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The occurrence and extent of cerebral infarction is determined by three basic factors: i) site of arterial occlusion, ii) the rapidity of arterial occlusion, and iii) the presence or absence of collateral circulation. Grossly, infarcts are usually divided into pale (non-hemorrhagic) and hemorrhagic types. Infarcts evolve over time, thus their gross appearance gives a clue to when they occurred. The temporal evolution of an infarct occurs in three stages: i) acute (1 day – 1 week) – the involved area is soft and edematous and there is a blurring of anatomic detail; ii) subacute (1 week – 1 month) – there is obvious tissue destruction and liquefactive necrosis of the involved brain; iii) chronic (>1 month) – the damaged tissue has been phagocytized and there is cavition with surrounding gliosis. Microscopically there is also a temporal evolution of cerebral infarcts. During the earliest phase of infarction (0-48 hours) chromatolysis and swollen eosinophilic neurons are seen. Neuronal cell necrosis and an acute inflammatory response are usually seen from 24-72 hours. This response is typically followed by an influx of mononuclear cells which begin to phagocytize necrotic debris (3-5 days). From 1-2 weeks after the infarct there is vascular proliferation and reactive astrocytosis. Over time (>1 month) the necrotic tissue will be completely removed and a cystic cavity surrounded by a glial scar will be formed.
Prediabetes means that your blood sugar level is higher than normal but not yet high enough to be type 2 diabetes. Without lifestyle changes, people with prediabetes are very likely to progress to type 2 diabetes. If you have prediabetes, the long-term damage of diabetes — especially to your heart, blood vessels and kidneys — may already be starting. There's good news, however. Progression from prediabetes to type 2 diabetes isn't inevitable. Eating healthy foods, incorporating physical activity in your daily routine and maintaining a healthy weight can help bring your blood sugar level back to normal. Prediabetes affects adults and children. The same lifestyle changes that can help prevent progression to diabetes in adults might also help bring children's blood sugar levels back to normal.
Bronchiolitis is a common lung infection in young children and infants. It causes inflammation and congestion in the small airways (bronchioles) of the lung. Bronchiolitis is almost always caused by a virus. Typically, the peak time for bronchiolitis is during the winter months. Bronchiolitis starts out with symptoms similar to those of a common cold but then progresses to coughing, wheezing and sometimes difficulty breathing. Symptoms of bronchiolitis can last for several days to weeks, even a month.
Cosmetic iris implants have not been evaluated by any U.S. regulatory agency or tested for safety in clinical trials. While the implants are not approved by the U.S. Food and Drug Administration, it has been reported in the media this month that the surgery is being performed overseas. During iris implant surgery, an artificial iris made of silicone is folded and inserted into a slit that has been cut into the cornea. Then the iris is unfolded and adjusted to cover the natural iris. Local anesthesia is used.
Portal hypertension is an increase in the blood pressure within a system of veins called the portal venous system. Veins coming from the stomach, intestine, spleen, and pancreas merge into the portal vein, which then branches into smaller vessels and travels through the liver.
X-linked adrenoleukodystrophy is a genetic disorder that occurs primarily in males. It mainly affects the nervous system and the adrenal glands, which are small glands located on top of each kidney. In this disorder, the fatty covering (myelin) that insulates nerves in the brain and spinal cord is prone to deterioration (demyelination), which reduces the ability of the nerves to relay information to the brain. In addition, damage to the outer layer of the adrenal glands (adrenal cortex) causes a shortage of certain hormones (adrenocortical insufficiency). Adrenocortical insufficiency may cause weakness, weight loss, skin changes, vomiting, and coma.
Ebstein anomaly is a congenital malformation of the heart that is characterized by apical displacement of the septal and posterior tricuspid valve leaflets, leading to atrialization of the right ventricle with a variable degree of malformation and displacement of the anterior leaflet.
There have been rapid and remarkable changes over the recent past in treating Parkinson's disease. The development of new drugs and an understanding of how best to use them and the older drugs have significantly improved the quality of life of people with the disease. There are two general approaches to the treatment of Parkinson's disease with medication. The first approach attempts to increase the levels of dopamine in the brain and the second approach attempts to improve the symptoms of Parkinson's disease by other means. Most patients with Parkinson's disease can initially be treated with drugs that adequately alleviate their symptoms. If or when medications are not sufficiently effective, new, highly effective and safe surgical treatments are also available.