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In JoVE (9)
- Isolation and Expansion of the Adult Mouse Neural Stem Cells Using the Neurosphere Assay
- Establishing Embryonic Mouse Neural Stem Cell Culture Using the Neurosphere Assay
- Neural-Colony Forming Cell Assay: An Assay To Discriminate Bona Fide Neural Stem Cells from Neural Progenitor Cells
- Intraluminal Middle Cerebral Artery Occlusion (MCAO) Model for Ischemic Stroke with Laser Doppler Flowmetry Guidance in Mice
- Isolation and Expansion of Human Glioblastoma Multiforme Tumor Cells Using the Neurosphere Assay
- The Neuroblast Assay: An Assay for the Generation and Enrichment of Neuronal Progenitor Cells from Differentiating Neural Stem Cell Progeny Using Flow Cytometry
- Identification and Isolation of Slow-Dividing Cells in Human Glioblastoma Using Carboxy Fluorescein Succinimidyl Ester (CFSE)
- Endothelin-1 Induced Middle Cerebral Artery Occlusion Model for Ischemic Stroke with Laser Doppler Flowmetry Guidance in Rat
- Utilizing a Cranial Window to Visualize the Middle Cerebral Artery During Endothelin-1 Induced Middle Cerebral Artery Occlusion
Other Publications (12)
- Stem Cells (Dayton, Ohio)
- Neurosurgery
- Brain : a Journal of Neurology
- Methods in Molecular Biology (Clifton, N.J.)
- PloS One
- Journal of Neurointerventional Surgery
- Pain Practice : the Official Journal of World Institute of Pain
- Anatomy & Cell Biology
- Anatomy & Cell Biology
- Anatomy & Cell Biology
- Anatomy & Cell Biology
- Methods in Molecular Biology (Clifton, N.J.)
Articles by Hassan Azari in JoVE
JoVE Neuroscience
Isolation and Expansion of the Adult Mouse Neural Stem Cells Using the Neurosphere Assay
1 Department of Anatomical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran, 2Department of Neurosurgery, University of Florida
This video protocol demonstrates the neurosphere assay method to generate and expand neural stem cells from the adult mouse periventricular region, and provides technical insights to ensure one can achieve reproducible neurosphere cultures.
JoVE Neuroscience
Establishing Embryonic Mouse Neural Stem Cell Culture Using the Neurosphere Assay
1Department of Anatomical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran, 2Department of Neurosurgery, The University of Florida
This video protocol demonstrates the application of the neurosphere assay for the isolation and expansion of neural stem cells from the ganglionic eminences of embryonic day 14-mouse brain.
JoVE Neuroscience
Neural-Colony Forming Cell Assay: An Assay To Discriminate Bona Fide Neural Stem Cells from Neural Progenitor Cells
1Department of Neurosurgery, University of Florida, 2Department of Anatomical Sciences, Shiraz University of Medical Sciences, 3STEMCELL Technologies, Inc.
This video protocol demonstrates how to discriminate and enumerate bona fide neural stem cells in a mixed population of neural precursor cells using the neural colony-forming cell assay.
JoVE Clinical and Translational Medicine
Intraluminal Middle Cerebral Artery Occlusion (MCAO) Model for Ischemic Stroke with Laser Doppler Flowmetry Guidance in Mice
1Department of Neurosurgery, University of Florida, 2Department of Anatomical Sciences, Shiraz University of Medical Sciences
The intraluminal middle cerebral artery occlusion (MCAO) model is the most frequent used model among experimental ischemic stroke models. Here we will demonstrate the entire model in detail with the guide of Laser Doppler flowmetry, and its representative results.
JoVE Neuroscience
Isolation and Expansion of Human Glioblastoma Multiforme Tumor Cells Using the Neurosphere Assay
1Department of Neurosurgery, University of Florida, 2Department of Anatomical Sciences, Shiraz University of Medical Sciences
This video protocol demonstrates the isolation and expansion of stem like cells from surgically resected human glioblastoma mutliforme (GBM) tumor tissue using the neurosphere assay culture method.
JoVE Neuroscience
The Neuroblast Assay: An Assay for the Generation and Enrichment of Neuronal Progenitor Cells from Differentiating Neural Stem Cell Progeny Using Flow Cytometry
1Department of Neurosurgery, The University of Florida, 2Laboratory for Stem Cell Research, Department of Anatomical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
This video protocol demonstrates a novel method for the generation and subsequent purification of neuronal progenitor cells from a renewable source of neural stem cells (NSCs) based on their physical (size and internal granularity) and fluorescent properties using flow cytometry technology.
JoVE Clinical and Translational Medicine
Identification and Isolation of Slow-Dividing Cells in Human Glioblastoma Using Carboxy Fluorescein Succinimidyl Ester (CFSE)
1Department of Neurosurgery, The University of Florida, 2Department of Anatomical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
This video protocol demonstrates the application of the fluorescent dye carboxyfluorescein succinimidyl ester (CFSE) for the identification and separation of different sub-populations of cells in human glioblastoma based on frequency of cell division.
JoVE Clinical and Translational Medicine
Endothelin-1 Induced Middle Cerebral Artery Occlusion Model for Ischemic Stroke with Laser Doppler Flowmetry Guidance in Rat
1Department of Neurosurgery, University of Florida, 2Department of Anatomical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran, 3Department of Physiology and Functional Genomics, University of Florida, 4Department of Neurology, University of Florida
Several animal models of cerebral ischemia have been developed to simulate the human condition of stroke. This protocol describes the endothelin-1 (ET-1) induced middle cerebral artery occlusion (MCAO) model for ischemic stroke in rats. In addition, important considerations, advantages, and shortcomings of this model are discussed.
JoVE Clinical and Translational Medicine
Utilizing a Cranial Window to Visualize the Middle Cerebral Artery During Endothelin-1 Induced Middle Cerebral Artery Occlusion
1Department of Physiology and Functional Genomics, University of Florida, 2Department of Neurosurgery, McKnight Brain Institute, University of Florida, 3Department of Anatomical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
This article describes a method for visualizing rat cerebral arteries through a cranial window using temporal craniectomy in order to view proximal portions of the middle cerebral artery (Figure 1). This versatile method can be combined with various techniques of drug delivery to measure cerebral artery reactivity in vivo.
Other articles by Hassan Azari on PubMed
Comparative Analysis of the Frequency and Distribution of Stem and Progenitor Cells in the Adult Mouse Brain
The neurosphere assay can detect and expand neural stem cells (NSCs) and progenitor cells, but it cannot discriminate between these two populations. Given two assays have purported to overcome this shortfall, we performed a comparative analysis of the distribution and frequency of NSCs and progenitor cells detected in 400 mum coronal segments along the ventricular neuraxis of the adult mouse brain using the neurosphere assay, the neural colony forming cell assay (N-CFCA), and label-retaining cell (LRC) approach. We observed a large variation in the number of progenitor/stem cells detected in serial sections along the neuraxis, with the number of neurosphere-forming cells detected in individual 400 mum sections varying from a minimum of eight to a maximum of 891 depending upon the rostral-caudal coordinate assayed. Moreover, the greatest variability occurred in the rostral portion of the lateral ventricles, thereby explaining the large variation in neurosphere frequency previously reported. Whereas the overall number of neurospheres (3730 +/- 276) or colonies (4275 +/- 124) we detected along the neuraxis did not differ significantly, LRC numbers were significantly reduced (1186 +/- 188, 7 month chase) in comparison to both total colonies and neurospheres. Moreover, approximately two orders of magnitude fewer NSC-derived colonies (50 +/- 10) were detected using the N-CFCA as compared to LRCs. Given only 5% of the LRCs are cycling (BrdU+/Ki-67+) or competent to divide (BrdU+/Mcm-2+), and proliferate upon transfer to culture, it is unclear whether this technique selectively detects endogenous NSCs. Overall, caution should be taken with the interpretation and employment of all these techniques.
The Cancer Stem Cell Hypothesis: Failures and Pitfalls
Based on the clonal evolution model and the assumption that the vast majority of tumor cells are able to propagate and drive tumor growth, the goal of cancer treatment has traditionally been to kill all cancerous cells. This theory has been challenged recently by the cancer stem cell (CSC) hypothesis, that a rare population of tumor cells, with stem cell characteristics, is responsible for tumor growth, resistance, and recurrence. Evidence for putative CSCs has been described in blood, breast, lung, prostate, colon, liver, pancreas, and brain. This new hypothesis would propose that indiscriminate killing of cancer cells would not be as effective as selective targeting of the cells that are driving long-term growth (ie, the CSCs) and that treatment failure is often the result of CSCs escaping traditional therapies.The CSC hypothesis has gained a great deal of attention because of the identification of a new target that may be responsible for poor outcomes of many aggressive cancers, including malignant glioma. As attractive as this hypothesis sounds, especially when applied to tumors that respond poorly to current treatments, we will argue in this article that the proposal of a stemlike cell that initiates and drives solid tissue cancer growth and is responsible for therapeutic failure is far from proven. We will present the point of view that for most advanced solid tissue cancers such as glioblastoma multiforme, targeting a putative rare CSC population will have little effect on patient outcomes. This review will cover problems with the CSC hypothesis, including applicability of the hierarchical model, inconsistencies with xenotransplantation data, and nonspecificity of CSC markers.
Evidence for Label-retaining Tumour-initiating Cells in Human Glioblastoma
Individual tumour cells display diverse functional behaviours in terms of proliferation rate, cell-cell interactions, metastatic potential and sensitivity to therapy. Moreover, sequencing studies have demonstrated surprising levels of genetic diversity between individual patient tumours of the same type. Tumour heterogeneity presents a significant therapeutic challenge as diverse cell types within a tumour can respond differently to therapies, and inter-patient heterogeneity may prevent the development of general treatments for cancer. One strategy that may help overcome tumour heterogeneity is the identification of tumour sub-populations that drive specific disease pathologies for the development of therapies targeting these clinically relevant sub-populations. Here, we have identified a dye-retaining brain tumour population that displays all the hallmarks of a tumour-initiating sub-population. Using a limiting dilution transplantation assay in immunocompromised mice, label-retaining brain tumour cells display elevated tumour-initiation properties relative to the bulk population. Importantly, tumours generated from these label-retaining cells exhibit all the pathological features of the primary disease. Together, these findings confirm dye-retaining brain tumour cells exhibit tumour-initiation ability and are therefore viable targets for the development of therapeutics targeting this sub-population.
Isolation and Characterization of Adult Neural Stem Cells
It has been thought for a long time that the adult brain is incapable of generating new neurons, or that neurons cannot be added to its complex circuitry. However, recent technology has resulted in an explosion of research demonstrating that neurogenesis, or the birth of new neurons from adult stem cells constitutively occurs in two specific regions of the mammalian brain; namely the subventricular zone and hippocampal dentate gyrus. Adult CNS stem cells exhibit three main characteristics: (1) they are "self-renewing," i.e., they possess a theoretically unlimited ability to produce progeny indistinguishable from themselves, (2) they are proliferative (undergoing mitosis) and (3) they are multipotent for the different neuroectodermal lineages of the CNS, including the different neuronal, and glial subtypes. CNS stem cells and all progenitor cell types are broadly termed "precursors." In this chapter, we describe methods to identify, isolate and experimentally manipulate stem cells of the adult brain. We outline how to prepare a precursor cell culture from naive brain tissue and how to test the "stemness" potential of different cell types present in that culture, which is achieved in a three-step paradigm. Following their isolation, stem/progenitor cells are expanded in neurosphere culture. Single cells obtained from these neurospheres are sorted for the expression of surface markers by flow cytometry. Finally, putative stem cells from cell sorting will be subjected to the so-called neural colony-forming cell assay, which allows discrimination between stem and progenitor cells. At the end of this chapter we will also describe how to identify neural stem cells in vivo.
Purification of Immature Neuronal Cells from Neural Stem Cell Progeny
Large-scale proliferation and multi-lineage differentiation capabilities make neural stem cells (NSCs) a promising renewable source of cells for therapeutic applications. However, the practical application for neuronal cell replacement is limited by heterogeneity of NSC progeny, relatively low yield of neurons, predominance of astrocytes, poor survival of donor cells following transplantation and the potential for uncontrolled proliferation of precursor cells. To address these impediments, we have developed a method for the generation of highly enriched immature neurons from murine NSC progeny. Adaptation of the standard differentiation procedure in concert with flow cytometry selection, using scattered light and positive fluorescent light selection based on cell surface antibody binding, provided a near pure (97%) immature neuron population. Using the purified neurons, we screened a panel of growth factors and found that bone morphogenetic protein-4 (BMP-4) demonstrated a strong survival effect on the cells in vitro, and enhanced their functional maturity. This effect was maintained following transplantation into the adult mouse striatum where we observed a 2-fold increase in the survival of the implanted cells and a 3-fold increase in NeuN expression. Additionally, based on the neural-colony forming cell assay (N-CFCA), we noted a 64 fold reduction of the bona fide NSC frequency in neuronal cell population and that implanted donor cells showed no signs of excessive or uncontrolled proliferation. The ability to provide defined neural cell populations from renewable sources such as NSC may find application for cell replacement therapies in the central nervous system.
Impact of Intracranial Self-expanding Stents in the Treatment of Acute Ischemic Stroke: Efficacy and Limitations
In recent years, endovascular self-expanding stents have become a viable option for neurointerventionalists treating acute ischemic stroke. Timely intervention for stroke could mean the difference between complete recovery and significant morbidity or death. Since 2006, a handful of clinical trials have demonstrated the potential of self-expanding stents in dependably achieving quick revascularization. These devices are expanding in utilization as new designs offer greater procedural flexibility and better clinical results. We discuss these clinical investigations, focusing on the procedural capabilities and limitations of each self-expanding stent design.
The Peridural Membrane of the Spinal Canal: A Critical Review
There exists substantial evidence that a peridural membrane (PM) is present in the spinal canal of humans and, like the pleura and peritoneum, has one or more physiologic functions. Innervation of the PM suggests that it may become a source of pain if injured. Although debated, the physiology of this structure has important implications with respect to neuraxial distribution of drugs and for back and radiating pain. This review, separated into embryological, anatomic, and physiologic discussions, provides an in-depth summary of the observations of this connective tissue. The discrepancies between accounts are highlighted within each section. Focused research to clearly elucidate the true nature of the PM, especially as related to neuraxial distribution of drugs and back and radiating pain, is warranted.▪
A Simple Technique for Morphological Measurement of Cerebral Arterial Circle Variations Using Public Domain Software (Osiris)
This article describes a straightforward method to measure the dimensions and identify morphological variations in the cerebral arterial circle using the general-purpose software program Osiris. This user-friendly and portable program displays, manipulates, and analyzes medical digital images, and it has the capability to determine morphometric properties of selected blood vessels (or other anatomical structures) in humans and animals. To ascertain morphometric variations in the cerebral arterial circle, 132 brains of recently deceased fetuses, infants, and adults were dissected. The dissection procedure was first digitized, and then the dimensions were measured with Osiris software. Measurements of each vessel's length and external diameters were used to identify and classify morphological variations in the cerebral arterial circle. The most commonly observed anatomical variations were uni- and bilateral hypoplasia of the posterior communicating artery. This study demonstrates that public domain software can be used to measure and classify cerebral arterial circle vessels. This method could be extended to examine other anatomical regions or to study other animals. Additionally, knowledge of variations within the circle could be applied clinically to enhance diagnostic and treatment specificity.
Abnormal Patterns of the Renal Veins
Knowledge of the renal vascular anatomy may greatly contribute to the success of surgical, invasive and radiological procedures of the retroperitoneal region. Here, morphometric and histological studies of a human cadaveric specimen presented a complex, anomalous pattern of renal veins. The left renal vein had an oblique retro-aortic course and received two lumbar veins. It bifurcated near its drainage point into the inferior vena cava. The right renal vein received the right testicular vein. In addition, the left kidney was located at a low position. The spleen was enlarged. The present case is unique and provides information that may help surgeons or angiologists to apply safer interventions.
Coexistence of Multiple Anomalies in the Hepatobiliary System
The co-occurrence of several anomalies in the hepatobiliary system is uncommon. In the present study, hepatic lobe anomalies occurring in combination with hepatic artery and biliary variations were observed in an adult male cadaver. There are no previous reports in the literature on the coexistence of such anatomical variations. Preoperative diagnosis of such coexisting anomalies is very difficult. Hence, a thorough knowledge of these variations will enable surgeons to select the most appropriate hepatobiliary surgical procedure and postoperative management.
Effects of High-fat Diet on the Numerical Density and Number of Neuronal Cells and the Volume of the Mouse Hypothalamus: a Stereological Study
It has been demonstrated that the type of diet affects the brain structure and function. Consumption of fat-rich food is one of the most important factors that lead to increase in the prevalence of cardiovascular and neurological diseases. High-fat diet may change the volume and neuronal number or density in the hypothalamus, which is the center of energy control. Therefore, this study was designed to study the effect of high-fat diet on the density and number of neurons, and also the volume of hypothalamus in adult male mice. Forty male mice were divided into the control and experimental groups. The control group were fed with standard and the experimental groups, with high-fat diet for 4 (short-term) or 8 (long-term) weeks. The animals were perfused and brains were immediately removed, post-fixed and cut coronally and serially using cryostat at 30-µm thickness. Every 6th sections were stained by cresyl violet. The numerical density and number of neuron and the volume of hypothalamus were estimated by using unbiased stereological methods. Data analysis showed that both short and long time consumption of high-fat diet decreased the neuronal cell density of the hypothalamus. Interestingly, despite a decrease in the neuronal cell density, long time consumption of high-fat diet could significantly increase the volume of hypothalamus (P<0.05). High fat diet decreased the neuronal cell density and increased the volume of the hypothalamus, but it did not significantly change its total neurons. These changes might be due to an increase in the extracellular space through inflammation or gliosis in the hypothalamus.
Qualitative Versus Quantitative Methods in Psychiatric Research
Qualitative studies are gaining their credibility after a period of being misinterpreted as "not being quantitative." Qualitative method is a broad umbrella term for research methodologies that describe and explain individuals' experiences, behaviors, interactions, and social contexts. In-depth interview, focus groups, and participant observation are among the qualitative methods of inquiry commonly used in psychiatry. Researchers measure the frequency of occurring events using quantitative methods; however, qualitative methods provide a broader understanding and a more thorough reasoning behind the event. Hence, it is considered to be of special importance in psychiatry. Besides hypothesis generation in earlier phases of the research, qualitative methods can be employed in questionnaire design, diagnostic criteria establishment, feasibility studies, as well as studies of attitude and beliefs. Animal models are another area that qualitative methods can be employed, especially when naturalistic observation of animal behavior is important. However, since qualitative results can be researcher's own view, they need to be statistically confirmed, quantitative methods. The tendency to combine both qualitative and quantitative methods as complementary methods has emerged over recent years. By applying both methods of research, scientists can take advantage of interpretative characteristics of qualitative methods as well as experimental dimensions of quantitative methods.
