24 research outputs found
Development of a human-size magnetic particle imaging device for sentinel lymph node biopsy of breast cancer
In this study, a novel human-size handheld magnetic particle imaging (MPI) system was developed for the high-precision detection of sentinel lymph nodes for breast cancer. The system consisted of a highly sensitive home-made MPI detection probe, a set of concentric coils pair for spatialization, a solenoid coil for uniform excitation at 8 [email protected] mT, and a full mirrored coil set positioned far away from the scanning area. The mirrored coils formed an extremely effective differential pickup structure which suppressed the system noise as high as 100 dB. The different combination of the inner and outer gradient current made the field free point (FFP) move in the Z direction with a uniform intensity of 0.54T/m, while the scanning in the XY direction was implemented mechanically. The third-harmonic signal of the Superparamagnetic Iron Oxide Nanoparticles (SPIONs) at the FFP was detected and then reconstructed synchronously with the current changes. Experiment results showed that the tomographic detection limit was 30 mm in the Z direction, and the sensitivity was about 10 μg Fe SPIONs at 40 mm distance with a spatial resolution of about 5 mm. In the rat experiment, 54 μg intramuscular injected SPIONs were detected successfully in the sentinel lymph node, in which the tracer content was about 1.2% total injected Fe. Additionally, the effective detection time window was confirmed from 4 to 6 min after injection. Relevant clinical ethics are already in the application process. Large mammalian SLNB MPI experiments and 3D preoperative SLNB imaging will be performed in the future
The Optimization Design of Macrophage Membrane Camouflaging Liposomes for Alleviating Ischemic Stroke Injury through Intranasal Delivery
Ischemic stroke is associated with a high mortality rate, and effective treatment strategies are currently lacking. In this study, we aimed to develop a novel nano delivery system to treat ischemic stroke via intranasal administration. A three-factor Box–Behnken experimental design was used to optimize the formulation of liposomes co-loaded with Panax notoginseng saponins (PNSs) and Ginsenoside Rg3 (Rg3) (Lip-Rg3/PNS). Macrophage membranes were coated onto the surface of the optimized liposomes to target the ischemic site of the brain. The double-loaded liposomes disguised by macrophage membranes (MM-Lip-Rg3/PNS) were spherical, in a “shell–core” structure, with encapsulation rates of 81.41% (PNS) and 93.81% (Rg3), and showed good stability. In vitro, MM-Lip-Rg3/PNS was taken up by brain endothelial cells via the clathrin-dependent endocytosis and micropinocytosis pathways. Network pharmacology experiments predicted that MM-Lip-Rg3/PNS could regulate multiple signaling pathways and treat ischemic stroke by reducing apoptosis and inflammatory responses. After 14 days of treatment with MM-Lip-Rg3/PNS, the survival rate, weight, and neurological score of middle cerebral artery occlusion (MCAO) rats significantly improved. The hematoxylin and eosin (H&E) and TUNEL staining results showed that MM-Lip-Rg3/PNS can reduce neuronal apoptosis and inflammatory cell infiltration and protect the ischemic brain. In vivo biological experiments have shown that free Rg3, PNS, and MM-Lip-Rg3/PNS can alleviate inflammation and apoptosis, especially MM-Lip-Rg3/PNS, indicating that biomimetic liposomes can improve the therapeutic effects of drugs. Overall, MM-Lip-Rg3/PNS is a potential biomimetic nano targeted formulation for ischemic stroke therapy
Natural variation of<em> C-repeat-binding factor </em>(CBFs) genes is a major cause of divergence in freezing tolerance among a group of <em>Arabidopsis thaliana</em> populations along the Yangtze River in China
We used a monophyletic group of four natural populations of Arabidopsis thaliana expanded from a single ancestor along the Yangtze River c. 90 000 yr ago to study the molecular mechanism of the divergence in their freezing tolerance, in order to gain an insight into the genetic basis of their local adaption to low temperatures. Freezing tolerance assays, measurements of metabolites in the raffinose biosynthesis pathway and transactivation-activity assays of variation in forms of cold-responsive transcription factors were conducted on the four populations. Quantitative trait locus mapping was adopted with F-2 populations of the most- and least freezing-tolerant populations. The degree of freezing tolerance among the four populations was negatively correlated with the lowest monthly average temperature of January in their native habitats, and positively correlated to the expression level of some cold-regulated genes. We identified a major locus harboring three cold-responsive transcription factor genes CBF1-3, and found a nucleotide insertion in CBF2 in all populations except SXcgx, which generated a dysfunctional CBF2 protein. The CBF2 in SXcgx experienced a stronger natural selection in the cooler environment after CBF3 lost its response to low temperature, which possibly reflects a local adaptation of these populations during the expansion from a common ancestor.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000322598700021&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Plant SciencesSCI(E)PubMed6ARTICLE41069-108019
High-Fat Diet Consumption in Adolescence Induces Emotional Behavior Alterations and Hippocampal Neurogenesis Deficits Accompanied by Excessive Microglial Activation
Adolescence is a developmental epoch characterized by massive neural circuit remodeling; thus, the brain is particularly vulnerable to environmental influences during this period. Excessive high-fat diet (HFD) consumption, which is very common among adolescents, has long been recognized as a potent risk factor for multiple mood disorders, including depression and anxiety. However, the precise mechanisms underlying the influences of HFD consumption in adolescence on emotional health are far from clear. In the present study, C57BL/6 mice were fed a control diet (CD) or HFD for about 4 weeks from postnatal day (P) 28 to P60, spanning most of the adolescence period, and then subjected to behavioral assessments and histological examinations. HFD mice exhibited elevated levels of depression and anxiety, decreased hippocampal neurogenesis, and excessive microglial activation in the ventral hippocampus. Furthermore, in HFD-fed mice, microglia showed increased DCX+ inclusions, suggesting aberrant microglial engulfment of newborn neurons in HFD-fed adolescents. To our knowledge, this is the first observation suggesting that the negative effects of HFD consumption in adolescence on emotion and neuroplasticity may be attributed at least in part to aberrant microglial engulfment of nascent neurons, extending our understanding of the mechanism underlying HFD-related affective disorders in young people
Arsenic trioxide combined with co-stimulatory molecule blockade prolongs survival of cardiac allografts in alloantigen-primed mice
health and education, Fujian Province [WKJ2008-2-50]Various memory cell populations existing before organ transplantation are believed to be important barriers to extending the graft survival time. Here, we report that arsenic trioxide (As2O3), a common component of some Chinese traditional preparations, could obviously reduce the proliferation of splenic T cells in alloantigen-primed mice in vitro. Furthermore, we evaluated As2O3 treatment alone or in combination with blocking monoclonal antibodies (mAb) against co-stimulatory molecules (LFA-1 and CD154) in the prevention of heart transplant rejection in alloantigen-primed mice. Alloantigen-primed mice were randomly divided into 4 groups of 6 animals each. The control group was given normal saline; the As2O3 group received As2O3 (5 mg/kg/d) (i.p.) on days 0-10 post-transplantation; the Ab group received 100 mu g anti-LFA-1 mAb + 250 mu g anti-CD154 mAb (i.p.) on the day of transplantation and 3 more times every alternate day and the As2O3 + Ab group received a combined As2O3 and Ab treatment protocol. The survival of the allografts was almost doubled among the As2O3 group and Ab group compared with the control group (5, 5.6 vs 3.3 days). A marked prolongation (16 days) of graft survival was achieved by the combination protocol compared with the control group (3.3 days; P<0.05). None of the treatment group showed side effects. Five days after transplantation, cardiac allografts, splenic T cells and serum were harvested for analysis. Compared with the control group, most of the treatment groups showed: (i) alleviation of allograft rejection in different levels; (ii) IFN-gamma expression was reduced and TGF-beta expression increased in both peripheral blood and within the grafts; (iii) the proportions of CD4(+) or CD8(+) memory T cells in the spleen of the recipients were significantly reduced while the expression of regulatory T cells (Tregs) was enhanced; (iv) the alloresponses of memory T cells were inhibited, and levels of alloantibodies in recipients' sera were also decreased. Among all these changes, the As2O3 + Ab group showed the most significant changes. Our study highlights an obvious synergistic action of As2O3 when combined with co-stimulatory molecules blockade in prolonging the survival of cardiac allografts in alloantigen-primed mice. (C) 2010 Elsevier B.V. All rights reserved
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Delayed Low-Intensity Extracorporeal Shock Wave Therapy Ameliorates Impaired Penile Hemodynamics in Rats Subjected to Pelvic Neurovascular Injury
BackgroundErectile dysfunction (ED) caused by pelvic neurovascular injury (PNVI) is often refractory to treatment. In many cases, erectogenic therapy is administered in a delayed fashion.AimTo evaluate penile hemodynamic effects and histologic changes associated with delayed low-intensity extracorporeal shock wave therapy (Li-ESWT) after PNVI ED in a rat model. We visualized images using immunofluorescence and 3-dimensional imaging of solvent-cleared organs (3DISCO), a novel imaging technique.MethodsA total of 32 Sprague-Dawley male rats aged 12 weeks were divided equally into 4 groups: sham surgery as normal controls (NC), PNVI controls (PC), PNVI with very-low-energy Li-ESWT (PVL), and PNVI with low-energy Li-ESWT (PL). Bilateral cavernous nerve crush and internal pudendal bundle ligation were performed in the 3 PNVI groups. Li-ESWT was administered twice a week for 4 weeks in the PL and PVL groups starting at 4 weeks after PNVI.OutcomesIntracavernous pressure (ICP) studies (normalized to mean arterial pressure [MAP]) were conducted in all subject animals. After testing, tissue was harvested for immunofluorescence staining and 3DISCO analysis.ResultsMean ICP/MAP was lower in PC animals compared with NC animals (0.37 ± 0.03 vs 0.91 ± 0.03, respectively; P = .001). The ICP/MAP ratio was significantly higher in PVL and PL animals (0.66 ± 0.07 and 0.82 ± 0.05, respectively) compared with PC animals (P = .002 and .001, respectively). Detailed microstructures and trajectories of nerves and vessels were identified with immunofluorescence and 3DISCO. The PC group had lower density of nerves, axons, neuronal nitric oxide synthase-positive nerves, and Schwann cells in the dorsal penis. Animals in the PL group had significantly higher expression of all of these markers compared with PC animals.Clinical implicationsLi-EWST may have utility in the management of severe ED related to PNVI from severe pelvic injury or radical pelvic surgeries, even when administered in a delayed fashion.Strength & limitationsThis study of a severe ED phenotype involved treatment administered in a delayed fashion, which is more consistent with how therapy likely would be delivered in a real-world clinical context. Moreover, because the treatment commenced at 4 weeks after injury, when nerve and tissue atrophy have already occurred, the results imply that Li-ESWT can be used for regenerative therapy. Additional studies on dose optimization and treatment interval are needed to inform the design of human clinical trials.ConclusionLi-ESWT ameliorates the negative functional and histologic effects of severe pelvic neurovascular injury in a rat model system. 3DISCO provides high-resolution images of neuroanatomy and neural regeneration. Wang HS, Ruan Y, Banie L, et al. Delayed Low-Intensity Extracorporeal Shock Wave Therapy Ameliorates Impaired Penile Hemodynamics in Rats Subjected to Pelvic Neurovascular Injury. J Sex Med 2019;16:17-26
Isatis tinctoria L combined with co-stimulatory molecules blockade prolongs survival of cardiac allografts in alloantigen-primed mice
Technological Project of Xiamen City [3502Z 20084013]Memory T cells present a unique challenge in transplantation. Although memory T cells express robust immune responses to invading pathogens. they may be resistant to the effects of immunosuppressive therapies used to prolong graft survival. In previous studies, we found that compound K. the synthesized analogue of highly unsaturated fatty acids from Isatis tinctoria L., reduced acute cardiac allograft rejection in mice (Wang et al., 2009 [1]). Here, we further investigated the effect of compound K on cardiac allograft rejection in alloantigen-primed mice. We found that compound K significantly inhibited CD4(+) and CD8(+) memory T cells proliferation in a mixed lymphocyte reaction (MLR). In vivo, compound K combined with anti-CD154 and anti-LFA-1 monoclonal antibodies (mAbs) significantly extended the survival time of heart grafts in alloantigen-primed mice with no obvious toxic side effects. Furthermore, our data suggests that compound K works by reducing the expression of both IL-2 and IFN-gamma within the graft rather than enhancing expression of regulatory T cells (Tregs). Compound K can also inhibit the alloresponses of memory T cells, while increasing the proportion of CD4(+) memory T cells in the spleen of the recipients and significantly reducing the level of alloantibodies in the serum. Our study highlights the unique immune effects of compound K that may be further explored for clinical use in extending the survival of transplant grafts. (C) 2010 Elsevier B.V. All rights reserved
Isatis tinctoria L. combined with co-stimulatory molecules blockade prolongs survival of cardiac allografts in alloantigen-primed mice
Memory T cells present a unique challenge in transplantation. Although memory T cells express robust immune responses to invading pathogens. they may be resistant to the effects of immunosuppressive therapies used to prolong graft survival. In previous studies, we found that compound K. the synthesized analogue of highly unsaturated fatty acids from Isatis tinctoria L., reduced acute cardiac allograft rejection in mice (Wang et al., 2009 [1]). Here, we further investigated the effect of compound K on cardiac allograft rejection in alloantigen-primed mice. We found that compound K significantly inhibited CD4(+) and CD8(+) memory T cells proliferation in a mixed lymphocyte reaction (MLR). In vivo, compound K combined with anti-CD154 and anti-LFA-1 monoclonal antibodies (mAbs) significantly extended the survival time of heart grafts in alloantigen-primed mice with no obvious toxic side effects. Furthermore, our data suggests that compound K works by reducing the expression of both IL-2 and IFN-gamma within the graft rather than enhancing expression of regulatory T cells (Tregs). Compound K can also inhibit the alloresponses of memory T cells, while increasing the proportion of CD4(+) memory T cells in the spleen of the recipients and significantly reducing the level of alloantibodies in the serum. Our study highlights the unique immune effects of compound K that may be further explored for clinical use in extending the survival of transplant grafts. (C) 2010 Elsevier B.V. All rights reserved