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Focused Ultrasound
High-intensity focused ultrasound (HIFU) is a non-invasive therapeutic technique that uses non-ionizing ultrasonic waves to heat or ablate tissue. HIFU can be used to increase the flow of blood or lymph or to destroy tissue, such as tumors, via thermal and mechanical mechanisms. Given the prevalence and relatively low cost of ultrasound generation mechanisms, The premise of HIFU is that it is expect a non-invasive and low-cost therapy that can at minimum outperform of care. The technology is different from that used in ultrasonic imaging, though lower frequencies and continuous, rather than pulsed, waves are used to achieve the necessary thermal doses. However, pulsed waves may also be used if mechanical rather than thermal damage is desired. Acoustic lenses are often used to achieve the necessary intensity at the target tissue without damaging the surrounding tissue. The ideal pattern diagram is the beam-focusing of a magnifying glass of sunlight; only the focal point of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-invasive Procedure
A medical procedure is defined as ''non-invasive'' when no break in the skin is created and there is no contact with the mucosa, or skin break, or internal body cavity beyond a natural or artificial body orifice. For example, deep palpation and percussion are non-invasive but a rectal examination is invasive. Likewise, examination of the ear-drum or inside the nose or a wound dressing change all fall outside the definition of ''non-invasive procedure''. There are many non-invasive procedures, ranging from simple observation, to specialised forms of surgery, such as radiosurgery. Extracorporeal shock wave lithotripsy is a non-invasive treatment of stones in the kidney, gallbladder or liver, using an acoustic pulse. For centuries, physicians have employed many simple non-invasive methods based on physical parameters in order to assess body function in health and disease (physical examination and inspection), such as pulse-taking, the auscultation of heart sounds and lung sounds ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalamocortical Dysrhythmia
Thalamocortical dysrhythmia (TCD) is a theoretical framework in which neuroscientists try to explain the positive and negative symptoms induced by neuropsychiatric disorders like Parkinson's Disease, neurogenic pain, tinnitus, visual snow syndrome, schizophrenia, obsessive–compulsive disorder, depressive disorder and epilepsy. In TCD, normal thalamocortical resonance is disrupted by changes in the behaviour of neurons in the thalamus. TCD can be treated with neurosurgical methods like the central lateral thalamotomy, which due to its invasiveness is only used on patients that have proven resistant to conventional therapies. Background At the base of the theory lies diminished excitatory or increased inhibitory input at the thalamic level. This leads to a switch of the thalamocortical neurons from tonic to burst firing and subsequently entrains thalamic and cortical areas with pathological oscillations at around 5 Hz. Evidence Evidence for TCD comes from Magnetoencephalogr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor Microenvironment
The tumor microenvironment (TME) is the environment around a tumor, including the surrounding blood vessels, immune cells, fibroblasts, signaling molecules and the extracellular matrix (ECM). The tumor and the surrounding microenvironment are closely related and interact constantly. Tumors can influence the microenvironment by releasing extracellular signals, promoting tumor angiogenesis and inducing peripheral immune tolerance, while the immune cells in the microenvironment can affect the growth and evolution of cancerous cells. History The importance of a stromal microenvironment, especially "wound" or regenerating tissue, has been recognized since the late 1800s. The interplay between the tumor and its microenvironment was part of Stephen Paget's 1889 "seed and soil" theory, in which he postulated that metastases of a particular type of cancer ("the seed") often metastasizes to certain sites ("the soil") based on the similarity of the original and secondary tumor sites. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonication
A sonicator at the Weizmann Institute of Science during sonicationSonication is the act of applying sound energy to agitate particles in a sample, for various purposes such as the extraction of multiple compounds from plants, microalgae and seaweeds. Ultrasonic frequencies (> 20 kHz) are usually used, leading to the process also being known as ultrasonication or ultra-sonication. In the laboratory, it is usually applied using an ''ultrasonic bath'' or an ''ultrasonic probe'', colloquially known as a ''sonicator''. In a paper machine, an ultrasonic foil can distribute cellulose fibres more uniformly and strengthen the paper. Effects Sonication has numerous effects, both chemical and physical. The chemical effects of ultrasound are concerned with understanding the effect of sonic waves on chemical systems, this is called sonochemistry. The chemical effects of ultrasound do not come from a direct interaction with molecular species. Studies have shown that no direct coupl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coagulative Necrosis
Coagulative necrosis is a type of accidental cell death typically caused by ischemia or infarction. In coagulative necrosis, the architectures of dead tissue are preserved for at least a couple of days. It is believed that the injury denatures structural proteins as well as lysosomal enzymes, thus blocking the proteolysis of the damaged cells. The lack of lysosomal enzymes allows it to maintain a "coagulated" morphology for some time. Like most types of necrosis, if enough viable cells are present around the affected area, regeneration will usually occur. Coagulative necrosis occurs in most bodily organs, excluding the brain. Different diseases are associated with coagulative necrosis, including acute tubular necrosis and acute myocardial infarction. Coagulative necrosis can also be induced by high local temperature; it is a desired effect of treatments such as high intensity focused ultrasound applied to cancerous cells. Causes Coagulative necrosis is most commonly caused by co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phacoemulsification
Phacoemulsification is a modern cataract surgery method in which the eye's internal lens is emulsified with an ultrasonic handpiece and aspirated from the eye. Aspirated fluids are replaced with irrigation of balanced salt solution to maintain the anterior chamber. Etymology The term originated from phaco- (Greek ''phako-'', comb. form of ''phakós'', lentil; see lens) + emulsification. Preparation and precautions Proper anesthesia is essential for ocular surgery. Topical anesthesia is most commonly employed, typically by the instillation of a local anesthetic such as tetracaine or lidocaine. Alternatively, lidocaine and/or longer-acting bupivacaine anesthetic may be injected into the area surrounding ( peribulbar block) or behind (retrobulbar block) the eye muscle cone to more fully immobilize the extraocular muscles and minimize pain sensation. A facial nerve block using lidocaine and bupivacaine may occasionally be performed to reduce lid squeezing. General anesthesia is r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cataract
A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble with bright lights, and trouble seeing at night. This may result in trouble driving, reading, or recognizing faces. Poor vision caused by cataracts may also result in an increased risk of falling and depression. Cataracts cause 51% of all cases of blindness and 33% of visual impairment worldwide. Cataracts are most commonly due to aging but may also occur due to trauma or radiation exposure, be present from birth, or occur following eye surgery for other problems. Risk factors include diabetes, longstanding use of corticosteroid medication, smoking tobacco, prolonged exposure to sunlight, and alcohol. The underlying mechanism involves accumulation of clumps of protein or yellow-brown pigment in the lens that reduces transmission of li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extracorporeal Shock Wave Lithotripsy
Extracorporeal shockwave therapy (ESWT) is a non-invasive, out-patient alternative to surgery for those with many joint and tendon disorders. ESWT sends acoustic shock waves into bone or soft tissue, in effect reinjuring the area on a cellular level and breaking up the scarring that has penetrated tendons and ligaments. The controlled reinjuring of tissue allows the body to regenerate blood vessels and bone cells. The resulting revascularization leads to faster healing and often a return to pre-injury activity levels. It is a treatment using powerful acoustic pulses which is mostly used to treat kidney stones and in physical therapy and orthopedics. Medical uses The most common use of extracorporeal shockwave therapy (ESWT) is for lithotripsy to treat kidney stones (urinary calculosis) and biliary calculi (stones in the gallbladder or in the liver) using an acoustic pulse. It is also reported to be used for salivary stones and pancreatic stones. In the UK, the National Insti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kidney Stone
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine stream. A small stone may pass without causing symptoms. If a stone grows to more than , it can cause blockage of the ureter, resulting in sharp and severe pain in the lower back or abdomen. A stone may also result in blood in the urine, vomiting, or painful urination. About half of people who have had a kidney stone will have another within ten years. Most stones form by a combination of genetics and environmental factors. Risk factors include high urine calcium levels, obesity, certain foods, some medications, calcium supplements, hyperparathyroidism, gout and not drinking enough fluids. Stones form in the kidney when minerals in urine are at high concentration. The diagnosis is usually based on symptoms, urine testing, and medical i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Institute For Health And Care Excellence
The National Institute for Health and Care Excellence (NICE) is an executive non-departmental public body of the Department of Health and Social Care in England that publishes guidelines in four areas: * the use of health technologies within England's National Health Service (NHS) and NHS Wales (such as the use of new and existing medicines, treatments and procedures) * clinical practice (guidance on the appropriate treatment and care of people with specific diseases and conditions) * guidance for public sector workers on health promotion and ill-health avoidance * guidance for social care services and users. These appraisals are based primarily on evidence-based evaluations of efficacy, safety and cost-effectiveness in various circumstances. It serves both the English NHS and the Welsh NHS. It was set up as the National Institute for Clinical Excellence in 1999, and on 1 April 2005 joined with the Health Development Agency to become the new National Institute for Health a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prostatic Urethra
The prostatic urethra, the widest and most dilatable part of the urethra canal, is about 3 cm long. It runs almost vertically through the prostate from its base to its apex, lying nearer its anterior than its posterior surface; the form of the canal is spindle-shaped, being wider in the middle than at either extremity, and narrowest below, where it joins the membranous portion. A transverse section of the canal as it lies in the prostate is horse-shoe-shaped, with the convexity directed forward. The keyhole sign, in ultrasound, is associated with a dilated bladder and prostatic urethra. Additional images File:Illu prostate lobes.jpg, Lobes of prostate File:Illu prostate zones.jpg, Zones of prostate File:Illu penis.jpg, Structure of the penis File:Gray1156.png, Vertical section of bladder The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catheter
In medicine, a catheter (/ˈkæθətər/) is a thin tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. Catheters are manufactured for specific applications, such as cardiovascular, urological, gastrointestinal, neurovascular and ophthalmic procedures. The process of inserting a catheter is ''catheterization''. In most uses, a catheter is a thin, flexible tube (''soft'' catheter) though catheters are available in varying levels of stiffness depending on the application. A catheter left inside the body, either temporarily or permanently, may be referred to as an "indwelling catheter" (for example, a peripherally inserted central catheter). A permanently inserted catheter may be referred to as a "permcath" (originally a trademark). Catheters can be inserted into a body cavity, duct, or vessel, brain, skin or adipose tissue. Functionally, they all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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