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The term subclavian steal describes retrograde blood flow in the vertebral artery associated with proximal ipsilateral subclavian artery stenosis or occlusion, usually in the setting of subclavian artery occlusion or stenosis proximal to the origin of the vertebral artery. Alternatively, innominate artery disease has also been associated with retrograde flow in the ipsilateral vertebral artery, particularly where the subclavian artery origin is involved. Subclavian steal is frequently asymptomatic and may be discovered incidentally on ultrasound or angiographic examination for other indications, or it may be prompted by a clinical examination finding of reduced unilateral upper limb pulse or blood pressure. In some cases, patients may develop upper limb ischemic symptoms due to reduced arterial flow in the setting of subclavian artery occlusion, or they may develop neurologic symptoms due to posterior circulation ischemia associated with exercise of the ipsilateral arm.[1] Treatment has traditionally consisted of open subclavian artery revascularization, typically via carotid-subclavian bypass or subclavian artery transposition, which are generally durable procedures. Newer, less invasive options include endovascular intervention with recanalization as appropriate and angioplasty and stenting if required. The clinical relevance of subclavian steal was described in 1961 by Reivich, Holling and Roberts; however, the recognition of retrograde vertebral artery flow dates back another 100 years to Harrison and Smyth. Some papers, including a previous version of this article, advocate restricting the term subclavian steal to patients with neurologic symptoms only, but this is incorrect in view of the substantial literature using this term to describe the hemodynamic scenario of retrograde vertebral flow and proximal subclavian artery disease.
X-linked agammaglobulinemia (XLA), or Bruton agammaglobulinemia, is an inherited immunodeficiency disease caused by mutations in the gene coding for Bruton tyrosine kinase (BTK). The disease was first elucidated by Bruton in 1952, for whom the gene is named. BTK is critical to the maturation of pre–B cells to differentiating mature B cells. The BTK gene defect has been mapped to the long arm of the X chromosome at band Xq21.3 to Xq22, spanning 37.5kb with 19 exons forming 659 amino acids to complete the BTK cytosolic tyrosine kinase. A database of BTK mutations (BTKbase: Mutation registry for X-linked agammaglobulinemia) lists 544 mutation entries from 471 unrelated families showing 341 unique molecular events. No single mutation accounts for more than 3% of mutations in patients. In addition to mutations, a number of variants or polymorphisms have been found.
Respiratory syncytial virus (RSV) is a virus that causes infections of the lungs and respiratory tract. It's so common that most children have been infected with the virus by age 2. Respiratory syncytial (sin-SISH-ul) virus can also infect adults. In adults and older, healthy children, the symptoms of respiratory syncytial virus are mild and typically mimic the common cold. Self-care measures are usually all that's needed to relieve any discomfort. Infection with respiratory syncytial virus can be severe in some cases, especially in premature babies and infants with underlying health conditions. RSV can also become serious in older adults, adults with heart and lung diseases, or anyone with a very weak immune system (immunocompromised).
A ventricular septal defect (VSD), a hole in the heart, is a common heart defect that's present at birth (congenital). The hole occurs in the wall that separates the heart's lower chambers (septum) and allows blood to pass from the left to the right side of the heart. The oxygen-rich blood then gets pumped back to the lungs instead of out to the body, causing the heart to work harder. A small ventricular septal defect may cause no problems, and many small VSDs close on their own. Larger VSDs need surgical repair early in life to prevent complications.
Hyponatremia is a condition that occurs when the level of sodium in your blood is abnormally low. Sodium is an electrolyte, and it helps regulate the amount of water that's in and around your cells. In hyponatremia, one or more factors — ranging from an underlying medical condition to drinking too much water during endurance sports — causes the sodium in your body to become diluted. When this happens, your body's water levels rise, and your cells begin to swell. This swelling can cause many health problems, from mild to life-threatening. Hyponatremia treatment is aimed at resolving the underlying condition. Depending on the cause of hyponatremia, you may simply need to cut back on how much you drink. In other cases of hyponatremia, you may need intravenous fluids and medications
A salivary gland stone -- also called salivary duct stone -- is a calcified structure that may form inside a salivary gland or duct. It can block the flow of saliva into the mouth. The majority of stones affect the submandibular glands located at the floor of the mouth. Less commonly, the stones affect the parotid glands, located on the inside of the cheeks, or the sublingual glands, which are under the tongue. Many people with the condition have multiple stones. Salivary Gland Stone Causes and Symptoms Salivary stones form when chemicals in the saliva accumulate in the duct or gland. They mostly contain calcium. The exact cause is not known. But factors contributing to less saliva production and/or thickened saliva may be risk factors for salivary stones. These factors include: dehydration, poor eating, and use of certain medications (such as antihistamines), blood pressure drugs, psychiatric drugs, and bladder control drugs. Trauma to the salivary glands may also raise the risk for salivary stones. The stones cause no symptoms as they form, but if they reach a size that blocks the duct, saliva backs up into the gland, causing pain and swelling. You may feel the pain off and on, and it may get progressively worse. Inflammation and infection within the affected gland may follow. Salivary Gland Stones Diagnosis and Treatments If you have symptoms of a salivary gland stone, your doctor will first check for stones with a physical exam. Sometimes tests may also be ordered, such as X-ray, CT scan, or ultrasound.
Menopause is defined as occurring 12 months after your last menstrual period and marks the end of menstrual cycles. Menopause can happen in your 40s or 50s, but the average age is 51 in the United States. Menopause is a natural biological process. Although it also ends fertility, you can stay healthy, vital and sexual. Some women feel relieved because they no longer need to worry about pregnancy. Even so, the physical symptoms, such as hot flashes, and emotional symptoms of menopause may disrupt your sleep, lower your energy or — for some women — trigger anxiety or feelings of sadness and loss. Don't hesitate to seek treatment for symptoms that bother you. Many effective treatments are available, from lifestyle adjustments to hormone therapy.
Breast cancer usually starts off in the inner lining of milk ducts or the lobules that supply them with milk. A malignant tumor can spread to other parts of the body. A breast cancer that started off in the lobules is known as lobular carcinoma, while one that developed from the ducts is called ductal carcinoma. The vast majority of breast cancer cases occur in females. This article focuses on breast cancer in women. We also have an article about male breast cancer. Breast cancer is the most common invasive cancer in females worldwide. It accounts for 16% of all female cancers and 22.9% of invasive cancers in women. 18.2% of all cancer deaths worldwide, including both males and females, are from breast cancer. Breast cancer rates are much higher in developed nations compared to developing ones. There are several reasons for this, with possibly life-expectancy being one of the key factors - breast cancer is more common in elderly women; women in the richest countries live much longer than those in the poorest nations. The different lifestyles and eating habits of females in rich and poor countries are also contributory factors, experts believe. According to the National Cancer Institute, 232,340 female breast cancers and 2,240 male breast cancers are reported in the USA each year, as well as about 39,620 deaths caused by the disease.
Fainting occurs when the blood supply to your brain is momentarily inadequate, causing you to lose consciousness. This loss of consciousness is usually brief. Fainting can have no medical significance, or the cause can be a serious disorder. Therefore, treat loss of consciousness as a medical emergency until the signs and symptoms are relieved and the cause is known. Discuss recurrent fainting spells with your doctor. If you feel faint Lie down or sit down. To reduce the chance of fainting again, don't get up too quickly. Place your head between your knees if you sit down. If someone else faints Position the person on his or her back. If the person is breathing, restore blood flow to the brain by raising the person's legs above heart level — about 12 inches (30 centimeters) — if possible. Loosen belts, collars or other constrictive clothing. To reduce the chance of fainting again, don't get the person up too quickly. If the person doesn't regain consciousness within one minute, call 911 or your local emergency number. Check the person's airway to be sure it's clear. Watch for vomiting. Check for signs of circulation (breathing, coughing or movement). If absent, begin CPR. Call 911 or your local emergency number. Continue CPR until help arrives or the person responds and begins to breathe.
A disease of the immune system due to infection with HIV. HIV destroys the CD4 T lymphocytes (CD4 cells) of the immune system, leaving the body vulnerable to life-threatening infections and cancers. Acquired immunodeficiency syndrome (AIDS) is the most advanced stage of HIV infection. To be diagnosed with AIDS, a person with HIV must have an AIDS-defining condition or have a CD4 count less than 200 cells/mm³ (regardless of whether the person has an AIDS-defining condition).
Gonorrhea is a sexually transmitted disease (STD). It’s caused by infection with the bacterium Neisseria gonorrhoeae. It tends to infect warm, moist areas of the body, including the: urethra (the tube that drains urine from the urinary bladder) eyes throat vagina anus female reproductive tract (the fallopian tubes, cervix, and uterus) Gonorrhea passes from person to person through unprotected oral, anal, or vaginal sex. People with numerous sexual partners or those who don’t use a condom are at greatest risk of infection. The best protections against infection are abstinence, monogamy (sex with only one partner), and proper condom usage. Behaviors that make a person more likely to engage in unprotected sex also increase the likelihood of infection. These behaviors include alcohol abuse and illegal drug abuse, particularly intravenous drug use.
A torn meniscus is one of the most common knee injuries. Any activity that causes you to forcefully twist or rotate your knee, especially when putting the pressure of your full weight on it, can lead to a torn meniscus. Each of your knees has two menisci — C-shaped pieces of cartilage that act like a cushion between your shinbone and your thighbone. A torn meniscus causes pain, swelling and stiffness. You also might have trouble extending your knee fully. Conservative treatment — such as rest, ice and medication — is sometimes enough to relieve the pain of a torn meniscus and give the injury time to heal on its own. In other cases, however, a torn meniscus requires surgical repair.
Cystinuria is a condition characterized by the buildup of the amino acid cystine, a building block of most proteins, in the kidneys and bladder. As the kidneys filter blood to create urine, cystine is normally absorbed back into the bloodstream. People with cystinuria cannot properly reabsorb cystine into their bloodstream, so the amino acid accumulates in their urine. As urine becomes more concentrated in the kidneys, the excess cystine forms crystals. Larger crystals become stones that may lodge in the kidneys or in the bladder. Sometimes cystine crystals combine with calcium molecules in the kidneys to form large stones. These crystals and stones can create blockages in the urinary tract and reduce the ability of the kidneys to eliminate waste through urine. The stones also provide sites where bacteria may cause infections.
A Pap smear (Papanicolau smear; also known as the Pap test) is a screening test for cervical cancer. The test itself involves collection of a sample of cells from a woman's cervix (the end of the uterus that extends into the vagina) during a routine pelvic exam
Most of the time when someone with cancer is told they have cancer in the bones, the doctor is talking about a cancer that has spread to the bones from somewhere else. This is called metastatic cancer. It can be seen in many different types of advanced cancer, like breast cancer, prostate cancer, and lung cancer. When these cancers in the bone are looked at under a microscope, they look like the tissue they came from. For example, if someone has lung cancer that has spread to bone, the cells of the cancer in the bone still look and act like lung cancer cells. They do not look or act like bone cancer cells, even though they are in the bones. Since these cancer cells still act like lung cancer cells, they still need to be treated with drugs that are used for lung cancer. For more information about metastatic bone cancer, please see our document called Bone Metastasis, as well as the document on the specific place the cancer started (Breast Cancer, Lung Cancer, Prostate Cancer, etc.). Other kinds of cancers that are sometimes called “bone cancers” start in the blood forming cells of the bone marrow − not in the bone itself. The most common cancer that starts in the bone marrow and causes bone tumors is called multiple myeloma. Another cancer that starts in the bone marrow is leukemia, but it is generally considered a blood cancer rather than a bone cancer. Sometimes lymphomas, which more often start in lymph nodes, can start in bone marrow. Multiple myeloma, lymphoma, and leukemia are not discussed in this document. For more information on these cancers, refer to the individual document for each. A primary bone tumor starts in the bone itself. True (or primary) bone cancers are called sarcomas. Sarcomas are cancers that start in bone, muscle, fibrous tissue, blood vessels, fat tissue, as well as some other tissues. They can develop anywhere in the body. There are several different types of bone tumors. Their names are based on the area of bone or surrounding tissue that is affected and the kind of cells forming the tumor. Some primary bone tumors are benign (not cancerous), and others are malignant (cancerous). Most bone cancers are sarcomas.
Vasculitis is an inflammation of your blood vessels. It causes changes in the walls of blood vessels, including thickening, weakening, narrowing and scarring. These changes restrict blood flow, resulting in organ and tissue damage. There are many types of vasculitis, and most of them are rare. Vasculitis might affect just one organ, such as your skin, or it may involve several. The condition can be short term (acute) or long lasting (chronic). Vasculitis can affect anyone, though some types are more common among certain groups. Depending on the type you have, you may improve without treatment. Or you will need medications to control the inflammation and prevent flare-ups. Vasculitis is also known as angiitis and arteritis.
Less than a decade ago, corneal transplantation took a big leap forward with the introduction of Descemet’s stripping endothelial keratoplasty (DSEK), which removes only Descemet’s membrane and the diseased endothelium and replaces them with a thin, tripartite donor graft of posterior corneal stroma, Descemet’s membrane, and healthy endothelium. Then came DSAEK, in which the donor graft is prepared with an automated microkeratome, allowing for easier donor preparation and reproducible results by surgeons and eye bank technicians.1 DSAEK has proved to have many advantages over penetrating keratoplasty (PK) and its endothelial predecessors (see “A Brief History of Endothelial Keratoplasty”). Now DSAEK is being compared with a newer technique, Descemet’s membrane endothelial keratoplasty (DMEK), which has emerged as a promising alternative—grafting only Descemet’s membrane and endothelium, allowing for a pure anatomical replacement of only what was removed and the possibility of even better vision with quicker healing.1 Although indications for these procedures are similar, each has unique benefits and drawbacks. Five cornea surgeons offer their perspectives on the procedures and their thoughts on whether it may be time to move to the newer surgery.