Alanine transaminase (ALT) blood test

Definition

The alanine transaminase (ALT) blood test measures the level of the enzyme ALT in the blood.

Alternative Names

SGPT; Serum glutamate pyruvate transaminase; Alanine transaminase; Alanine aminotransferase

How the Test is Performed

A blood sample is needed.

How to Prepare for the Test

No special preparation is needed.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

ALT is an enzyme found in a high level in the liver. An enzyme is a protein that causes a specific chemical change in the body.

Injury to the liver results in release of ALT into the blood.

This test is mainly done along with other tests (such as AST, ALP, and bilirubin) to diagnose and monitor liver disease.

Normal Results

The normal range is 4 to 36 U/L.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different samples. Talk to your health care provider about the meaning of your specific test results.

What Abnormal Results Mean

An increased ALT level is often a sign of liver disease. Liver disease is even more likely when the levels of substances checked by other liver blood tests have also increased.

An increased ALT level may be due to any of the following:

• Scarring of the liver (cirrhosis)
• Death of liver tissue
• Swollen and inflamed liver (hepatitis)
• Too much iron in the body (hemochromatosis)
• Too much fat in the liver (fatty liver)
• Lack of blood flow to the liver (liver ischemia)
• Liver tumor or cancer
• Use of drugs that are toxic to the liver
• Mononucleosis (“mono”)
• Swollen and inflamed pancreas (pancreatitis)

Risks

There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but may include:

• Excessive bleeding
• Fainting or feeling lightheaded
• Multiple punctures to locate veins
• Hematoma (blood collecting under the skin)
• Infection (a slight risk any time the skin is broken)

Images

References

Chernecky CC, Berger BJ. Alanine aminotransferase (ALT, alanine transaminase, SGPT) – serum. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:109-110.

Daniels L, Khalili M, Goldstein E, Bluth MH, Bowne WB, Pincus MR. Evaluation of liver function. In: McPherson RA, Pincus MR, eds. Henry’s Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 22.

Pratt DS. Liver chemistry and function tests. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran’s Gastrointestinal and Liver Disease: Pathophysiology/Diagnosis/Management. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 73.

Last reviewed January 24, 2021 by David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team..

Related specialties

Alanine transaminase – wikidoc

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Alanine transaminase (ALT) is a transaminase enzyme (EC 2.6.1.2). It is also called alanine aminotransferase (ALAT) and was formerly called serum glutamate-pyruvate transaminase (SGPT) or serum glutamic-pyruvic transaminase (SGPT) and was first characterized in the mid-1950s by Arthur Karmen and colleagues. ^[1] ALT is found in plasma and in various body tissues, but is most common in the liver. It catalyzes the two parts of the alanine cycle. Serum ALT level, serum AST (aspartate transaminase) level, and their ratio (AST/ALT ratio) are commonly measured clinically as biomarkers for liver health. The tests are part of blood panels.

Contents

• 1 Function
• 2 Clinical significance
  • 2.1 Elevated levels
• 3 See also
• 4 References
• 5 External links

Function

ALT catalyzes the transfer of an amino group from L-alanine to α-ketoglutarate, the products of this reversible transamination reaction being pyruvate and L-glutamate.

L-alanine + α-ketoglutarate ⇌ pyruvate + L-glutamate

File:Alanine transaminase.png

ALT (and all aminotransferases) require the coenzyme pyridoxal phosphate, which is converted into pyridoxamine in the first phase of the reaction, when an amino acid is converted into a keto acid.

Clinical significance

ALT is commonly measured clinically as part of liver function tests and is a component of the AST/ALT ratio.^[2] When used in diagnostics, it is almost always measured in international units/liter (IU/L)^[3] or µkat. While sources vary on specific reference range values for patients, 0-40 IU/L is the standard reference range for experimental studies.^[2]

Elevated levels

Test results should always be interpreted using the reference range from the laboratory that produced the result. However typical reference intervals for ALT are:

Significantly elevated levels of ALT (SGPT) often suggest the existence of other medical problems such as viral hepatitis, diabetes, congestive heart failure, liver damage, bile duct problems, infectious mononucleosis, or myopathy, so ALT is commonly used as a way of screening for liver problems. Elevated ALT may also be caused by dietary choline deficiency. However, elevated levels of ALT do not automatically mean that medical problems exist. Fluctuation of ALT levels is normal over the course of the day, and they can also increase in response to strenuous physical exercise.^[5]

When elevated ALT levels are found in the blood, the possible underlying causes can be further narrowed down by measuring other enzymes. For example, elevated ALT levels due to hepatocyte damage can be distinguished from bile duct problems by measuring alkaline phosphatase. Also, myopathy-related elevations in ALT should be suspected when the aspartate transaminase (AST) is greater than ALT; the possibility of muscle disease causing elevations in liver tests can be further explored by measuring muscle enzymes, including creatine kinase. Many drugs may elevate ALT levels, including Zileuton, omega-3-acid ethyl esters (Lovaza),^[6] anti-inflammatory drugs, antibiotics, cholesterol medications, some antipsychotics such as risperidone, and anticonvulsants. ^{[citation needed]}Paracetamol (also known as acetaminophen) may also elevate ALT levels.^[7]

For years, the American Red Cross used ALT testing as part of the battery of tests to ensure the safety of its blood supply by deferring donors with elevated ALT levels. The intent was to identify donors potentially infected with hepatitis C because no specific test for that disease was available at the time. Prior to July 1992, widespread blood donation testing in the USA for hepatitis C was not carried out by major blood banks. With the introduction of second-generation ELISA antibody tests for hepatitis C, the Red Cross changed the ALT policy. As of July 2003, donors previously disqualified for elevated ALT levels and no other reason may be reinstated as donors by contacting the donor-counseling department of their regional Red Cross organization.^[8]

In 2000, the American Association for Clinical Chemistry determined that the appropriate terminology for AST and ALT are aspartate aminotransferase and alanine aminotransferase. The term transaminase is outdated and no longer used in liver disease.^[9]

See also

• Aspartate transaminase
• Liver function tests

References

1. ↑ Karmen A, Wroblewski F, Ladue JS (January 1955). “Transaminase activity in human blood”. The Journal of Clinical Investigation. 34 (1): 126–31. doi:10.1172/JCI103055. PMC 438594. PMID 13221663.
2. ↑ ^2.02.1Lala V, Minter DA (January 2018). “Liver Function Tests”. Stat Pearls. PMID 29494096.
3. ↑ Ghouri N, Preiss D, Sattar N (September 2010). “Liver enzymes, nonalcoholic fatty liver disease, and incident cardiovascular disease: a narrative review and clinical perspective of prospective data”. Hepatology. 52 (3): 1156–61. doi:10.1002/hep.23789. PMID 20658466.
4. ↑ “Alanine aminotransferase: analyte monograph” (PDF). Association for Clinical Biochemistry and Laboratory Medicine. Retrieved 7 October 2013.
5. ↑ Paul T. Giboney M.D., Mildly Elevated Liver Transaminase Levels in the Asymptomatic Patient, American Family Physician.
6. ↑ Dubbeldam JL, de Jongh HJ, Osse JW (2008). “Pieter Dullemeijer, professor of animal morphology”. Acta Morphologica Neerlando-Scandinavica. 27 (1–2): 9–16. PMC 2683599.
7. ↑ Watkins PB, Kaplowitz N, Slattery JT, Colonese CR, Colucci SV, Stewart PW, Harris SC (July 2006). “Aminotransferase elevations in healthy adults receiving 4 grams of acetaminophen daily: a randomized controlled trial”. Jama. 296 (1): 87–93. doi:10.1001/jama.296.1.87. PMID 16820551.
8. ↑ “Red Cross Donor Requirements”. Archived from the original on 3 November 2005. Retrieved 1 August 2005.
9. ↑ Clin Chem 2000;46:2027-2049

External links

• Alanine+transaminase at the US National Library of Medicine Medical Subject Headings (MeSH)
• ALT: analyte monograph; The Association for Clinical Biochemistry and Laboratory Medicine
• Alanine aminotransferase (ALT) at Lab Tests Online

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Black Box Testing / Sudo Null IT News

A Practitioner’s Guide to Software Test Design by Lee Copeland was published in 2003.
Since then, it has firmly established itself in the list of books that any tester should read. It is worth reading in the original. It is very pleasant to read: the language is not difficult, the style is easy. In the course of the book, the author slightly sneers at himself, his students, readers and, in general, at the sphere of our activity.

The following is not a translation, but rather a detailed synopsis of the Black Box Testing Techniques section, which describes the application of test design techniques.

The book came into my hands on the advice of a former colleague, for which special thanks to him.

To be most effective and efficient test case must be designed, not just slapped together.

Equivalence Class Testing
Boundary Value Testing
Decision Table Testing
Pairwise Testing
State-Transition Testing
Use Case Testing

Equivalence Class Testing

900 23 Technology

1. Define equivalence classes.
2. Create test cases for each equivalence class.

An equivalence class is a set of data that runs the same modules and must produce the same results.

Any data within the class is equivalent, which means that if one test case in the equivalence box found / did not find a defect, then all other test cases within this equivalence class find / do not find the same defect.

An alternative approach is to use equivalence classes not for inputs, but for outputs. Divide output options into equivalence classes, determine which input values ​​can trigger such outputs. The advantage is that every possible exit is checked. The disadvantage is that multiple input equivalence classes can be hidden inside an output equivalence class.

If there are several variables:

1. valid classes of several variables are combined into one test case;
2. invalid classes are tested separately.
   
   

   Let your designers and programmers know when they have helped you. They’ll appreciate the thought and may do in again.

Boundary Value Testing

Engineering

1. Determine equivalence classes
2. Define the boundaries of each equivalence class
3. Create test cases for each boundary value, selecting one point at a time directly on the boundary, above and below the boundary.

Note that a point above or below the boundary can be an instance of another equivalence class, in which case you do not need to duplicate the test.

The values ​​are defined by the type. If the boundary is 5, then for the field where integers are entered, points 4 and 6 are tested, and for the field where amounts in rubles and kopecks are entered, points 4.99 and 5.01 are tested.

If there are several variables:

1. the minimum values ​​of the valid limits are combined into one test case;
2. the maximum values ​​of the valid bounds are merged into another test case;
3. invalid bounds are tested separately, as is the case with invalid classes.
   
   

   Boundary value testing focuses on the boundaries because that is where so many defects hide.

Decision Table Testing

Technique

1. Determine all conditions
2. Compose all possible combinations of conditions
3. Remove unnecessary combinations. Removed those in which changing the values ​​​​does not affect the result obtained (Don’t care – DC)
4. Define actions
5. Create test cases for each combination

Decision table – Represents the relationship of compound conditions and resulting actions.

If the condition is a range of values, then tests are additionally created to check values ​​above and below the limit.

Looking carefully at the table, you can see that in rules 1, 2, 3, 4, if the stock code is invalid, then checking the remaining conditions does not make sense. Rules 5 and 6 can be combined as the condition of checking funds does not affect the result in any way. Conditions that do not affect the result are marked as “DC”. Table converted:

there is always a possibility that the table may be converted incorrectly or the code is written incorrectly; it is better to have the original table at hand anyway.

Famous Software Tester Mick Jagger gives excellent advice regarding this “You can’t always get what you want, but if you try sometimes, you just might find, you get what you need.”

Pair testing

Technology

1. Determine variables
2. Determine the number of values ​​for each parameter (choices for variable)
3. Construct an array containing columns for each parameter and values ​​in columns that contain all combinations of these parameter values ​​with each other.
4. Match the resulting orthogonal array for testing purposes.
5. Build test cases.

It has been experimentally determined that most defects are either single-mode defects or double-mode defects, i.e. appearing when one parameter is combined with only one other parameter, while the value of the other parameters does not matter.

If the number of combinations of variable values ​​is large, it is not worth trying to test all possible combinations, it is better to focus on testing all pairs of variable values.
Two pairwise testing approaches: the orthogonal array method and the allpair algorithm.

Orthogonal array is a two-dimensional array with a special property: if you select any two columns in the array, they will contain all possible combinations of parameter values, all pairs of columns have the same property.

All pairs – to create an array, an algorithm is used that generates pairs directly, without using additional balancing. If there are a large number of parameters that take a small number of values, then it is better to use this method for pairing.

It is not necessary to make pairing combinations manually, there are many tools for this.

It should be taken into account that restrictions may arise due to the fact that some combinations of parameters will never take place.

There is no underlying “software defect physics” that guarantees pairwise testing will be of benefit. There is only one way to know – try it.

State transition diagram

Engineering

State (State) – The condition in which the system waits for one or more events. The state remembers what was received at the input and determines the response that should occur. This event may be to bring to a new state and/or initiate a new action. The state usually reflects the value of some variable in the system. Depicted in the form of a circle.

Transition – Represents a transition from the current state to a new one, as a result of performing some action. Shown as an arrow.

Event – The event that caused the state change. Typically, an event enters the system from the outside world through some interface. Sometimes this event is triggered within the system itself, such as a timer expiration, a drop below a certain level. It is believed that the event occurs instantly. An event can be either independent or linked. When an event occurs, the system may change state or remain in the same state and/or initiate an action. Events can have parameters associated with them (card number, account amount). Displayed as a caption for the transition arrow.

Action – The operation initiated as a result of a state change. Often this is some kind of system response. Remember that the action happens when you transition between states. States themselves are static. Specified through a slash in the caption of the transition arrow after the event.

A state transition diagram is one specific entity (eg, a redundancy process). A common mistake is to try to mix different entities in one diagram (for example, Reservation and Passenger with events and actions associated with each of them).

Can be used when the system needs to know the history or the correct order of operations.

Based on the State Transition Diagram, a State Transition Table is compiled. The table contains 4 columns: current state, event, action, next state.

The advantage of the State Transition Table is that it is a list of all possible combinations of state transitions, including invalid ones. When analyzing such a table, gaps in the requirements can be noticed. Using a state transition table can help track down invalid state transitions.

One of 4 options for creating test cases can be selected:

1. Create test case sets so that all states of are passed at least once. In one test case, a transition through several states can be described. This is a rather weak level of test coverage.
2. Create test case sets so that all events are triggered at least once. Test cases that cover all events at the same time cover all states. Weak test coverage again.
3. Create sets of test cases so that all paths are traversed at least once. This method is good from the point of view of test coverage, but it is practically not feasible. If the diagram has cycles, then the number of possible paths can be infinite.
4. Create sets of test cases so that all transitions are executed at least once. This method provides a good level of test coverage, so it is recommended to use it.

   The recommended strategy for creating test cases is to test all state transitions at least once. In high-risk systems, where more reliable test coverage is required, it is possible to create test cases for each path (chain of transitions) between states.

   And now for something completely different. Monty Python

Use Case Testing

Technique

Use case are scenarios that describe how an actor (usually a human, but may be another system) uses the system to achieve a specific goal. Use cases are described from the perspective of the user, not the system. The internal work to keep the system up and running is not part of the use case.

At least one test case must test the main scenario and at least one test case must fall into alternative scenarios.

Recommendations for creating test cases based on use cases

1. Start with valid data and the most common scenarios.
2. Check limit values ​​and invalid values ​​(using previously discussed techniques).
3. Rarely used scenarios that are critical to the system (so-called Shut Down The Nuclear Reactor)
4. Tests for each branch-alternative (Extension) of each step
5. Try to perform an operation in an unusual order
6. Pervert the precondition if it can actually happen
7. If a transaction has cycles, run it in a cycle, and not once or twice – be tougher
8. Find a very long and winding path and follow it
9. If it is expected that the transaction will be executed in a logical order, try to execute it in reverse order (for example, fill in the fields not from top to bottom, but from bottom to top)
10. Create fool proof tests

Use case template

If you don’t try strange things. you know the users will.

Operators have lost another opportunity to quickly launch 5G in Russia

Operators are not yet able to use frequencies suitable for the rapid deployment of 5G networks / Reuters

Cellular operators will not yet be able to use the frequencies they already have at their disposal to deploy 5G networks (ie. e. make them technologically neutral). Permission to use the bands in which communication of the second, third and fourth generations (2G, 3G, LTE) is currently operating was supposed to be given at its next meeting by the State Commission on Radio Frequencies (SCRF). But after the conciliation meeting held on Monday, the corresponding item disappeared from the draft decision of the commission, sources close to the three communications companies and a person familiar with the materials of the State Committee for Radio Frequencies told Vedomosti.

Two Vedomosti interlocutors also claim that the commission’s meeting (which was supposed to take place on March 10) has been postponed. Bye – until March 17, one of them says.

The initial version of the decision of the State Committee for Radio Frequencies, which was reviewed by Vedomosti, proposed to allow operators to provide 5G services in the ranges from 791-862 MHz to 2500-2690 MHz (at such frequencies, in particular, LTE networks now operate). The range of 1710-1880 MHz mentioned in the document is used by GSM (2G) and LTE cellular networks, and 1920-1980 MHz and 2110-2170 MHz – 3G and LTE.

When asked why the provision on technological neutrality of frequencies disappeared from the materials of the SCRF, representatives of the Ministry of Communications did not answer. A person who saw the materials of the commission and a source familiar with the managers of several operators say that representatives of several departments spoke out against it. Among them are the FSB and Roskosmos, one of them claims. Government users whose equipment operates on adjacent frequencies fear that 5G in the bands listed in the SCRF decision will interfere with their radio equipment, he explains. We are talking, in particular, about space communication systems, he clarifies.

5G allows subscribers to use the mobile Internet at very high speeds (up to several gigabits per second). This is up to 100 times faster than current LTE networks. In addition, on the basis of 5G, it is planned to create control systems for unmanned vehicles, telemedicine services, integrated urban management systems, and so on.

When will 5G be launched? She gave 2024 as a tentative launch date.

According to Vadim Poskakukhin, project manager at Spectrum Management, the frequencies mentioned in the draft decision of the SCRF allow for the combination of 5G and LTE networks in one channel, which makes it possible to quickly launch networks in these bands without a complete replacement of equipment. According to him, the introduction of technological neutrality now would lead to the fact that the first 5G base stations would start working in the spring, and large-scale coverage would appear by the end of the year. Postponing this issue to the second half of the year will lead to the fact that more or less large 5G networks will work no earlier than 2021.

Technologically neutral frequencies allow 5G coverage of large areas, even entire cities. But only at the first stages of technology development, when there are still few users of fifth generation communications, he explains. These frequencies would allow testing and commercial testing of new 5G services, warming up the market by demonstrating the capabilities of the new technology, the expert notes. However, for the mass introduction of 5G, they will still not be enough, since they are overloaded with traffic from LTE networks, Poskakuhin is sure. For the mass provision of 5G services, it is necessary to resolve the issue of operator access to frequencies of 3.4-3.8 GHz, he adds. First of all, it is necessary to resolve the issue with this range, an employee of one of the operators agrees.

The 3.4-3.8 GHz band, for which popular 5G equipment is intended, is used in Russia by the Ministry of Defense and Roscosmos, Deputy Prime Minister Maxim Akimov said in 2019. In August, the Security Council expressed a negative position on the allocation of frequencies of this range to telecom operators, and President Vladimir Putin imposed a resolution “I agree,” Vedomosti’s sources in the telecom industry and relevant departments reported. SCRF has the right to allocate these frequencies locally for testing. In particular, MTS may receive the right to operate equipment at frequencies of 3.4-3.8 GHz to study the environmental impact in Moscow, RBC previously reported.

“Unfortunately, there is no progress towards the allocation of 3.4-3.8 GHz, in which the whole world will build 5G networks,” complains a Rostelecom representative. There is no alternative to 3.4-3.8 GHz, and it is necessary to look for opportunities for their conversion and release, he is sure.

MTS representative Alexei Merkutov says that while the issue of providing new frequencies for 5G has not been resolved in Russia, the operator considers the joint operation of LTE and 5G on the same frequencies as key in the evolution of networks from LTE to 5G. But this technology requires technology neutrality across all LTE frequency bands, he stresses.

MegaFon’s representative, on the contrary, does not agree that the introduction of the principle of technological neutrality will help the development of 5G: “Such a solution may adversely affect the quality of communication in existing standards, since it will not solve the problem of network capacity shortage. Every year, the traffic of LTE subscribers increases by an average of 30%, according to forecasts, such growth is guaranteed for another 4-5 years ahead. If you launch 5G at frequencies where 3G or 4G networks are already operating, then this will divert a significant part of network resources from serving 3G / 4G users. There will be an unacceptable degradation of the quality of service for the bulk of our subscribers. Therefore, only the allocation of a new separate band 3.4-3.8 GHz can fully unlock the potential of 5G technology.”

There are alternative frequency bands 4.8-4.99 GHz and 24.25-29.5 GHz. However, the deployment of a 5G network on them will require much higher costs, which means that the price of services will be much higher, says Denis Kuskov, CEO of the Telecom Daily agency.

In Russia, the 4.8-4.99 GHz frequency resource has a low load, but it intersects with the 4.4-4.99 GHz band, which is actively used by the military of NATO countries for the identification system of aircraft “friend or foe”, the source notes close to one of the operators.