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Source ABC7, 24 November 2009 An initial single-arm Phase II trial (ACT II) has reported promising preliminary data in 23 patients who received CDX-110 vaccine. Median time to disease progression was 16.6 months and estimated median overall survival was 33.1 months. This compared favorably with data for a historical control group in which median time to progression was 6.4 months and median overall survival was 15.2 months. The study was sponsored by Celldex Therapeutics Inc. of Phillipsburg, NJ
Learn about electromagnetic navigation diagnostic bronchoscopy, a new technology used to diagnose small lung cancer tumors as small as a pencil eraser before they have the chance to spread. Cleveland Clinic physician Dr. Thomas Gildea demonstrates how this endobronchial ultrasound procedure, which involves using a small camera probe inserted thru the nose into the lungs, allows doctors to reach possible cancer in the lungs that they could never reliably get to before
Recurrent varicose veins are a common problem. The patient in this video was operated for great saphenous vein insufficiency and a “neocrosse” occurred after few years. Surgical exploration revealed a “cavernoma” just over the nodes of the crural area, feeding varicose veins of thigh and leg.
The 3rd Annual W. B. Ingalls Memorial
Prostate Health and Cancer Seminar features nationally renowned physicians and scientists presenting the most current study and practices for the diagnosis and treatment of prostate cancer. This day-long program offers in-depth exploration of prostate issues that range from monitoring PSA counts to cutting-edge research to current treatment trends.
Neurotransmitter 3D Animation
on Tuesday, December 21, 2010
Neurotransmitters are endogenous chemicals which transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to receptors in the membrane on the postsynaptic side of the synapse. Release of neurotransmitters usually follows arrival of an action potential at the synapse, but may also follow graded electrical potentials. Low level "baseline" release also occurs without electrical stimulation. Neurotransmitters are synthesized from plentiful and simple precursors, such as amino acids, which are readily available from the diet and which require only a small number of biosynthetic steps to convert. The chemical identity of neurotransmitters is often difficult to determine experimentally. For example, it is easy using an electron microscope to recognize vesicles on the presynaptic side of a synapse, but it may not be easy to determine directly what chemical is packed into them. The difficulties led to many historical controversies over whether a given chemical was or was not clearly established as a transmitter. In an effort to give some structure to the arguments, neurochemists worked out a set of experimentally tractable rules. According to the prevailing beliefs of the 1960s, a chemical can be classified as a neurotransmitter if it meets the following conditions: * There are precursors and/or synthesis enzymes located in the presynaptic side of the synapse. * The chemical is present in the presynaptic element. * It is available in sufficient quantity in the presynaptic neuron to affect the postsynaptic neuron; * There are postsynaptic receptors and the chemical is able to bind to them. * A biochemical mechanism for inactivation is present. There are many different ways to classify neurotransmitters. Dividing them into amino acids, peptides, and monoamines is sufficient for some classification purposes. Major neurotransmitters: * Amino acids: glutamate, aspartate, D-serine, γ-aminobutyric acid (GABA), glycine * Monoamines and other biogenic amines: dopamine (DA), norepinephrine (noradrenaline; NE, NA), epinephrine (adrenaline), histamine, serotonin (SE, 5-HT), melatonin * Others: acetylcholine (ACh), adenosine, anandamide, nitric oxide, etc. In addition, over 50 neuroactive peptides have been found, and new ones are discovered regularly. Many of these are "co-released" along with a small-molecule transmitter, but in some cases a peptide is the primary transmitter at a synapse. β-endorphin is a relatively well known example of a peptide neurotransmitter; it engages in highly specific interactions with opioid receptors in the central nervous system. Single ions, such as synaptically released zinc, are also considered neurotransmitters by some[by whom?], as are some gaseous molecules such as nitric oxide (NO) and carbon monoxide (CO). These are not classical neurotransmitters by the strictest definition, however, because although they have all been shown experimentally to be released by presynaptic terminals in an activity-dependent way, they are not packaged into vesicles. By far the most prevalent transmitter is glutamate, which is excitatory at well over 90% of the synapses in the human brain. The next most prevalent is GABA, which is inhibitory at more than 90% of the synapses that do not use glutamate. Even though other transmitters are used in far fewer synapses, they may be very important functionally—the great majority of psychoactive drugs exert their effects by altering the actions of some neurotransmitter systems, often acting through transmitters other than glutamate or GABA. Addictive drugs such as cocaine and amphetamine exert their effects primarily on the dop