Carcinosinumproduces phenotypic changes of 4T1 tumor cells in vitro

Considering that there are few published studies that specifically address the exclusive use of Carcinosinumin different potencies and, most of them focused on genotypic and clinical effects, the present study was proposed to identify possible phenotypic changes, including viability, expression of HER-2 and metastatic abilities, using 4T1 cells in vitroas a model. Carcinosinum was tested in different homeopathic potencies (12cH; 30cH; 200cH) mechanically prepared using sterile pure water. The time space between preparing the potencies and using them was 24 hours.The final dilutions were inserted into the culture medium in a volume equal to 10%, at the time of cell seeding. The same succussed vehicle used to prepare the drugs (70% ethanol) diluted 1:100 in sterile pure water was used as control. All treated cells were cultured in 25 mL flasks, with cell density of 5 x 105cells/mL. After 24 hours of treatment, cells were analyzed for apoptosis index using Annexin V kit and the Countess® system. The morphology of 4T1 cells was monitored by staining cell smears with hematoxylin-eosin and Giemsa methods. HER-2 expression was assessed by immunocytochemistry and metalloproteinase activity was assessed by zymography. The determination of the cytokine profile was performed using Cytometric Bead Array (CBA). The samples were evaluated in quadruplicate and the data were analyzed by one-way ANOVA. Carcinosinum30cH presented the highest apoptotic index and reduction of MMP-9-Pro expression; Carcinosinum200cH produced the highest positivity for HER-2 and no specific effect was seen after the treatment with Carcinosinum12cH. No change in cytokine expression was seen among treatments. We conclude that Carcinosinum30cH and 200cH can change phenotypic features important totumor development in vitro. The clinical meaning of these data deserves further investigation.

Rutin inhibits the in vitro formation of advanced glycation products and protein oxidation more efficiently than quercetin

Introduction: The exacerbated generation of advanced glycation end products (AGEs) triggers the onset of diabetic complications associated with hyperglycemia. The search for natural bioactive compounds that can inhibit AGE formation has gained immense interest. Quercetin and its glycoside derivative, rutin, are powerful antioxidants. They have been studied due to their potential to mitigate the disturbances observed in diabetes; however, studies comparing their antiglycation effects are limited. The aim of the present study was to compare the in vitro antiglycation potentials of quercetin and rutin. Methods: The in vitro model system of protein glycation was applied using bovine serum albumin (10 mg/mL) incubated with glucose (0.5 M) in the absence or presence of aminoguanidine (1 mM, prototype anti-AGE agent), metformin (1 mM), quercetin (100, 50, or 12.5 µM), or rutin (100, 50, or 12.5 µM). Before initiating incubations (day 0) and after 10, 20, and 30 days, aliquots were assayed for fluorescent AGEs. Markers of amino acid oxidation (dityrosine, N'-formylkynurenine, kynurenine), protein carbonyl groups (PCO), and protein crosslink formation were assessed after 30 days. Results: Both quercetin and rutin inhibited the formation of AGEs and decreased the PCO levels in a concentration-dependent manner, and moreover, the effect of rutin was more prominent than that of quercetin. Quercetin and rutin also decreased the formation of amino acid oxidation products and protein crosslinks; the best effects were observed in incubations with rutin. Conclusion: Rutin exhibited the most potent antiglycation and antioxidant activities, which may be attributed to the minor occurrence of interactions between albumin and rutin, making rutinnoside more available to exert its effects.

Research status of dynamic three-dimensional tissue culture driving methods / 中国组织工程研究

BACKGROUND: In vitro models are widely used in toxicology, pathology, and pharmaceutical research due to their short experimental cycles, low cost, and small species differences compared with animal models. Dynamic three-dimensional tissue culture mode is an important trend in the development of in vitro models. Dynamic three-dimensional culture in vitro models can be achieved by means of driving fluids in microfluidic systems. OBJECTIVE: To describe the microfluidic driving methods in the field of microfluidics, their respective advantages and disadvantages, and the application of different driving methods to different tissue culture requirements. METHODS: A computed-based retrieval of CNKI and Web of Science databases was performed for the articles concerning dynamic three-dimensional tissue culture and microfluidic driving methods to achieve dynamic culture of cells or tissues. The search terms were “microfluidic; micropump; organ-on-chip; three-dimensional tissue culture” in English and Chinese, respectively. RESULTS AND CONCLUSION: The microfluidic driving methods include passive driving and active driving. Whereas passive driving includes surface tension pump, osmotic pump and gravity pump. Active driving includes syringe pump and peristaltic pump. Each driving method has its advantages and disadvantages. To achieve accurate control of the medium flow rate in a dynamic three-dimensional tissue culture system, the best choice is to use syringe pumps or valve-type peristaltic pumps. To achieve closed-loop flow of culture medium in a dynamic three-dimensional tissue culture system, the best choice is to use gravity pumps or peristaltic pumps. To fulfill the need for a sterile environment in the experimental process in a dynamic three-dimensional tissue culture system, the best choices are surface tension pumps, gravity pumps, and pneumatic peristaltic pumps. To achieve high-throughput culture in dynamic three-dimensional tissue culture systems, the best choices are surface tension pumps, gravity pumps and pneumatic peristaltic pumps.

Toxicological Technology in Evaluation and Application of Traditional Chinese Medicine Healthcare Food / 中国实验方剂学杂志

China is rich in herbs that can be used as medicine and food. The application of this kind of traditional Chinese medicine (TCM) as raw material is the basis for guiding the development of TCM healthcare food. TCM healthcare food has advantages in keeping in good health and reducing the risk of disease. At the same time, with the implementation of " Healthy China 2030" , it is urgent to develop a series of herbal compound healthcare food with the characteristics of TCM to meet the national and social needs. With the development of scientific research, however, there is a lack of research on the scientific evaluation of the safety of TCM healthcare food raw materials, which results in insufficient risk assessment theory and technology of healthcare food at present. Therefore, the prediction and evaluation of the toxicity of important components in this kind of raw materials has become an urgent task of food safety. Toxicology plays an important role in human health risk assessment, and its sub-disciplines have been constantly emerging. Computational toxicology, monolayer culture cell model technology, in vitro induced activity screening engineering cell technology, microfluidic chip technology and in vivo toxicology technology have become important research tools for toxicity prediction and evaluation in this field. With the rapid development of toxicology technology, food safety and human life and health can be effectively guaranteed. It will effectively promote the safety production of healthcare food industry in China and guarantee the quality and safety of terminal products. It has a great social significance, plays a positive leading role in the technological progress of the whole industry, and generates considerable economic benefits. This paper reviews recent advances and applications of new toxicological methods and models for predicting and evaluating important ingredients in TCM healthcare food raw materials.

Comparative Toxicity of Nanomaterials to Air-blood Barrier Permeability Using an In Vitro Model / 生物医学与环境科学（英文）

OBJECTIVE@#To comparatively study the toxicity of four metal-containing nanoparticles (MNPs) and their chemical counterparts to the air-blood barrier (ABB) permeability using an in vitro model.@*METHODS@#ABB model, which was developed via the co-culturing of A549 and pulmonary capillary endothelium, was exposed to spherical CuO-NPs (divided into CuO-40, CuO-80, and CuO-100 based on particle size), nano-Al2O3 (sheet and short-rod-shaped), nano-ZnO, nano-PbS, CuSO4, Al2(SO4)3, Zn(CH3COO)2, and Pb(NO3)2 for 60 min. Every 10 min following exposure, the cumulative cleared volume (ΔTCL) of Lucifer yellow by the model was calculated. A clearance curve was established using linear regression analysis of ΔTCL versus time. Permeability coefficient (P) was calculated based on the slope of the curve to represent the degree of change in the ABB permeability.@*RESULTS@#The results found the increased P values of CuO-40, CuO-80, sheet, and short-rod-shaped nano-Al2O3, Al2(SO4)3, and Pb(NO3)2. Among them, small CuO-40 and CuO-80 were stronger than CuO-100 and CuSO4; no difference was observed between Al2(SO4)3 and sheet and short-rod-shaped nano-Al2O3; and nano-PbS was slightly weaker than Pb(NO3)2. So clearly the MNPs possess diverse toxicity.@*CONCLUSION@#ABB permeability abnormality means pulmonary toxicity potential. More studies are warranted to understand MNPs toxicity and ultimately control the health hazards.

The potential use of prodigiosin as a shrimp feed additive and its dynamic influence on the shrimp gut microbial community – an in vitro gut model

Aims@#A simple in vitro model system was applied in this study assessing the dynamics of the microbial community associated with the shrimp gut system to understand the changes that influence dietary variables. @*Methodology and results@#The diversity and abundance of microbiome were monitored within two different treatment slurries inoculated with shrimp faecal samples as to mimic the effect of diet manipulation, and 16S rRNA gene of MiSeq Illumina-based sequencing was applied. The different diets tested were a commercial standard diet and a prodigiosin added diet. There was very clear separation between the commercial standard diet and prodigiosin added diet as revealed by the total viable counts (TVC) and sequencing data. It suggested that the microbial community of the shrimp gut system exhibited a dynamic response with the treatments and allochthonous bacterial present. The prodigiosin added diet was clearly separated from the commercial standard diet serving as a potential shrimp feed additive. The sequencing data analysis showed that members of the genera Vibrio, Shigella and Photobacterium became predominant on the commercial standard diet treatment. The prodigiosin-added diet treatments indicated an abundance of members of the genera Micrococcus, Arthrobacter, and Shigella. @*Conclusion, significance and impact of study@#In vitro model system-based testing of diets could be a useful method to determine the potential effect of diet manipulation on shrimp gut system microbiome members.

Alteration of Genomic Imprinting Status of Human Parthenogenetic Induced Pluripotent Stem Cells during Neural Lineage Differentiation

BACKGROUND AND OBJECTIVES: Genomic imprinting modulates growth and development in mammals and is associated with genetic disorders. Although uniparental embryonic stem cells have been used to study genomic imprinting, there is an ethical issue associated with the destruction of human embryos. In this study, to investigate the genomic imprinting status in human neurodevelopment, we used human uniparental induced pluripotent stem cells (iPSCs) that possessed only maternal alleles and differentiated into neural cell lineages. METHODS: Human somatic iPSCs (hSiPSCs) and human parthenogenetic iPSCs (hPgiPSCs) were differentiated into neural stem cells (NSCs) and named hSi-NSCs and hPgi-NSCs respectively. DNA methylation and gene expression of imprinted genes related neurodevelopment was analyzed during reprogramming and neural lineage differentiation. RESULTS: The DNA methylation and expression of imprinted genes were altered or maintained after differentiation into NSCs. The imprinting status in NSCs were maintained after terminal differentiation into neurons and astrocytes. In contrast, gene expression was differentially presented in a cell type-specific manner. CONCLUSIONS: This study suggests that genomic imprinting should be determined in each neural cell type because the genomic imprinting status can differ in a cell type-specific manner. In addition, the in vitro model established in this study would be useful for verifying the epigenetic alteration of imprinted genes which can be differentially changed during neurodevelopment in human and for screening novel imprinted genes related to neurodevelopment. Moreover, the confirmed genomic imprinting status could be used to find out an abnormal genomic imprinting status of imprinted genes related with neurogenetic disorders according to uniparental genotypes.

Keratinocyte Migration in a Three-Dimensional In Vitro Wound Healing Model Co-Cultured with Fibroblasts

BACKGROUND: Because three-dimensional (3D) models more closely mimic native tissues, one of the goals of 3D in vitro tissue models is to aid in the development and toxicity screening of new drug therapies. In this study, a 3D skin wound healing model comprising of a collagen type I construct with fibrin-filled defects was developed. METHODS: Optical imaging was used to measure keratinocyte migration in the presence of fibroblasts over 7 days onto the fibrin-filled defects. Additionally, cell viability and growth of fibroblasts and keratinocytes was measured using the alamarBlue® assay and changes in the mechanical stiffness of the 3D construct was monitored using compressive indentation testing. RESULTS: Keratinocyte migration rate was significantly increased in the presence of fibroblasts with the cells reaching the center of the defect as early as day 3 in the co-culture constructs compared to day 7 for the control keratinocyte monoculture constructs. Additionally, constructs with the greatest rate of keratinocyte migration had reduced cell growth. When fibroblasts were cultured alone in the wound healing construct, there was a 1.3 to 3.4-fold increase in cell growth and a 1.2 to 1.4-fold increase in cell growth for keratinocyte monocultures. However, co-culture constructs exhibited no significant growth over 7 days. Finally, mechanical testing showed that fibroblasts and keratinocytes had varying effects on matrix stiffness with fibroblasts degrading the constructs while keratinocytes increased the construct's stiffness. CONCLUSION: This 3D in vitro wound healing model is a step towards developing a mimetic construct that recapitulates the complex microenvironment of healing wounds and could aid in the early studies of novel therapeutics that promote migration and proliferation of epithelial cells.

Applications of simulated gastro-intestinal model in foodborne pathogens: tolerance and pathogenesis / 生物工程学报

We evaluated the tolerance and pathogenesis of foodborne pathogens with a simulated gastro-intestinal tract model that simulates the chemical, physical and biological effects of human digestion process under laboratory conditions. This could be used to study the tolerance, pathogenesis, gut microbiota interaction and vaccine development of foodborne pathogens, so as to contribute to control and treatment of foodborne pathogens. This review introduces the applications of simulated gastro-intestinal tract model tp evaluate foodborne pathogens, which includes in-vitro static gastro-intestinal model, in-vitro dynamic gastro-intestinal model, conventional animal model and humanized animal model. And the concepts and characteristics of all models are described in detail. Also, the shortcomings of existing models are analyzed, and improvements of artificial gastro-intestinal tract model are prospected. In conclusion, this review could provide comprehensive data for promoting the progress of studying tolerance and pathogenesis of foodborne pathogens.

Effects of apolipoprotein E deficiency on neuromyelitis model in vitro / 中华神经科杂志

Objective To investigate the effects of apolipoprotein E (ApoE) deficiency on neuromyelitis optica (NMO) model of spinal cord sections induced by NMO-IgG and complement in vitro.Methods NMO-IgG was extracted from the patients with NMO,and complementary serum from healthy people.The spinal cord sections of seven days old C57BL / 6J mice with wild type (WT) or ApoE knockout (ApoE-/-) were cultured for seven days.The spinal cords of the two genotypes were randomly divided into experimental groups (NMO-ApoE-/-group,NMO-WT group) and control groups (C-AopE-/-group,C-WT group),respectively.The experimental groups were treated with NMO-IgG and complementary serum,and the control groups only with complementary serum.Then all the sections were continued incubating for 24 h before harvested.Immunofluorescence staining and modified thick tissue film immunofluorescence were used to detect the expression of aquaporin 4 (AQP4),glial fibrillary acidic protein (GFAP),ionic calcium fibronectin (IBA1),myelin basic protein (MBP) and human neurofilament protein L (NFL) respectively.The lesion score was calculated according to the areas percentage of AQP4 and GFAP deficiency in spinal cord sections.Results Compared with the respective control groups,the expressions of AQP4,GFAP,MBP and NFL were deficient in the experimental groups (The percentages of missing area in the NMO-ApoE-/-group were 83.88％ ± 5.01％,82.44％ ± 6.11％,45.02％ ± 5.11％ and 54.65％ ± 7.66％ respectively,while the percentages of missing area in the C-ApoE-/-group were 10.44％ ± 4.07％,5.73％ ±0.82％,9.12％ ±1.41％ and 5.72％ ±0.81％,t=34.143,37.269,20.300,19.051,allP ＜0.05;The percentages of missing area in the NMO-WT group were 77.74％ ± 6.75％,75.62％ ± 5.76％,37.60％ ± 4.88％ and 46.29％ ± 4.98％,while the percentages of missing area in the C-WT group were 9.31％ ± 2.97％,5.80％ ± 0.82％,9.10％ ± 1.63％,5.80％ ± 0.81％ respectively,t =27.828,35.934,16.613,24.057,all P ＜ 0.05).While IBA1 was up-regulated and the damage scores were higher in both the NMO-ApoE-/-group and the NMO-WT group.The percentages of missing area in the NMO-ApoE-/-group and the NMO-WT group showed statistically significant difference (t =2.194,2.436,3.149,2.746,all P ＜ 0.05).The expression level of IBA1 in the NMO-WT group was higher than that in the C-WT group (19.88 ± 1.11 vs 11.18 ±0.65,t =25.270,P ＜0.05),while the expression level of IBA1 in the NMO-ApoE-/-group was higher than that in the NMO-WT group (25.81 ± 1.61 vs 19.88 ± 1.11,t =9.101,P ＜0.05).The degree of deficiency or up-regulation of above-mentioned proteins was more obvious in the NMO-ApoE-/-group than that in the NMO-WT group.Conclusions NMO-IgG extracted from NMO patients can induce NMO-like damage in isolated tissue at the presence of complement.ApoE deficiency promotes the further activation of microglia,thereby aggravates the injury of astrocyte in the model of NMO.

Establishment of in-vitro model of complement activation and its application / 药学学报

Complement activation-related pseudo-allergic reactions (CARPA) may represent 77% of all immune-mediated immediate hypersensitivity reactions. Because of the universality of the CARPA response and correlation between it and drug properties, complement activity tests are recommended as one of the tests for immunotoxicity and bioequivalence of drugs. However, in-vivo tests of complement activation are complicated, and the immunological differences between different individuals and between human and animal, making it very necessary to establish a standard and sample evaluation model for testing the effects of drugs on complement activity. In this study, the standard reaction serum was prepared by pooling sera collected from 40 healthy blood donors; a standard positive control was prepared by incubation with a heat-agglutinated IgG and zymosan A; SC5b-9, C5a, C4d and Bb were chosen as the test targets and evaluation criteria of the results was defined, all of these constituted the in-vitro model. By using this in-vitro model, the immunological toxicity of the different prescription of antifungal drug amphotericin B, and voriconazole for injection, and the bioequivalence of amphotericin B liposome formulations were studied.

Effects of arecoline and calcium ion on the permeability of dysplastic oral epithelia model in vitro / 口腔疾病防治

Objective @# To study the effects of arecolineand Calcium ion (Ca 2+) on the permeability of dysplastic oral epithelia model in vitro.@*Methods@#To establish the dysplastic oral epithelia model in vitro by culturing oral keratinocyte(DOK) and harvesting a DOK cell monolayer. The models were divided into control group, arecoline group and "Ca 2++ arecoline" group. The values of Lucifer Yellow Papp were used to estimate the permeability changes of models after treatedwith arecoline and Ca 2+. @*Results @# In arecoline group, the lucifer yellow Papp values of each subgroup were higher than that of control group (P < 0.05), and the values increased as arecoline concentration elevated and time lasted (P < 0.05). When the "Ca 2++ arecoline" group were pretreated with Ca 2+, the values of subgroup "10 μg/mL" was lower than that of the corresponding arecoline group (P > 0.05). However, the value of subgroup "4 h 10 μg/mL" of "Ca 2++ arecoline" group had no statistical difference with that of control group (P > 0.05), while the other subgroups were increased (P < 0.05); Besides, these values in "Ca 2++ arecoline" group were increased as the arecoline concentration elevated and time lasted too (P < 0.05).@*Conclusion@#Intervention of arecoline contributes to the increase of permeability of DOK cell monolayer model, which maybe an important reason for the cancerization of dysplastic oral epithelia, however Ca 2+might weaken these effects of arecoline in the process.

Evaluation of hepatoprotective potential of functional food formulations using in vitro and in vivo models of CCl4 radical induced toxicity.

Carbon tetra chloride (CCl4) induced acute hepatotoxicity causes severe damage to hepatocytes and affects the liver functions which resemble various liver ailments like hepatitis, jaundice, cancer etc. Using 12-different fruits, formulation F1 and F2 were prepared. Hepatoprotective potential of the formulations was assessed using HepG2 cell (in vitro) and rat model (in vivo). Biochemical parameters like alkaline phosphatase, lactate dehydrogenase, serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, bilirubin, blood urea nitrogen, plasma TBARS, trolox equivalent antioxidant capacity, total cholesterol, triglycerides were studied. Various markers of liver functions viz., super oxide dismutase, catalase, glutathione peroxidase, reduced glutathione, tissue Thio barbituric acid reactive substances (TBARS) were assessed. Significant decrease in the activity of aminotransferases, alkaline phosphatase and bilirubin was observed in formulation F1 followed by F2 groups as compared with CCl4 treated group. The biochemical and histopathological observations supported hepatoprotective effect. Antioxidant enriched polyherbal formulations F1 and F2 effectively ameliorated CCl4 induced acute hepatotoxicity by improving antioxidant status in rats.

Potential Interactions of Herbal Extracts of St. John´s Wort with Metabolites of Diazepam in an Organotypical Sandwich Culture of Primary Porcine Hepatocytes.

Extracts of St. John’s Wort (Hypericum perforatum) are known to cause interactions with certain conventional drugs. Herein, we focus on two clinically relevant concepts. First, St. John´s Wort has been used by people of all ages as an herbal treatment for depression without medical prescription. Second, diazepam-like substances called endogenous benzodiazepines are found in cases of acute liver failure without previous exposure to diazepam. Currently diazepam has over 500 brands name and well marketed throughout the world and became one most frequently prescribed medication in different form (oral, injectable, inhalation and rectal forms) for four decades. Based on this concept, we investigated diazepam biotransformation by incubation of a widely accepted in vitro organotypical culture model with Hypericum methanolic extract, powdered drug, infusion, oil, and with the pure Hypericum compounds hyperforin and hypericin. The amounts of the preparations and compounds were chosen according to the recommended daily medication doses. We measured the activities of ethoxyresorufin-O-deethylase (EROD), ethoxy coumarin O-deethylase (ECOD) and the potential induction of diazepam metabolites (desmethyldiazepam, temazepam and oxazepam) during biotransformation. None of the preparations or substances induced EROD or ECOD. However, different preparations did induce the formation of desmethyldiazepam and temazepam. The strongest activity was caused by the extract, followed by the powdered drug and hyperforin. All preparations and compounds increased the formation of the diazepam metabolite oxazepam, but only the extract, the drug powder and the pure compounds had marked effects. Therefore, we report here the potential interference of St. John´s Wort with all three metabolites of diazepam in an organotypical sandwich model that can be utilized to study potential interaction of metabolites of many drugs with herbal ingredients in preclinical stage of drug discovery process.

Hemolysis of human blood cells induced by gasohol in vitro model: the preliminary study.

Background: Ethanol has been shown to inhibit spontaneous cell-mediated cytotoxicity and antibody-dependent cell-mediated cytotoxicity in vitro in a dose-dependent manner. A mixture of ethanol in biofuel may show interaction with respect to spontaneous and cell-mediated cytotoxicity. Methods: The cytotoxicity on Human Red Blood Cells (RBCs) and White Blood Cells (WBCs) was studied in vitro model of 4 types of biofuels (gasohol) (octane 91, octane 95, E 20, and E 80) in serial dilutions. The lysis and abnormal morphology of cells were analyzed by colorimetric and microscopic methods. Results: Quantitative hemolysis of RBCs was increased with rising ethanol concentration as well as abnormal morphology of RBCs like spherocyte. Moreover, ethanol might effect to lysis and morphology of WBCs. Conclusion: It is suggested that the gasohol-induced cytotoxicity may be related to concentration of ethanol in gasohol. However, it is possible to future study on mechanism of action leading to cell lysis and kinetic of morphological change in RBCs and WBCs.

Medición in vitro del flujo con Doppler en diferentes condiciones mecánicas y su comparación con el real / Measuring in vitro Doppler flow at different mechanical conditions and compared with the real

Objective: to compare Doppler measurements with real flow in a in-vitro model, with variable diameters and insonation angle. Methods: The silicone tubes were 3-8 mm width, and set with variable inclinations from 40° to 70°. Two pumps with constant flow were used for all combinations of diameters and angles. A Sonoace 8000 from Medison was used. Real flow was compared to measured flow. Results: The measured flows varied importantly in different conditions. In a 3 mm tube, estimated flow increased from 212 ml/min to 403 ml/min when the angle was increased from 40° to 70°, when real flow was 140 ml. As well, in 8 mm tubes, estimated flow increased from 651 ml/min to 1.080 ml/min when the angle was increased from 40° to 70°, when real flow was 360 ml/min. Measured flows were 1.6 times greater than real flow. Conclusion: Measured flows were greater than real, with greater increase in larger tubes and greater angles. This confirms that velocity measurements need lowest angles possible. Measured flows are only representations of real flow, but can be considered useful as they were reproducible.

Objetivos: Recientes aplicaciones del Doppler pulsado se han orientado hacia la medición del flujo (ml/s) de la vena umbilical fetal, sin embargo sus mediciones han tenido cuestionamientos desde el punto de vista de la validez, por el efecto del ángulo y el flujo laminar. El objetivo de este estudio es probar la validez de las mediciones ecográficas en un modelo in vitro. Métodos: Se construyó un sistema dentro de un reservorio de agua, en que se instalaron tubos de silicona variando el lumen (3-8 mm), inclinación del tubo (40°-70°) y dos velocidades de infusión de agua. Se instaló la sonda convexa del transductor transabdominal a 5 cm sobre el tubo, de modo que todo el trayecto del tubo sea visualizado en la pantalla del ecógrafo SONOACE 8000 de Medison. Se corrigió el ángulo con la función del ecógrafo. El flujo se estimó por ecografía al multiplicar la velocidad medida por Doppler pulsado por el área interna del tubo. Se comparó el flujo medido real, obtenido por el volumen de agua obtenida en un minuto de funcionamiento de la bomba, y el medido por ecografía Doppler. El flujo medido por Doppler se obtuvo 2 veces, para comparar la variación intrínseca del método y verificar su confiabilidad. Resultados: Los flujos obtenidos variaron según las condiciones mecánicas importantemente. En tubos de 3 mm de diámetro, con ángulos crecientes de 40° a 70°, los fl ujos estimados aumentaron de 212 ml/min a 403 ml/min cuando el flujo real era de 140 ml/min. A su vez, en tubos de 8 mm, con ángulos crecientes de 40° a 70°, los flujos estimados aumentaron de 651 ml/min a 1.080 ml/min, cuando el flujo real era de 360 ml/min. Se demostró una correlación lineal entre el flujo estimado y el real de: Qestimado=(Qreal x 1,63)+181, r= 0,84. La aplicación del test de Bland y Altman demostró que las mediciones son repetibles y consistentes. Conclusión: Los flujos medidos en ecografía fueron 1,6 veces más que los obtenidos en flujo real en las condiciones mecánicas...

Advances in cytomechanics in orthodontic tooth movement / 医用生物力学

In recent years, great development has been made in cytomechanics in orthodontic tooth movement（OTM）.The essential role of periodontal ligament in OTM has been widely accepted. The in vitro models have become an important way to reveal the biological mechanism in OTM,largely based on periodontal ligament cells(PDLCs), as well as other cells, including bone marrow mesenchymal stem cells, osteoblast, cementoblast and myoblast.The in vitro models have been renovated from the traditional ways stressing the 2D cultured cells by deformation of the bottom,gravity, hydrostatic pressure or centrifugation, to the establishment of various novel models loading mechanical stimulation on cells 3D cultured in bioscaffolds. The molecular expression involved in the osteoblastic differentiation and osteoclastogenesis induction in the bone remodeling cycle has drawn great attention, and will continue to be a focus of study. Furthermore, with the identification of periodontal ligament stem cells(PDLSCs), the cytomechanics involved in OTM and periodontitis, will undoubtedly be a promising new direction.

Study on HBV Gene Replication and Expression of Experimental Hepatitis B Model Using Baculovirus Gene Delivery System

PURPOSE: The lack of reliable in vitro infection systems or convenient animal models has hindered the progress of hepatitis B virus (HBV) research and the development of new treatment options. We established an in vitro model of hepatitis B, using recombinant HBV encoding baculovirus, which provided HBV replication and antigens expression in HepG2 cells. The objectives of this study were to characterize the magnitude of HBV expression and the level of replication obtainable in HepG2 cells, to establish the optimum infection and culture conditions of HBV expression and replication. METHODS: Replication of a competent HBV genome encoding the baculovirus, RC-HBV-Bac, was generated for delivering the HBV genome to HepG2 cells. HBV replication and antigens expression were determined in relation to the infection and culture conditions. RESULTS: In RC-HBV-Bac infected HepG2 cells, HBsAg, HBeAg and HBcAg were expressed in the cytoplasm and nuclei, and secreted into the medium. HBV replication was evidenced by the presence of a replication complex and covalently closed circular (ccc) DNA in the cytoplasmic fraction of infected cells. The level of HBV expression was directly proportional to the multiplication of RC-HBV-Bac infection. Polyethylene glycol was able to enhance the infection efficiency of the baculovirus to HepG2 cells. High levels of HBV replication were achieved under culture conditions supplemented with dimethyl sulfoxide and a low serum concentration. CONCLUSION: This in vitro model of hepatitis B, generated by baculovirus gene delivery, represents a simple and flexible system for the study of HBV replication and drug testing.

Integretion of pharmacokinetics and pharmacodynamics in antibacterial drug development and pharmacotherapy / 中国临床药理学与治疗学

There is a pressing need for new antibacterial agents due to the development of drug-resistant pathogens. Unfortunately drug development is a difficult and complicated process. The traditional approach in searching for a right dose is quite empirical, both costly and time-consuming. To enhance the ability to predict the likelihood of success for lead compound selection, in vitro pharmacodynamic and in vivo animal infection models are now extensively used. The value of these pre-clinical experiments, combined with mathematical modeling, helps to identify a pharmacokinetic (PK)-pharmacodynamic (PD) exposure measure which best predicts the therapeutic efficacy, and to quantify the magnitude of this index required for in vivo efficacy. PK-PD target attainment analyses using Monte Carlo simulation to integrate interpatient variability in drug exposure (PK), drug potency (MIC), and in vivo exposure targets that are predictive of positive therapeutic outcomes are influencing antibacterial drug development for proof of concept, for dose and dosing interval selection, for determining susceptibility breakpoints, and for evaluating the clinical meaning of antibacterial resistance. In this article, the key concepts of antibacterial PK-PD and model based antibacterial drug development strategy and process are critically reviewed.

Establishment of coculture model of blood-brain barrier in vitro for nanoparticle's transcytosis and toxicity evaluation / 药学学报

Aim A method of coculture of brain capillary endothelial cells (BCECs) and astrocytes of rats was used to evaluate nanoparticle' s blood-brain barrier (BBB) transcytosis and toxicity at the endothelial tight junction. Methods A lipophilic fluorescent probe, 6-coumarin, was incorporated in poly(ethyleneglycol)-poly (lactide) nanoparticle using double emulsion/solvent evaporation method. BCECs and astrocytes were firstly isolated from brain of newborn rats and characterized by their morphology and immunocytochemistry staining, separately. Subsequently, a coculture model with BCECs on the top of micro-porous membrane of cell culture insert and astrocytes on the bottom side was established. The permeability of 14C-labeled sucrose and nanoparticle were determined, separately. Results The meanweight-based diameter of 6-coumarin loaded nanoparticles was ( 102.4 ± 6.8) nm, with zeta potential of ( - 16.81 ± 1.05) mV. BCECs were positive for factor Ⅷ staining and glial fibrillary acidic protein was tight junction between BCECs in the coculture model could be visualized by both scanning electron microscopy and transmission electron microscopy. The unchanged paracellular transport of sucrose proved vivo situation for examination of the permeability of nanoparticle and toxicity evaluation.