Applications of nanomaterials in anti-VEGF treatment for ophthalmic diseases.

Angiogenesis has been determined to be essential in the occurrence and metastasis of diabetic retinopathy (DR), age-related macular degeneration (AMD), retinal vein occlusion (RVO), choroidal neovascularization (CNV), retinopathy of prematurity (ROP), tumor, etc. However, the clinical use of anti-vascular endothelial growth factors (VEGF) drugs is currently limited due to its high cost, potential side effects, and need for repeated injections. In recent years, nanotechnology has shown promising results in inhibiting neovascularization and reducing reactive oxygen species (ROS) or inflammatory factors. Some nanomaterials can also act as vehicles for drug delivery, such as lipid nanoparticles and PLGA. The process of angiogenesis and its molecular mechanism are discussed in this article. At the same time, this study aims to systematically review the research progress of nanotechnology and offer more treatment options for neovascularization-related diseases in clinical ophthalmology.

Antenna Array Design Based on Low-Temperature Co-Fired Ceramics.

With the continuous development of wireless communication technology, the frequency band of 6G communication systems is moving towards higher frequencies such as millimeter waves and terahertz. In such high-frequency situations, wireless transmission requires antenna modules to be provided with characteristics of miniaturization, high integration, and high gain, which presents new challenges to the development of antenna technology. In this article, a 4 × 4 antenna array using multilayered low-temperature co-fired ceramic is proposed, operating in W-band, with a feeding network based on substrate-integrated waveguide, and an antenna element formed through the combination of a substrate-integrated cavity and surface parasitic patches, which guaranteed the array to possess the advantages of high integration and high gain. Combined with the substrate-integrated waveguide to a rectangular waveguide transition structure designed in the early stage, a physical array with a standard metal rectangular waveguide interface was fabricated and tested. The test results show that the gain of the antenna array is higher than 18 dBi from 88 to 98 GHz, with a maximum of 20.4 dBi.

A new ultra-wide-field fundus dataset to diabetic retinopathy grading using hybrid preprocessing methods.

Diabetic retinopathy(DR) is a common early diabetic complication and one of the main causes of blindness. In clinical diagnosis and treatment, regular screening with fundus imaging is an effective way to prevent the development of DR. However, the regular fundus images used in most DR screening work have a small imaging range, narrow field of vision, and can not contain more complete lesion information, which leads to less ideal automatic DR grading results. In order to improve the accuracy of DR grading, we establish a dataset containing 101 ultra-wide-field(UWF) DR fundus images and propose a deep learning(DL) automatic classification method based on a new preprocessing method. The emerging UWF fundus images have the advantages of a large imaging range and wide field of vision and contain more information about the lesions. In data preprocessing, we design a data denoising method for UWF images and use data enhancement methods to improve their contrast and brightness to improve the classification effect. In order to verify the efficiency of our dataset and the effectiveness of our preprocessing method, we design a series of experiments including a variety of DL classification models. The experimental results show that we can achieve high classification accuracy by using only the backbone model. The most basic ResNet50 model reaches an average of classification accuracy(ACA) 0.66, Macro F1 0.6559, and Kappa 0.58. The best-performing Swin-S model reaches ACA 0.72, Macro F1 0.7018, and Kappa 0.65. DR grading using UWF images can achieve higher accuracy and efficiency, which has practical significance and value in clinical applications.

HO-1 protects the nerves of rats with cerebral hemorrhage by regulating the PI3K/AKT signaling pathway.

Objective: This study aimed to investigate the neuroprotective effect of heme oxygenase-1 (HO-1) on the PI3K/AKT signaling pathway in rats with cerebral hemorrhage. Materials and methods: Adult male Sprague-Dawley rats were randomly divided into: a sham group, a model group and an HO-1 inhibitor group (ZnPP group). Functional defects after surgery were scored according to the Longa5 standard. Hemotoxylin and eosin staining was used to detect whether the model was constructed successfully. Superoxide dismutase (SOD) vitality and malondialdehyde (MDA) content were calculated by the xanthine oxidase method and thiobarbituric acid method, respectively. Blood-brain barrier permeability was measured by Evans Blue. Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The expression of Bcl-2 and BAX was evaluated by immunohistochemistry and the expression of PI3K, p-PI3K, AKT and p-AKT was tested by Western blotting. Results: The rat intracerebral hemorrhage model was successfully constructed. Compared with the model group, the bleeding in the ZnPP group was more serious, the cell edema and deformation were aggravated, and the neurological deficit score in the rat was significantly increased. In addition, the content of Evans blue, MDA, the number of apoptotic cells, the water content of brain tissue and the expression of BAX were significantly increased, while the SOD activity and the expressions of Bcl-2, p-PI3K and p-AKT protein were decreased. Conclusion: HO-1 could protect the nerves of rats with cerebral hemorrhage by regulating the PI3K/AKT signaling pathway.

Down-Regulation of Mir-145 Improves Learning and Memory Abilities in Epileptic Rats by Regulating Hippocampal Neuron Apoptosis.

OBJECTIVES: To investigate effect of miR-145 on learning and memory ability in rats with epilepsy. METHODS: Rats with epilepsy were induced by lithium chloride-pilocarpine. miR-145 antagomir and antagomir-control were injected into epileptic brains by the stereotactic technique, respectively. Then, rats were divided into a normal group (N), epilepsy group (Ep), miR-145 antagomir group (A) and antagomir-control group (C). After 1 and 7 days of treatment, the expression of miR-145 and Caspase-9 were detected, and the apoptosis of hippocampal neurons in CA1 of hippocampus was detected. After 7 days of treatment, the learning and memory abilities of rats was measured by using the Morris water maze test. RESULTS: The rat epilepsy model was successfully constructed. Compared with the N group, the target quadrant time and platform crossing times were reduced and the expression of miR-145 and Caspase-9 was increased in the epilepsy groups (P < 0.05). Compared with the Ep and C groups, the target quadrant time and platform crossing times were increased and the expression of miR-145 and Caspase-9 was down-regulated in the A group (P < 0.05). The number of apoptotic hippocampal neurons in the hippocampal CAl area of the Ep group was more than that in the N group and in the A group was less than that in the C group at 1 and 7 days after modeling respectively (P < 0.05). CONCLUSIONS: Down-regulated miR-145 improved the apoptosis of hippocampal neurons by reducing the Caspase-9 expression in hippocampus and further affected learning and memory abilities of rats with epilepsy.

Dexmedetomidine Improves Cerebral Ischemia-Reperfusion Injury in Rats via Extracellular Signal-Regulated Kinase/Cyclic Adenosine Monophosphate Response Element Binding Protein Signaling Pathway.

OBJECTIVE: To investigate the mechanism of dexmedetomidine (Dex) in improving brain damage induced by cerebral ischemia-reperfusion injury in rats. METHODS: Rats were randomly divided into a sham operation group, ischemia-reperfusion group, Dex group, piracetam group, and yohimbine + Dex group, with 12 rats per group. 2,3,5-Triphenyltetrazolium chloride staining was used to analyze cerebral infarct size. Hematoxylin-eosin staining and immunohistochemistry were used to observe brain damage caused by ischemia-reperfusion. Cognitive and memory functions was detected by Morris water maze test, and the expression of phosphorylated extracellular signal-regulated kinases 1 and 2 (ERK1/2) and phosphorylated cyclic adenosine monophosphate response element binding protein (CREB) were measured by Western blot. RESULTS: Cognitive dysfunction was improved in the Dex group and the piracetam group compared with the ischemia-reperfusion group. Compared with the ischemia-reperfusion group, infarct size and neuronal cell death rates were decreased in the Dex group and the piracetam group. The expression of phosphorylated ERK1/2 and phosphorylated CREB in the Dex group was increased, whereas the expression of phosphorylated ERK1/2 and phosphorylated CREB in the yohimbine + Dex group was lower than in the Dex group (P < 0.05). CONCLUSIONS: Dex improved ischemic brain damage by promoting signal transduction of the ERK/CREB pathway, which may provide new ways for clinical treatment of cerebral ischemia-reperfusion injury.

Expression and shifting subcellular localization of the transcription factor, Foxd3, in embryonic and adult pancreas.

Multipotent progenitor cells self renew throughout an animal's lifetime and can differentiate to give rise to different cell types. Before we can fully understand the developmental potential of progenitor cells and control their differentiation both in vivo and in vitro as stem cells, identification and characterization of the genes that control stem cell fate must first be obtained. Foxd3, a member of the forkhead family of transcriptional regulators, is required for the maintenance of embryonic stem cells and trophoblast stem cells of the early mouse embryo. We describe here the expression of this protein in the developing pancreas. Foxd3 is expressed in most beta cells and infrequently in alpha and PP cells but is not expressed in somatostatin cells. The subcellular localization of Foxd3 varies with fat content in the diet; with a high fat diet the protein is found primarily in the cytoplasm while a low fat diet results in nuclear localization. Foxd3 is differentially localized in a rat model of diabetes: it is nuclear in ZDF rats but cytoplasmic in their lean counterparts. Foxd3 is nuclear in Lep(Ob/Ob) mice.

Neural crest stem cells.

Stem cells are defined by their ability to both self-renew and give rise to multiple lineages in vivo and/or in vitro. As discussed in other chapters in this volume, the embryonic neural crest is a multipotent tissue that gives rise to a plethora of differentiated cell types in the adult organism and is unique to vertebrate embryos. From the point of view of stem cell biology, the neural crest is an ideal source for multipotent adult stem cells. Significant advances have been made in the past few years isolating neural crest stem cell lines that can be maintained in vitro and can give rise to many neural crest derivatives either in vitro or when placed back into the context of an embryo. The initial work identifying these stem cells was carried out with premigratory neural crest from the embryonic neural tube. Later, neural crest stem cells were isolated from postmigratory neural crest, presumably more restricted in developmental potential. More recently it has been demonstrated that neural crest stem cell progenitors persist in the adult in at least two differentiated tissues, the enteric nervous system of the gut and the whisker follicles of the facial skin. In all cases, the properties of the stem cells derived reflect their tissue of origin and the potential of the progenitors becomes more restricted with age. In this chapter we will review this work and speculate on future possibilities with respect to combining our knowledge of neural crest gene function in the embryo and the manipulation of adult neural crest stem cells in vitro and eventually in vivo.

Copolymers Based on 1,3-Bis(carbazol-9-yl)benzene and Three 3,4-Ethylenedioxythiophene Derivatives as Potential Anodically Coloring Copolymers in High-Contrast Electrochromic Devices.

In this study, copolymers based on 1,3-bis(carbazol-9-yl)benzene (BCz) and three 3,4-ethylenedioxythiophene derivatives (3,4-ethylenedioxythiophene (EDOT), 3,4-(2,2-dimethylpropylenedioxy)thiophene (ProDOT-Me2), and 3,4-ethylenedithiathiophene (EDTT)) were electrochemically synthesized and their electrochemical and electrochromic properties were characterized. The anodic copolymer P(BCz-co-ProDOT) with BCz/ProDOT-Me2 = 1/1 feed molar ratio showed high optical contrast (ΔT%) and coloring efficiency (η), measured as 52.5% and 153.5 cm²âˆ™C-1 at 748 nm, respectively. Electrochromic devices (ECDs) based on P(BCz-co-EDOT), P(BCz-co-ProDOT), and P(BCz-co-EDTT) as anodic polymer layers, and poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT-PSS) as cathodic polymer layer were fabricated. P(BCz-co-ProDOT)/triple-layer PEDOT-PSS ECD showed three different colors (light yellow, yellowish-blue, and dark blue) at different applied potentials. In addition, the highest optical contrast (ΔT%) of P(BCz-co-ProDOT)/triple-layer PEDOT-PSS ECD was found to be 41% at 642 nm and the coloration efficiency was calculated to be 416.5 cm²âˆ™C-1 at 642 nm. All ECDs showed satisfactory optical memories and electrochemical cyclic stability.

Circulating versus local angiotensin II in blood pressure control: lessons from tissue-specific expression of angiotensin-converting enzyme (ACE).

The renin angiotensin system (RAS) is a central player in blood pressure control. Its effector peptide, angiotensin II, regulates blood pressure through coordinated actions in multiple tissues. The RAS is generally considered to be an endocrine system, and angiotensin II to be a circulating hormone. In recent years, however, a role for locally produced angiotensin II has been proposed. The major site for angiotensin II production is endothelium, where angiotensin-converting enzyme (ACE) is abundantly expressed. To elucidate the relative importance of circulating angiotensin II versus locally produced angiotensin II, one approach is to create a mouse model in which ACE is expressed in a tissue-specific manner. In this review, we discuss strategies to create such a model. In a mouse model we generated using a novel promoter-swapping technique, the endothelial ACE is eliminated and replaced by ectopic production of ACE in the liver. This model specifically addresses the question of whether local production of angiotensin II is essential for RAS function.

The labeling of C57BL/6j derived embryonic stem cells with enhanced green fluorescent protein.

OBJECTIVE: To labele MESPU35, a embryonic stem (ES) cell line derived from C57BL/6j mouse, with enhanced green fluorescent protein (EGFP) for further application. METHODS: The EGFP gene was controlled by the hybrid CA promoter/enhancer (CMV enhancer/chicken beta-actin promoter/beta-actin intron) to construct the vector of the transgene, pCA-EGFP. The vector was transfected into MESPU35 by electroporation. RESULTS: We generated EGFP expressing ES cells demonstrating normal properties. The green fluorescence of EGFP expressing cells was maintained in propagation of the ES cells for more than 30 passages as well as in differentiated cells. Cultured in suspension, the "green" ES cells aggregated, and formed embryoid bodies maintaining the green fluorescence at varying developmental stages. The "green" embryoid bodies could expand and differentiate into various types of cells, exhibiting ubiquitous green fluorescence. CONCLUSIONS: The hybrid CA promoter/enhancer used to control the EGFP expressing ES cells, resulted in more intense and ubiquitous activity. The EGFP transfected cells yield bright green fluorescence, which can be visualized in real time and in situ. In addition, the ES cells, MESPU35, are derived from C57BL/6j mice, which are the most widely used in oncology, physiology and genetics. Compared to 129 substrains, C57BL/6j mice avoid a number of potential problems apparent in the other strains.

Labeling embryonic stem cells with enhanced green fluorescent protein on the hypoxanthineguanine phosphoribosyl transferase locus.

OBJECTIVE: To label embryonic stem (ES) cells with enhanced green fluorescent protein (EGFP) on the hypoxanthineguanine phosphoribosyl transferase (HPRT) gene locus for the first time to provide a convenient and efficient way for cell tracking and manipulation in the studies of transplantation and stem cell therapy. METHODS: Homologous fragments were obtained by polymerase chain reaction (PCR), from which the gene targeting vector pHPRT-EGFP was constructed. The linearized vector was introduced into ES cells by electroporation. The G418(r)6TG(r) cell clones were obtained after selection with G418 and 6TG media. The integration patterns of these resistant cell clones were identified with Southern blotting. RESULTS: EGFP expressing ES cells on the locus of HPRT were successfully generated. They have normal properties, such as karyotype, viability and differentiation ability. The green fluorescence of EGFP expressing cells was maintained in propagation of the ES cells for more than 30 passages and in differentiated cells. Cultured in suspension, the "green" ES cells aggregated and formed embryoid bodies, retaining the green fluorescence at varying developmental stages. The "green" embryoid bodies could expand and differentiate into various types of cells, exhibiting ubiquitous green fluorescence. CONCLUSIONS: This generation of "green" targeted ES cells is described in an efficient protocol for obtaining the homologous fragments by PCR. Introducing the marker gene in the genome of ES cells, we should be able to manipulate them in vitro and use them as vehicles in cell-replacement therapy as well as for other biomedical and research purposes.

Effect of emodin on proliferation and differentiation of 3T3-L1 preadipocyte and FAS activity.

OBJECTIVE: To study the effects of emodin on proliferation and differentiation of 3T3-L1 preadipocyte and the possible mechanism. METHODS: Cell proliferation was determined by MTT spectrophotometry, cell differentiation was determined by Oil Red O staining,and fatty acid synthase (FAS) activity was determined by spectrophotometry. RESULTS: Emodin promoted proliferation of 3T3-L1 preadipocyte at low concentration and inhibited the proliferation at high concentration in a dose-related manner. In contrast, it inhibited cell differentiation into adipocyte at low concentration in a dose-related manner. In vitro emodin inhibited the activity of FAS in a dose-related manner. CONCLUSIONS: The effects of emodin on 3T3-L1 cell's proliferation and differentiation are dose dependent. Emodin inhibits the activity of FAS. Our results suggest that emodin should have a potential to serve as a fat-reducing drug.

[Establishing mouse embryonic stem cell line carrying a fluorescent undifferentiated marker].

To label mouse ES cells,a cell line derived from the inner cell mass of 3.5-day blastocysts,with enhanced green fluorescent protein (EGFP), the vector of pRex-1-EGFP was transferred into mouse ES cells by electroporation. The expressions of Rex-1 in undifferentiated and differentiated ES cells were detected by the microscopic observation of EGFP and by RT-PCR. The results showed that the EGFP gene was transferred into the mouse ES cell line, and the transfected cells in undifferentiated state showed high levels of EGFP expression. When the cells began to differentiate, the EGFP expressions were gradually reduced. A mouse ES cell line expressing EGFP under the control of Rex-1 gene promoter was generated. The cell line provides a powerful approach for the research of the process of mammalian development and for the screening of small molecules that can regulate this process.

[Researches on the methodology of establishment of BALB/c murine embryonic stem cell lines].

Several methods and processes of establishment and culture of BALB/c mouse ES cell lines were discussed detailedly. A new method to establish and culture ES cell lines derived from BALB/c mouse was set up successfully using mouse embryonic fibroblast feeder layer and rat-heart-cell-conditioned medium (RH-CM). These culture conditions not only maintain the undifferentiated state and normal diploid karyotypes of BALB/c mouse ES cells effectively, but also maintain a series of their characteristics of murine stem cells. two different kinds of digestive methods and Two kinds of digestive juice with different concentrations were designed to dissociate proliferous inner cell mass (ICM) and ES cell colonies derived from dissociative ICM. two different kinds of digestive methods are "single time dissociation method" and "several times dissociation method", two kinds of digestive juice are 0.25% Trypsin-0.04% EDTA and 0.05% Trypsin-0.008% EDTA. At the same time, appropriate dissociated occasion of ICM and the effect of RH-CM on establishment and culture of BALB/c mouse ES cell lines were discussed. The results suggested that it is a reasonable method to establish BALB/c mouse ES cell lines using low concentration digestive juice and "several times dissociation method" to dissociate ICM after 4 days' proliferation. Judged by the form of ES cells and its colonies, proliferous capability, karyotypes examine, alkaline phosphatase activity assay and differentiation capability in vitro and in vivo, the 9 ES cell lines that we established satisfied the all traits of murine ES cell line.

Requirement for Foxd3 in the maintenance of neural crest progenitors.

Understanding the molecular mechanisms of stem cell maintenance is crucial for the ultimate goal of manipulating stem cells for the treatment of disease. Foxd3 is required early in mouse embryogenesis; Foxd3(-/-) embryos fail around the time of implantation, cells of the inner cell mass cannot be maintained in vitro, and blastocyst-derived stem cell lines cannot be established. Here, we report that Foxd3 is required for maintenance of the multipotent mammalian neural crest. Using tissue-specific deletion of Foxd3 in the neural crest, we show that Foxd3(flox/-); Wnt1-Cre mice die perinatally with a catastrophic loss of neural crest-derived structures. Cranial neural crest tissues are either missing or severely reduced in size, the peripheral nervous system consists of reduced dorsal root ganglia and cranial nerves, and the entire gastrointestinal tract is devoid of neural crest derivatives. These results demonstrate a global role for this transcriptional repressor in all aspects of neural crest maintenance along the anterior-posterior axis, and establish an unprecedented molecular link between multiple divergent progenitor lineages of the mammalian embryo.

Newly recognized physiologic and pathophysiologic actions of the angiotensin-converting enzyme.

Despite several decades of research into the renin-angiotensin system, new aspects of this endocrine system are elucidated every few years, expanding its role not only in hypertension but also in diabetes, oncology, and cardiology. In this review, we describe newly recognized physiologic actions of the angiotensin-converting enzyme (ACE). These include the role of local versus systemic ACE in maintaining blood pressure, the physiology of bradykinin accumulation during ACE inactivation, and the role of alternate "non-angiotensin" substrates and potential non-enzymatic properties of ACE.

The use of knockout mouse technology to achieve tissue selective expression of angiotensin converting enzyme.

The resin angiotensin system (RAS) plays an essential role in blood pressure regulation and electrolyte homeostasis. The effecter peptide of the RAS, angiotensin II, is produced by angiotensin converting enzyme (ACE) in multiple tissues. Genetic deletion of ACE in mice resulted a phenotype of low blood pressure, anemia and kidney defects. However, it is not clear whether the lack of the systemic or the local production of angiotensin II caused these defects. To understand the role of local angiotensin II production, we developed a method to achieve tissue specific ACE expression through homologous recombination. In this review, we discuss mouse models in which endothelial ACE was eliminated and replaced by hepatic ACE. These studies suggest that both circulating angiotensin II and local angiotensin II production play a role in angiotensin II generation; the elimination of local angiotensin II generation up-regulates systemic production and maintains physiologic homeostasis.