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Thursday, April 19, 2012

Aplastic Anemia

Aplastic anemia is a rare but serious blood disorder. If you have it, your bone marrow doesn't make enough new blood cells. Causes include
  • Being exposed to toxic substances, such as pesticides, arsenic, and benzene
  • Radiation therapy and chemotherapy for cancer
  • Certain medicines
  • Infections such as hepatitis, Epstein-Barr virus, or HIV
  • Autoimmune disorders
  • Certain inherited conditions
In many people, the cause is unknown.

Aplastic anemia

Your doctor will diagnose aplastic anemia based on your medical and family histories, a physical exam, and test results. Once your doctor knows the cause and severity of the condition, he or she can create a treatment plan for you. Treatments include blood transfusions, blood and marrow stem cell transplants, and medicines.

aplastic anemia

Aplastic anemia is a disorder in which the bone marrow fails to make enough blood cells. The bone marrow is the soft, inner part of bones where the 3 types of blood cells are made:


  • Red blood cells, which carry oxygen to the tissues from the lungs
  • White blood cells, which fight infection
  • Platelets, which seal damaged blood vessels to prevent bleeding

These cells are made by blood-forming stem cells in the bone marrow. In aplastic anemia, the stem cells are damaged and there are very few of them. As a result, too few blood cells are produced. In most cases of aplastic anemia, all 3 types of blood cells are low (which is called pancytopenia). Rarely, just one of the cell lines, such as red cells, white cells, or platelets, is abnormal.

Aplastic anemia is not a type of cancer but may be associated with certain cancers (especially those affecting the bone marrow, such as leukemia) or cancer treatments. A small number of patients with aplastic anemia may develop leukemia.

Aplastic anemia can be inherited or acquired. Acquired aplastic anemia is much more common than the inherited type.


Inherited aplastic anemia

Aplastic anemia is considered inherited when it is caused by gene mutations (abnormal copies of genes) that have been passed on from the parents to their child. Inherited aplastic anemia is more common in children and young adults.


Fanconi anemia

The most common cause of inherited aplastic anemia is called Fanconi anemia (FA). There are many different genes that can cause Fanconi anemia. They include FANCA, FANCB, FANCC, FANCD1, FANCD2, FANCE, FANCF, FANCG, FANCI, FANCJ, FANCL, FANCM, and FANCN. In order to get FA, a child must inherit 2 abnormal copies of one of these genes -- one from each parent. Someone with only one abnormal copy will not develop the disease and is called a carrier.

The genetic material (DNA) in our cells is packaged into chromosomes. In FA, the chromosomes are easily damaged by things in the environment like toxins or radiation. This can lead to aplastic anemia, leukemia, and other cancers. Cancers of the mouth and throat, esophagus, and the vulva (female genital area) are seen at a higher rate and at a younger age in those with FA (as compared with people who don't have FA).

In many cases, FA is suspected when a child is born because he or she is missing a thumb or a bone in the arm called the radius. A child with FA anemia also may not grow well (called growth retardation) or have a small head (called microcephaly). Dark spots on the skin (called café au lait spots) can be another symptom of FA. In some cases though, the child will look completely normal. People with FA can start to have low blood counts at a very early age. The low blood counts may be treated with medications called androgens at first, but only a bone marrow transplant can actually cure aplastic anemia in someone with FA.

Some people with FA do not develop low blood counts (or aplastic anemia), but may be diagnosed with FA when they get cancer. In order to diagnose FA anemia, a chromosome breakage test will be ordered. For this test, a small sample of blood is taken from the patient. Then some of the cells in the blood (called lymphocytes) are exposed to a certain chemical to see if it causes the chromosomes in the cells to break and rearrange. Chromosomes in normal cells aren't damaged easily, but the chromosomes in FA cells will be damaged.


Dyskeratosis congenita

Another inherited cause of aplastic anemia is called dyskeratosis congenita (DC). Defects in some of the genes that help protect the chromosomes cause this disease. The chromosomes in our cells are fitted with caps at each end calledtelomeres. These caps help protect the ends of the chromosomes from being damaged. Telomerase is the protein that maintains the telomeres. Two different genes, called TERC and TERT, are needed to make telomerase. An abnormal copy of either one of these genes can cause DC. Another gene, DKC1, makes a protein called dyskerin that is needed for telomerase to work. Abnormalities in this gene also cause DC. Symptoms of this disorder include abnormal skin pigmentation, abnormal nails, and white patches in the mouth (called leukoplakia). People with this problem have a high risk of developing aplastic anemia and certain cancers, such as cancer of the mouth and throat and cancer of the anus. Some people are only diagnosed with DC when they come in with aplastic anemia and are found to have abnormal telomerase genes. These people may not have any of the other signs or symptoms of DC.
Other causes of inherited aplastic anemia

Another cause of inherited aplastic anemia is called the Diamond-Blackfan syndrome. In this disease, red blood cells are low, but the number of other blood cells is normal.

A fourth disorder is the Shwachman-Diamond syndrome, which is caused by abnormal copies of a gene called SDS. Here, the major problem is poor production of white blood cells, although the other cell lines can also be abnormal. In both of these, patients will often have other problems such as short stature and other bone abnormalities.


Acquired aplastic anemia


Acquired aplastic anemia usually occurs in adults, but children may also be affected. Most have no gene abnormalities. Scientists have found that some of the people who they thought had acquired aplastic anemia actually have an abnormality in one of the genes responsible for inherited aplastic anemia. The aplastic anemia in these people is not really acquired -- it is inherited. Some cases of aplastic anemia seem to be triggered by a drug or exposure to a toxic chemical. In most cases of aplastic anemia, however, the cause is never found.

Paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a disease in which some of the stem cells in the bone marrow become damaged and make abnormal red blood cells. The red blood cells in PNH are missing certain proteins that normally help protect the cells. Without these proteins, the red blood cells are killed by the immune system (this is called hemolysis). PNH is caused when the gene called PIG-A is damaged (mutated) in some of the stem cells in the bone marrow. People with PNH have anemia (low red blood cells) along with fatigue, stomach pain, and blood clots. Sometimes the hemoglobin from the destroyed red blood cells will cause the urine to become very dark (like the color of tea). PNH seems to be linked to aplastic anemia. Some patients have small numbers of PNH cells when they are diagnosed with aplastic anemia. Also, some survivors of aplastic anemia will go on to get PNH. PNH can be treated with bone marrow transplant or with a drug called eculizumab that blocks the hemolysis.

Tuesday, April 17, 2012

Rh Incompatibility

There are four major blood types: A, B, O, and AB. The types are based on substances on the surface of the blood cells. Another blood type is called Rh. Rh factor is a protein on red blood cells. Most people are Rh-positive; they have Rh factor. Rh-negative people don't have it. Rh factor is inherited though genes.
When you're pregnant, blood from your baby can cross into your bloodstream, especially during delivery. If you're Rh-negative and your baby is Rh-positive, your body will react to the baby's blood as a foreign substance. It will create antibodies (proteins) against the baby's blood. These antibodies usually don't cause problems during a first pregnancy.
But Rh incompatibility may cause problems in later pregnancies, if the baby is Rh-positive. This is because the antibodies stay in your body once they have formed. The antibodies can cross the placenta and attack the baby's red blood cells. The baby could get Rh disease, a serious condition that can cause a serious type of anemia.
Blood tests can tell whether you have Rh factor and whether your body has made antibodies. Injections of a medicine called Rh immune globulin can keep your body from making Rh antibodies. It helps prevent the problems of Rh incompatibility. If treatment is needed for the baby, it can include supplements to help the body to make red blood cells and blood transfusions.
Part1
Rh incompatibility occurs when the mother's blood type is Rh negative and her fetus' blood type is Rh positive.

Rh Incompatibility 1


Part 2

If some of the fetus' blood passes into the mother's blood stream, her body will produce antibodies in response.

Rh Incompatibility 2


Part 3

These antibodies could pass back through the placenta and harm the fetus' red blood cells, causing mild to serious anemia in the fetus.

Rh Incompatibility 3




Monday, April 16, 2012

Eosinophilia


Eosinophils are a type of white blood cell. They contain particles filled with chemicals that fight off infections and play a role in your body's immune response. Normally your blood doesn't have a large number of eosinophils. Your body may produce more of them in response to allergic disorders, inflammation of the skin, and parasitic infections. They can also increase in response to some infections or to some bone marrow disorders. In some conditions, the eosinophils can move outside the bloodstream and into organs and tissues. Treatment of the problem depends on the cause.


Causes

Eosinophilia can be idiopathic (primary) or, more commonly, secondary to another disease.In the United States, allergic or atopicdiseases are the most common causes, especially those of the respiratory or integumentary systems. In the developing world, parasites are the most common cause. A parasitic infection of nearly any bodily tissue can cause eosinophilia. Diseases that feature eosinophilia as a sign include the following:
Allergic disorders
Asthma
Hay fever
Drug allergies
Allergic skin diseases
Pemphigus
Dermatitis herpetiformis
Parasitic infections
Some forms of malignancy
Hodgkin's lymphoma
Some forms of Non-Hodgkin lymphoma
Systemic autoimmune diseases
Some forms of vasculitis
Cholesterol embolism (transiently)
Coccidioidomycosis (Valley Fever), a fungal disease prominent in the US Southwest.

Eosinophilia


Neoplastic eosinophilia

Hodgkin lymphoma (Hodgkin’s disease) often elicits severe eosinophilia, however, non-Hodgkin lymphoma and leukemia produce less marked eosinophilia. Of solid tumor neoplasms,ovarian cancer is most likely to provoke eosinophilia, though any other cancer can cause the condition. Solid epithelial cell tumors have been shown to cause both tissue and blood eosinophilia, with some reports indicating that this may be mediated by interleukin production by tumor cells, especially IL-5 or IL-3. This has also been shown to occur Hodgkin lymphoma, in the form of IL-5 secreted by Reed-Sternberg cells. In primary cutaneous T-cell lymphoma, blood and dermal eosinophilia are often seen. Lymphoma cells have also been shown to produce IL-5 in these disorders. Other types of lymphoid malignancies have been associated with eosinophilia, as in lymphoblastic leukemia with a translocation between chromosomes 5 and 14. Patients displaying eosinophilia overexpress a gene encoding an eosinophil hematopoietin. A translocation between chromosomes 5 and 14 n patients with acute B lymphocytic leukemia resulted in the juxtaposition of the IL-3 gene and the immunoglobulin heavy-chain gene, causing overproduction production of IL-3, leading to blood and tissue eosinophilia.
Drug reactions

Drug hypersensitivity reactions (allergies) are a common cause of eosinophilia, with manifestations ranging from diffuse maculopapular rash, to severe life threatening drug reactions with eosinophilia and systemic symptoms (DRESS). Drugs that have been shown to cause DRESS are aromatic anticonvulsants and other antiepileptics, sulfonamides, allopurinol,nonsteroidal anti-inflammatory drugs (NSAIDs), and certain antibiotics. The reaction which has been shown to be T-cell mediated may also cause eosinophilia-myalgia syndrome.
Pathophysiology

IgE mediated eosinophil production is induced by compounds released by basophils and mast cells, including eosinophil chemotactic factor of anaphylaxis, leukotriene B4, complement complex (C5-C6-C7), interleukin 5, and histamine (though this has a narrow range of concentration).
Diagnosis

Diagnosis is by complete blood count (CBC). However, in some cases, a more accurate absolute eosinophil count may be needed. Medical history is taken, with emphasis on travel, allergies and drug use.Specific test for causative conditions are performed, often including chest x-ray, urinalysis, liver and kidney function tests, and serologic tests for parasitic and connective tissue diseases. The stool is often examined for traces of parasites (i.e. eggs, larvae, etc.) though a negative test does not rule out parasitic infection; for example, trichinosisrequires a muscle biopsy. Elevated serum B12 or low white blood cell alkaline phosphatase, or leukocytic abnormalities in a peripheral smear indicates a disorder of myleoproliferation. In cases of idiopathic eosinophilia, the patient is followed for complications. A brief trial of corticosteroids can be diagnostic for allergic causes, as the eosinophilia should resolve with suppression of the immune over response.Neoplastic disorders are diagnosed through the usual methods, such as bone marrow aspiration and biopsy for the leukemias, MRI/CT to look for solid tumors, and tests for serum LDH and other tumor markers.
Treatment

Treatment is directed toward the underlying cause. However, in primary eosinophilia, or if the eosinophil count must be lowered, corticosteroids such as prednisone may be used. However, immune suppression, the mechanism of action of corticosteroids, can be fatal in patients with parasitosis.

Friday, April 13, 2012

Chronic Myeloid Leukemia



Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, however, the bone marrow produces abnormal white blood cells. These cells crowd out the healthy blood cells, making it hard for blood to do its work. In chronic myeloid leukemia (CML), there are too many of a specific type of white blood cell called a granulocyte.

Sometimes CML does not cause any symptoms at all. If you have symptoms, they may include:
Feeling very tired
Weight loss
Night sweats
Fever
Pain or a feeling of fullness below the ribs on the left side

Tests that examine the blood and bone marrow diagnose CML. Treatments include chemotherapy, radiation therapy, stem cell transplants, infusion of donated white blood cells following stem cell transplants, immune therapy, or surgery to remove the spleen.

Chronic Myeloid Leukemia

Wednesday, April 11, 2012

Actions To Fight The Flu



“Take 3” Actions To Fight The Flu


Flu is a serious contagious disease that can lead to hospitalization and even death.
CDC urges you to take the following actions to protect yourself and others from influenza (the flu):

  • Take time to get a flu vaccine.
  • CDC recommends a yearly flu vaccine as the first and most important step in protecting against flu viruses.
  • While there are many different flu viruses, the flu vaccine protects against the three viruses that research suggests will be most common.
  • The 2011-2012 vaccine will protect against an influenza A H3N2 virus, an influenza B virus and the H1N1 virus that emerged in 2009 to cause a pandemic.
  • Everyone 6 months of age and older should get a flu vaccine as soon as the 2011-2012 vaccines are available.
  • Vaccination of high risk persons is especially important to decrease their risk of severe flu illness.
  • People at high risk of serious flu complications include young children, pregnant women, people with chronic health conditions like asthma, diabetes or heart and lung disease and people 65 years and older.
  • Vaccination also is important for health care workers, and other people who live with or care for high risk people to keep from spreading flu to high risk people.
  • Children younger than 6 months are at high risk of serious flu illness, but are too young to be vaccinated. People who care for them should be vaccinated instead.
flu vaccine


  • Take everyday preventive actions to stop the spread of germs.
  • Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
  • Wash your hands often with soap and water. If soap and water are not available, use an alcohol-based hand rub.
  • Avoid touching your eyes, nose and mouth. Germs spread this way.
  • Try to avoid close contact with sick people.
  • If you are sick with flu-like illness, CDC recommends that you stay home for at least 24 hours after your fever is gone except to get medical care or for other necessities. (Your fever should be gone without the use of a fever-reducing medicine.)
  • While sick, limit contact with others as much as possible to keep from infecting them

flu handwashing

  • Take flu antiviral drugs if your doctor prescribes them.
  • If you get the flu, antiviral drugs can treat your illness.
  • Antiviral drugs are different from antibiotics. They are prescription medicines (pills, liquid or an inhaled powder) and are not available over-the-counter.
  • Antiviral drugs can make illness milder and shorten the time you are sick. They may also prevent serious flu complications.
  • It’s very important that antiviral drugs be used early (within the first 2 days of symptoms) to treat people who are very sick (such as those who are hospitalized) or people who are sick with flu symptoms and who are at increased risk of severe flu illness, such as pregnant women, young children, people 65 and older and people with certain chronic health conditions.
  • Flu-like symptoms include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. Some people also may have vomiting and diarrhea. People may be infected with the flu, and have respiratory symptoms without a fever.

flu antiviral drugs

Cholesterol Test



Cholesterol testing is recommended as a screening test to be done on all adults at least once every five years. It is frequently done in conjunction with a routine physical exam. It is usually ordered in combination with other tests including HDL-C, LDL-C, and triglycerides — often called a lipid profile.

Cholesterol is tested at more frequent intervals (often several times per year) in patients who have been prescribed diet and/or drugs to lower their cholesterol. The test is used to track how well these measures are succeeding in lowering cholesterol to desired levels and in turn lowering the risk of developing heart disease.

Cholesterol testing may be ordered more frequently for those who have one or more risk factors for heart disease. Major risk factors include:

  • Cigarette smoking
  • Age (men 45 years or older or women 55 years or older)
  • Hypertension (blood pressure of 140/90 or higher or taking high blood pressure medications)
  • Family history of premature heart disease (heart disease in an immediate family member—male relative under age 55 or female relative under age 65)
  • Pre-existing heart disease or already having had a heart attack
  • Diabetes mellitus

Cholesterol is a waxy, fat-like substance that occurs naturally in all parts of the body. Your body needs some cholesterol to work properly. But if you have too much in your blood, it can stick to the walls of your arteries. This is called plaque. Plaque can narrow your arteries or even block them.



Cholesterol Test



High levels of cholesterol in the blood can increase your risk of heart disease. Your cholesterol levels tend to rise as you get older. There are usually no signs or symptoms that you have high blood cholesterol, but it can be detected with a blood test. You are likely to have high cholesterol if members of your family have it, if you are overweight or if you eat a lot of fatty foods.



Cholesterol


You can lower your cholesterol by exercising more and eating more fruits and vegetables. You also may need to take medicine to lower your cholesterol.



Tuesday, April 10, 2012

Childhood Leukemia

Leukemia is cancer of the white blood cells. It is the most common type of childhood cancer.
Your blood cells form in your bone marrow. White blood cells help your body fight infection. In leukemia, however, the bone marrow produces abnormal white blood cells. These cells crowd out the healthy blood cells, making it hard for blood to do its work. Leukemia can develop quickly or slowly. Acute leukemia is a fast growing type while chronic leukemia grows slowly. Children with leukemia usually have one of the acute types.
Risk factors for childhood leukemia include having a brother or sister with leukemia, having certain genetic disorders and having had radiation or chemotherapy. Treatment often cures childhood leukemia. Treatment options include chemotherapy, other drug therapy and radiation. In some cases bone marrow and blood stem cell transplantation might help.

Childhood leukemia

Monday, April 9, 2012

Heart Failure



Heart failure is a condition in which the heart can't pump enough blood throughout the body. Heart failure does not mean that your heart has stopped or is about to stop working. It means that your heart is not able to pump blood the way it should.
  • The weakening of the heart's pumping ability causes
  • Blood and fluid to back up into the lungs
  • The buildup of fluid in the feet, ankles and legs - called edema
  • Tiredness and shortness of breath

The leading causes of heart failure are coronary artery disease, high blood pressure and diabetes.

Treatment includes treating the underlying cause of your heart failure, medicines, and heart transplantation if other treatments fail.

Heart failure is a serious condition. About 5 million people in the U.S. have heart failure. It contributes to 300,000 deaths each year.

Heart Failure

Friday, April 6, 2012

Heart Diseases



If you're like most people, you think that heart disease is a problem for other folks. But heart disease is the number one killer in the U.S. It is also a major cause of disability. There are many different forms of heart disease. The most common cause of heart disease is narrowing or blockage of the coronary arteries, the blood vessels that supply blood to the heart itself. This is called coronary artery disease and happens slowly over time. It's the major reason people have heart attacks.

Other kinds of heart problems may happen to the valves in the heart, or the heart may not pump well and cause heart failure. Some people are born with heart disease.

You can help reduce your risk of heart disease by taking steps to control factors that put you at greater risk:

Heart Diseases

Thursday, April 5, 2012

Sudden Cardiac Death



The heart has an internal electrical system that controls the rhythm of the heartbeat. Problems can cause abnormal heart rhythms, called arrhythmias. There are many types of arrhythmia. During an arrhythmia, the heart can beat too fast, too slow, or it can stop beating. Sudden cardiac arrest occurs when the heart develops an arrhythmia that causes it to stop beating. This is different than a heart attack, where the heart usually continues to beat but blood flow to the heart is blocked.

There are many possible causes of cardiac arrest. They include coronary heart disease, heart attack, electrocution, drowning, or choking. There may not be a known cause to the cardiac arrest.

Without medical attention, the person will die within a few minutes. People are less likely to die if they have early cardiopulmonary resuscitation (CPR) and defibrillation. Defibrillation is delivering an electric shock to restore the heart rhythm to normal.

Sudden Cardiac Death 




Signs and symptoms

Cardiac arrest is an abrupt cessation of pump function in the heart (as evidenced by the absence of a palpable pulse). Prompt intervention can usually reverse a cardiac arrest, but without such intervention it will almost always lead to death. In certain cases, it is an expected outcome to a serious illness.

However, due to inadequate cerebral perfusion , the patient will be unconscious and will have stopped breathing. The main diagnostic criterion to diagnose a cardiac arrest, (as opposed to respiratory arrest which shares many of the same features), is lack of circulation, however there are a number of ways of determining this. Near death experiences are reported by 10-20% of people who survived cardiac arrest.




Causes

Coronary heart disease


Coronary heart disease is the leading cause of sudden cardiac arrest. Many other cardiac and non-cardiac conditions also increase ones risk.

Approximately 60–70% of SCD is related to coronary heart disease. Among adults, ischemic heart disease is the predominant cause of arrest with 30% of people at autopsy showing signs of recent myocardial infarction.

Cardiac Arrest



Non-ischemic heart disease

A number of other cardiac abnormalities can increase the risk of SCD including: cardiomyopathy, cardiac rhythm disturbances, hypertensive heart disease, congestive heart failure.

In a group of military recruits aged 18–35, cardiac anomalies accounted for 51% of cases of SCD, while in 35% of cases the cause remained unknown. Underlying pathology included:coronary artery abnormalities (61%), myocarditis (20%), and hypertrophic cardiomyopathy (13%). Congestive heart failure increases the risk of SCD by 5 fold.

Many additional conduction abnormalities exist that place one at higher risk for cardiac arrest. For instance, long QT syndrome, a condition often mentioned in young people's deaths, occurs in 1/5000-1/7000 newborns and is estimated to be responsible 3000 deaths each year compared to the approximately 300000 cardiac arrests seen by emergency services . These conditions are a fraction of the overall deaths related to cardiac arrest, but represent conditions which may be detected prior to arrest, which may be treatable.


Non-cardiac

SCDs is unrelated to heart problems in 35% of cases. The most common non-cardiac causes: trauma, non-trauma related bleeding (such as gastrointestinal bleeding, aortic rupture, and intracranial hemorrhage), overdose, drowning and pulmonary embolism.

Wednesday, April 4, 2012

Coronary Artery Disease

Coronary artery disease (CAD) is the most common type of heart disease. It is the leading cause of death in the United States in both men and women.
CAD happens when the arteries that supply blood to heart muscle become hardened and narrowed. This is due to the buildup of cholesterol and other material, called plaque, on their inner walls. This buildup is called atherosclerosis. As it grows, less blood can flow through the arteries. As a result, the heart muscle can't get the blood or oxygen it needs. This can lead to chest pain (angina) or a heart attack. Most heart attacks happen when a blood clot suddenly cuts off the hearts' blood supply, causing permanent heart damage.
Over time, CAD can also weaken the heart muscle and contribute to heart failure and arrhythmias. Heart failure means the heart can't pump blood well to the rest of the body. Arrhythmias are changes in the normal beating rhythm of the heart.

Coronary Artery Disease

Monday, April 2, 2012

Coronary Artery Bypass Surgery

If you have coronary artery disease (CAD), the arteries that supply blood and oxygen to the heart muscle become hardened and narrowed. If lifestyle changes and medicines don't help, your doctor may recommend coronary artery bypass surgery.

The surgery uses a piece of a vein from the leg or artery from the chest or wrist. The surgeon attaches this to the coronary artery above and below the narrowed area or blockage. This allows blood to bypass the blockage. Some people need more than one bypass.

You may need bypass surgery for various reasons. Another procedure for CAD,angioplasty, may not have widened the artery enough. In some cases, the angioplasty tube can't reach the blockage.

A bypass also can close again. This happens in more than 10 percent of bypass surgeries, usually after 10 or more years.
coronary artery