating macrophage polarization. These results may provide a new insight into the mechanisms of BM-MSCs in the therapy of AA.

The methylation of Notch1 promoter mediates the osteogenesis differentiation in human aortic valve interstitial cells through Wnt/ß-catenin signaling.

Aortic valve interstitial cells (AVICs) have the potential to undergo calcification, which has been regarded as a critical issue during the pathology of calcific aortic valve disease (CAVD). In the past decade, epigenetics, in particular, DNA methylation dysregulation, has been reported to play a vital role in the occurrence and development of CAVD. In the present study, the expression of Notch1, which can inhibit the osteogenesis differentiation of valve interstitial cells, was downregulated whereas the expression of methyltransferases was upregulated in CAVD tissues, suggesting the potential role of DNA methylation in Notch1 expression and CAVD progression. As revealed by DNA extraction and bisulfite sequencing polymerase chain reaction (PCR), the methylation level in Notch1 promoter was much higher in CAVD tissues and human AVICs on Day 14 of osteogenesis differentiation induction. The silence of Notch1 intercellular domain (NICD) promoted while the treatment of demethylation agent, 5-Aza-dC, inhibited the osteogenesis differentiation. Moreover, NICD overexpression significantly suppressed the transcriptional activity of ß-catenin on TCF4, and the expression of osteogenesis differentiation factors, indicating the involvement of Wnt/ß-catenin signaling in Notch1 modulating the osteogenesis differentiation in human AVICs (hAVICs). Taken together, Notch1 promoter methylation leads to a decreased Notch1 expression and subsequent decreased release of NICD in the nucleus of hAVICs, therefore promoting the activation of Wnt/ß-catenin signaling and the expression of osteogenesis differentiation factors, finally promoting the osteogenesis differentiation in hAVICs. DNA methylation might act as an important bridge to link epigenetic variation and CAVD progression.

Diverse roles of macrophage polarization in aortic aneurysm: destruction and repair.

Aortic aneurysm (AA) is defined as an enlargement of the aorta greater than 1.5 times its normal size. Early diagnosis of AA is challenging and mortality of AA is high. Curative pharmacological treatments for AA are still lacking, highlighting the need for better understanding of the underlying mechanisms of AA progression. Accumulating studies have proven that the polarization state of circulating monocyte-derived macrophages plays a crucial role in regulating the development of AA. Distinct macrophage subtypes display different functions. Several studies targeting macrophage polarization during AA formation and progression showed potential treatment effects. In this review, we focus on the recent advances of research on macrophage polarization in the progression of AA and propose that targeting macrophage polarization could hold great promise for preventing and treating AA.

WITHDRAWN: Severe Pulmonary Embolism Secondary to Cement Embolism in the Inferior Vena Cava after Percutaneous Vertebroplasty.

The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.avsg.2018.01.003. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Severe Pulmonary Embolism was Secondary to Cement Inferior Vena Cava Embolism after Percutaneous Vertebroplasty.

Cement pulmonary embolism (cPE) and inferior vena cava embolism (cIE) are rare but potentially life-threatening complications of percutaneous vertebroplasty (PVP). Most cPE and cIE occurred simultaneously. In this case, a 65-year-old woman complained of dyspnea after PVP for 4 days. Patient's symptom and image tests manifest that the cPE was secondary to cIE. Although cIE was found at the first day after PVP, the local surgeons treat the patient with a regular anticoagulant without another more effective therapeutic measure. Eventually, the long cement inferior vena cava embolus was broken and result in left pulmonary embolism via the systemic circulation. She was admitted to our hospital and performed with embolectomy surgery by cardiopulmonary bypass and discharged after 7 days. We report this case to show that cIE embolism is still underestimated by some spine surgeons in China, and cIE may be developed to severe cPE during conservation management with anticoagulation.

Aortic Remodeling Following Sun's Procedure for Acute Type A Aortic Dissection.

BACKGROUND Sun's procedure is a surgical technique widely used in type A aortic dissection. The purpose of this study was to analyze clinical outcomes and morphologic changes in true and false lumen by computed tomography (CT) angiography after Sun's procedure. MATERIAL AND METHODS We retrospectively reviewed 51 patients who underwent Sun's procedure for acute Stanford type A aortic dissection extending down to iliac bifurcation between January 2013 and December 2014. The images of preoperative, one-month, three-month, and six-month follow-up were analyzed by CT angiography to measure the area and diameter of true and false lumen. RESULTS Four patients died before surgical intervention and postoperative deaths occurred in five patients (in-hospital mortality rate 10.6%). Only 42 patients (36 male, 6 female; mean age, 45.9±9.8 years; range, 24-65 years) with acute type A aortic dissection were involved in our study. Thirty-five patients (83.3%) suffered from chest or abdominal pain and only one patient (2.4%) was asymptomatic. Thirty-seven patients (88.1%) had hypertension as the most common comorbidity. In the ascending aorta, false lumen was eliminated and the change of true lumen was not significant (p>0.05). In the descending aorta, complete and partial thrombosis of false lumen were observed in eight patients (19.0%) and 33 patients (78.6%) by one-month follow-up CT scan, respectively. After the six-month follow-up, the rate of complete thrombosis increased to 36.1% and partial thrombosis decreased to 61.9%. The area and maximal diameter of true lumen were increased significantly (p<0.05), whereas significant decreases were found in the area and maximal diameter of false lumen (p<0.05). In the abdominal aorta, thrombosis was found in 52.4% patients at one-month follow-up CT. Furthermore, there were no significant changes in both true and false lumen within three months (p>0.05). Nevertheless, the false luminal area and maximal diameter decreased significantly (p<0.05) after six months, while these changes of true lumen were not significant (p>0.05). CONCLUSIONS After Sun's procedure, aortic remodeling was a continuous process and occurred in a predictable model, and the extent of aortic remodeling varied at different levels. Remodeling in descending thoracic aorta was earlier than it was in abdominal aorta.

The Relationship between Galectin-3 and Different Patterns of Ventricular Geometry Remodelling in Aortic Valve Stenosis.

BACKGROUND: This study was conducted to assess expression of Galectin-3 (Gal-3) in patients with different types of left ventricle (LV) hypertrophy geometry, and the relationship between Gal-3 expression and LV remodelling in patients with aortic valve stenosis (AS). METHODS: Galectin-3 expression was measured in the plasma and myocardia of AS patients who underwent an aortic valve replacement procedure. RESULTS: The study enrolled 77 consecutive patients with severe AS. Fifty-five (71.43%) of the enrolled patients had concentric hypertrophy (CH group), and had the highest degree of fibrosis (27.10±5.25%; p<0.001) and expression of Gal-3 in both plasma (19.11±2.06 ng/mL) and myocardial tissue (3.01±0.79). There was a strong positive correlation between the levels of fibrosis and Gal-3 expression in both plasma (r=0.584, p<0.001) and myocardium (r=0.522, p<0.001). Relative wall thickness (RWT) was strongly correlated with Gal-3 expression in both myocardium (r=0.594, p<0.001) and plasma (r=0.323, p=0.005). Additionally, N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were positively correlated with both fibrosis (r=0.313, p=0.036) and LV mass index (r=0.559, p<0.001). CONCLUSIONS: Concentric hypertrophy geometry was the most common type of myocardium remodelling, and AS patients with CH geometry showed the highest levels of Gal-3 expression. Galectin-3 levels were positively correlated with fibrosis and RWT, both of which are crucial indicators of geometric remodelling. Galectin-3 and NT-proBNP levels may be valuable prognostic predictors in AS patients with myocardial remodelling.

Apelin attenuates the osteoblastic differentiation of aortic valve interstitial cells via the ERK and PI3-K/Akt pathways.

Aortic valve calcification (AVC), which used to be recognized as a passive and irreversible process, is now widely accepted as an active and regulated process characterized by osteoblastic differentiation of aortic valve interstitial cells (AVICs). Apelin, the endogenous ligand for G-protein-coupled receptor APJ, was found to have protective cardiovascular effects in several studies. However, the effects and mechanisms of apelin on osteoblastic differentiation of AVICs have not been elucidated. Using a pro-calcific medium, we devised a method to produce calcific human AVICs. These cells were used to study the relationship between apelin and the osteoblastic calcification of AVICs and the involved signaling pathways. Alkaline phosphatase (ALP) activity/expression and runt-related transcription factor 2 (Runx2) expression were examined as hallmark proteins in this research. The involved signaling pathways were studied using the extracellular signal-regulated kinase (ERK) inhibitor, PD98059, and the phosphatidylinositol 3-kinase (PI3-K) inhibitor, LY294002. The results indicate that apelin attenuates the expression and activity of ALP, the expression of Runx2, and the formation of mineralized nodules. This protective effect was dependent on the dose of apelin, reaching the maximum at 100 pM, and was connected to activity of ERK and Akt (a downstream effector of PI3-K). The activation of ERK and PI3-K initiated the effects of apelin on ALP activity/expression and Runx2, but PD98059 and LY294002 abolished the effect. These results demonstrate that apelin attenuates the osteoblastic differentiation of AVICs via the ERK and PI3-K/Akt pathway.

[Diagnostic experience in 3 cases of cardiac occupying lesion].

The clinic symptoms of cardiac occupying lesions are complex and difficult to diagnose currently. In this study, three cases of atrial angiosarcoma, left ventricular aneurysm and left ventricular diverticulum were selected, respectively. The clinical characteristics, imaging features (echocardiogram, cardiac CT and MRI) and the postoperative and pathological results for patients were studied. We compared the differences in clinical symptoms, morphology, histology and haemodynamics among the three patients. The diagnosis were confirmed by intraoperative and postoperative pathological examination. We conclude that proper imaging approaches would be beneficial to diagnose the cardiac occupying lesions. Accurate preoperative diagnosis is beneficial to preoperative preparation as well as the decrease in operative risks.

The target region focused imaging method for scanning ion conductance microscopy.

Scanning ion conductance microscopy (SICM) has developed rapidly and has wide applications in biomedicine, single-cell science and other fields. SICM scanning speed is limited by the conventional raster-type scanning method, which spends most of time on imaging the substrate and does not focus enough on the target area. In order to solve this problem, a target region focused (TRF) method is proposed, which can effectively avoid the scanning of unnecessary substrate areas and enables SICM to image the target area only to achieve high-speed and effective local scanning. TRF method and conventional hopping mode scanning method are compared in the experiments using breast cancer cells and rat basophilic leukemia cells as experimental materials. It was demonstrated that our method can reduce the scanning time for a single sample image significantly without losing scanning information or compromising the quality of imaging. The TRF method developed in this paper can provide an efficient and fast scanning strategy for improving the imaging performance of SICM systems, which can be applied to the dynamic features of cell samples in the fields of biology and pharmacology analysis.

Rapid scanning method for SICM based on autoencoder network.

Scanning Ion Conductance Microscopy (SICM) enables non-destructive imaging of living cells, which makes it highly valuable in life sciences, medicine, pharmacology, and many other fields. However, because of the uncertainty retrace height of SICM hopping mode, the time resolution of SICM is relatively low, which makes the device fail to meet the demands of dynamic scanning. To address above issues, we propose a fast-scanning method for SICM based on an autoencoder network. Firstly, we cut under-sampled images into small image lists. Secondly, we feed them into a self-constructed primitive-autoencoder super-resolution network to compute high-resolution images. Finally, the inferred scanning path is determined using the computed images to reconstruct the real high-resolution scanning path. The results demonstrate that the proposed network can reconstruct higher-resolution images in various super-resolution tasks of low-resolution scanned images. Compared to existing traditional interpolation methods, the average peak signal-to-noise ratio improvement is greater than 7.5823 dB, and the average structural similarity index improvement is greater than 0.2372. At the same time, using the proposed method for high-resolution image scanning leads to a 156.25% speed improvement compared to traditional methods. It opens up possibilities for achieving high-time resolution imaging of dynamic samples in SICM and further promotes the widespread application of SICM in the future.

Association of vitamin D receptor BsmI gene polymorphism with risk of osteoporosis: a meta-analysis of 41 studies.

Vitamin D receptor (VDR) BsmI gene polymorphism has been reported to be strongly associated with osteoporosis risk in some studies. However, the results from those studies are still conflicting. We performed a meta-analysis of studies relating the VDR BsmI gene polymorphism to the risk of osteoporosis. The search was performed in the databases of PubMed, Embase, Cochrane Library and CBM-disc (China Biological Medicine Database) as of October 1, 2011, and the eligible investigations were recruited for this meta-analysis. Forty-one investigations were identified for the meta-analysis of association between VDR BsmI gene polymorphism and osteoporosis risk. There lacked an association between VDR BsmI gene polymorphism and osteoporosis risk for overall populations, Caucasians and Asians (overall populations: B vs b: p = 0.65, BB vs (Bb + bb): p = 0.14, bb vs (BB + Bb): p = 0.86; Caucasians: B vs b: p = 0.65, BB vs (Bb + bb): p = 0.38, bb vs (BB + Bb): p = 0.83; Asians: B vs b: p = 0.87, BB vs (Bb + bb): p = 0.62, bb vs (BB + Bb): p = 0.66). In conclusion, VDR BsmI B/b gene polymorphism is not associated with the susceptibility of osteoporosis in overall populations, Caucasians, and Asians.

[8.5 year-follow-up of combined heart-lung transplantation in a patient].

To summarize the case of combined heart-lung transplantation for a patient who survived for 8.5 years. On September 20, 2003, at Second Xiangya Hospital of Central South University, homologous heartlung transplantation was performed on a male patient who was diagnosed with cardiopulmonary failure secondary to congenital ventricular septal defect with severe pulmonary hypertension. Heart-lung allograft was preserved with 1500 mL modified St.Thomas solution and 3000 mL modified LPD solution. Postoperative immunosuppressive therapies included: methylprednisolone and human anti-lymphocyte globulin protein in the induction period; and combination of ciclosporin A, CellCept and prednisolone in the stable period. In 2007, the treatment was changed to CellCept mg, twice a day+FK506 4 mg, twice a day. The patient lived 8.5 years of normal life with cardiac function of NYHA I-II. Echocardiogram showed left ventricular ejection fraction of 61% to 74%. Heart-lung transplantation proved reliable therapy modality for terminal cardiopulmonary failure. Excellent donor organ preservation and proper perioperative treatment are key factors for long-term survival after heart-lung transplantation.