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Due to the special physiological and pathological characteristics of gliomas, most therapeutic drugs are prevented from entering the brain. To improve the poor prognosis of existing therapies, researchers have been continuously developing non-invasive methods to overcome barriers to gliomas therapy. Although these strategies can be used clinically to overcome the blood‒brain barrier (BBB), the accurate delivery of drugs to the glioma lesions cannot be ensured. Nano-drug delivery systems (NDDS) have been widely used for precise drug delivery. In recent years, researchers have gathered their wisdom to overcome barriers, so many well-designed NDDS have performed prominently in preclinical studies. These meticulous designs mainly include cascade passing through BBB and targeting to glioma lesions, drug release in response to the glioma microenvironment, biomimetic delivery systems based on endogenous cells/extracellular vesicles/protein, and carriers created according to the active ingredients of traditional Chinese medicines. We reviewed these well-designed NDDS in detail. Furthermore, we discussed the current ongoing and completed clinical trials of NDDS for gliomas therapy, and analyzed the challenges and trends faced by clinical translation of these well-designed NDDS.
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Objective To evaluate the therapeutic effect of endothelin antagonist on ultraviolet B (UVB)-induced pigmentation in guinea pigs.Methods A skin pigmentation model was established by UVB irradiation in guinea pigs.The modeled animals were divided into 3 groups to be treated with sodium chloride physiological solution (blank control group),an endothelin antagonist (endothelin antagonist group) and arbutin (positive control group),respectively.Before the UVB irradiation,as well as after 15-and 30-day UVB irradiation,Mexameter(R) MX 18 was used to detect the melanin index in the dorsal skin of guinea pigs.After 30-day consecutive treatment,melanin index,the number of melanocytes in the epidermis and melanin content were compared among the above 3 groups.Results After 30-day UVB irradiation,the melanin index in the 9 UVB-irradiated areas on the dorsal skin of guinea pigs significantly increased compared with that before the radiation (P ＜ 0.0001).After 30-day treatment with the 1‰ endothelin antagonist,the melanin index in the UVB-irradiated areas significantly decreased compared with that in the positive control group (P ＜ 0.0001).Melanin content index-1 (MCI-1) was significantly lower in the endothelin antagonist group than in the blank control group (P ＜ 0.05),while no significant difference in MCI-2 was observed among the 3 groups (P ＞ 0.05).Conclusion Topical application of the endothelin antagonist has a certain therapeutic effect on UVB-induced pigmentation in guinea pigs.
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Trace elements is the main content in Biochemistry and Molecular Biology courses through students' self-study.This topic takes the trace elements as the content of open video courses to make the medical students and the public be able to scientifically understand the relationship between trace elements and human health and pay attention to the influence of dietary nutrition and environmental pollution on human society.This course is based on audience online teaching rules and online learning needs,to achieve high-quality resources sharing and popularity as the goal,using typical case,vividly describes the source of the common trace element,function,and the relationship between health and disease.In the course construction,we realize that the selection of teaching content,optimization of teachers,professional recording team are the basic elements of the success of open video courses production.The combination of open video courses and flipped classroom teaching has gained a high degree of satisfaction in improving students' independent learning ability,expanding knowledge and so on.
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Based on the concept of three-orientation medical personnel training, this article fo-cuses on practice ability oriented professional quality training, and has constructed the integrated experi-mental teaching course system based on medicine. The curriculum system not only builds the experimental teaching platform ofhigh quality resource, but also constructs the experimental teaching mode which is based on a large and diverse method to promote students'!autonomous learning. The article also discusses the reform of basic experiment course system based on the practice ability from the concept of experimental curriculum system reform, the goal of the training of the experimental course system, the implementation of the program and the evaluation system.
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Ulta performance liqiuid chromatography-triple quadrupole tandem mass spectrometry ( UPLC-MS/MS) was used to monitor the relative levels of bufadienolides in toad venom in normal and bensulfuron-polluted groups. Methanol extract of toad venom was separated by UPLC ( ODS-C18 ) using a gradient elution of water contains 0. 1% formic acid and acetonitrile. Mass spectrometry was used in an ESI source operated in positive ion and MRM mode. The parameters in the source were set as follows: capillary voltage 3. 0 kV; sampling cone voltage 30 V; and desolvation temperature 500℃. In this method, external calibrations of 6 standards were typically constructed (R2=0. 9953-0. 9992). The LOD was 0. 42-4. 86 ng/mL. Intra- and inter-day precision was 3. 8%-6. 8% and 4. 0%-8. 8%, respectively. The recovery of standard was evaluated by spiking the standard compound into toad venom. Their average recoveries were 96. 9%-109. 6%, and RSDs were 2. 0%-8. 1%. This method was further employed into monitoring the levels of 36 bufadienolides. The levels of more than 20 bufadienolides were greatly different after bensulfuron pollution, suggesting that the bensulfuron pollution could change the chemical expression pattern of bufadienolides in toad venom.
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<p><b>OBJECTIVE</b>To investigated the chemical structures and bioactivity of polysaccharides from Isatidis Radix.</p><p><b>METHOD</b>Polysaccharides were extracted and purified by column chromatograph and their chemical structures were identified by UV, IR, NMR, periodic acid oxadation and Smith degradation method and their stimulation effects to macrophage were evaluated by using MTT method.</p><p><b>RESULT</b>Five polysaccharides, polysaccharide A , B, C, D and E were gotten and their molecular weights were 2 000, 1 757.1, 1 34 2.7, 955.6, 11.7 kDa, respectively. Polysaccharide A was composed of arabinose, polysaccharide E was composed of arabinose and galactose, polysaccharides B, C, D were composed of glucose and 1 --> 2, 1 --> 3, 1 --> 4, 1 --> 6 linkages existed in polysaccharides A-E, of A, B, C, D, E were alpha-configurations. Polysaccharides B, C and D showed better bioactivity than polysaccharides A and E with stimulation index (SI) of 5.31, 4.76, 5.17.</p><p><b>CONCLUSION</b>Five polysaccharides are seperated firstly from Isatidis Radix.</p>
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Animals , Mice , Isatis , Chemistry , Magnetic Resonance Spectroscopy , Polysaccharides , Chemistry , PharmacologyABSTRACT
AIM To study the protective and antiperoxidative effects of baicalin on myocardial ischemia. METHODS The rat anterior decenging branch of left coronary artery was occluded for 40 min and reperfusion for 120 min. Hemodynamics (LVP, LV d p /d t ) and electrocardiogram (ECG, lead Ⅱ) monitored continuously with polygraph,then the myocardium were taken to assay lactate dehydrogenase(LDH), malondialdehyde (MDA) contents and superoxide dismatase (SOD). RESULTS Baicalin 10 or 40 mg?kg -1 iv depressed changes in LDH, MDA and SOD in myocardium after ischemia for 40 min and reperfusion for 120 min in rats. Baicalin 10 and 40 mg?kg -1 iv markedly improved the ?d p /d t max (kPa?s -1 ), LVSP in rat after ischemia for 40 min and reperfusion. CONCLUSION Baicalin possesses a protective effect against myocardial ischemia via attenuating lipid peroxidation.