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Find video protocols related to scientific articles indexed in Pubmed.
Biphasic influence of dexamethasone exposure on embryonic vertebrate skeleton development.
Toxicol. Appl. Pharmacol.
PUBLISHED: 08-31-2014
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Dexamethasone (Dex) has anti-inflammatory and immunomodulatory properties against many conditions. There is a potential teratogenic risk, however, for pregnant women receiving Dex treatment. It has been claimed that Dex exposure during pregnancy could affect osteogenesis in the developing embryo, which still remains highly controversial. In this study, we employed chick embryos to investigate the effects of Dex exposure on skeletal development using combined in vivo and in vitro approach. First, we demonstrated that Dex (10(-8)-10(-6)?mol/egg) exposure resulted in a shortening of the developing long bones of chick embryos, and it accelerated the deposition of calcium salts. Secondly, histological analysis of chick embryo phalanxes exhibited Dex exposure inhibited the proliferation of chondrocytes, increased apoptosis of chondrocytes and osteocytes, and led to atypical arranged hypertrophic chondrocytes. The expression of genes related to skeletogenesis was also analyzed by semi-quantitative RT-PCR. The expression of ALP, Col1a2 and Col2a1 was decreased in the Dex treated phalanxes. A detectable increase was observed in Runx-2 and Mmp-13 expression. We next examined how Dex affected the different stages of skeletogenesis in vitro. Utilizing limb bud mesenchyme micromass cultures, we determined that Dex exposure exerted no effect on apoptosis but impaired chondrogenic cell proliferation. Interestingly, low dose of Dex moderately prompted nodule formation as revealed by alcian blue staining, but higher doses of Dex significantly inhibited similar chondrogenic differentiation. Dex exposure did not induce apoptosis when the chondrogenic precursors were still at the mesenchymal stage, however, cell viability was suppressed when the mesenchyme differentiated into chondrocytes. Alizarin red staining revealed that the capacity to form mineralized bone nodules was correspondingly enhanced as Dex concentrations increased. The mRNA level of Sox-9 was slightly increased in mesenchymal cell mass treated by low concentration of Dex. Mmp-13 expression was obviously up-regulated by Dex in both mesenchymal cells and primary chondrocyte cultures. And Col10a1 expression was also increased by Dex exposure in chondrocyte. In summary, we have revealed that different concentrations of Dex exposure during early gestation could exert a biphasic effect on vertebrate skeletal development.
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Effects of high salt-exposure on the development of retina and lens in 5.5-day chick embryo.
Cell. Physiol. Biochem.
PUBLISHED: 08-20-2014
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Excess maternal salt intake during pregnancy may alter fetal development. However, our knowledge on how an increased salt intake during pregnancy influences fetal eye development is limited. In this study, we investigated the effects of high-salt treatment on the developing eyes in chick embryos, especially focusing on the development of the retina and the lens.
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Adverse effects of high glucose levels on somite and limb development in avian embryos.
Food Chem. Toxicol.
PUBLISHED: 05-18-2014
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Gestational diabetes has an adverse impact on fetal musculoskeletal development, but the mechanism involved is still not completely understood. In this study, we investigated the effects of high glucose on the developing somites and their derivate using the chick embryo as a model. We demonstrated that under high glucose, the number of generated somites was reduced and their morphology altered in 2-day old chick embryos. In addition, high glucose repressed the development of the limb buds in 5.5-day old chick embryos. We also demonstrated that high glucose abridged the development of the sclerotome and the cartilage in the developing limb bud. The sonic hedgehog (Shh) gene has been reported to play a crucial role in the development and differentiation of sclerotome. Hence, we examined how Shh expression in the sclerotome was affected under high glucose. We found that high glucose treatment significantly inhibited Shh expression. The high glucose also impaired myotome formation at trunk level - as revealed by immunofluorescent staining with MF20 antibodies. In the neural tube, we established that Wnt3a expression was also significantly repressed. In summary, our study demonstrates that high glucose concentrations impair somite and limb bud development in chick embryos, and suggests that Shh and Wnt genes may play a role in the underlying mechanism.
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Aerobic transformation of BDE-47 by a Pseudomonas putida sp. strain TZ-1 isolated from PBDEs-contaminated sediment.
Bull Environ Contam Toxicol
PUBLISHED: 02-13-2014
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A bacterial isolate, TZ-1, was isolated from contaminated sediment near electronic waste dismantling workshops, Taizhou, China that degraded 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47). The isolate was identified as Pseudomonas putida sp. with respect to its morphology, biochemical characteristics and 16SrDNA sequence analysis. TZ-1 can use BDE-47 as the sole carbon and energy source for growth in mineral salt medium. The isolate degraded BDE-47 up to 49.96 % of the initially applied concentration of 50 ?g L(-1) after 7 days of incubation at 150 rpm, 30°C. Static conditions with pH 6.5 and temperature 30°C were considered to be optimum for BDE-47 biodegradation. Addition of co-substrates promoted cell growth, but decreased the degradation rate for BDE-47.
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Molecular dynamics simulation of mechanical behavior of osteopontin-hydroxyapatite interfaces.
J Mech Behav Biomed Mater
PUBLISHED: 02-05-2014
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Bone is characterized with an optimized combination of high stiffness and toughness. The understanding of bone nanomechanics is critical to the development of new artificial biological materials with unique properties. In this work, the mechanical characteristics of the interfaces between osteopontin (OPN, a noncollagenous protein in extrafibrillar protein matrix) and hydroxyapatite (HA, a mineral nanoplatelet in mineralized collagen fibrils) were investigated using molecular dynamics method. We found that the interfacial mechanical behavior is governed by the electrostatic attraction between acidic amino acid residues in OPN and calcium in HA. Higher energy dissipation is associated with the OPN peptides with a higher number of acidic amino acid residues. When loading in the interface direction, new bonds between some acidic residues and HA surface are formed, resulting in a stick-slip type motion of OPN peptide on the HA surface and high interfacial energy dissipation. The formation of new bonds during loading is considered to be a key mechanism responsible for high fracture resistance observed in bone and other biological materials.
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Excess caffeine exposure impairs eye development during chick embryogenesis.
J. Cell. Mol. Med.
PUBLISHED: 01-22-2014
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Caffeine has been an integral component of our diet and medicines for centuries. It is now known that over consumption of caffeine has detrimental effects on our health, and also disrupts normal foetal development in pregnant mothers. In this study, we investigated the potential teratogenic effect of caffeine over-exposure on eye development in the early chick embryo. Firstly, we demonstrated that caffeine exposure caused chick embryos to develop asymmetrical microphthalmia and induced the orbital bone to develop abnormally. Secondly, caffeine exposure perturbed Pax6 expression in the retina of the developing eye. In addition, it perturbed the migration of HNK-1(+) cranial neural crest cells. Pax6 is an important gene that regulates eye development, so altering the expression of this gene might be the cause for the abnormal eye development. Thirdly, we found that reactive oxygen species (ROS) production was significantly increased in eye tissues following caffeine treatment, and that the addition of anti-oxidant vitamin C could rescue the eyes from developing abnormally in the presence of caffeine. This suggests that excess ROS induced by caffeine is one of the mechanisms involved in the teratogenic alterations observed in the eye during embryogenesis. In sum, our experiments in the chick embryo demonstrated that caffeine is a potential teratogen. It causes asymmetrical microphthalmia to develop by increasing ROS production and perturbs Pax6 expression.
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[Effects of low temperature stress on photosynthetic performance of different genotypes wheat cultivars].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 11-02-2013
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Different genotypes wheat cultivars (spring wheat Yangmai 18, semi-spring wheat Zhengmai 9023, and semi-winter wheat Yannong 19) were chosen to study their photosynthetic and chlorophyll fluorescence characteristics at tillering and stem elongation stages under low temperature stress. After treated with low temperature (-10 degrees C at night) at tillering stage for 2 days, the net photosynthetic rate (Pn), stomata conductance (g(s)), maximum quantum yield of PSII (Fv/Fm), photochemical quenching (q(P)), non-photochemical quenching coefficient (NPQ), and acyclic photosynthetic electron transfer rate of PSII (ETR) of Yannong 19 were significantly higher than those of Yangmai 18 and Zhengmai 9023, the g(s), Fv/Fm, qP, and NPQ of Zhengmai 9023 were significantly higher than those of Yangmai 18, while the intercellular CO2 concentration (Ci) of Yannong 19 was significantly lower than that of Zhengmai 9023 and Yangmai 18. In addition, the minimal fluorescence (Fo) of Yangmai 18 was significantly higher than that of Zhengmai 9023 and Yannong 19. Similarly, after treated with low temperature (0 degrees C at night) at stem elongation stage for 3 days, the Pn, g(s), qP, and Fv/Fm of Yannong 19 were significantly higher than those of Yangmai 18 and Zhengmai 9023, and the NPQ and ETR of Yannong 19 were significantly higher than those of Yangmai 18. In addition, the Pn, g(s), Fv/Fm, and qP of Zhengmai 9023 were significantly higher than those of Yangmai 18, the Fo of Zhengmai 9023 was significantly higher than that of Yannong 19, and the Ci and Fo of Yangmai 18 were significantly higher than those of Zhengmai 9023 and Yannong 19. It was suggested that under low temperature stress at tillering and stem elongation stages, semi-winter wheat Yannong 19 had the highest photosynthetic activity and the best self-protection mechanism, followed by semi-spring wheat Zhengmai 9023, and spring wheat Yangmai 18.
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Enhanced beta-catenin expression and inflammation are associated with human ectopic tubal pregnancy.
Hum. Reprod.
PUBLISHED: 06-19-2013
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Is there a molecular link between Wnt signaling in fallopian tube inflammation and ectopic tubal implantation?
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Freeway safety estimation using extreme value theory approaches: A comparative study.
Accid Anal Prev
PUBLISHED: 05-17-2013
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The validity of traffic conflicts and other surrogate events has been a great concern in the development and application of surrogate safety measures. Extreme value theory (EVT) offers a strong modeling framework for linking surrogate measures of safety to crash frequency. This study aims at developing, validating, and comparing two EVT modeling approaches for characterizing extreme events. The two alternative EVT approaches, block maxima (BM) and peak over threshold (POT), are used to relate surrogates and lane change maneuver-related crashes on freeways. The surrogate measure is post encroachment times measured from 4189 lane change maneuvers recorded at 29 directional freeway segments with approximately 3-h observation for each segment. The sample size, serial dependency, and non-stationarity issues for both approaches are examined. The comparison of results from the two modeling approaches indicates that the POT approach performs better than BM approach from the aspects of data utilization, estimate accuracy and estimate reliability. This conclusion is drawn on condition of relatively short time observations. An additional comparison is conducted between the estimated crashes and estimated return levels from two approaches. Due to large variances in the estimated crashes, much more robust estimated return levels are recommended for freeway safety evaluation.
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Identification of dicalcium phosphate dihydrate deposited during osteoblast mineralization in vitro.
J. Inorg. Biochem.
PUBLISHED: 04-20-2013
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The hydroxyapatite (HAP) with variable chemical substitutions has been considered as the major component in the mineralized part of bones. Various metastable crystalline phases have been suggested as transitory precursors of HAP in bone, but there are no consensuses as to the nature of these phases and their temporal evolution. In the present study, we cultured rat calvarial osteoblasts with ascorbate and ?-glycerophosphate to explore which calcium phosphate precursor phases comprise the initial mineral in the process of osteoblast mineralization in vitro. At the indicated time points, the deposited calcium phosphate was analyzed after removing organic substances from the extracellular matrix with hydrazine. The features comparable to dicalcium phosphate dihydrate (DCPD) and octacalcium phosphate (OCP), in addition to HAP, were detected in the mineral phases by high resolution transmission electron microscopy. And there was a trend of conversion from DCPD- and OCP-like phases to HAP in the course of mineralization, as indicated by Fourier-transform infrared microspectroscopy, energy-dispersive X-ray spectroscopy and synchrotron X-ray powder diffraction analyses. Besides, biochemical assay showed a progressive decrease in the ratio of mineral-associated proteins to calcium with time. These findings suggest that DCPD- and OCP-like phases are likely to occur on the course of osteoblast mineralization, and the mineral-associated proteins might be involved in modulating the mineral phase transformation.
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Retention of stem cell plasticity in avian primitive streak cells and the effects of local microenvironment.
Anat Rec (Hoboken)
PUBLISHED: 02-04-2013
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Primitive streak (PS) is the first structure occurring in embryonic gastrulation, in which the epiblast cells undergo the epithelial-mesenchymal transition to become the loose mesoderm cells subsequently. Because the mesoderm cells departing from different portions of PS are blessed with disparate migration trajectory and differentiation fate, one question is when the cell fate is determinated. To understand whether the cell fate and cell migration pattern will be alternated along with the microenvironment transformation, the traditional transplantation technology was used to replace the anterior PS cells in HH4 host embryo using posterior PS tissue labeled by green fluorescent protein (GFP) in the same stage donor embryo, and then, we tracked the migration trajectory of the GFP-positive cells with fluorescence stereomicroscope after incubation, and eventually verified the cell contribution from the transplants with in situ hybridization and immunocytochemistry. The same experimental strategy applied for posterior PS site replacement in host embryo. We found that the transplanted posterior PS cells to anterior part of streak followed the anterior PS cell migration pattern rather than kept its posterior streak cell migration trajectory, and so did vice versa. In addition, the transplants were involved in the contribution to the subsequent organogenesis as the local PS tissues affirmed by specific expression of myocardial or hematopoietic markers. Therefore, our data strongly suggest that the PS cells still keep stem cell plasticity during gastrulation and the eventual cell fate will depend on the spatial gene expression within local microenvironment along with development.
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Photoluminescent gold nanoclusters as sensing probes for uropathogenic Escherichia coli.
PLoS ONE
PUBLISHED: 01-30-2013
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Glycan-bound nanoprobes have been demonstrated as suitable sensing probes for bacteria containing glycan binding sites. In this study, we demonstrated a facile approach for generating glycan-bound gold nanoclusters (AuNCs). The generated AuNCs were used as sensing probes for corresponding target bacteria. Mannose-capped AuNCs (AuNCs@Mann) were generated and used as the model sensors for target bacteria. A one-step synthesis approach was employed to generate AuNCs@Mann. In this approach, an aqueous solution of tetrachloroauric acid and mannoside that functionized with a thiol group (Mann-SH) was stirred at room temperature for 48 h. The mannoside functions as reducing and capping agent. The size of the generated AuNCs@Mann is 1.95±0.27 nm, whereas the AuNCs with red photoluminescence have a maximum emission wavelength of ~630 nm (?excitation = 375 nm). The synthesis of the AuNCs@Mann was accelerated by microwave heating, which enabled the synthesis of the AuNCs@Mann to complete within 1 h. The generated AuNCs@Mann are capable of selectively binding to the urinary tract infection isolate Escherichia coli J96 containing the mannose binding protein FimH expressed on the type 1 pili. On the basis of the naked eye observation, the limit of detection of the sensing approach is as low as ~2×10(6) cells/mL.
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Msl2 is a novel component of the vertebrate DNA damage response.
PLoS ONE
PUBLISHED: 01-01-2013
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hMSL2 (male-specific lethal 2, human) is a RING finger protein with ubiquitin ligase activity. Although it has been shown to target histone H2B at lysine 34 and p53 at lysine 351, suggesting roles in transcription regulation and apoptosis, its function in these and other processes remains poorly defined. To further characterize this protein, we have disrupted the Msl2 gene in chicken DT40 cells. Msl2(-/-) cells are viable, with minor growth defects. Biochemical analysis of the chromatin in these cells revealed aberrations in the levels of several histone modifications involved in DNA damage response pathways. DNA repair assays show that both Msl2(-/-) chicken cells and hMSL2-depleted human cells have defects in non-homologous end joining (NHEJ) repair. DNA damage assays also demonstrate that both Msl2 and hMSL2 proteins are modified and stabilized shortly after induction of DNA damage. Moreover, hMSL2 mediates modification, presumably ubiquitylation, of a key DNA repair mediator 53BP1 at lysine 1690. Similarly, hMSL1 and hMOF (males absent on the first) are modified in the presence of hMSL2 shortly after DNA damage. These data identify a novel role for Msl2/hMSL2 in the cellular response to DNA damage. The kinetics of its stabilization suggests a function early in the NHEJ repair pathway. Moreover, Msl2 plays a role in maintaining normal histone modification profiles, which may also contribute to the DNA damage response.
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Validation of the Chinese version of the Functional Performance Inventory Short Form in patients with chronic obstructive pulmonary disease.
J Clin Nurs
PUBLISHED: 04-18-2011
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To determine the reliability and validity of the Chinese version of the Functional Performance Inventory Short Form (FPI-SF-C) in patients with chronic obstructive pulmonary disease in Beijing, China.
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Intensity-modulated radiation therapy reduces radiation-induced trismus in patients with nasopharyngeal carcinoma: a prospective study with >5 years of follow-up.
Cancer
PUBLISHED: 01-24-2011
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Intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma (NPC) provides better temporomandibular joint (TMJ) sparing and, thus, may reduce the incidence of radiation-induced trismus after radiotherapy. The objectives of this study were to evaluate radiation-induced trismus in patients with NPC who had received IMRT and to assess the pretreatment factors, relevant treatment factors, and dosimetry parameters associated with trismus.
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Molecular mechanisms of "off-on switch" of activities of human IDH1 by tumor-associated mutation R132H.
Cell Res.
PUBLISHED: 10-26-2010
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Human cytosolic NADP-IDH (IDH1) has recently been found to be involved in tumorigenesis. Notably, the tumor-derived IDH1 mutations identified so far mainly occur at Arg132, and mutation R132H is the most prevalent one. This mutation impairs the oxidative IDH activity of the enzyme, but renders a new reduction function of converting ?-ketoglutarate (?KG) to 2-hydroxyglutarate. Here, we report the structures of the R132H mutant IDH1 with and without isocitrate (ICT) bound. The structural data together with mutagenesis and biochemical data reveal a previously undefined initial ICT-binding state and demonstrate that IDH activity requires a conformational change to a closed pre-transition state. Arg132 plays multiple functional roles in the catalytic reaction; in particular, the R132H mutation hinders the conformational changes from the initial ICT-binding state to the pre-transition state, leading to the impairment of the IDH activity. Our results describe for the first time that there is an intermediate conformation that corresponds to an initial ICT-binding state and that the R132H mutation can trap the enzyme in this conformation, therefore shedding light on the molecular mechanism of the "off switch" of the potentially tumor-suppressive IDH activity. Furthermore, we proved the necessity of Tyr139 for the gained ?KG reduction activity and propose that Tyr139 may play a vital role by compensating the increased negative charge on the C2 atom of ?KG during the transfer of a hydride anion from NADPH to ?KG, which provides new insights into the mechanism of the "on switch" of the hypothetically oncogenic reduction activity of IDH1 by this mutation.
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Association of the renin gene polymorphism, three angiotensinogen gene polymorphisms and the haplotypes with essential hypertension in the Mongolian population.
Clin. Exp. Hypertens.
PUBLISHED: 07-29-2010
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Renin is a rate-limiting enzyme of the renin-angiotensin system and plays a crucial role in the regulation of blood pressure (BP). Angiotensinogen (AGT) is the precursor of potent vasoactive hormone angiotensin II and the AGT gene has been incriminated as a marker for genetic predisposition to essential hypertension (EH) in some ethnic groups. The purpose of the study is to explore the association of a new genetic marker of renin gene, and AGT gene M235T, A-6G, and A-20C polymorphisms and their haplotypes with EH in the Mongolian population. On the basis of the prevalence survey, 243 hypertensives and 258 normotensives who had no blood relationship with each other were selected as subjects. All the subjects were interviewed with questionnaires and their blood specimens were collected. Renin gene insertion/ deletion (I/D) polymorphism was genotyped by PCR-polyacrylamide gel electrophoresis. AGT gene M235T, A-6G, and A-20C polymorphisms were genotyped by a PCR-restriction fragment length polymorphism and single-strand conformation polymorphism. The frequencies of renin genotype DD and allele D in hypertensives (36.21%, 63.79%, respectively) were significantly higher than those in normotensives (29.84%, 57.17%, respectively, P < 0.05). The odds ratios (OR) of renin genotype ID, DD to renin genotype II on hypertension were 1.98 (OR 95% CI 1.08-3.72) and 2.51 (OR 95% CI 1.33-4.88), respectively. There were no significant differences in the distributions of genotypes and alleles for AGT gene M235T, A-6G, and A-20C polymorphisms and all different haplotypes between the two groups. Renin gene I/D polymorphism is associated with EH, whereas AGT gene M235T, A-6G, and A-20C polymorphisms and the haplotypes are not associated with EH in the Mongolian population.
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[Reliability and validity of modified pulmonary functional status and dyspnea questionnaire in Chinese patients with chronic obstructive pulmonary disease].
Zhonghua Jie He He Hu Xi Za Zhi
PUBLISHED: 07-22-2010
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To determine the reliability and validity of the modified pulmonary functional status and dyspnea questionnaire (PFSDQ-M) Chinese version in patients with chronic obstructive pulmonary disease (COPD) at 2 hospitals in Beijing, China.
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Silicosis in automobile foundry workers: a 29-year cohort study.
Biomed. Environ. Sci.
PUBLISHED: 06-03-2010
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The purposes were to determine the relationship between silicosis among foundry workers and their cumulative exposure to silica dust, and to establish a regression model to predict the risk for developing silicosis by a given length of employment and air concentrations of silica at worksites.
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[Study on severity, status of awareness and therapy regarding urinary incontinence in elderly people from rural areas in Jixian county, Tianjin].
Zhonghua Liu Xing Bing Xue Za Zhi
PUBLISHED: 03-15-2010
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To understand the prevalence of urinary incontinence (UI) and its severity in rural elderly people, as well as to investigate the awareness on UI in the elderly and health-care service seeking behavior.
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[Study on the relationship between chronic diseases and falls in the elderly].
Zhonghua Liu Xing Bing Xue Za Zhi
PUBLISHED: 10-19-2009
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To explore the risk factors on chronic diseases related to falls in the urban-community elderly and to provide evidence for developing a three-tier program for prevention.
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[Study on the prevalence of urinary incontinence and its related factors among elderly in rural areas, Jixian county, Tianjin].
Zhonghua Liu Xing Bing Xue Za Zhi
PUBLISHED: 10-19-2009
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To understand the prevalence of urinary incontinence (UI) and its related factors so as to develop a three-tier program for prevention of the disease.
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Prevalence and related factors of falls among the elderly in an urban community of Beijing.
Biomed. Environ. Sci.
PUBLISHED: 09-04-2009
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To understand the prevalence, consequences and risk factors of falls among urban community-dwelling elderly in Beijing.
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[Acceptability of vaginal microbicides among female sex workers in urban Beijing, China].
Zhonghua Liu Xing Bing Xue Za Zhi
PUBLISHED: 07-02-2009
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To explore the attitudes and willingness towards vaginal microbicides use among female sex workers (FSWs) for HIV/AIDS and sexually transmitted infection (STI) prevention in an urban district of Beijing, China, as well as its related factors.
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[Factors influencing the rate on retention to methadone maintenance treatment program among heroin addicts in Guizhou, China].
Zhonghua Liu Xing Bing Xue Za Zhi
PUBLISHED: 07-02-2009
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To understand the situation of client-retention to methadone maintenance treatment (MMT) program and related factors.
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Crystal structure of the ARL2-GTP-BART complex reveals a novel recognition and binding mode of small GTPase with effector.
Structure
PUBLISHED: 01-02-2009
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ARL2 is a member of the ADP-ribosylation factor family but has unique biochemical features. BART is an effector of ARL2 that is essential for nuclear retention of STAT3 and may also be involved in mitochondria transport and apoptosis. Here we report the crystal structure and biochemical characterization of human ARL2-GTP-BART complex. ARL2-GTP assumes a typical small GTPase fold with a unique N-terminal alpha helix conformation. BART consists of a six alpha helix bundle. The interactions between ARL2 and BART involve two interfaces: a conserved N-terminal LLXIL motif of ARL2 is embedded in a hydrophobic cleft of BART and the switch regions of ARL2 interact with helix alpha3 of BART. Both interfaces are essential for the binding as verified by mutagenesis study. This novel recognition and binding mode is different from that of other small GTPase-effector interactions and provides molecular basis for the high specificity of ARL2 for BART.
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Fingerprinting and simultaneous determination of alkaloids in Picrasma quassioides from different locations by high performance liquid chromatography with photodiode array detection.
J Sep Sci
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A simple and sensitive method was developed and validated for profiling and simultaneous quantitation of seven alkaloids (6-hydroxy-?-carboline-1-carboxylic acid, ?-carboline-1-carboxylic acid, ?-carboline-1-propanoic acid, 3-methylcanthin-5,6-dione, 5-hydroxy-4-methoxycanthin-6-one, 1-methoxycarbony-?-carboline, and 4,5-dimethoxycanthin-6-one) in Picrasma quassioide grown in different locations by high-performance liquid chromatography with photodiode array detection. The analysis was conducted on a Phenomenex Gemini C(18) column at 35°C with mobile phase of 25 mM aqueous ammonium acetate (pH 4.0, adjusted by glacial acetate acid) and acetonitrile. A common fingerprint chromatograph under 254 nm consisting of 27 peaks was constructed for the evaluation of the similarities among 31 P. quassioide samples. Samples from Guangdong and Guangxi Provinces were found to be within group linkage and showed significant difference from that of Jiangxi Province origin by using principal component analysis and hierarchical clustering analysis. In addition, the seven alkaloids were identified by electrospray ionization mass spectrometry and comparing with reference standards and literature data. All of them were determined simultaneously using the established HPLC method. This rapid and effective analytical method could be employed for quality assessment of P. quassioide, as well as pharmaceutical products containing this herbal material.
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Exposure to 2,5-hexanedione can induce neural malformations in chick embryos.
Neurotoxicology
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Worldwide, n-hexane is an organic solvent widely used in numerous industries such as chemical engineering, pharmaceutical and cosmetic industry. 2,5-Hexanedione (2,5-HD) is the main metabolite of n-hexane. It is now gradually recognized that chronic exposure to n-hexane could harm the health of people. Nevertheless, it is still unclear whether or not 2,5-HD is potentially teratogenic during pregnancies. In this study, we investigated the effects of 2,5-HD exposure on embryonic development in the chick embryo. We first determine the effect of 2,5-HD on neurodevelopment - specifically looking for neural tube defects in the forebrain, midbrain, and also for malformation in the eyes. We established that in the presence of 2,5-HD, the dorsal neural tubes were malformed during the closure of the neural folds. In addition, exposure to 2,5-HD could also inhibit neural differentiation as revealed by immunofluorescent staining for neurofilament (NF). We also demonstrated that the impaired neurodevelopment was attributed to negative effect of 2,5-HD on neurite development and positive effect on apoptosis in developing neurons. Specifically, we found 2,5-HD treatment resulted in fewer neurons and the neurites projecting from the neurons were significantly shorten when compared with control cultures. In addition, MTT and mitochondrial membrane potential (MMP) assays revealed neuron cell viability was reduced by exposure to 2,5-HD in a dose-dependent fashion. In sum, our results suggest that chronic exposure to 2,5-HD is harmful to the developing embryo, especially in the context of neurodevelopment.
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Exploring the caffeine-induced teratogenicity on neurodevelopment using early chick embryo.
PLoS ONE
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Caffeine consumption is worldwide. It has been part of our diet for many centuries; indwelled in our foods, drinks, and medicines. It is often perceived as a "legal drug", and though it is known to have detrimental effects on our health, more specifically, disrupt the normal fetal development following excessive maternal intake, much ambiguity still surrounds the precise mechanisms and consequences of caffeine-induced toxicity. Here, we employed early chick embryos as a developmental model to assess the effects of caffeine on the development of the fetal nervous system. We found that administration of caffeine led to defective neural tube closures and expression of several abnormal morphological phenotypes, which included thickening of the cephalic mesenchymal tissues and scattering of somites. Immunocytochemistry of caffeine-treated embryos using neural crest cell markers also demonstrated uncharacteristic features; HNK1 labeled migratory crest cells exhibited an incontinuous dorsal-ventral migration trajectory, though Pax7 positive cells of the caffeine-treated groups were comparatively similar to the control. Furthermore, the number of neurons expressing neurofilament and the degree of neuronal branching were both significantly reduced following caffeine administration. The extent of these effects was dose-dependent. In conclusion, caffeine exposure can result in malformations of the neural tube and induce other teratogenic effects on neurodevelopment, although the exact mechanism of these effects requires further investigation.
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Caffeine interferes embryonic development through over-stimulating serotonergic system in chicken embryo.
Food Chem. Toxicol.
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The potential harmful effects of caffeine in pregnant women aroused public interests due to its possibility to jeopardize fetal development. Monoamine neurotransmitters are thought to regulate neural development processes through maternal-fetal interactions, which may have long term impact on mental and behavioral effects. The current study focuses on investigating the effects of caffeine on the monoamine neurotransmitter system using developmental chicken embryos. The ED(50) value of caffeine toxicity was 27.3 ?mol/egg in chicken embryo. Administration of caffeine, with lower dosage than ED(50) (2.5, 5.0 and 10.0 ?mol/egg), caused failure of neural tube closure. In addition, contents of 5-HT and its metabolite 5-HIAA were increased under dosage of 10.0 ?mol/egg caffeine administration. Gene expression of TPH2 was also increased by caffeine treatment. Caffeine could result in defect of neural tube closure and induce disorder of serotonergic system development, which may increase teratogenic rate of embryos. Meanwhile, it is probably an underlying factor for inducing psychological and behavioral disorders in adult. Moreover, caffeine was found to be accumulated in the embryonic brain and not being metabolized, which may incur a magnification of adverse effects. This study may provide valuable data for further investigations on toxicology of caffeine during different stages of pregnancy.
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Body mass index and hypertension hemodynamic subtypes in Yi farmers and migrants.
Biomed. Environ. Sci.
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To examine the relationship between overweight or obesity and the risk of the various hypertension hemodynamic subtypes in Yi farmers and migrants.
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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.

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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.