Urobilinogen is a chemical substance formed during the breakdown of red blood cells in the liver and intestines. It is then excreted into the urine and stool. The amount of urobilinogen in the urine can be used as an indicator of liver and biliary system function.
In this article, we will discuss the formation and excretion of urobilinogen, the purpose and methods of urine urobilinogen testing, the normal range of urine urobilinogen, causes of abnormal levels, and diagnosis and treatment options. Read Old Article
Introduction of Urine Urobilinogen:
Urobilinogen is a byproduct of the breakdown of red blood cells that is formed in the liver and intestines. It is then excreted into the urine and stool. The measurement of urobilinogen in urine can provide valuable information about liver and biliary system function.
Abnormal levels of urobilinogen in urine can indicate various conditions, including liver disease, hemolytic anemia, and bile duct obstruction. Therefore, urine urobilinogen testing is an important diagnostic tool that can help healthcare providers identify and manage underlying health conditions.
Defination of Urine Urobilinogen:
Urine urobilinogen refers to the amount of urobilinogen present in a person’s urine. Urobilinogen is a colorless substance that is produced by the breakdown of hemoglobin, the oxygen-carrying molecule found in red blood cells. The liver converts urobilinogen into bilirubin, which is then excreted into bile and stool. However, a small amount of urobilinogen is also excreted into the urine.
Formation and Excretion:
Urobilinogen is formed during the breakdown of hemoglobin, which is the oxygen-carrying molecule found in red blood cells. When red blood cells reach the end of their lifespan, they are broken down and their components are recycled by the body. Hemoglobin is broken down into heme and globin. The heme is then converted to biliverdin, which is further converted to bilirubin. Bilirubin is transported to the liver, where it is conjugated (chemically modified) and excreted into bile.
Some of the conjugated bilirubin is converted back to urobilinogen in the intestines by bacterial action. Most of this urobilinogen is either excreted in the feces or reabsorbed into the bloodstream and processed by the liver. However, a small amount is also excreted into the urine.
Therefore, the amount of urobilinogen in urine is influenced by the rate of red blood cell breakdown, liver function, and the bacterial action in the intestines.
Purpose of Urine Urobilinogen Testing:
The purpose of urine urobilinogen testing includes:
- Diagnosing liver disease: Elevated levels of urobilinogen in urine can indicate liver damage or disease.
- Identifying bile duct obstruction: Obstruction in the bile duct can cause an increase in urobilinogen in urine.
- Diagnosing hemolytic anemia: Hemolytic anemia is a condition where red blood cells are destroyed faster than they can be produced, resulting in an increase in urobilinogen levels.
- Monitoring liver function: Urine urobilinogen levels can be used to monitor liver function in patients with liver disease.
- Assessing the effectiveness of treatment: Urine urobilinogen testing can be used to monitor the response to treatment for liver disease or hemolytic anemia.
- Screening for liver disease: Urine urobilinogen testing can be used as a screening tool to identify individuals at risk for liver disease, such as heavy alcohol consumers or those with a family history of liver disease.
Why Get Tested:
Some of the reasons why a healthcare provider may order a urine urobilinogen test include:
- Jaundice: If a person has symptoms of jaundice, such as yellowing of the skin and eyes, their healthcare provider may order a urine urobilinogen test to help diagnose the cause.
- Liver disease: If a person has a history of liver disease or if their healthcare provider suspects liver disease, a urine urobilinogen test may be ordered to assess liver function.
- Hemolytic anemia: Hemolytic anemia is a condition where red blood cells are destroyed faster than they can be produced. A urine urobilinogen test can help diagnose this condition.
- Bile duct obstruction: If a person has symptoms of bile duct obstruction, such as abdominal pain or dark urine, their healthcare provider may order a urine urobilinogen test to help diagnose the cause.
- Monitoring treatment: If a person is undergoing treatment for liver disease or hemolytic anemia, their healthcare provider may order a urine urobilinogen test to monitor the effectiveness of treatment.
- Routine screening: In some cases, a urine urobilinogen test may be ordered as part of a routine screening for liver disease or other conditions that affect liver function.
When to get Tested:
A healthcare provider may order a urine urobilinogen test if a person experiences the following:
- Symptoms of liver disease, such as jaundice, abdominal pain, and fatigue.
- Symptoms of bile duct obstruction, such as abdominal pain, nausea, vomiting, and dark urine.
- Symptoms of hemolytic anemia, such as fatigue, weakness, and pale skin.
- Routine screening for liver disease, especially in individuals with risk factors such as heavy alcohol consumption, a family history of liver disease, or a history of hepatitis.
- Monitoring of liver function in patients with liver disease.
- Monitoring of treatment effectiveness in patients with liver disease or hemolytic anemia.
Sample Required for Urine Urobilinogen:
A urine sample is required for urine urobilinogen testing. The sample can be collected at any time of day, and there is no special preparation required. However, it is important to follow any instructions provided by the healthcare provider or laboratory performing the test.
To collect a urine sample, a person should:
- Wash their hands thoroughly with soap and water.
- Clean the genital area with a cleansing wipe provided by the healthcare provider.
- Begin urinating into the toilet.
- Without stopping the stream of urine, collect a midstream urine sample in a sterile container provided by the healthcare provider.
- Seal the container tightly and label it with their name and other identifying information as instructed.
- Deliver the sample to the healthcare provider or laboratory as soon as possible after collection, or as instructed.
It is important to ensure that the urine sample is collected correctly to ensure accurate test results. If a person has any questions or concerns about collecting a urine sample, they should discuss them with their healthcare provider or the laboratory performing the test.
Type of urine samples:
- Random sample:
This is a diluted urine sample and may give an inaccurate interpretation of patient health. But is best to do microscopy to evaluate WBC or RBC. - First Morning sample:
This is the best sample for microscopy and urine analysis. This is the concentrated urine because of urine remained throughout the night in the urinary bladder. This will contains an increased concentration of analytes and cellular elements. Urine must have remained in the bladder for 8 hours is considered as the first-morning sample. - Urine for sugar (Postprandial 2 hours):
Postprandial 2 hours sample collected after 2 hours of high carbohydrate diet. - Midstream clean catch urine:
This sample is needed for the culture and sensitivity of urinary infection. The patient is advised to clean the urethra, then discard the first few mL of urine. Now midstream of the urine is collected in the sterile container. - 24 Hours of a urine sample
- In this case, discard the first urine and note the time.
- Now collect urine in the container for 24 hours and put the last sample in the container.
- Refrigerate the sample.
- This 24 hours samples are needed for measuring urea, creatinine, sodium, potassium, glucose, and catecholamines.
- Suprapubic collection of the urine sample:
This is done in the patients who cannot be catheterized and the sample is needed for culture. This sample is collected by the needle. - Catheter collection of urine:
This is done by patients who are bedridden and can not urinate. - Pediatric urine sample:
In infants, special collection bags are made adherent around the urethra. Then urine is transferred to a container.
Normal Values of Urine Urobilinogen:
| Sample Type | Age Group | Normal Value |
|---|---|---|
| Random urine | Adults | 0.2-1.0 mg/dL |
| Children | < 0.2 mg/dL | |
| 24-hour urine | Adults | 0.3-3.0 mg/24h |
| Children | < 2.0 mg/24h | |
| Spot urine | Adults | 0.2-1.0 mg/dL |
| Children | < 0.2 mg/dL |
Note that normal values may vary slightly depending on the laboratory performing the test and the specific method used. It is important to discuss test results with a healthcare provider to understand what they mean for an individual’s health. Elevated levels of urine urobilinogen may indicate a problem with liver or biliary system function, and further testing may be necessary to determine the underlying cause.
Techniques and Methods of Testing:
There are several techniques and methods available for urine urobilinogen testing, including:
- Dipstick test: This is a rapid, semi-quantitative method for detecting urobilinogen in urine. The dipstick contains a pad impregnated with a reagent that reacts with urobilinogen to produce a color change. The color is then compared to a color chart on the dipstick container to determine the approximate concentration of urobilinogen in the urine.
- Ehrlich’s test: This is a colorimetric test that involves the addition of p-dimethylaminobenzaldehyde to urine, which reacts with urobilinogen to produce a pink or red color. The intensity of the color is proportional to the amount of urobilinogen present in the urine.
- Watson-Schwartz test: This is another colorimetric test that involves the addition of a reagent containing chloroform and p-dimethylaminobenzaldehyde to urine. Urobilinogen reacts with the reagent to produce a blue or purple color, which can be quantified by measuring the absorbance of light at a specific wavelength.
- Hoesch test: This is a modification of the Ehrlich’s test that involves the addition of sodium nitrite and acetic acid to urine before the addition of p-dimethylaminobenzaldehyde. This test is more sensitive than the Ehrlich’s test and can detect lower levels of urobilinogen.
- Multistix test: This is a simple and convenient test that uses a dipstick impregnated with a reagent that reacts with urobilinogen to produce a color change. The intensity of the color can be compared to a color chart provided with the test kit to estimate the amount of urobilinogen present in the urine.
- Automated urinalysis: This is a method that uses automated instruments to analyze urine samples for various parameters, including urobilinogen. The instruments use a variety of techniques, such as reflectance photometry and ion-selective electrode analysis, to measure urobilinogen levels.
- Spectrophotometry: This method measures the absorption of light by urobilinogen in the urine at a specific wavelength, typically 546 nm. The amount of light absorbed is proportional to the urobilinogen concentration in the sample.
- High-performance liquid chromatography (HPLC): This is a laboratory method that separates and quantifies different substances in a urine sample, including urobilinogen. HPLC provides a highly accurate measurement of urobilinogen levels and can be used to identify other substances in the urine that may interfere with urobilinogen measurement.
The choice of method for urine urobilinogen testing may depend on factors such as the availability of equipment, the volume of samples to be tested, and the sensitivity and specificity of the test. Healthcare providers and laboratory personnel can help determine the most appropriate method for a specific situation.
Interpretation of Results:
Interpretation of urine urobilinogen test results depends on the individual’s clinical presentation, medical history, and other laboratory test results. Generally, elevated levels of urobilinogen in urine may indicate liver or biliary system dysfunction. However, urobilinogen levels can also be affected by certain medications, diet, and physical activity.
Below are some possible interpretations of urine urobilinogen test results:
- Normal: A normal result means that the concentration of urobilinogen in urine is within the expected range. However, it is important to note that normal values may vary slightly depending on the laboratory performing the test and the specific method used.
- Low: Low levels of urobilinogen in urine are generally not clinically significant and may occur in individuals with low red blood cell breakdown or those on certain medications.
- High: Elevated levels of urobilinogen in urine may indicate liver or biliary system dysfunction, such as hepatitis, cirrhosis, or obstruction of the bile ducts. However, it is important to note that other factors such as hemolytic anemia, excessive exercise, or certain medications may also cause high urobilinogen levels.
Causes of Abnormal Urine Urobilinogen Levels:
Abnormal levels of urobilinogen in urine can be caused by a variety of factors, including:
- Liver disease: Conditions such as hepatitis, cirrhosis, and liver cancer can cause abnormal urobilinogen levels in urine.
- Biliary obstruction: Obstruction of the bile ducts can lead to increased levels of urobilinogen in urine.
- Hemolytic anemia: This is a condition in which red blood cells break down more rapidly than usual, leading to increased urobilinogen levels in urine.
- Certain medications: Some medications, such as phenobarbital and rifampin, can cause abnormal urobilinogen levels in urine.
- Excessive exercise: Intense physical activity can lead to increased breakdown of red blood cells and increased urobilinogen levels in urine.
- Malabsorption syndromes: Conditions such as celiac disease and inflammatory bowel disease can interfere with the absorption of nutrients, including bilirubin, leading to abnormal urobilinogen levels in urine.
- Inherited disorders: Certain inherited disorders such as Gilbert’s syndrome and Crigler-Najjar syndrome can cause abnormal urobilinogen levels in urine.
It is important to note that abnormal urobilinogen levels in urine can also be caused by other factors not listed above, and a healthcare provider should be consulted for a proper diagnosis and treatment plan.
Increased Urine Urobilinogen:
Increased urine urobilinogen levels can be caused by various conditions, including:
- Liver diseases: Conditions such as hepatitis, cirrhosis, and liver cancer can cause liver dysfunction and increase the production of bilirubin, which can lead to increased levels of urobilinogen in urine.
- Biliary obstruction: Obstruction of the bile ducts can cause bilirubin to accumulate in the liver and increase the production of urobilinogen, leading to elevated levels in urine.
- Hemolytic anemia: This is a condition in which red blood cells break down more rapidly than usual, leading to an increased production of bilirubin and urobilinogen in urine.
- Certain medications: Some medications, such as phenobarbital and rifampin, can increase the production of urobilinogen and cause elevated levels in urine.
- Inherited disorders: Certain inherited disorders such as Gilbert’s syndrome and Crigler-Najjar syndrome can cause abnormal bilirubin metabolism and increase the production of urobilinogen.
- Excessive exercise: Intense physical activity can lead to increased breakdown of red blood cells and increased urobilinogen levels in urine.
- Malabsorption syndromes: Conditions such as celiac disease and inflammatory bowel disease can interfere with the absorption of nutrients, including bilirubin, leading to increased urobilinogen levels in urine.
It is important to note that elevated urobilinogen levels in urine may also be caused by other factors not listed above and should be evaluated by a healthcare provider for a proper diagnosis and treatment plan.
Decreased Urine Urobilinogen:
Decreased urine urobilinogen levels may be caused by several conditions, including:
- Hepatic dysfunction: Liver diseases such as cirrhosis and hepatitis can decrease the production of bilirubin, which in turn can lead to decreased urobilinogen levels in urine.
- Biliary obstruction: Obstruction of the bile ducts can lead to decreased bilirubin production and subsequently decreased urobilinogen levels in urine.
- Alcohol consumption: Alcohol can cause liver damage, which can affect the production of bilirubin and subsequently decrease urobilinogen levels in urine.
- Medications: Certain medications such as phenobarbital and chloramphenicol can decrease the production of urobilinogen and cause decreased levels in urine.
- Congenital disorders: Inherited disorders such as Dubin-Johnson syndrome and Rotor syndrome can affect the metabolism of bilirubin and lead to decreased urobilinogen levels in urine.
It is important to note that decreased urobilinogen levels in urine may also be caused by other factors not listed above and should be evaluated by a healthcare provider for a proper diagnosis and treatment plan.
Factors Affecting Urine Urobilinogen Levels:
Several factors can affect urine urobilinogen levels, including:
- Diet: Consumption of foods rich in chlorophyll, such as spinach and broccoli, can increase urobilinogen levels in urine.
- Medications: Certain medications such as phenobarbital and rifampin can increase urobilinogen levels in urine, while others such as chloramphenicol can decrease levels.
- Exercise: Intense physical activity can increase urobilinogen levels in urine.
- Dehydration: Dehydration can cause urine to become more concentrated and lead to increased urobilinogen levels.
- Menstruation: Menstruation can cause temporary increases in urobilinogen levels in urine.
- Liver function: Changes in liver function due to disease or other factors can affect urobilinogen production and subsequently affect urine levels.
- Aging: Aging can lead to decreased liver function and subsequently affect urobilinogen production and urine levels.
It is important to note that urine urobilinogen levels should be interpreted in the context of clinical history and other laboratory results for a proper diagnosis and treatment plan.
Follow-up Testing and Diagnosis:
Follow-up testing and diagnosis may be necessary if urine urobilinogen levels are abnormal. The appropriate course of action will depend on the underlying cause of the abnormal results. Some possible follow-up tests and diagnostic procedures include:
- Liver function tests: These tests can evaluate liver function and help identify any underlying liver diseases.
- Bilirubin tests: Bilirubin levels can help determine the cause of abnormal urobilinogen levels and identify conditions such as hemolytic anemia, liver disease, and biliary obstruction.
- Imaging tests: Imaging tests such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) may be used to evaluate the liver and biliary system.
- Biopsy: A liver biopsy may be recommended to evaluate liver function and diagnose liver diseases.
- Additional urine tests: Additional urine tests such as urine bilirubin, urine urobilin, and urine porphyrin tests may be ordered to help identify the underlying cause of abnormal urobilinogen levels.
It is important to consult a healthcare provider for proper evaluation and management if urine urobilinogen levels are abnormal.
Treatment and Preventions of Abnormal Urine Urobilinogen Levels:
The treatment and prevention of abnormal urine urobilinogen levels will depend on the underlying cause. Some possible treatments and preventative measures include:
- Liver disease: If abnormal urobilinogen levels are due to liver disease, treatment may include medications to manage symptoms and prevent further liver damage, lifestyle changes to reduce alcohol consumption and improve nutrition, and in some cases, liver transplantation.
- Hemolytic anemia: If abnormal urobilinogen levels are due to hemolytic anemia, treatment may include medications to manage symptoms, blood transfusions to replace lost red blood cells, and in severe cases, surgery to remove the spleen.
- Biliary obstruction: If abnormal urobilinogen levels are due to biliary obstruction, treatment may include procedures such as endoscopic retrograde cholangiopancreatography (ERCP) to remove the obstruction and relieve symptoms.
- Medications: If abnormal urobilinogen levels are due to medications, a healthcare provider may adjust the dose or switch to a different medication.
- Lifestyle changes: Certain lifestyle changes such as improving nutrition, reducing alcohol consumption, and maintaining a healthy weight may help prevent liver disease and other conditions that can cause abnormal urobilinogen levels.
It is important to follow a healthcare provider’s recommendations for treatment and preventative measures to manage abnormal urobilinogen levels effectively.
Differences Between Urine Bilirubin and Urobilinogen:
Here are differences between urine bilirubin and urobilinogen:
- Source: Bilirubin is produced from the breakdown of hemoglobin in the liver, while urobilinogen is produced from the breakdown of bilirubin in the intestines.
- Production: Bilirubin is produced in the liver, while urobilinogen is produced in the intestines.
- Color: Bilirubin is yellow-green in color, while urobilinogen is colorless.
- Solubility: Bilirubin is insoluble in water, while urobilinogen is soluble in water.
- Excretion: Bilirubin is excreted in the urine and feces, while urobilinogen is excreted mainly in the feces.
- Chemical properties: Bilirubin is a tetrapyrrole compound, while urobilinogen is a colorless tetrapyrrole compound.
- Function: Bilirubin is a waste product of heme metabolism, while urobilinogen is involved in the production of stercobilin, which gives feces their characteristic brown color.
- Clinical significance: Elevated urine bilirubin levels are often associated with liver dysfunction or bile duct obstruction, while elevated urobilinogen levels may indicate liver disease or hemolytic anemia.
- Testing method: Urine bilirubin is typically measured using a dipstick test, while urobilinogen is measured using a chemical reaction in a laboratory.
- Normal values: Normal values for urine bilirubin are usually negative or trace, while normal values for urobilinogen can range from 0.2 to 1.0 mg/dL.
- Sample requirement: Urine bilirubin can be measured in a random urine sample, while urobilinogen levels are typically measured in a 24-hour urine sample.
- Age: Urine bilirubin levels may be higher in newborns due to the breakdown of fetal red blood cells, while urobilinogen levels may be higher in older adults due to decreased liver function.
- Medications: Certain medications can affect urine bilirubin levels, while others can affect urobilinogen levels.
- Dehydration: Dehydration can cause a false-positive result for urine bilirubin on a dipstick test, while it does not affect urobilinogen levels.
- Hematuria: The presence of blood in urine can interfere with the measurement of urine bilirubin levels, while it does not affect urobilinogen levels.
- Reference ranges: The reference ranges for urine bilirubin and urobilinogen may differ between laboratories.
- Sensitivity: Urine bilirubin is less sensitive than urobilinogen for detecting liver disease or hemolytic anemia.
- Specificity: Urine bilirubin is more specific than urobilinogen for detecting liver dysfunction or bile duct obstruction.
- Diagnostic utility: Urine bilirubin is often used as a screening test for liver disease, while urobilinogen is often used to monitor liver function in people with liver disease.
- Follow-up testing: Elevated urine bilirubin levels may require follow-up testing with blood tests or imaging studies to determine the underlying cause, while elevated urobilinogen levels may require monitoring or treatment for liver disease or hemolytic anemia.
Table of differences between Urine Bilirubin and Urobilinogen:
| Urine Bilirubin | Urobilinogen | |
|---|---|---|
| Source | Produced from the breakdown of hemoglobin in the liver | Produced from the breakdown of bilirubin in the intestines |
| Production | Produced in the liver | Produced in the intestines |
| Color | Yellow-green | Colorless |
| Solubility | Insoluble in water | Soluble in water |
| Excretion | Excreted in the urine and feces | Excreted mainly in the feces |
| Chemical properties | Tetrapyrrole compound | Colorless tetrapyrrole compound |
| Function | Waste product of heme metabolism | Involved in the production of stercobilin, which gives feces their characteristic brown color |
| Clinical significance | Elevated levels may indicate liver dysfunction or bile duct obstruction | Elevated levels may indicate liver disease or hemolytic anemia |
| Testing method | Measured using a dipstick test | Measured using a chemical reaction in a laboratory |
| Normal values | Negative or trace | 0.2-1.0 mg/dL |
| Sample requirement | Random urine sample | 24-hour urine sample |
| Age | Higher in newborns due to the breakdown of fetal red blood cells | Higher in older adults due to decreased liver function |
| Medications | Some medications can affect levels | Some medications can affect levels |
| Dehydration | Can cause a false-positive result on a dipstick test | Does not affect levels |
| Hematuria | Presence of blood in urine can interfere with measurement | Does not affect levels |
| Reference ranges | May differ between laboratories | May differ between laboratories |
| Sensitivity | Less sensitive for detecting liver disease or hemolytic anemia | More sensitive for detecting liver disease or hemolytic anemia |
| Specificity | More specific for detecting liver dysfunction or bile duct obstruction | Less specific for detecting liver dysfunction or bile duct obstruction |
| Diagnostic utility | Often used as a screening test for liver disease | Often used to monitor liver function in people with liver disease |
| Follow-up testing | May require follow-up testing with blood tests or imaging studies to determine underlying cause | May require monitoring or treatment for liver disease or hemolytic anemia |
FAQs:
What is urine urobilinogen?
Urine urobilinogen is a waste product formed from the breakdown of hemoglobin in red blood cells. It is excreted in the urine and can be measured as an indicator of liver and blood disorders.
How is a urine urobilinogen test performed?
A urine urobilinogen test is usually done on a urine sample collected in a clean container. The sample is analyzed using a dipstick or other laboratory methods.
What is a normal range for urine urobilinogen?
The normal range for urine urobilinogen is 0.1 to 1.0 mg/dL or less than 17 µmol/L.
What causes high levels of urine urobilinogen?
High levels of urine urobilinogen can be caused by liver disease, hemolytic anemia, or biliary obstruction, among other conditions.
What causes low levels of urine urobilinogen?
Low levels of urine urobilinogen are not typically a cause for concern and may be due to a low level of red blood cell breakdown or other factors.
Can medications affect urine urobilinogen levels?
Yes, certain medications such as rifampin, phenazopyridine, and phenothiazines can increase urine urobilinogen levels.
How can abnormal urine urobilinogen levels be treated?
The treatment for abnormal urine urobilinogen levels depends on the underlying cause, but may include medications, lifestyle changes, and surgery in some cases.
Can urine urobilinogen levels fluctuate?
Yes, urine urobilinogen levels can fluctuate based on factors such as medication use, diet, and underlying health conditions.
How often should urine urobilinogen testing be done?
Urine urobilinogen testing may be done as part of routine blood or urine testing or as recommended by a healthcare provider based on symptoms or risk factors.
Can urine urobilinogen testing be done at home?
Yes, urine urobilinogen testing can be done at home using dipstick tests, but it is recommended to consult a healthcare provider for proper interpretation of results.
Are there any risks associated with urine urobilinogen testing?
There are no known risks associated with urine urobilinogen testing.
What can interfere with urine urobilinogen testing?
Certain medications, exposure to light, and contamination of the urine sample can interfere with urine urobilinogen testing.
Can abnormal urine urobilinogen levels indicate cancer?
Abnormal urine urobilinogen levels are not typically indicative of cancer, but may be a sign of underlying liver or blood disorders.
Can diet affect urine urobilinogen levels?
Diet may have a minor effect on urine urobilinogen levels, but it is not a major factor in determining abnormal levels.
Conclusion:
In conclusion, urine urobilinogen testing is a useful tool for assessing liver and blood disorders. The test can be performed using dipstick or laboratory methods, and normal ranges vary based on age and sample type. Abnormal levels of urine urobilinogen can indicate underlying health conditions and may require follow-up testing and treatment. However, fluctuations in urine urobilinogen levels can be caused by a variety of factors, including medication use and diet. It is important to consult a healthcare provider for proper interpretation of urine urobilinogen test results and to discuss any concerns or symptoms.
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