Sphingolipids and the CNS
Sphingolipids encompass a complex range of membrane lipids in which a fatty acid is linked to a long sphingosine carbon backbone, primarily C18-sphinganine (18:0) and C18-sphingosine (C18:1) in mammals. Figure 1 shows a schematic representation of the sphingolipid metabolic pathway. Ceramide is central in sphingolipid metabolism and is produced by de novo and recycling pathways.37 In de novo synthesis, serine and palmitoyl-CoA are substrates of serine palmitoyl-transferase (SPT), the rate limiting enzyme that generates ketosphinganine (bottom). Ketosphinganine is reduced to form sphinganine, which is then N-acylated with fatty acids of different chain lengths by ceramide synthases (CerS), producing dihydroceramides.
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Thus, CerS determine the acyl chain length of sphingolipids, including ceramides, sphingomyelin and glycosphingolipids. The six CerS are differently expressed among tissues and cell types, yielding to distinct sphingolipids-acyl chain length profiles for each cell/tissue. As an example, in the brain, CerS1 (which targets C18 acyl-chains) is distributed primarily in neurons, whereas CerS2, responsible for the synthesis of C22-C24 acyl-chain sphingolipids, is expressed specifically in oligodendrocytes and Schwann cells.38 The next step in de novo synthesis is the desaturation of dihydro-ceramides to generate ceramides, by the dihydroceramide desaturase (DES). Ceramides can be further metabolized to sphingomyelin, by the addition of a phosphocholine head group from phosphatidyl-choline by the sphingomyelin synthases, or to glycosphingolipids, by the addition of a sugar group. Serine-palmitoyl transferase can alternatively utilize alanine instead of serine resulting in the synthesis of deoxyceramides, which …show more content…
They exert a wide range of functions in neuronal/glial proliferation, differentiation and apoptosis, as well as in maintaining the membrane permeability to ions and in the stabilization of synaptic transporters and receptors, the latest processes relevant to the generation and propagation of the nervous impulse and synaptic transmission.20,39,40 Moreover, cell and animal models underscore the key function of sphingolipids in the neurite growth and myelination of the cerebellum and forebrain, among other brain regions.41,42 Deficiency of ceramide synthase-2 that generates sphingolipids with C22-C24 fatty acyl chains results in 50% loss of compacted myelin and 80% loss of CNS myelin basic protein.42 Similarly, a 60% reduction of myelin-associated glycoprotein in the cerebellum and forebrain characterizes mice deficient in ceramide synthase-1, the enzyme that generates C18:0 sphingolipids.41 Interestingly, mice deficient of ceramide synthase -6, which generates C16:0 sphingolipids, as well as mice deficient of GM3 synthase that is responsible for one of the first steps in the production of gangliosides, both present hyperactive behavior and have been postulated as suitable animal models for
Dr. Colleen Winters – BIO 655 Vishall G. Kaistha TITLE: “Recombination-Directed DNA Repair Promote Homologous Stimulating Transcription of Genes That That Preserves Genomic Integrity by MEN1 Is a Melanoma Tumor Suppressor”.
Medical biller is a position that will require you to take in medical claims and code them and bill out medical claims to insurance companies, Medicare and Medicaid on a daily basis. You will have to reconcile Explanation of Benefits (EOB) weekly. Verify if insurance companies require that patients get PA for certain procedure and products. Five requirements for Medical Biller position 1. How to bill claims 2.
The Effect of Exercise on the Cell Continuity of Betta Splendens Keerthana Arjuna Joe Gibson George Washington High School Abstract The objective of ted this experiment was to observe how exercise would affect the cell continuity of betta splendens’ muscle cells. To conduct this experiment, three fish were put under three different amounts of exercise for fourteen days. After fourteen days, the fish were euthanized and tissue samples were obtained. The tissue samples were stained with acid fuchsin.
Unknown Lab Report Unknown # 25 By: Jenna Riordan March 19, 2018 Bio 2843 1. Introduction Microbiology is the study of microorganisms found in all different environments throughout Earth, from the hot thermal vents at the bottom of the ocean to the ice at the top of a mountain.
Tn 4351 was originally isolated from bacteroides fragilis [30] . The transposon was successfully introduced into Cytophaga succinicans, Flavobacterium meningosepticum, Flexibacter canadiansis, Flexibacter strain SFI and Sporocytophaga myxococcoides by conjugation [25]. Tn 4351carries two antibiotic resistance gene. One of the codes for resistance to erythromycin and clindamycin which is expressed in bactroides but not in E.Coli. The other gene codes for resistance in tetracycline and is expressed in aerobically grpwn E. coli, but not in anaerobically grpwn E. coli or in bacteroides.
In this three-week long experiment conducted in the Bio 13 Lab, we were able to analyze a single nucleotide polymorphism (SNP) in our own genomic DNA and then determine our genotype at this specific SNP. In week one, we extracted genomic DNA from our cheek cells with swabs and prepared our DNA for PCR (Polymerase Chain Reaction) that would amplify the region with the intended SNP of interest. After one week and after the PCR was run outside of the lab section, the resulting PCR product was purified and treated with restriction enzyme Ahdl in order to prepare for the final analysis of our genotypes. In the third and final week of the project, we analyzed our PCR products by means of agarose gel electrophoresis. By the conclusion of the experiment, we had completed the analysis at the SNP of interest and determined our genotypes for this SNP.
Introduction The purpose of this lab is to use control variables to help identify different macromolecules. Biological systems are made up of these four major macromolecules: carbohydrates, lipids, proteins and nucleic acids. Carbohydrates are sugar molecules (monosaccharides, disaccharides, and polysaccharides) which make them the most abundant macromolecule on the earth. Lipids (oils and fats, phospholipids and steroids) are insoluble in water and perform many functions such as energy source, essential nutrients, hormones and insulators (Lehman, 1955).
David Lynn (Emory University), which helps the audience to have a good knowledge of the structures and forces during the supramolecular self-assembly process, and understand how the chemical information will be stored and translated into the new molecules in this process. His talk mainly focused on the mutant peptides of Aβ Amyloid protein that is well-known to be responsible for Alzheimer’s disease. By characterizing the properties of self-assembly of different pieces of peptides from Aβ Amyloid protein, he showed that this sequence specificity played an important role in self-assembly of these mutant peptides in vitro. In addition, I think he clearly explained the design of an in vivo genetic assay that is based on the use of the yeast prion, the Sup35 of S. cereviseiae. They studied the mechanism of this supramolecular self-assembly process according to the score able phenotype with this in vivo assay.
ROS are produced by metabolic processes in the body (Oxidative Stress, 2014). In aerobic metabolism the mitochondria uses about 90% of oxygen—this means that the mitochondria are most responsible for the production of ROS (Barber, S. C., Meade, R. J., & Shaw, P. J.,2006). The over abundance of intracellular Ca2+ levels in the neuron is closely linked with oxidative stress. Excessive intracellular Ca2+ are not only responsible for the swelling and death of neurons, but it also is one of the causes of the production of ROS. When ROS are over produced they cause the inhibition of glutamate uptake through EEA2 transporters, hence the vicious cycle of excitotoxicity.
My doctor said my vital signs showed I had a normal temperature of 98.6, a blood pressure of 140/90, a heart rate of 100, and an oxygen level of 80%. I took multiple tests, such as a chest examination where my doctor used a stethoscope to listen to my chest. Apparently I have crepitation’s. He can also hear me wheeze, and that it is clear I have difficulty breathing. I also took a spirometry test.
Experiment #7: Column Chromatography of Food Dye Arianne Jan D. Tuozo Mr. Carlos Edward B. Santos October 12, 2015 Abstract Column chromatography is the separation of mixture’s components through a column. Before proceeding with the column chromatography itself, a proper solvent system must be chosen among the different solvents. The green colored food dye is the mixture whose components are separated.
This forms an oxyiminium ion as an intermediate that eventually undergoes intramolecular C-C bond with indole nucleophile to form an oxacarboline product. As compared to the oxime and hydrazone conjugates, the oxacarbolines are very much stable towards the hydrolysis under physiological relevant conditions as depicted by their experiment. In order to use this strategy for site specific chemical modification of formylglycine and glyoxalglycine-functionalized, they use an aldehyde-tagged variant of the Herceptin( a therapeutic monoclonal antibody). All the experiments performed by them showed that the Pictet-spengler reaction has a bright future in the research for the
INTRODUCTION: Lipase also called as triacylglycerol acylhydrolaseis an enzyme known for its enormous applications for industry and diagnostics. Their basic activity is to convert fats into fatty acids and glycerol. These enzymes are water soluble in nature. They also convert polar solvents into more lipolytic substances.
Biochemical tests are the tests used for the identification of bacterial species based on the differences in the biochemical activities of different bacteria. Bacterial physiology differs from one species to the other. These differences in carbohydrate metabolism, protein metabolism, fat metabolism, production of certain enzymes and ability to utilize a particular compound help them to be identified by the biochemical tests. Gram’s stain was originally devised by histologist Hans Christian Gram in 1884. Gram-positive bacteria stain purple, while Gram-negative bacteria stain pink when subjected to Gram staining.
They may also be prepared from amphiphilic ionic molecules which are negatively charged or positively charged stearylamine. Niosomes are very much like liposomes in their physical characteristics but they differ in their chemical compositions. Niosomes in the form of micelles or vesicles can be used as carriers for the transport of drugs such as anticancer and topical preparations. Anticancer niosomes do accumulate in tumor cells and are mostly taken up by the liver therefore they can be used as drug delivery vehicles to the liver and spleen. Antigens were formulated as niosomes in water in oil emulsions which increases the activity of the antigens due it's controlled release