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Find video protocols related to scientific articles indexed in Pubmed.
Molecular determinants of caspase-9 activation by the Apaf-1 apoptosome.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 10-13-2014
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Autocatalytic activation of an initiator caspase triggers the onset of apoptosis. In dying cells, caspase-9 activation is mediated by a multimeric adaptor complex known as the Apaf-1 apoptosome. The molecular mechanism by which caspase-9 is activated by the Apaf-1 apoptosome remains largely unknown. Here we demonstrate that the previously reported 1:1 interaction between Apaf-1 caspase recruitment domain (CARD) and caspase-9 CARD is insufficient for the activation of caspase-9. Rather, formation of a multimeric CARD:CARD assembly between Apaf-1 and caspase-9, which requires three types of distinct interfaces, underlies caspase-9 activation. Importantly, an additional surface area on the multimeric CARD assembly is essential for caspase-9 activation. Together, these findings reveal mechanistic insights into the activation of caspase-9 by the Apaf-1 apoptosome and support the induced conformation model for initiator caspase activation by adaptor complexes.
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Evidence for the involvement of JAK/STAT/SOCS pathway in the mechanism of Tangshen formula-treated diabetic nephropathy.
Planta Med.
PUBLISHED: 05-22-2014
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Diabetic nephropathy is one of the most significant microvascular complications associated with diabetes. Until now, there is no effective treatment and the gene mechanism of diabetic nephropathy is still unclear. Tangshen formula is a traditional Chinese medicine, and has been shown to have good clinical efficacy in diabetic nephropathy treatment. The objective of this study was to investigate the changes of gene expression profiling and explore the molecular mechanism using a db/db mice model treated by Tangshen formula. After administration for 12 weeks, a microarray was applied to detect the gene expression of db/db mice kidney tissues. Quantitative real-time PCR was used to confirm the differential gene expression and carry out a JAK/STAT/SOCS signaling pathway study. Treatment with Tangshen formula reduced the levels of serum glucose and urinary albumin in db/db mice, and the effects of Tangshen formula on db/db mice were significantly different from the positive control (Losartan potassium tablets) on microarray data. It also showed that the JAK/STAT/SOCS signaling pathway played an important role in the treatment process. The expressions of JAK1, JAK2, and STAT3 were upregulated, and STAT4 was downregulated in Tangshen formula-treated db/db mice. SOCS1, 3, and 7 were all activated, while negative feedback regulated other related genes in the JAK/STAT/SOCS pathway. Our study suggested that Tangshen formula has beneficial effects on diabetic nephropathy treatment via regulating the JAK/STAT/SOCS signaling pathway. This study will help to provide evidence-based recommendations for Tangshen formula clinical treatment.
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A high-throughput device for size based separation of C. elegans developmental stages.
Lab Chip
PUBLISHED: 03-27-2014
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Caenorhabditis elegans is a widely used model organism to study development, aging and behavior. Many of these biological studies require staging a large number of worms to assay a synchronized population of animals. Conventional synchronization techniques such as manual picking, gravity stratification and chemical bleaching are labor-intensive and could perturb animals' physiology. Thus, there is a need for a simple inexpensive technology to sort a mixed population of worms based on their developmental stages with minimal perturbation. Here we demonstrate a simple but accurate and high-throughput technique to sort based on animal size, which correlates well with developmental stages. The device consists of an array of geometrically optimized pillars that act as a sieve to allow worms of specific sizes to rapidly move through. With optimized chamber heights, pillar spacing and driving pressures, these binary separation devices are capable of independently separating a mixture of worms at two different stages at average efficiency of around 95%, and throughput of hundreds of worms per minute. In addition, when four devices are used sequentially, we demonstrate the ability to stratify a mixture of worms of all developmental stages with >85% overall efficiency.
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Biomarkers for early diagnosis of type 2 diabetic nephropathy: a study based on an integrated biomarker system.
Mol Biosyst
PUBLISHED: 05-30-2013
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Diabetic nephropathy is a devastating disease that affects a growing number of diabetic patients. A complete cure is very hard to achieve once the disease has been diagnosed, therefore the diagnosis of early stages in diabetic nephropathy has become a hot area. Numbers of molecules have been proposed to be potential biomarkers for this purpose. However, some problems still remain, such as discovering effective biomarkers to diagnose the disease before obvious clinical evidence appears. Thus, the main purpose of this study was to find plasma biomarkers for early diagnosis of type 2 diabetic nephropathy stage 1 and stage 2, as well as separating them from diabetes. 182 subjects (Chinese) were recruited for this study, including 50 healthy controls, 33 type 2 diabetic patients and 99 type 2 diabetic nephropathy patients (33 of these were stage 3). Important clinical indicators including proteinuria, serum creatinine, and urea nitrogen were measured and the glomerular filtration rate was estimated to assess kidney function; fasting blood glucose, postprandial blood glucose and glycated hemoglobin were measured to assess the blood glucose control. Key metabolites and genes in plasma samples were identified and determined using -omic and quantitative techniques. The potential biomarkers were then combined and carefully screened to determine the most informative ones for early diagnosis of type 2 diabetic nephropathy. An integrated biomarker system (IBS) incorporating 6 clinical indicators, 40 metabolites and 5 genes was established. Correlation analysis results revealed that most of the potential biomarkers significantly correlated with the 6 clinical indicators. Discriminant analysis results showed that the developed IBS gave the highest total predictive accuracy (98.9%). Significant test and receiver operating characteristic analysis results indicated that inosine had the highest sensitivity (0.889), specificity (1.000), positive predictive rate (1.000) and negative predictive rate (0.900) amongst the 48 potential biomarkers when separating patients with diabetes from patients with diabetic nephropathy stage 3. Finally, inosine with a cutoff of 0.086 mg L(-1) was combined with estimated GFR to differentiate between diabetic nephropathy stages 1 and 2 from diabetes. The results demonstrate that IBS combined with a proper statistical analysis technique is a powerful tool for biomarker screening.
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Identification and analysis of absorbed components and their metabolites in rat plasma and tissues after oral administration of Ershiwuwei Shanhu pill extracts by UPLC-DAD/Q-TOF-MS.
J Ethnopharmacol
PUBLISHED: 04-17-2013
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Ershiwuwei Shanhu pill (ESP), a classical and famous prescription of traditional Tibetan medicine, has a long history of empirical clinical use for the treatment of cerebrovascular and neurological diseases, but the absence of scientific evidence for its effect restricted its clinical application and further development.
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Identification and analysis of the constituents in an aqueous extract of tricholoma matsutake by HPLC coupled with diode array detection/electrospray ionization mass spectrometry.
J. Food Sci.
PUBLISHED: 03-31-2013
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The main constituents in an aqueous extract of Tricholoma matsutake (Tm) were identified by high-performance liquid chromatography coupled with diode array detection and electrospray ionization time-of-flight mass spectrometry (HPLC-DAD/TOF-MS) and ion trap mass spectrometry (HPLC-DAD/Trap-MSn). The main factors in the extraction process which affect the yields of nutrients were optimized by single-factor experiments and orthogonal experiment design. In total, 12 constituents were identified from the aqueous extract of Tm, including tyrosine, cytidine, uridine, eritadenine, phenylalanine, nicotinamide, inosine, guanosine, tryptophan, adenosine, 5-deoxy-5-methylthioadenosine and riboflavin. The optimized extraction conditions were: the ratio of water to sample was 10 : 1 (v/w), Tm was extracted by ultrasonic-assisted extraction for 10 min, followed by water bath heating at 60 °C for 1 h. Among these extraction factors, the heating temperature is significant based on analysis of variance (ANOVA). The yields of nutrients were affected dramatically at high temperature leading to the loss of nutrients, especially for nucleosides and some amino acids.
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Screening and evaluation of traditional Chinese medicine by microarray expression analysis.
J Ethnopharmacol
PUBLISHED: 03-07-2013
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Salvia miltiorrhiza is a Chinese medicinal herb, which is widely used for the treatment of cardiovascular disorders. In this article, we investigated the effects of Salvia miltiorrhiza and its hydrophilic and lipophilic components (HCS and LCS) on human umbilical vein endothelial cells (HUVECs), and the molecular mechanism was explored by microarray gene expression profiling.
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Proteomic analysis of the inhibitory effect of epigallocatechin gallate on lipid accumulation in human HepG2 cells.
Proteome Sci
PUBLISHED: 02-25-2013
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(-)-Epigallocatechin-3-gallate (EGCG), the most abundant catechin found in green tea, effectively reduces body weight and tissue and blood lipid accumulation. To explore the mechanism by which EGCG inhibits cellular lipid accumulation in free fatty acid (FFA) induced HepG2 cell culture, we investigated the proteome change of FFA-induced HepG2 cells exposed to EGCG using two-dimensional gel electrophoresis and mass spectrometry.
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[Effect of compatibilities and proportions of shuanglong formula on acute myocardial infarction in rats].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 12-21-2011
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To verify the rational of Chinese medicine Shuanglong formula.
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Comprehensive two-dimensional manipulations of picoliter microfluidic droplets sampled from nanoliter samples.
Anal. Chem.
PUBLISHED: 09-23-2011
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A facile method is presented for achieving comprehensive two-dimensional droplet manipulations in closed microstructures consisting of microwell arrays and a straight microchannel. In this method, picoliter/nanoliter droplets with controllable sizes and numbers are sampled from nanoliter samples/reagents with almost 100% efficiency. Droplet motions are precisely controlled in the ±X-direction and ±Y-direction by managing hydrostatic pressure and magnetic repulsion, respectively. As a demonstration, a fluorescein-labeled droplet and a deionized droplet are successively generated and trapped in adjacent microwells. Then their positions are quickly exchanged without cross-contamination and fusion is implemented on-demand. After operations, hydrophobic ferrofluid can be completely replaced by mineral oil and droplets still remain in microwells safely. A typical fluorescence intensity-based assay is demonstrated: droplet arrays containing copper ion are diluted disproportionately first and then detected by addition of droplet arrays containing Calcein. With the ability of comprehensive two-dimensional droplet manipulations, this method could be used in various miniaturized biochemical analyses including requirements of multistep procedures and in situ monitoring.
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Metabonomic study on the cumulative cardiotoxicity of a pirarubicin liposome powder.
Talanta
PUBLISHED: 08-20-2011
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Pirarubicin (THP) is an anthracycline frequently used in the chemotherapy against acute leukemia, malignant lymphoma and several solid tumors. However, its clinical use is severely limited by the development of a progressive dose-dependent cardiomyopathy that results in irreversible congestive heart failure. To provide a strategy for constraining or minimizing the cumulative cardiotoxicity of THP, a pirarubicin liposome powder (L-THP) was appropriately prepared, and the cumulative cardiotoxicity of L-THP and free THP (F-THP) were investigated on Sprague-Dawley rats after 3 successive doses. Urinary samples for metabonomic study, serum samples for biochemical assay, and heart samples for histopathology test were collected. As a result, the metabonomics-based findings such as PLS-DA plotting showed minimal metabolic alterations in L-THP as compared to F-THP, and correlated with the changes of serum biochemical assay and cardiac histopathology as measurements of damage to heart tissue. Our results confirm that when encapsulated into liposomes, the cumulative cardiotoxicity of THP can be greatly ameliorated. Lipophilic aglycone metabolites of THP associated with redox cycling are cardiotoxic for the possibility of reactive oxygen species (ROS) formation. Also, metabonomic analysis shows that the successive doses of THP will lead to severe metabolic pathways disturbances in the cell energy production. Further, the preliminary efficacy study of L-THP on lung cancer was evaluated in the approach of in vitro cytotoxicity on A549 cells by high content screening (HCS) analysis, and L-THP was found to exhibit better therapeutic index against lung cancer than THP.
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[A metabonomic study on the treatment of diabetic nephropathy with traditional Chinese medicine tang-shen-fang].
Se Pu
PUBLISHED: 07-21-2011
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An ultra performance liquid chromatography-time of flight mass spectrometry (UP-LC/TOF MS)-based method for plasma metabolic fingerprinting analysis was established. Acquired data were analyzed by principal component analysis and orthogonal projection to latent structure-discriminant analysis. The effect of tang-shen-fang (TSF) on the treatment of diabetic nephropathy patients was evaluated. Significant changes were found after 3 and 6 months treatment of TSF compared with placebo controls. Nineteen metabolites in plasma were identified as potential biomarkers, including lipids, fatty acids and amino acids. The present metabonomic study is helpful to grasp the changes of global metabolic networks during the treatment of TSF and to testify its clinical efficacy and understand its action mechanism.
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Intrarenal metabolomics reveals the association of local organic toxins with the progression of diabetic kidney disease.
J Pharm Biomed Anal
PUBLISHED: 06-20-2011
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The pathological development of diabetic kidney disease (DKD) might involve metabolic perturbations in kidney tissue. The present study was designed to detect the systematic alterations of renal cortex metabolites thereby exploring the related mechanisms of DKD development and fosinopril treatment. Based on combined gas chromatography/time-of-flight mass spectrometry (GC-TOF MS) and liquid chromatography/time-of-flight mass spectrometry (UPLC-TOF MS) data acquiring platform, we have performed a metabolomic analysis of perfused renal cortex samples from the diabetic rats induced by streptozocin and treated with or without fosinopril, a pharmacological inhibitor of angiotensin II converting enzyme (ACEI). We identified a number of abnormal metabolites in the diabetic kidney, including groups of amino acids, carbohydrates, polyols, lyso-phospholipids, glucuronides and other unidentified metabolites. Of them, an increase in intrarenal organic toxins including uremic toxins, glucuronides and glucotocixity-associated metabolites are highly correlated with diabetic kidney injury including 24h urinary protein levels and tubulointerstitial injury index. Treatment with fosinopril significantly attenuated diabetic kidney injury, and simultaneously blocked the intrarenal accumulation of these organic toxins, especially hippurate and glucuronides. These results indicate that intrarenal accumulation of organic toxins may be significant for the development of DKD and the related mechanisms deserve to be further investigated.
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On-demand microfluidic droplet manipulation using hydrophobic ferrofluid as a continuous-phase.
Lab Chip
PUBLISHED: 02-15-2011
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Multiple essential microdroplet operation units, including splitting, dispensing, oil-phase exchange, trapping, release and demulsification, were successfully implemented by combining hydrophobic ferrofluid with microfluidic chips.
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Transcriptional profiling analysis of HMP-treated rats with experimentally induced myocardial infarction.
J Ethnopharmacol
PUBLISHED: 01-22-2011
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Heart-protecting musk pill (HMP), a traditional Chinese medicine prescription, has extensive cardioprotective effects against angina pectoris and myocardial infarction (MI), but the molecular mechanism behind such cardio protective effects still remains unclear. In this article, we aim to investigate the effect of HMP on mRNA expression in MI rat.
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A metabonomic approach applied to predict patients with cerebral infarction.
Talanta
PUBLISHED: 01-06-2011
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Cerebral infarction is always of sudden onset, and usually leading to serious consequence. It is of therapeutic significance to develop fast and accurate diagnosis methods for cerebral infarction so that patients can be treated timely and properly. A metabonomic approach was then proposed to investigate the potential biomarkers and metabolic pathways associated with cerebral infarction and also establish a prediction model of cerebral infarction for the fast diagnosis. Serum metabolic profiling of sixty-seven cerebral infarction patients and sixty-two controls was obtained using UPLC-TOF MS. The resulting data were then processed by multivariate statistical analysis to graphically demonstrate metabolic variations. The PLS-DA model was validated with cross validation and permutation tests to assure the models reliability, and significant difference was obtained between the original and hypothetical models (p<0.0001). A series of endogenous metabolites in the one-carbon cycle, such as folic acid, cysteine, S-adenosyl homocysteine and oxidized glutathione, were determined as potential biomarkers of cerebral infarction. A prediction model developed using PLS-KNN algorithm was established to differentiate cerebral infarction patients from controls, and an average accuracy of 100% was obtained. In conclusion, metabonomic approach is a powerful tool to investigate the pathogenesis of stroke and is expected to be developed as a useful method for the fast diagnosis.
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Development of a strategy and process parameters for a green process in counter-current chromatography: purification of tanshinone IIA and cryptotanshinone from Salvia miltiorrhiza Bunge as a case study.
J Chromatogr A
PUBLISHED: 01-06-2011
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A strategy for the development of a green process using counter-current chromatography technology is presented in this paper. The strategy began with solvent system selection, followed by linear scale-up from an analytical to a preparative process with optimized operating parameters. A two-stage separation using a multi-injection method was performed with a solvent system of hexane-dichloromethane-methanol-water (4:0.75:4:1) for the 1st stage and a hexane-ethanol-water (4:2:2) for the 2nd stage. A 191.8 mg of tanshinone IIA was purified, with a 97% purity and 34.4% recovery and a 276.7 mg of cryptotanshinone was separated, with a 95% purity and 31.8% recovery from 2.1g of crude extract. Process parameters (throughput, efficiency, environmental risk factor and general process evaluation) and mass factors (mass intensity, separation mass efficiency and greenness) of a target were developed for monitoring of the counter-current chromatography process.
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Metabonomic study of Chinese medicine Shuanglong formula as an effective treatment for myocardial infarction in rats.
J. Proteome Res.
PUBLISHED: 12-14-2010
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A UPLC/TOF-MS-based metabonomic study was conducted to assess the holistic efficacy of Traditional Chinese Medicine Shuanglong Formula (SLF) for myocardial infarction in rats. Thirty male Sprague-Dawley rats were randomly divided into five groups after surgery. The Panax ginseng group, Salvia miltiorrhiza group, and SLF group were treated with water extractions of Panax ginseng (PG), Salvia miltiorrhiza (SM), and SLF (the ratio of SM to PG was 3:7) at a dose of 5 g/kg·w·d for 21 consecutive days, respectively; the model group and sham surgery group were both treated with 0.9% saline solution. Urinary samples for metabonomic study, serum samples for biochemical measurement, and heart samples for histopathology were collected. As a result, metabonomics-based findings such as the PCA and PLS-DA plotting of metabolic state and analysis of potential biomarkers in urine correlated well to the assessment of serum biochemistry and histopathological assay, confirming that SLF exerted synergistic therapeutic efficacies to exhibit better effect on MI compared to PG or SM. The shifts in urinary TCA cycle as well as pentose phosphate pathway suggested that SLF may diminish cardiac injury of MI with its potential pharmacological effect in the regulation of myocardial energy metabolism.
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Metabonomic study on women of reproductive age treated with nutritional intervention: screening potential biomarkers related to neural tube defects occurrence.
Biomed. Chromatogr.
PUBLISHED: 04-16-2010
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Nutritional intervention is effective in reducing the risk of neural tube defects (NTDs). To determine the effects of nutritional supplementation on human metabolism, a metabonomic study was carried out on 96 women of reproductive age. Subjects with nutritional intervention were given fortified wheat flour (containing folic acid, vitamin B?, vitamin B?, ferric sodium edetate and zinc oxide) for 8 months. Serum metabolic fingerprinting was detected via ultraperformance liquid chromatography in tandem with time-of-flight mass spectrometry (UPLC-TOF MS), and data acquired was processed by multivariate statistical analysis. The result revealed a significant difference between the control and intervention group. Twenty potential biomarkers, including fructose 6-phosphate, sphingosine 1-phosphate, docosahexaenoic acid and hexadecanoic acid, were located and identified by the accurate mass measurement of TOF MS. These compounds are believed to be functionally related to anti-oxidative competence in vivo. In conclusion, metabonomics study is a valuable approach in exploring the effect mechanism of nutritional intervention on NTD prevention.
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Preparative isolation and purification of ginsenosides Rf, Re, Rd and Rb1 from the roots of Panax ginseng with a salt/containing solvent system and flow step-gradient by high performance counter-current chromatography coupled with an evaporative light sca
J Chromatogr A
PUBLISHED: 01-14-2010
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Ginseng is a popular herb worldwide and has had varied uses in traditional Asian medicine for thousands of years. There are several different species of the herb, but all share the same constituents. Ginsenosides, the most extensively studied chemical components of ginseng, are generally considered to be one of the most important active ingredients of the plant. In this study, we have developed fast and efficient methodology for isolation of four known ginsenosides Rf, Rd, Re and Rb1 from Ginseng by high performance counter-current chromatography (HPCCC) coupled with evaporative light scattering detection (ELSD). The crude sample for HPCCC was purified firstly from a ginseng extraction using macroporous resin. The enriched saponin fraction (480 mg) was separated by using methylene chloride-methanol-5 mM aqueous ammonium acetate-isopropanol (6:2:4:3, v/v,) as the two-phase solvent system and yielded 10.7 mg of Rf, 11.0 mg of Rd, 13.4 mg of Re and 13.9 mg of Rb1. The purity of these ginsenosides was 99.2%, 88.3%, 93.7% and 91.8%, respectively assessed by HPLC-DAD-ELSD, and their structures were characterized by electrospray ionization mass spectrometry (ESI-MS) and compared with standards. Ammonium acetate was used to shorten the separation time and eliminate emulsification together with a flow step-gradient. The salt can be removed by re-dissolving the sample using acetone.
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Crystal structure of the Caenorhabditis elegans apoptosome reveals an octameric assembly of CED-4.
Cell
PUBLISHED: 01-07-2010
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The CED-4 homo-oligomer or apoptosome is required for initiation of programmed cell death in Caenorhabditis elegans by facilitating autocatalytic activation of the CED-3 caspase zymogen. How the CED-4 apoptosome assembles and activates CED-3 remains enigmatic. Here we report the crystal structure of the complete CED-4 apoptosome and show that it consists of eight CED-4 molecules, organized as a tetramer of an asymmetric dimer via a previously unreported interface among AAA(+) ATPases. These eight CED-4 molecules form a funnel-shaped structure. The mature CED-3 protease is monomeric in solution and forms an active holoenzyme with the CED-4 apoptosome, within which the protease activity of CED-3 is markedly stimulated. Unexpectedly, the octameric CED-4 apoptosome appears to bind only two, not eight, molecules of mature CED-3. The structure of the CED-4 apoptosome reveals shared principles for the NB-ARC family of AAA(+) ATPases and suggests a mechanism for the activation of CED-3.
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On-chip manipulation of continuous picoliter-volume superparamagnetic droplets using a magnetic force.
Lab Chip
PUBLISHED: 07-09-2009
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A microfluidic device for generating monodisperse superparamagnetic droplets and rapidly manipulating desired droplets into designated sub-microchannels by an external magnetic force is described. Superparamagnetic magnetite (Fe3O4) nanoparticles are synthesized by a chemical co-precipitation method. They are well dispersed in the water-phase to form a superparamagnetic fluid that is sheared into picoliter-volume monodisperse superparamagnetic droplets by the oil-phase in a T-junction PDMS microchannel. Superparamagnetic droplets always flow into sub-microchannel 1 due only to laminar flow without a magnetic field. But they are deflected from the direction of laminar flow by a perpendicular magnetic field. The results show that the deflection is proportional to the magnetic field gradient and magnetic nanoparticle concentration, and it is closely related to the magnet position. The observed experimental results make a good match with theoretical analysis. Single or bulk superparamagnetic droplets are successfully manipulated into the designated sub-microchannels 2 and 3 respectively, only by changing the positions of the magnet. Relatively high efficiency is obtained with more than 10 superparamagnetic droplets precisely manipulated per second. This simple and robust apparatus has wide applications in high throughput drug delivery/screening, immunoassay, cell research and synthesis of magnetic microparticles due to good biological compatibility and monodispersity of superparamagnetic droplets.
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Simultaneous determination of 15 steroids in rat blood via gas chromatography-mass spectrometry to evaluate the impact of emasculation on adrenal.
Talanta
PUBLISHED: 06-01-2009
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Adrenal was believed to affect the prostate tumor tissue growth by its secretion of adrenal androgens. However, the mechanisms regulating these effects were not fully understood. In this work, a sensitive and specific method for the determination of 15 steroids in blood via gas chromatography-mass spectrometry in selective ion storage detection mode was established to evaluate the impact of emasculation on adrenal steroids metabolism. Steroids were isolated by solid-phase extraction using Oasis HLB cartridge, and then derivated with heptafluorobutyric anhydride before analysis. The limits of detection were between 0.15 and 1.0 ng/mL and limits of quantification were between 0.62 and 2.6 ng/mL. The recoveries of steroids were above 83%, and both the intra-day and inter-day precisions (RSD%) were lower than 8%. Pregnenolone, progesterone, 17alpha-hydroxyprogesterone (17alphaP), 17alpha-hydroxypregnenolone (17alphaH), dehydroepiandrosterone (DHEA), estrone, 17beta-estradiol, dihydrotestosterone (DHT), testosterone (T), 4-androstenedione (4-A), 1,4-androstadiene-3,17-dione, 11-deoxycortisol, 11-deoxycorticosterone, cortisol and aldosterone were quantified in 156 major male SD rats at 0, 1, 2, 4, 7 days, 2, 4, 6, 8, 10, 12, 14, and 16 weeks following emasculation. T and DHT decreased by 86.2% and 73.4%, respectively in the first 7 days following emasculation, but adrenal androgens (DHEA, 4-A) stabled at the normal level accordingly. Adrenal androgens and their precursors (17alphaH, 17alphaP) increased from the 2nd week along with the increase of androgens and the decrease of mineralocorticoids. These facts revealed that adrenal possibly enhanced its function of producing adrenal androgens from the 2nd week responding to the low androgens level induced by emasculation.
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Laminar flow used as "liquid etch mask" in wet chemical etching to generate glass microstructures with an improved aspect ratio.
Lab Chip
PUBLISHED: 05-26-2009
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A new method of anisotropic etching an amorphous bulk material is proposed in this paper. Laminar flow is employed in this method to mask the flow of an etchant and is termed as "liquid etch mask". Since this mask has the physical properties of a liquid, it brings several advantages that could not be achieved by any kind of other etch mask in the solid phase. As a consequence, the aspect ratio of the glass channel could be improved to approximately 1 while in an inexpensive and convenient manner.
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Investigation on the interactions between pirarubicin and phospholipids.
Biophys. Chem.
PUBLISHED: 03-18-2009
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Differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy and quantum calculation based on molecular modeling were applied to investigate the interaction between pirarubicin (THP), an anthracycline antibiotic frequently used in chemotherapy, and zwitterionic distearoylphosphatidylcholine (DSPC) or anionic distearoylphosphatidylglycerol (DSPG). DSC and FTIR studies suggested that DSPG bilayers were less perturbed by THP than those of DSPC, and this might be due to the strong interactions between NH(3)(+) of THP and the phosphate (PO(2)(-)) group in the polar head of DSPG, which limit the further access of THP into its bilayers. Quantum calculation results based on molecular modeling could further confirm the DSC and FTIR conclusions. Meanwhile, it could well translate the calorimetric and spectroscopic phenomena into the underlying physical knowledge. Interactions between THP and phospholipids can play a critical role in the liposomal drug delivery system, especially in the safety mechanism elucidation and rational formulation design.
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Miniaturized high throughput detection system for capillary array electrophoresis on chip with integrated light emitting diode array as addressed ring-shaped light source.
Lab Chip
PUBLISHED: 03-07-2009
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A novel miniaturized, portable fluorescence detection system for capillary array electrophoresis (CAE) on a microfluidic chip was developed, consisting of a scanning light-emitting diode (LED) light source and a single point photoelectric sensor. Without charge coupled detector (CCD), lens, fibers and moving parts, the system was extremely simplified. Pulsed driving of the LED significantly increased the sensitivity, and greatly reduced the power consumption and photobleaching effect. The highly integrated system was robust and easy to use. All the advantages realized the concept of a portable micro-total analysis system (micro-TAS), which could work on a single universal serial bus (USB) port. Compared with traditional CAE detecting systems, the current system could scan the radial capillary array with high scanning rate. An 8-channel CAE of fluorescein isothiocyanate (FITC) labeled arginine (Arg) on chip was demonstrated with this system, resulting in a limit of detection (LOD) of 640 amol.
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Rapid and high-throughput purification of salvianolic acid B from Salvia miltiorrhiza Bunge by high-performance counter-current chromatography.
J Chromatogr A
PUBLISHED: 01-10-2009
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A large-scale purification of salvianolic acid B from Salvia miltiorrhiza Bunge is presented. The method development began with selection of the solvent system, then optimization of the operating parameters and ended up with linear scale-up from an analytical to a preparative instrument. Three factors were used for method optimization and scale-up estimation: purity, process throughput and process efficiency. Preparation was achieved using a two-phase solvent system comprising hexane-ethyl acetate-methanol-acetic acid-water (1:5:1.5:0.00596:5, v/v). This preparation yielded 475 mg of salvianolic acid B with a purity of 96.1% from 1.5 g of crude extract. The process throughput of crude was 2.23 g/h while process efficiency per gram of target compound was 0.769 g/h. Two factors-process environmental risk factor and process evaluation factor were used for evaluation of the separation process.
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A metabonomic approach to the effect evaluation of treatment in patients infected with influenza A (H1N1).
Talanta
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The pandemic influenza A virus (H1N1) was transmitted to the human population since 2009, resulting in some consequences of viral pneumonia, respiratory failure, multiple organ failure and, most severely, death. In clinical practice, Chinese medicine possessed extensive experience for prevention and treatment of influenza, but its mechanism still remain unclear. In addition, the efficacy of combination therapy of Chinese and Western medicine was attractive, but not yet clear. In the present study, 131 patients from Guangzhou China referred for H1N1 virus mRNA testing for the evaluation of possible influenza A-infected were eligible for participation. A metabonomics study was carried out to explore the difference between before and after treatment in patients with H1N1 through Chinese and/or Western medicine. Results from metabolic profiling and biochemical detection indicated significant metabolic change in the arachidonic acid metabolic pathway. In the group of combination therapy of Chinese and western medicine, its efficacy was best and the potential biomarkers were significantly changed compared with untreated state. Those results indicated that the potential metabolic biomarker could be supplemented with biochemical detection to obtain more precise diagnosis for H1N1 infection.
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Anti-obesity and hypolipidemic effects of Fuzhuan brick tea water extract in high-fat diet-induced obese rats.
J. Sci. Food Agric.
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Fuzhuan brick tea is a kind of microbial fermented tea, which has received increasing attention in recent years owing to its benefits for human health. In this study, the anti-obesity and hypolipidemic effects of Fuzhuan brick tea water extracts (FTEs) were investigated.
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Controlling gas/liquid exchange using microfluidics for real-time monitoring of flagellar length in living Chlamydomonas at the single-cell level.
Lab Chip
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Chlamydomonas reinhardtii is widely used for studying cilia/flagella, organelles important for human health and disease. In situ monitoring of flagellar assembly/disassembly kinetics in single living cells has been difficult with conventional methods because of time-consuming media exchange and the requirement of whole cell fixation. Here, we develop a PDMS/glass hybrid microfluidic device for real-time tracking of flagellar length in single living cells of Chlamydomonas. Media exchange is precisely controlled by sequential gas-liquid plugs and complete medium replacement occurs within seconds. Rapid medium exchange allows the capture of transient flagellar dynamics. We show that Chlamydomonas cells respond to acidic medium exchange and deflagellate. However, the two flagella may shed asynchronously. After subsequent medium exchange, cells regenerate full-length flagella. Cells are also induced to shorten their flagella after being exposed to extracellular stimuli. The long-term kinetics of flagellar regeneration and disassembly for the whole cell population on the chip are comparable to those from conventional methods; however, individual cells display non-uniform response kinetics. We also find that flagellar growth rate is dependent on flagellar length. This device provides a potential platform to continuously monitor molecular activities associated with changes in flagellar length and to capture transient molecular changes upon flagellar loss, and initiation of flagellar assembly/disassembly.
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Antifungal activity in plants from Chinese traditional and folk medicine.
J Ethnopharmacol
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From over 100 Chinese clinical trial publications, we retrieved 22 commercial preparations and 17 clinical prescriptions used as Traditional Chinese Medicine (TCM) for treating mycotic vaginitis, typically caused by Candida albicans. The 8 most frequently used plants as well as another 7 TCM and 18 folk medicinal plants used in the South of China for antifungal therapy were investigated for in vitro antifungal activity.
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A simple way to configure on-line two-dimensional liquid chromatography for complex sample analysis: acquisition of four-dimensional data.
Talanta
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An on-line comprehensive two-dimensional liquid chromatography (HPLC×UPLC-TOF MS) was set up just using the injection valve of the ultra performance liquid chromatography (UPLC) as the interface through which the effluent of high performance liquid chromatography (HPLC) was injected automatically to UPLC coupled to time-of-flight mass spectrometry (TOF MS). As a demonstrative application, a complex sample of Traditional Chinese Medicine, Qingkailing was analyzed. As a result, a four-dimensional (4D) data containing 2D retention times, peak intensity and m/z ratios was plotted, where 398 peaks were counted and low concentration components were distinguished from the high concentration ones with a total peak capacity of 1090. Comparing with traditional 3D data acquired by HPLC×HPLC, the 4D data generated by HPLC×UPLC-TOF MS can increase the number of recognized components by three times, reduce the analysis time by 75%. Such a configuration of HPLC×UPLC-TOF MS can realize easily upon commercial chromatographs while exhibited enhanced separation efficiency, high sensitivity, huge peak capacity and great potential in complex sample analysis.
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Determination of main categories of components in corn steep liquor by near-infrared spectroscopy and partial least-squares regression.
J. Agric. Food Chem.
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Corn steep liquor (CSL) is an important raw material that has a high nutritional value and serves as a nitrogen source. This study aimed to develop a fast, versatile, cheap, and environmentally safe analytical method of quantifying the total acidity (TA) of CSL as well as its contents of dry matter (DM), total sugars (TS), total reducing sugars (TRS), total free amino acids (TFAA), total nitrogen (TN), and total sulfite (TSu). The near-infrared (NIR) spectroscopy measurements of 66 samples (22 batches) of CSL were analyzed by partial least-squares regression using several spectral preprocessing methods. Multivariate models developed in the NIR area showed good predictive abilities for DM, TA, TS, TRS, TFAA, TN, and TSu determination. These results confirm the feasibility of the multivariate spectroscopic approach as a replacement for expensive and time-consuming conventional chemical methods. Thus, a convenient and feasible method for the quality control of fermentation raw materials for food additives and fine chemicals, especially in CSL, is established.
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Oil-water biphasic parallel flow for the precise patterning of metals and cells.
Biomed Microdevices
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Fluidic patterning is a convenient and versatile tool for the patterning of materials, cells and microstructures on surface and in microchannels. However, its performance is usually limited by transverse diffusion between fluid streams. It would blur the boundary and deteriorate the precision of patterns. In this paper, we adopted geometric confinement to generate biphasic parallel flow that is constituted of oil and water. Since there is minimum transverse diffusion in biphasic parallel flow, the performance of fluid patterning is expected to be improved. The results show that the metal (Silver and Chromium) patterns have distinct boundary and well-controlled geometry in comparison with that by conventional laminar flow patterning. Furthermore, the high biocompatibility of oil phase (perfluorodecalin, PFD) enables the precise patterning of viable bacteria inside microchannels. Our work demonstrated a new route of using biphasic parallel flow to patterning, which would serve wide applications in prototyping and research settings.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.