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Superficial Siderosis
Superficial hemosiderosis of the central nervous system is a disease of the brain resulting from chronic iron deposition in neuronal tissues associated with cerebrospinal fluid. This occurs via the deposition of hemosiderin in neuronal tissue, and is associated with neuronal loss, gliosis, and demyelination of neuronal cells. This disease was first discovered in 1908 by R.C. Hamill after performing an autopsy. Detection of this disease was largely post-mortem until the advent of MRI technology, which made diagnosis far easier. Superficial siderosis is largely considered a rare disease, with less than 270 total reported cases in scientific literature as of 2006, and affects people of a wide range of ages with men being approximately three times more frequently affected than women. The number of reported cases of superficial siderosis has increased with advances in MRI technology, but it remains a rare disease. Symptoms Superficial siderosis is characterized by many symptoms result ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemosiderosis
Hemosiderosis is a form of iron overload disorder resulting in the accumulation of hemosiderin. Types include: * Transfusion hemosiderosis * Idiopathic pulmonary hemosiderosis * Transfusional diabetes Organs affected: * Hemosiderin deposition in the lungs is often seen after diffuse alveolar hemorrhage, which occurs in diseases such as Goodpasture's syndrome, granulomatosis with polyangiitis, and idiopathic pulmonary hemosiderosis. Mitral stenosis can also lead to pulmonary hemosiderosis. * Hemosiderin collects throughout the body in hemochromatosis. * Hemosiderin deposition in the liver is a common feature of hemochromatosis and is the cause of liver failure in the disease. * Selective iron deposition in the beta cells of pancreatic islets leads to diabetes due to distribution of transferrin receptor on the beta cells of islets and in the skin leads to hyperpigmentation. * Hemosiderin deposition in the brain is seen after bleeds from any source, including chron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subarachnoid Hemorrhage
Subarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space—the area between the arachnoid membrane and the pia mater surrounding the brain. Symptoms may include a severe headache of rapid onset, vomiting, decreased level of consciousness, fever, and sometimes seizures. Neck stiffness or neck pain are also relatively common. In about a quarter of people a small bleed with resolving symptoms occurs within a month of a larger bleed. SAH may occur as a result of a head injury or spontaneously, usually from a ruptured cerebral aneurysm. Risk factors for spontaneous cases include high blood pressure, smoking, family history, alcoholism, and cocaine use. Generally, the diagnosis can be determined by a CT scan of the head if done within six hours of symptom onset. Occasionally, a lumbar puncture is also required. After confirmation further tests are usually performed to determine the underlying cause. Treatment is by prompt neurosurgery or endovascular coiling. Medic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brainstem
The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is continuous with the thalamus of the diencephalon through the tentorial notch, and sometimes the diencephalon is included in the brainstem. The brainstem is very small, making up around only 2.6 percent of the brain's total weight. It has the critical roles of regulating cardiac, and respiratory function, helping to control heart rate and breathing rate. It also provides the main motor and sensory nerve supply to the face and neck via the cranial nerves. Ten pairs of cranial nerves come from the brainstem. Other roles include the regulation of the central nervous system and the body's sleep cycle. It is also of prime importance in the conveyance of motor and sensory pathways from the rest of the brain to the body, and from the bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Lobes
The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe is involved in processing sensory input into derived meanings for the appropriate retention of visual memory, language comprehension, and emotion association. ''Temporal'' refers to the head's temples. Structure The temporal lobe consists of structures that are vital for declarative or long-term memory. Declarative (denotative) or explicit memory is conscious memory divided into semantic memory (facts) and episodic memory (events). Medial temporal lobe structures that are critical for long-term memory include the hippocampus, along with the surrounding hippocampal region consisting of the perirhinal, parahippocampal, and entorhinal neocortical regions. The hippocampus is critical for memory formation, and the surrounding medial temporal cortex is curr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schwann Cells
Schwann cells or neurolemmocytes (named after German physiologist Theodor Schwann) are the principal glia of the peripheral nervous system (PNS). Glial cells function to support neurons and in the PNS, also include satellite cells, olfactory ensheathing cells, enteric glia and glia that reside at sensory nerve endings, such as the Pacinian corpuscle. The two types of Schwann cells are myelinating and nonmyelinating. Myelinating Schwann cells wrap around axons of motor and sensory neurons to form the myelin sheath. The Schwann cell promoter is present in the downstream region of the human dystrophin gene that gives shortened transcript that are again synthesized in a tissue-specific manner. During the development of the PNS, the regulatory mechanisms of myelination are controlled by feedforward interaction of specific genes, influencing transcriptional cascades and shaping the morphology of the myelinated nerve fibers. Schwann cells are involved in many important aspects of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthochromia
Xanthochromia, from the Greek ''xanthos'' (ξανθός) "yellow" and ''chroma'' (χρώμα) "colour", is the yellowish appearance of cerebrospinal fluid that occurs several hours after bleeding into the subarachnoid space caused by certain medical conditions, most commonly subarachnoid hemorrhage. Its presence can be determined by either spectrophotometry (measuring the absorption of particular wavelengths of light) or simple visual examination. It is unclear which method is superior. Physiology Cerebrospinal fluid, which fills the subarachnoid space between the arachnoid membrane and the pia mater surrounding the brain, is normally clear and colorless. When there has been bleeding into the subarachnoid space, the initial appearance of the cerebrospinal fluid can range from barely tinged with blood to frankly bloody, depending on the extent of bleeding. Within several hours, the red blood cells in the cerebrospinal fluid are destroyed, releasing their oxygen-carrying molecule he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferritin
Ferritin is a universal intracellular protein that stores iron and releases it in a controlled fashion. The protein is produced by almost all living organisms, including archaea, bacteria, algae, higher plants, and animals. It is the primary ''intracellular iron-storage protein'' in both prokaryotes and eukaryotes, keeping iron in a soluble and non-toxic form. In humans, it acts as a buffer against iron deficiency and iron overload. Ferritin is found in most tissues as a cytosolic protein, but small amounts are secreted into the serum where it functions as an iron carrier. Plasma ferritin is also an indirect marker of the total amount of iron stored in the body; hence, serum ferritin is used as a diagnostic test for iron-deficiency anemia. Aggregated ferritin transforms into a toxic form of iron called hemosiderin. Ferritin is a globular protein complex consisting of 24 protein subunits forming a hollow nanocage with multiple metal–protein interactions. Ferritin th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biliverdin
Biliverdin (latin for green bile) is a green tetrapyrrolic bile pigment, and is a product of heme catabolism.Boron W, Boulpaep E. Medical Physiology: a cellular and molecular approach, 2005. 984-986. Elsevier Saunders, United States. It is the pigment responsible for a greenish color sometimes seen in bruises. Metabolism Biliverdin results from the breakdown of the heme moiety of hemoglobin in erythrocytes. Macrophages break down senescent erythrocytes and break the heme down into biliverdin along with hemosiderin, in which biliverdin normally rapidly reduces to free bilirubin. Biliverdin is seen briefly in some bruises as a green color. In bruises, its breakdown into bilirubin leads to a yellowish color. Role in disease Biliverdin has been found in excess in the blood of humans suffering from hepatic diseases. Jaundice is caused by the accumulation of biliverdin or bilirubin (or both) in the circulatory system and tissues. Jaundiced skin and sclera (whites of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heme Oxygenase 1
''HMOX1'' (heme oxygenase 1 gene) is a human gene that encodes for the enzyme heme oxygenase 1 (). Heme oxygenase (abbreviated HMOX or HO) mediates the first step of heme catabolism, it cleaves heme to form biliverdin. The ''HMOX'' gene is located on the long (q) arm of chromosome 22 at position 12.3, from base pair 34,101,636 to base pair 34,114,748. Related conditions * Heme oxygenase-1 deficiency Heme oxygenase Heme oxygenase, an essential enzyme in heme catabolism, cleaves heme to form biliverdin, carbon monoxide, and ferrous iron. The biliverdin is subsequently converted to bilirubin by biliverdin reductase. Heme oxygenase activity is induced by its substrate heme and by various nonheme substances. Heme oxygenase occurs as 2 isozymes, an inducible heme oxygenase-1 and a constitutive heme oxygenase-2. HMOX1 and HMOX2 belong to the heme oxygenase family. See also * HMOX2 * Focal segmental glomerulosclerosis Focal segmental glomerulosclerosis (FSGS) is a histopatho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microglia
Microglia are a type of neuroglia (glial cell) located throughout the brain and spinal cord. Microglia account for about 7% of cells found within the brain. As the resident macrophage cells, they act as the first and main form of active immune defense in the central nervous system (CNS). Microglia (and other neuroglia including astrocytes) are distributed in large non-overlapping regions throughout the CNS. Microglia are key cells in overall brain maintenance—they are constantly scavenging the CNS for plaques, damaged or unnecessary neurons and synapses, and infectious agents. Since these processes must be efficient to prevent potentially fatal damage, microglia are extremely sensitive to even small pathological changes in the CNS. This sensitivity is achieved in part by the presence of unique potassium channels that respond to even small changes in extracellular potassium. Recent evidence shows that microglia are also key players in the sustainment of normal brain functions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bergmann Glia
Radial glial cells, or radial glial progenitor cells (RGPs), are bipolar-shaped progenitor cells that are responsible for producing all of the neurons in the cerebral cortex. RGPs also produce certain lineages of glia, including astrocytes and oligodendrocytes. Their cell bodies ( somata) reside in the embryonic ventricular zone, which lies next to the developing ventricular system. During development, newborn neurons use radial glia as scaffolds, traveling along the radial glial fibers in order to reach their final destinations. Despite the various possible fates of the radial glial population, it has been demonstrated through clonal analysis that most radial glia have restricted, unipotent or multipotent, fates. Radial glia can be found during the neurogenic phase in all vertebrates (studied to date). The term "radial glia" refers to the morphological characteristics of these cells that were first observed: namely, their radial processes and their similarity to astrocytes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
