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Pinealoma
A pinealoma is a tumor of the pineal gland, a part of the brain that produces melatonin. If a pinealoma destroys the cells of the pineal gland in a child, it can cause precocious puberty. Signs and symptoms The pineal gland produces the hormone melatonin which plays a role in regulating circadian rhythms. A pinealoma may disrupt production of this hormone, and insomnia may result. Frequently, paralysis of upward gaze along with several ocular findings such as convergence retraction nystagmus and eyelid retraction also known as Collier's sign and Light Near Dissociation (pupil accommodates but doesn't react to light) are known collectively as Parinaud's syndrome or Dorsal Mid-brain syndrome, are the only physical symptoms seen. This is caused by the compression of the vertical gaze center in the midbrain tectum at the level of the superior colliculus and cranial nerve III. Work-up usually includes Neuro-imaging as seen on the right. A pinealoma may cause interruption of hypo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Pineal Gland
The pineal gland (also known as the pineal body or epiphysis cerebri) is a small endocrine gland in the brain of most vertebrates. It produces melatonin, a serotonin-derived hormone, which modulates sleep, sleep patterns following the diurnal cycles. The shape of the gland resembles a pine cone, which gives it its name. The pineal gland is located in the epithalamus, near the center of the brain, between the two cerebral hemisphere, hemispheres, tucked in a groove where the two halves of the thalamus join. It is one of the neuroendocrinology, neuroendocrine Circumventricular organs, secretory circumventricular organs in which capillaries are mostly Vascular permeability, permeable to solutes in the blood. The pineal gland is present in almost all vertebrates, but is absent in Protochordata, protochordates in which there is a simple pineal homologue. The hagfish, archaic vertebrates, lack a pineal gland. In some species of amphibians and reptiles, the gland is linked to a light-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Oncology
Oncology is a branch of medicine that deals with the study, treatment, diagnosis, and prevention of cancer. A medical professional who practices oncology is an ''oncologist''. The name's Etymology, etymological origin is the Greek word ὄγκος (''ónkos''), meaning "tumor", "volume" or "mass". Oncology is focused on the diagnosis of cancer in a person, therapy (e.g., surgery, chemotherapy, radiotherapy and other modalities), monitoring of patients after treatment, palliative care of people with advanced-stage cancers, Ethics, ethical questions surrounding cancer care, Screening (medicine), screening of patients, and the study of cancer treatments through clinical research. An oncologist typically focuses on a specialty area in cancer treatment, such as surgery, Radiation therapy, radiation, gynecology, gynecologic oncology, geriatrics, geriatric oncology, pediatrics, pediatric oncology, and various organ-specific disciplines (breast, brain, liver, among others). The exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Pineocytoma
Pineocytoma, is a rare, benign, slowly growing tumor of the pineal gland. The pineal gland is a small endocrine gland close to the center of the brain that secretes melatonin into the bloodstream. Pineocytomas can cause pressure and fluid build-up in the brain. They are more common in adults. Symptoms include vision problems, nausea, vomiting, memory problems, and headaches. Signs and symptoms Because of their massive growth, pineocytoma symptoms are related to increased intracranial pressure. Some common symptoms of pineocytomas include Parinaud syndrome, headaches, dizziness, papilledema, tremors, ataxia, impaired vision, ambulation, ptosis, nausea, and vomiting. Causes The true cause of pineocytomas is unknown. No genetic mutations have been linked to pineocytomas however, there have been some associations with certain chromosomal abnormalities. There are no known risk factors for pineocytomas. Diagnosis Pineocytomas typically present on a CT scan as round and well-delineat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Radiotherapy
Radiation therapy or radiotherapy (RT, RTx, or XRT) is a treatment using ionizing radiation, generally provided as part of cancer therapy to either kill or control the growth of malignant cells. It is normally delivered by a linear particle accelerator. Radiation therapy may be curative in a number of types of cancer if they are localized to one area of the body, and have not spread to other parts. It may also be used as part of adjuvant therapy, to prevent tumor recurrence after surgery to remove a primary malignant tumor (for example, early stages of breast cancer). Radiation therapy is synergistic with chemotherapy, and has been used before, during, and after chemotherapy in susceptible cancers. The subspecialty of oncology concerned with radiotherapy is called radiation oncology. A physician who practices in this subspecialty is a radiation oncologist. Radiation therapy is commonly applied to the cancerous tumor because of its ability to control cell growth. Ionizin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Germinoma
A germinoma is a type of germ-cell tumor, which is not differentiated upon examination. It may be benign or malignant. Cause Germinomas are thought to originate from an error of development, when certain primordial germ cells fail to migrate properly. Germinomas lack histologic differentiation, whereas nongerminomatous germ-cell tumors display a variety of differentiation. Like other germ-cell tumors, germinomas can undergo malignant transformation. Histology The tumor is uniform in appearance, consisting of large, round cells with vesicular nuclei and clear or finely granular cytoplasm that is eosinophilic. On gross examination, the external surface is smooth and bosselated (knobby), and the interior is soft, fleshy, and either cream-coloured, gray, pink, or tan. Microscopic examination typically reveals uniform cells that resemble primordial germ cells. Typically, the stroma contains lymphocytes, and about 20% of patients have sarcoid-like granulomas. Diagnosis Metas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Germ Cell
A germ cell is any cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells originate in the primitive streak and migrate via the gut of an embryo to the developing gonads. There, they undergo meiosis, followed by cellular differentiation into mature gametes, either eggs or sperm. Unlike animals, plants do not have germ cells designated in early development. Instead, germ cells can arise from somatic cells in the adult, such as the floral meristem of flowering plants. Introduction Multicellular eukaryotes are made of two fundamental cell types: germ and somatic cells. Germ cells produce gametes and are the only cells that can undergo meiosis as well as mitosis. Somatic cells are all the other cells that form the building blocks of the body and they only divide by mitosis. The lineage of germ cells is called the germline. Germ cell specification begins during cleavage in many animals or in the epiblast during gastr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Astrocytoma
Astrocytoma is a type of brain tumor. Astrocytomas (also astrocytomata) originate from a specific kind of star-shaped glial cell in the cerebrum called an astrocyte. This type of tumor does not usually spread outside the brain and spinal cord, and it does not usually affect other organs. After glioblastomas, astrocytomas are the second most common glioma and can occur in most parts of the brain and occasionally in the spinal cord. Within the astrocytomas, two broad classes are recognized in literature, those with: * Narrow zones of infiltration (mostly noninvasive tumors; e.g., pilocytic astrocytoma, subependymal giant cell astrocytoma, pleomorphic xanthoastrocytoma), that often are clearly outlined on diagnostic images * Diffuse zones of infiltration (e.g., high-grade astrocytoma), that share various features, including the ability to arise at any location in the central nervous system, but with a preference for the cerebral hemispheres; they occur usually in adults, and have an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Astrocyte
Astrocytes (from Ancient Greek , , "star" and , , "cavity", "cell"), also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord. They perform many functions, including biochemical control of endothelial cells that form the blood–brain barrier, provision of nutrients to the nervous tissue, maintenance of extracellular ion balance, regulation of cerebral blood flow, and a role in the repair and scarring process of the brain and spinal cord following infection and traumatic injuries. The proportion of astrocytes in the brain is not well defined; depending on the counting technique used, studies have found that the astrocyte proportion varies by region and ranges from 20% to around 40% of all glia. Another study reports that astrocytes are the most numerous cell type in the brain. Astrocytes are the major source of cholesterol in the central nervous system. Apolipoprotein E transports cholesterol from astrocytes to neurons and ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Pineocytomas
Pineocytoma, is a rare, benign, slowly growing tumor of the pineal gland. The pineal gland is a small endocrine gland close to the center of the brain that secretes melatonin into the bloodstream. Pineocytomas can cause pressure and fluid build-up in the brain. They are more common in adults. Symptoms include vision problems, nausea, vomiting, memory problems, and headaches. Signs and symptoms Because of their massive growth, pineocytoma symptoms are related to increased intracranial pressure. Some common symptoms of pineocytomas include Parinaud syndrome, headaches, dizziness, papilledema, tremors, ataxia, impaired vision, ambulation, ptosis, nausea, and vomiting. Causes The true cause of pineocytomas is unknown. No genetic mutations have been linked to pineocytomas however, there have been some associations with certain chromosomal abnormalities. There are no known risk factors for pineocytomas. Diagnosis Pineocytomas typically present on a CT scan as round and well-delineat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Pineocyte
Pinealocytes are the main cells contained in the pineal gland, located behind the third ventricle and between the two hemispheres of the brain. The primary function of the pinealocytes is the secretion of the hormone melatonin, important in the regulation of circadian rhythms. In humans, the suprachiasmatic nucleus of the hypothalamus communicates the message of darkness to the pinealocytes, and as a result, controls the day and night cycle. It has been suggested that pinealocytes are derived from photoreceptor cells. Research has also shown the decline in the number of pinealocytes by way of apoptosis as the age of the organism increases. There are two different types of pinealocytes, type I and type II, which have been classified based on certain properties including shape, presence or absence of infolding of the nuclear envelope, and composition of the cytoplasm. Types of pinealocytes Type 1 pinealocytes Type 1 pinealocytes are also known as light pinealocytes because they sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Gait Disturbance
Gait deviations are nominally referred to as any variation of gait (human), standard human gait, typically manifesting as a coping mechanism in response to an anatomical impairment. Amputation, Lower-limb amputees are unable to maintain the characteristic walking patterns of an able-bodied individual due to the removal of some portion of the impaired leg. Without the anatomy, anatomical structure and neuromechanics, neuromechanical control of the removed leg segment, amputees must use alternative compensatory strategies to walk efficiently. Prosthetic, Prosthetic limbs provide support to the user and more advanced models attempt to mimic the function of the missing anatomy, including biomechatronics, biomechanically controlled ankle and knee joints. However, amputees still display quantifiable differences in many measures of walking, ambulation when compared to able-bodied individuals. Several common observations are whole-body movements, slower and wider steps, shorter strides, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Hydrocephalus
Hydrocephalus is a condition in which cerebrospinal fluid (CSF) builds up within the brain, which can cause pressure to increase in the skull. Symptoms may vary according to age. Headaches and double vision are common. Elderly adults with normal pressure hydrocephalus (NPH) may have poor balance, difficulty controlling urination, or mental impairment. In babies, there may be a rapid increase in head size. Other symptoms may include vomiting, sleepiness, seizures, and downward pointing of the eyes. Hydrocephalus can occur due to birth defects (primary) or can develop later in life (secondary). Hydrocephalus can be classified via mechanism into communicating, noncommunicating, ''ex vacuo'', and normal pressure hydrocephalus. Diagnosis is made by physical examination and medical imaging, such as a CT scan. Hydrocephalus is typically treated through surgery. One option is the placement of a shunt system. A procedure called an endoscopic third ventriculostomy has gained ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
