Proangiogenic Effect of Affinin and an Ethanolic Extract from Heliopsis longipes Roots: Ex Vivo and In Vivo Evidence

Angiogenesis, the formation of new blood vessels, underlies tissue development and repair. Some medicinal plant-derived compounds can modulate the angiogenic response. Heliopsis longipes, a Mexican medicinal plant, is widely used because of its effects on pain and inflammation. The main bioactive phytochemicals from H. longipes roots are alkamides, where affinin is the most abundant. Scientific studies show various medical effects of organic extracts of H. longipes roots and affinin that share some molecular pathways with the angiogenesis process, with the vasodilation mechanism of action being the most recent. This study investigates whether pure affinin and the ethanolic extract from Heliopsis longipes roots (HLEE) promote angiogenesis. Using the aortic ring rat assay (ex vivo method) and the direct in vivo angiogenesis assay, where angioreactors were implanted in CD1 female mice, showed that affinin and the HLEE increased vascular growth in a dose-dependent manner in both bioassays. This is the first study showing the proangiogenic effect of H. longipes. Further studies should focus on the mechanism of action and its possible therapeutic use in diseases characterized by insufficient angiogenesis.     

体内胰岛素的测定

体内胰岛素的分析方法发展已经四十年,无论在临床或实验室中,已有各种各样的方法测定体内胰岛素的浓度。本文拟对体内胰岛素的测定方法作一综述。     

Application of Ulex europaeus agglutinin I-modified liposomes for oral vaccine: Ex Vivo bioadhesion and in Vivo immunity

The conjugation of Ulex europaeus agglutinin I (UEAI) onto surface of liposomes has been demonstrated to effectively improve the intestinal absorption of antigen, subsequently induced strong mucosal and systemic immune responses. In this context, we prepared bovine serum albumin (BSA)-encapsulating UEAI-modified liposomes (UEAI-LIP) and unmodified ones (LIP). The specific bioadhesion on mice gastro-intestinal mucosa was studied ex vivo. An important increase of interaction between UEAI-conjugated liposomes and the intestinal segments with Peyer's Patches (PPs) was observed compared with the unconjugated one (p<0.01). However, under the presence of α-L-fucose, which is the reported specific sugar for UEAI, specifically inhibited the activity of these conjugates. The immune-stimulating activity in vivo was studied by measuring immunoglobulin G (IgG) levels in serum and immunoglobulin A (IgA) levels in intestinal mucosal secretions following oral administration of BSA solution, LIP and UEAI-LIP in mice. Results indicate that antigen encapsulated in liposomes, especially the UEAI-modified ones, was favorable for inducing immune response. At 42 d after the first immunization, the highest IgG and IgA antibody levels produced by UEAI-LIP occurred, respectively showing 4.4-fold and 5-fold higher levels compared to those of the groups receiving BSA alone. This data demonstrated high potential of UEAI-modified liposomes for their use as carrier for oral vaccines.     

Low-Fouling Fluoropolymers for Bioconjugation and In Vivo Tracking

The conjugation of hydrophilic low-fouling polymers to therapeutic molecules and particles is an effective approach to improving their aqueous stability, solubility, and pharmacokinetics. Recent concerns over the immunogenicity of poly(ethylene glycol) has highlighted the importance of identifying alternative low fouling polymers. Now, a new class of synthetic water-soluble homo-fluoropolymers are reported with a sulfoxide side-chain structure. The incorporation of fluorine enables direct imaging of the homopolymer by ¹⁹F MRI, negating the need for additional synthetic steps to attach an imaging moiety. These self-reporting fluoropolymers show outstanding imaging sensitivity and remarkable hydrophilicity, and as such are a new class of low-fouling polymer for bioconjugation and in vivo tracking.     

微型葡萄糖传感器及其在活体分析中的应用和进展

对微型化葡萄糖传感器的原理、制备方法及其在活体分析中所遇到的问题和进展作了评述，并对今后的工作进行了展望。     

Polymorphism of Amyloid Fibrils In Vivo

Polymorphism is a wide‐spread feature of amyloid‐like fibrils formed in vitro, but it has so far remained unclear whether the fibrils formed within a patient are also affected by this phenomenon. In this study we show that the amyloid fibrils within a diseased individual can vary considerably in their three‐dimensional architecture. We demonstrate this heterogeneity with amyloid fibrils deposited within different organs, formed from sequentially non‐homologous polypeptide chains and affecting human or animals. Irrespective of amyloid type or source, we found in vivo fibrils to be polymorphic. These data imply that the chemical principles of fibril assembly that lead to such polymorphism are fundamentally conserved in vivo and in vitro.     

Determination of trans-Resveratrol in Bio-Matrices for in Vitro,ex Vivo,and in Vivo Pharmacokinetic Studies by LC Spectrometric Analysis

A high-performance liquid chromatography-electrospray ionization-mass spectromentry (LC–ESI–MS) method has been developed for the determination of picroside II in dog plasma. Plasma samples were deproteinated with acetonitrile and a Hypersil ODS2 column was used with a mobile phase consisted of methanol-water. The determination was validated in the concentration range of 0.10–50 μg mL⁻¹ using 50 μL of plasma. The method was successfully applied to a pharmacokinetic study of picroside II.

     

Determination of trans-Resveratrol in Bio-Matrices for in Vitro, ex Vivo, and in Vivo Pharmacokinetic Studies by LC Spectrometric Analysis

A simple and reproducible liquid chromatographic method was developed for analyzing trans-resveratrol (TR) in cell suspension, intestinal Krebs’ buffer and rat plasma. TR and internal standard (IS, caffeine) were extracted by simple liquid–liquid extraction with acetonitrile. A chromatographic separation of TR and IS was achieved by Hypersil ODS₂ C₁₈ column using the mobile phase consisting of a mixture of methanol and distilled water with approximate retention times of 5.5 and 3.4 min, respectively. The detector wavelength was 303 nm. The limit of quantifications in cell suspension, Krebs’ buffer, and rat plasma were 0.10 μM, 0.05 μg mL^?1, and 0.05 μg mL^?1. The coefficients of correlation were better than 0.9995 in all solvents. The recovery of TR in the three bio-samples ranged from 86.64 to 102.4%. Intra-day and inter-day accuracy were in the range 0.55–11.50%. The proposed method was successfully applied to Caco-2 cells, everted gut sac and rat pharmacokinetic studies. Among the pharmacokinetic data obtained, TR was concentration-dependent uptaken by Caco-2 cells. The colon was the best situation for TR absorption. The absorption of TR after oral administration was rapid, T _1/2 and AUC _0~∞ were 104 min, and 3.49 ± 0.55 min·(μg mL mg)^?1, respectively.     

In Vivo Detection of Hydrogen Sulfide in Brain and Cell

Hydrogen sulfide (H₂S), is proposed as a cytoprotectant and gasotransmitter, involving in many physiological processes and regulating of some diseases. In addition, H₂S is a small molecular with a minimum of steric hindrance compared with other reactive sulfur species. In physiological atmosphere, H₂S is mainly existent in HS⁻, which has a strong nucleophilicity and reducing potency. It also can precipitate with some metal ions forming metallic sulfides with high precipitation coefficient. In recent years, the researchers have a desire to develop methods to achieve real-time detection of H₂S in vivo, further understanding the physiology and pathology of H₂S. In this minireview, we summarize recent progress for detecting of H₂S in brain or cell and briefly expound the principle of methods with the comparison of the different methods between performance and temporal resolution.     

Profiling and Identification of Biocatalyzed Transformation of Sulfoxaflor In Vivo

In the present study, we investigated the biotransformation of the neonicotinoid pesticide sulfoxaflor and the metabolic responses in Sprague‐Dawley rats. Sulfoxaflor transformation was catalyzed by cytochrome P450 while five phase I and four phase II metabolites were identified for the first time in vivo. The experimental results demonstrated that sulfoxaflor brought about the metabolic profiling disturbances in liver and bile. Exposure to sulfoxaflor caused dysregulation of bile acid synthesis and reabsorption by the expression of farnesoid X receptor (FXR). Our data provided insights into biotransformation of chemicals while enabling the implementation of a new toolbox for the design of sulfoximine compounds.     

In Vivo Monitoring of Neurotransmitters with Voltammetry and Smallbore HPLC

The temporal and concentration response of microdialysis probes in vivo was characterized. The temporal response was monitored using step changes in dopamine (DA) concentration which were followed with one minute sampling using smallbore HPLC. The response under three conditions was examined: in vitro sampling of DA, in vitro infusion of DA, and local infusion of DA. The dialysate DA concentration stabilized within two minutes after each change. These results suggest that relatively fast changes in DA levels in tissue can be followed by microdialysis probes. The rapid stabilization also suggests that the DA concentration profile does not extend very far from the probe. To characterize the concentration response, the linearity of the gain or loss of DA diffusing between the probe and tissue was determined. The difference in the inflow and outflow concentrations was plotted as a function of the inflow concentration. The correlation coefficient of the linear regression curve was 0.99. The zero point intercept, the extracellular concentration of DA, was 3.8 nM and the slope, or recovery, was 63.4%. There was no break at the zero point which is indicative of symmetrical diffusion into and out of the probe.     

Biofuel Cell Operating in Vivo in Rat

Biocatalytic electrodes made of buckypaper were modified with PQQ‐dependent glucose dehydrogenase on the anode and with laccase on the cathode. The enzyme modified electrodes were assembled in a biofuel cell which was first characterized in human serum solution and then the electrodes were placed onto exposed rat cremaster tissue. Glucose and oxygen dissolved in blood were used as the fuel and oxidizer, respectively, for the implanted biofuel cell operation. The steady‐state open circuitry voltage of 140±30 mV and short circuitry current of 10±3 µA (current density ca. 5 µA cm^?2 based on the geometrical electrode area of 2 cm²) were achieved in the in vivo operating biofuel cell. Future applications of implanted biofuel cells for powering of biomedical and sensor devices are discussed.     

活体小鼠耳朵的拉曼成像方法研究

利用扫描技术获取活体小鼠耳朵组织不同深度的微区拉曼光谱,选取分别归属于血糖、脂类、血红蛋白、蛋白质分子结构的物质的特征谱带1125,1300,1549和1660 cm"1进行峰面积计算,利用这些数据重建二维三维拉曼光谱图像。图像清晰显示了不同物质在活体组织中空间分布情况。实验表明,活体拉曼成像技术可以成为活体研究的新手段。     

In Vivo Imaging of Inflammatory Phagocytes

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Highlights? Inflammation status can be determined by luminol (acute) or lucigenin (chronic) ? Neutrophils mediate MPO-dependent luminol luminescence during acute inflammation ? Macrophages rely on Phox to produce lucigenin luminescence in chronic inflammation ? No need for ectopic expression of reporters using this imaging method     

In Vivo Production of RNA Aptamers and Nanoparticles: Problems and Prospects

RNA aptamers are becoming increasingly attractive due to their superior properties. This review discusses the early stages of aptamer research, the main developments in this area, and the latest technologies being developed. The review also highlights the advantages of RNA aptamers in comparison to antibodies, considering the great potential of RNA aptamers and their applications in the near future. In addition, it is shown how RNA aptamers can form endless 3-D structures, giving rise to various structural and functional possibilities. Special attention is paid to the Mango, Spinach and Broccoli fluorescent RNA aptamers, and the advantages of split RNA aptamers are discussed. The review focuses on the importance of creating a platform for the synthesis of RNA nanoparticles in vivo and examines yeast, namely Saccharomyces cerevisiae, as a potential model organism for the production of RNA nanoparticles on a large scale.     

In Vitro and In Vivo Trypanocidal Efficacy of Synthesized Nitrofurantoin Analogs

African trypanosomes cause diseases in humans and livestock. Human African trypanosomiasis is caused by Trypanosoma brucei rhodesiense and T. b. gambiense. Animal trypanosomoses have major effects on livestock production and the economy in developing countries, with disease management depending mainly on chemotherapy. Moreover, only few drugs are available and these have adverse effects on patients, are costly, show poor accessibility, and parasites develop drug resistance to them. Therefore, novel trypanocidal drugs are urgently needed. Here, the effects of synthesized nitrofurantoin analogs were evaluated against six species/strains of animal and human trypanosomes, and the treatment efficacy of the selected compounds was assessed in vivo. Analogs 11 and 12, containing 11- and 12-carbon aliphatic chains, respectively, showed the highest trypanocidal activity (IC₅₀ < 0.34 µM) and the lowest cytotoxicity (IC₅₀ > 246.02 µM) in vitro. Structure-activity relationship analysis suggested that the trypanocidal activity and cytotoxicity were related to the number of carbons in the aliphatic chain and electronegativity. In vivo experiments, involving oral treatment with nitrofurantoin, showed partial efficacy, whereas the selected analogs showed no treatment efficacy. These results indicate that nitrofurantoin analogs with high hydrophilicity are required for in vivo assessment to determine if they are promising leads for developing trypanocidal drugs.     

Imaging Glycosylation In Vivo by Metabolic Labeling and Magnetic Resonance Imaging

Glycosylation is a ubiquitous post‐translational modification, present in over 50 % of the proteins in the human genome, 1 with important roles in cell–cell communication and migration. Interest in glycome profiling has increased with the realization that glycans can be used as biomarkers of many diseases, 2 including cancer. 3 We report here the first tomographic imaging of glycosylated tissues in live mice by using metabolic labeling and a gadolinium‐based bioorthogonal MRI probe. Significant N‐azidoacetylgalactosamine dependent T₁ contrast was observed in vivo two hours after probe administration. Tumor, kidney, and liver showed significant contrast, and several other tissues, including the pancreas, spleen, heart, and intestines, showed a very high contrast (>10‐fold). This approach has the potential to enable the rapid and non‐invasive magnetic resonance imaging of glycosylated tissues in vivo in preclinical models of disease.     

Development and In Vivo Test of Sol-Gel Derived Bone Grafting Materials

A novel bioceramic derived via sol gel method was developed and very good resorption properties in long term period of implantation were established.Calcium phosphate materials are bioactive, osteoconductive materials used as guides for bone regeneration. An identical sequence of events apparently occurred at the contact of the ceramics when implanted in vivo. Two kinds of calcium phosphate ceramics have been produced in a form of threads with 1 mm in diameter: hydroxyapatite SiO₂-containing ceramic and hydroxyapatite—-tricalcium phosphate SiO₂-containing ceramic. Above mentioned calcium phosphate ceramic established an interconnecting macroporous structure, which is responsible for growth of bone and for replacement of ceramic by bone. Three ranges of pores were designed.Viscosity measurements were made to control the point of gelation and production phase of transplant material.In vivo experiments were carried out for 5 weeks and 8 months. The results after the short period of examination have shown the early stage of bone formation and material dissolution. Within 6 months nearly 100% of implanted ceramic was resorpted and new bone around place of intervention was formed.