Liver Blood Test

What are the basic functions of the liver?

The liver, located in the right upper portion of the abdominal cavity just beneath the right side of the rib cage, has many vital functions. Briefly, some of these functions are:

• Detoxification of blood
  
• Production of important clotting factor and other important proteins
  
• Metabolizing (processing) medications and nutrients
  
• Processing of waste products of hemoglobin
  
• Storing of vitamins, fat, cholesterol, and bile
  
• Production of glucose

What are common liver blood tests?

Liver blood tests are some of the most commonly performed blood tests. These tests can assess liver functions or liver injury. An initial step in detecting liver damage is a simple blood test to determine the presence of certain liver enzymes (proteins) in the blood. Under normal circumstances, these enzymes reside within the cells of the liver. But when the liver is injured for any reason, these enzymes are spilled into the blood stream. Enzymes are proteins that are present throughout the body, each with a unique function. Enzymes help to speed up (catalyze) routine and necessary chemical reactions in the body.
Among the most sensitive and widely used liver enzymes are the aminotransferases. They include aspartate aminotransferase (AST or SGOT) and alanine aminotransferase (ALT or SGPT). These enzymes are normally contained within liver cells. If the liver is injured or damaged, the liver cells spill these enzymes into the blood, raising the enzyme levels in the blood and signaling liver disease.
Other blood tests pertaining to the liver are measurements of some of the other enzymes found the liver. In addition to AST and ALT, alkaline phosphatase, 5' nucleotidase, and gamma-glutamyl transpeptidase (GGT) are other enzymes located in the liver. The focus of this article is mainly on the most common liver enzymes, AST and ALT.

What are the aminotransferases?

The aminotransferases catalyze chemical reactions in which an amino group from one amino acid (amino acids are building blocks of proteins) is transferred from a donor molecule to a recipient molecule. Hence, the names "aminotransferases."
Medical terms can sometimes be confusing, as is the case with these enzymes.

• Another name for aminotransferase is transaminase.
  
• The enzyme aspartate aminotransferase (AST) is also known as serum glutamic oxaloacetic transaminase (SGOT).
  
• Alanine aminotransferase (ALT) is also known as serum glutamic pyruvic transaminase (SGPT).

To put matters briefly, AST = SGOT and ALT = SGPT.

Normally, where are the aminotransferases?

AST (SGOT) is normally found in a variety of tissues including liver, heart, muscle, kidney, and brain. It is released into the serum when any one of these tissues is damaged. For example, its level in serum rises in heart attacks or with muscle disorders. It is therefore, not a highly specific indicator of liver injury as it can occur from other injured tissues.
ALT (SGPT) is, by contrast, normally found largely in the liver. This is not to say that it is exclusively located in liver, but that is where it is most concentrated. It is released into the bloodstream as the result of liver injury. Thus, it serves as a fairly specific indicator of liver status.

What are normal levels of AST and ALT?

• The normal range of values for AST (SGOT) is from 5 to 40 units per liter of serum (the liquid part of the blood).
  
• The normal range of values for ALT (SGPT) is from 7 to 56 units per liter of serum.

The ranges of AST and ALT numbers may differ slightly depending on the technique and protocols used by different laboratories. However, normal reference ranges are routinely provided by each laboratory and printed in the report.

What do elevated liver tests (AST and ALT) mean?

AST (SGOT) and ALT (SGPT) are sensitive indicators of liver damage or injury from different types of diseases. But it must be emphasized that higher-than-normal levels of these liver enzymes should not be automatically equated with liver disease. They may mean liver problems or they may not. For example, elevations of these enzymes can occur with muscle damage. The interpretation of elevated AST and ALT levels depends upon the entire clinical evaluation of an individual, and so it is best done by physicians experienced in evaluating liver disease and muscle disease.
Moreover, the precise levels of these enzymes do not correlate well with the extent of liver damage or the prognosis (outlook). Thus, the exact levels of AST (SGOT) and ALT (SGPT) cannot be used to determine the degree of liver disease or predict the future. For example, individuals with acute viral hepatitis A may develop very high AST and ALT levels (sometimes in the thousands of units/liter range). But most people with acute viral hepatitis A recover fully without residual liver disease. Conversely, people with chronic hepatitis C infection typically have only a little elevation in their AST and ALT levels while having substantial liver injury and even  advanced scarring of the liver (cirrhosis).

Heart Disease and Stress

Heart disease and stress introduction

Are stress and heart disease related? Does stress increase the risk of heart disease? Stress is a normal part of life. But if left unmanaged, stress can lead to emotional, psychological, and even physical problems, including heart disease, high blood pressure, chest pains, or irregular heart beats.

How Does Stress Increase the Risk for Heart Disease?

Medical researchers aren't sure exactly how stress increases the risk of heart disease. Stress itself might be a risk factor, or it could be that high levels of stress make other risk factors (such as high cholesterol or high blood pressure) worse. For example, if you are under stress, your blood pressure goes up, you may overeat, you may exercise less, and you may be more likely to smoke.
If stress itself is a risk factor for heart disease, it could be because chronic stress exposes your body to unhealthy, persistently elevated levels of stress hormones like adrenaline and cortisol. Studies also link stress to changes in the way blood clots, which increases the risk of heart attack.

Does Stress Affect Everyone the Same?

No. People respond in different ways to events and situations. One person may find an event joyful and gratifying, but another person may find the same event miserable and frustrating. Sometimes, people may handle stress in ways that make bad situations worse by reacting with feelings of anger, guilt, fear, hostility, anxiety, and moodiness. Others may face life's challenges with ease.

What Causes Stress?

Stress can be caused by a physical or emotional change, or a change in your environment that requires you to adjust or respond. Things that make you feel stressed are called "stressors."
Stressors can be minor hassles, major lifestyle changes, or a combination of both. Being able to identify stressors in your life and releasing the tension they cause are the keys to managing stress.
Below are some common stressors that can affect people at all stages of life.

• Illness, either personal or of a family member or friend.
• Death of a friend or loved one.
• Problems in a personal relationship.
• Work overload.
• Starting a new job.
• Unemployment.
• Retirement.
• Pregnancy.
• Crowds.
• Relocation.
• Daily hassles.
• Legal problems.
• Financial concerns.
• Perfectionism.

• What Are the Warning Signs of Stress?

  When you are exposed to long periods of stress, your body gives warning signals that something is wrong. These physical, cognitive, emotional and behavioral warning signs should not be ignored. They tell you that you need to slow down. If you continue to be stressed and you don't give your body a break, you are likely to develop health problems like heart disease. You could also worsen an existing illness.
  Below are some common warning signs and symptoms of stress.
  

  Physical signs	Dizziness, general aches and pains, grinding teeth, clenched jaws, headaches, indigestion, muscle tension, difficulty sleeping, racing heart, ringing in the ears, stooped posture, sweaty palms, tiredness, exhaustion, trembling, weight gain or loss, upset stomach
  Mental signs	Constant worry, difficulty making decisions, forgetfulness, inability to concentrate, lack of creativity, loss of sense of humor, poor memory
  Emotional signs	Anger, anxiety, crying, depression, feeling powerless, frequent mood swings, irritability, loneliness, negative thinking, nervousness, sadness
  Behavioral signs	Bossiness, compulsive eating, critical attitude of others, explosive actions, frequent job changes, impulsive actions, increased use of alcohol or drugs, withdrawal from relationships or social situations

   

Polio

What is the history of polio?

Polio is caused by a virus and has been around for thousands of years. There are even Egyptian artifacts portraying individuals with typical features of post-polio paralysis. Polio has been called many different names, including infantile paralysis, debility of the lower extremities, and spinal paralytic paralysis. We now refer to the virus and disease as polio, which is short for poliomyelitis and has Greek derivation: polios (gray), myelos (marrow), and itis (inflammation).
Polio is caused by a very infectious enterovirus, poliovirus (PV), which primarily affects young children and is spread through direct person-to-person contact, with infected mucus, phlegm, feces, or by contact with food and water contaminated by feces of another infected individual. The virus multiplies in the gastrointestinal tract where it can also invade the nervous system, causing permanent neurological damage in some individuals.
Most individuals infected with polio remain asymptomatic or develop only mild flu-like symptoms, including fatigue, malaise, fever, headache, sore throat, and vomiting. In fact, the symptoms, if present, may only last 48-72 hours; however, those individuals will continue to shed virus in their stools for a prolonged period, serving as a reservoir for subsequent infections. About 2%-5% of infected individuals go on to develop more serious symptoms that may include respiratory problems and paralysis. Currently, there is no cure for polio; only vaccination can prevent the spread of the disease, and although in the developed world it is almost unheard of, globally, polio remains a fairly common disease. Originally, international organizations believed it possible to eradicate polio by 2000, though this has been more difficult than initially hoped for.

What causes polio?

The symptoms of polio are caused by the poliovirus, which is a small RNA virus that is spread through contact with the oral mucosa (mouth, nose, etc). Most commonly, the virus attaches to and infects intestinal cells, multiplies, and is excreted in the stool of the infected individual. Rarely, in 2% of the cases, the virus spreads from the gastrointestinal tract to the nervous system and causes paralytic disease.

How is polio spread?

Polio is spread in an "oral-fecal" manner. Person-to-person infection occurs by contact with infected mucus, phlegm, feces, or by contact with food and water contaminated by feces of another infected individual.

What are signs and symptoms of polio?

The signs and symptoms of polio differ depending on the extent of the infection. Signs and symptoms can be divided into paralytic and non-paralytic polio.
In non-paralytic polio which accounts for most individuals infected with polio, patients remain asymptomatic or develop only mild flu-like symptoms, including fatigue, malaise, fever, headache, sore throat, and vomiting. The symptoms, if present, may only last 48-72 hours, though usually they last for one to two weeks.
Paralytic polio occurs in about 2% of people infected with the polio virus and is a much more serious disease. Symptoms occur as a result of nervous system and spinal cord infection and inflammation. Symptoms can include

• abnormal sensation,
• breathing difficulty,
• difficulty swallowing,
• urinary retention,
• constipation,
• drooling,
• headache,
• mood swings,
• muscle pain and spasms, and
• paralysis.

Approximately 5%-10% of patients who develop paralytic polio often die from respiratory failure, since they are unable to breathe on their own. That is why it is imperative that patients receive appropriate medical evaluation and treatment. Prior to the vaccine era and the use of modern ventilators, patients would be placed in an "iron lung" (a negative pressure ventilator, which was used to support breathing in patients suffering from paralytic polio).

How is polio diagnosed?

The diagnosis of polio is a clinical one. History of exposure with no history of previous vaccination is the initial hint. Often, a spinal tap for CSF fluid is done to help distinguish polio from other diseases that initially have similar symptoms (for example, meningitis). After that, viral cultures (taken from throat washings, stools, or CSF fluid) and measurement of polio antibodies support the diagnosis.

How is polio treated?

There is no cure for polio, so prevention is very important. Patients with non-paralytic polio need to be monitored for progression to paralytic polio. Patients with paralytic polio need to be monitored for signs and symptoms of respiratory failure, which may require lifesaving therapies such as respiratory support. In addition, a number of treatments are available to decrease some of the less severe symptoms. There are medications to treat urinary infections and urinary retention and pain management plans for muscle spasms. Unfortunately, there are only supportive measures available to treat the symptoms of paralytic polio. Patients who recover from polio may require physical therapy, leg braces, or even orthopedic surgery to improve physical function.

Is there a vaccine that prevents polio?

The story of polio vaccine is a true medical success story. It is not over yet since polio still causes significant illness in less developed areas of the world such as in India and Africa.
During the last half of the 19th century and into the first half of the 20th century, polio was a global epidemic. Even the future U.S. president, Franklin D. Roosevelt, contracted paralytic polio in 1921. President Franklin D. Roosevelt was quite influential in increasing both public awareness and scientific research dedicated to eradicating the disease. In 1938, after the founding of the National Foundation for Infantile Paralysis (March of Dimes), there was a significant effort to develop a vaccine to prevent polio. This came to fruition in 1955 when Dr. Jonas Salk developed an injectable inactivated polio vaccine (IVP) which was soon distributed and administered to children all over the United States and Canada. The current inactivated polio vaccine has evolved over time, but since 1999, it has been the recommended form of the polio vaccine in developed nations.
In 1961, an oral live virus vaccine against polio (OVP) was developed by Albert Sabin which became available and widely used from 1963 to 1999 in developed countries and to present day in underdeveloped countries. This oral virus vaccine is still recommended to control polio pandemics all over the world due to its ease of administration (no needles needed).
Both vaccines were developed for children since they are the group that generally seemed to be at highest risk. However, the oral vaccine (OVP) should not be given to children who are immunodepressed as they can develop vaccine-associated paralytic poliomyelitis (VAPP).
The newest injected vaccine is an enhanced inactivated polio vaccine that is more immunogenic (produces a strong immune system response) than the previous IVP and is used in the U.S.; it does not cause VAPP. The original OVP (also termed tOVP) was a trivalent oral vaccine (polio viruses types 1-3) but caused a measurable immune response in only about 40%-50% of people who obtained it. Unfortunately, this trivalent oral vaccine was often not immunogenic fast enough to withstand dilution or removal from the gastrointestinal tract by chronic diarrhea that existed in many patients. OVP was modified in 2005 to a monovalent (type 1 polio virus only) termed mOVP1. This change caused the vaccine to be three times more immunogenic than the original trivalent OVP and generated an immune response in over 80% of people who obtained this oral vaccine. This newer oral vaccine is used in many developing countries where no needles or trained personnel are available and where chronic diarrhea further reduces the effectiveness of the original trivalent OVP. Other monovalent OVP (for example, mOVP3, used for the infrequent polio type 3 outbreaks) are occasionally used.
Currently, four doses of inactivated polio vaccine (IPV) are recommended for children when they are 2 months old, 4 months old, 6-18 months old, and finally at 4-6 years of age.
Due to vaccination programs, there have been very few cases of polio in the western hemisphere since the 1970s, and although current worldwide eradication programs continue to be successful, there is still work to be done to eliminate polio in developing countries.