Clinical Chemistry Diagnostic Exams

I.                  IDENTIFICATION: 

1. The major bile pigment.
2. The enzyme responsible for the conversion of B1 to B2.
3.  In automation, this is the method of removing interfering substances from serum .
4. This automated aspect corresponds to sample delivery in the manual method.
5. The normal pH of  blood.
6. The normal bicarbonate and carbonic acid ratio in the body.
7.  The major intracellular cation.
8.  The major extracellular cation.
9.  It is described as the constant concentration at half of the maximum velocity of  enzyme activity.
10. It is the S.I. units of  enzyme activity.
11. Enzyme alcoholic marker.
12. Characterized by elevated bicarbonate, normal PCO2 and abnormal pH.
13. The 3 major cardiac enzymes
14. Same as above
15. Same as above
16. Prostate carcinoma  marker
17. Normal value for AST.
18. Conversion factor for calcium.
19. -20. Formula for Henderson-Hasselbalch equation

 


ANSWERS TO BE POSTED NEXT WEEK.

Read All about FPIA Fluorescence Polarization Immunoassay

• Fluorescein-labeled drug competes with unlabeled drug for antibody

•Sample excited with plane polarized light (490 nm)

•Fluorescein emits plane polarized light (520 nm)

•Small, free drug-fluorescein, rotates faster leading to less emission

•Larger, antibody-drug-fluorescein, rotates slower and emits plane polarized light (520 nm)

Principle: Drug in sample competes for antibody with fluorescein bound drug

•More drug in the sample; less fluorescein labeled drug bound to antibody; lower

emission of plane polarized light.

•Higher drug concentration results in lower light emission values.

FPIA

•Available for a variety of drugs

Advantages

Rapid turnaround times, sensitivity, ease of operation

Disadvantages

Background interference in serum sample (requires blank measurement).

All about polarization

What capillary puncture is and how it is performed

Capillary puncture is one of the three general methods of blood specimen collection.   Called capillary puncture because blood comes from the capillaries, it is usually the preferred method of collection in infants and in adults when venipuncture is not feasible.

Materials used in capillary puncture

Sterile dry cotton
Sterile wet cotton
Lancet or penlet
Capillary tube of capillette or an appropriate collection vessel

Steps in Capillary Puncture

The practitioner prepares materials and place them within reach.

They then identify the patient properly by asking his/her name.

A suitable site is selected, usually the ring finger of the left hand for adults and the big heel or big toe for infants.

The site of puncture is sterilized from the center going outwards in a circular manner.

With a smooth and deliberate manner, the site is punctured

The first blood is wiped and the specimen is collected making use of the capillary tubes or other appropriate container.

The wound is pressed for 3-5 minutes and a sterile dry cotton and a micropore or plaster are applied.

Additional Tips on Capillary Puncture

Practitioners should smile and introduce themselves before asking the name of the patient.

They should give a brief description of the test to be done.

Children 5 years old and below would most likely would need a restraining blanket or device.

Older children will usually understand if the doctor explains why they need to perform the procedure.

The practitioner needs to make them an active participant by making them understand that they need their cooperation for the success of the blood collection.

The other pads of the fingers and the earlobes are other alternative capillary puncture sites. Determine which is best for your patient by examining the site.

Practitioners should say thank you after the procedure.

Precautions on Capillary Puncture

The practitioner should not state the patient's name but let the patient state it. The patient may not hear correctly and still say yes or no.

He may state it, or have him spell it out, or best if he can write it down; and then patient identification can be done properly.

The practitioner's material should not be near the patient, especially if the patient is a child. Children can pull the material.

The practitioner should not underestimate children. They can become stronger when intimidated and afraid.  They should be restrained properly.

The practitioner should not puncture sites which have hematoma or bruises.

The practitioner should wipe the first drop of blood, as it contains mainly tissue juices and may yield inaccurate results.

If the test is bleeding time (BT) or clotting time (CT) then the practitioner should not wipe the first drop of blood. There is protocol with these two tests.

The practitioner should make sure that all materials are sterile and dry to prevent infecting the patient and contaminating the blood samples.

What is Type I Diabetes?

Diabetes is a metabolic condition composed of several clinical symptoms. It may also be classified into diabetes mellitus and diabetes insipidus.

The former is caused primarily by the insufficiency of the pancreatic hormone, insulin; while diabetes insipidus is the insufficiency of the posterior pituitary hormone ADH (antidiuretic hormone), or vasopressin.

Type 1 diabetes is of the diabetes mellitus type. The clinical symptoms for diabetes mellitus are the following:

Hyperglycemia: elevation of blood sugar levels, above 126 mg/dL, tested in the blood of an 8-12-hour fasting patient.

Hyperglucosuria: presence of glucose in urine as shown by the urine testing positive (change in the
blue color of the reagent strip) in the chemical phase of the routine laboratory urinalysis.

Polyphagia: this is one of the 3 P's that characterizes diabetes mellitus. It is described as experiencing excessive hunger in spite of having eaten a meal. After meals, the person grows weaker instead of becoming stronger.

This is because when a diabetic person eats, the more his blood sugar increases which exacerbates the condition leading to body weakness. If left untreated this would lead to comma and eventually death.

Polyuria: this is the 2nd P. It is characterized by excessive urination. This occurs because glucose is a diuretic substance which induces urination and enhances excretion of water from the body; so the more elevated your blood glucose levels are, the more you urinate frequently.

Polydypsia: this is the 3rd P. It is excessive thirst. Because of the frequent urination, the person's metabolism has to cope now with the water loss and therefore has the urge to drink more to compensate for the loss.

What is the etiology of type 1 DM, (diabetes mellitus)?

Homeostasis (the body's built in, automatic process of maintaining balance of the different substances in the blood), is responsible in maintaining the blood glucose levels by increasing the secretion of insulin in the beta cells of the pancreas when blood glucose levels are high; and increasing the secretion of glucagon in the alpha cells of the pancreas when the blood glucose levels are low.

This occurs automatically only when the pancreatic gland is functioning properly.

In diabetes mellitus, the pancreas is dysfunctional and is not able to produce sufficient insulin. It may also be because of the surgical removal of the pancreas (pancreatectomy); thereby resulting to the complete absence of the insulin production.

There are other secondary causes too like the dysfunction. of other endocrine glands.

What is Type I DM (diabetes mellitus?

Type 1 diabetes mellitus is also called IDDM (Insulin Dependent Diabetes Mellitus). It is called as such because the treatment requires treatment with insulin to maintain normal blood glucose levels. Under normal conditions, the insulin which is produced by the beta cells of the Islets of Langerhans is sufficient to maintain the glucose levels in the bloodstream.

Type I DM may be thin compared to Type II DM patients, who are usually obese and overweight.

Type I DM also occurs at an early age (usually during adolescence or even earlier), while type II DM occurs at a later age (usually about 40 years and above.)

Type I DM's serum is characterized by the elevation of auto-antibodies which is absent in Type II DM.

There is elevation too of ketone bodies (acetoacetate, acetone, betahydroxybutyrate) in a type I DM patient, which may lead to ketonemia (elevation of ketone bodies in the blood) and the resulting condition, ketosis. In Type II patients this do not often occur.

Ketosis can lead to a change in the blood pH; making it more acidic, resulting to coma and eventually death.

What is the normal range of glucose in a fasting patient?

Glucose is generally tested in a patient who has fasted for 8-12 hours; FBS (Fasting Blood Sugar). The normal value ranges from 70 to 100 mg/dL depending upon the method used for the laboratory test.
The 2-HPPT (Two Hour Post Prandial Test) could also be done and is a more sensitive test for DM than the FBS test.

Sometimes the OGTT (Oral Glucose Tolerance Test) is performed on the blood of pregnant women to determine whether they have GDM (Gestational Diabetes Mellitus).

What is the cure for Type I diabetes mellitus?

There is no cure for diabetes mellitus; but diet, exercise and a healthy lifestyle could help a lot in maintaining the normal blood glucose levels. Insulin or drugs may be prescribed by the physician to help lower the glucose levels if it is too elevated.

It is also vital to remember that DM should not be taken for granted as all functional organs are affected in the body; the eyes, the heart, the kidneys, and the lungs. What more, wounds do not heal easily when one has uncontrolled DM.

This is often the cause of the amputation of the arms or legs of diabetic patients because the wound could not heal and that portion of that body had developed gangrene: even simple pedicure/manicure wounds should be promptly attended to.

Knowing about Type I DM and diabetes mellitus in general would be of great help in staying healthy and maintaining wellness.

Be knowledgeable and stay healthy!

Body Systems and How They Work

The body systems operate as one to maintain man’s health and well-being. There are various systems involved to ensure that the human body stays healthy. These systems are the nervous, circulatory, excretory, muscular, digestive, skeletal, integumentary, endocrine and respiratory.  Each system supports the others to maintain homeostasis and balance inside the complex network of cells, tissues and organs of the body.\

Nervous system

The hypothalamus, in the brain, is the center of the central nervous system, where stimuli from the different parts of the body are sent. It is the hypothalamus that recognizes these stimuli, and then initiates a respond appropriate for that specific stimulus.

An example is when the body is hypoglycemic, the low concentration of glucose in the body would be the stimulus recognized by the hypothalamus. It would then initiate the pancreas to secrete more glucagon so that blood sugar concentration would increase. The nervous system is composed of the spinal cord and the brain, which is composed of neurons and neuralgia.

Image credit. newhacks.info

Circulatory system

This is responsible in bringing blood and essential nutrients to the different parts of the body. It is composed of the heart, the veins and the arteries that transport blood for the survival of the human body.

The blood contains cellular elements (red blood cells, white blood cells, platelets) that are crucial for maintaining life. When a person loses large volumes of blood, he can bleed to death. That is how crucial the circulatory system’s function is.

Excretory system

The body has to excrete the toxic waste products of the body to allow proper functioning of the organs. The major organs involved in excretion are the kidneys. The kidneys are also responsible in maintaining the critical 7.35 to 7.45 pH (alkalinity or acidity) of blood.

This slight alkalinity of the body makes it possible for the normal function to occur. When the body’s pH is increased or decreased from the normal, conditions result which could cause coma and eventually death. The kidneys could maintain the normal pH through the retention and excretion of bicarbonate and hydrogen ions, and through the excretion of acidic waste products of metabolism.

Muscular system

This system provides the muscular structure and support for the body. Through the muscular system, man could move and function well. He is able to flex his arms, stand straight and lift weights because of his muscles. There are several types of muscles, such as, skeletal, cardiac, voluntary and involuntary; each with its specific role in the human body.

Digestive system

It includes the mouth, the esophagus, the stomach, the small and large intestines and the rectum. Without this system the food that people eat would not be digested. It also allows the essential nutrients from foods to be absorbed by the intestinal villi in the small intestines.

Skeletal system

This provides the skeleton of the body where the muscles and organs are housed. It also protects major organs, namely, the brain, the heart, lungs, kidneys and the digestive organs. It provides support for the whole body, and also in locomotion.

Integumentary system

The integumentary system is the skin, which is the largest organ of the body.  It protects all the internal organs, including the muscles, from invading foreign substances. It also acts as a thermal regulator, preserving the human body’s temperature. Without the skin, the body would be easily invaded by infectious microorganisms and toxic substances, too.

Endocrine system

This involves the ductless glands which secrete hormones directly into the bloodstream. These hormones are responsible for important body functions like the maintenance of blood sugar concentration through insulin and glucagon; the growth and development of the body through growth hormone, thyroxine and triiodothyronine.

Respiratory system

This involves the lungs, which are responsible in respiration. Through the lungs man breathes in oxygen and exhales carbon dioxide. Body cells could obtain oxygen so they could perform their biological functions well.

These are some of the systems involved in the human body and how the body systems work. All of them are interdependent on each other and are expected to perform their functions in conjunction with the function of the other organs.

Element Facts Fluorine

Flourine (F) has a special place in science because it is the most reactive of all the elements, and participates in almost all inorganic and organic chemical reactions. The reactions exclude oxygen, neon, krypton and helium.

Its name has originated from the French word “fluere,” meaning to flow, because it allowed metals "to flow." This deadly element was discovered and isolated by a French chemist, Henri Moissan, in 1886, for which he received the 1906 Nobel Prize in Chemistry.

Chemical properties of Fluorine

Fluorine has an atomic number of 9, an atomic weight of 18.998403, a specific gravity of 1.108, a boiling point of -188.14°C, and a melting point of -219.62°C. When it combines with water, metals, carbon and other substances, it burns and fluoresces.  It is extremely flammable and highly corrosive. With water, it produces hydrofluoric acid, one of the highly corrosive products of fluorine.

Physical characteristics

Fluorine is the lightest among the halogens, which include chlorine, iodine and bromine, to name some. It has a characteristic pungent odor, and is pale yellow in color. Previously, it could not be isolated from any of its compounds, but Moissan did this through “electrolysis of dry potassium hydrogen fluoride and anhydrous hydrofluoric acid.”

Sources

Fluorine is a halogen and is widely distributed in combination with other substances, such as in fluorspar (CaF) and cryolite (Na2AF6). It could be isolated using electrolysis with a “solution of potassium hydrogen fluoride in anhydrous hydrogen fluoride.”

Uses

Although it is a dangerous element by itself, fluorine, in combination with other substances, has its own usefulness in the field of science. Fluorine, in the forms of sodium fluoride and sodium monofluorophosphate, is added to toothpaste and drinking water to help in the prevention of tooth decay. Calcium fluoride crystals are used in the construction of infrared lenses and other bulbs. In the form of uranium hexafluoride, fluorine also plays a major role in processing nuclear fuel.

It is used too in the manufacture of high-temperature plastics, such as Teflon.  It has been originally used as a refrigerant in air-conditioning units in the form of chlorofluorocarbons, but these products were banned because of their dangerous depletion of the ozone layer, which protects the Earth from the deadly rays of the sun.

Fluorine, just like any substance here on Earth, has its own advantages and disadvantages. It is up to man to use it to his own advantage and progress. After all, science is there to develop the world into something progressive but safe for the human race.

An Explanation of Diffusion

Diffusion is defined by Hyperphysics as the process by which molecules intermingle with each other randomly as a result of their kinetic energy.

In layman’s terms, it is the movement of particles in solution from a higher concentration to a lower concentration. There are two common types of diffusion: the facilitated and the passive. Facilitated diffusion

This process requires the presence of energy for its occurrence. A good example is the application of heat to increase the movement of the particles in solution so they can move faster.

An example also is when molecules move through cells in the body with the use of transport proteins. This is how essential nutrients are usually transported to different cells and tissues in the body. Passive or simple diffusion

This process does not need applied energy to occur. An example is when water and its particles, from higher areas, diffuse into low lying areas until equilibrium is reached. The water seeks its own level. This is a simple but clear example of diffusion.

The spread of a teaspoon of coffee in water demonstrates also passive or simple diffusion. The granules diffuse into the areas where it is less concentrated, thereby allowing the coffee granules to spread and make the solution homogeneous.

Stirring the coffee and using warm water would make it facilitated diffusion, wherein the coffee spreads until equilibrium is achieved. Diffusion in the human body

There is also a process called net diffusion in cells, in which particles or substances in solution pass through pores or tissue walls from a higher concentration gradient to a lower concentration gradient.

As mentioned in facilitated diffusion, the human body uses this method to bring food and vital substances to cells and tissues.

Respiration is one good example of diffusion, as well. Carbon dioxide comes out when we exhale, instead of oxygen, because the concentration of carbon dioxide outside of the body is lower.

On the other hand, oxygen enters the lungs because it diffuses into the area where it is less concentrated.

Diffusion in plants Diffusion also occurs in plants in the same manner that it occurs in animals. This movement is from a higher concentration gradient to a lower one, too.

This is how essential nutrients for plants, such as carbon dioxide, are transported from the stomata to the cells. Diffusion, specifically termed transpiration, is the manner by which oxygen is excreted by plants.

Hence, diffusion is a vital process that occurs in vivo (inside the body) and in vitro (outside the body) that is significant for the existence of man.

How Excess Salt Negatively Affects the Kidneys

Salt, scientifically called sodium chloride, lends taste to food, and helps in maintaining the water electrolyte balance in the body.

Taken in excess, however, salt has detrimental effects on the kidneys. The kidneys are the major excretory organs of the body, and are responsible in eliminating excess, unwanted substances.

Due to this function, it is the primary organ affected when these excess substances are not excreted. Excess salt exerts the same extra workload on the kidneys.

Because of homeostasis, the body could sense if there is too much salt or electrolytes in the body. When salt is in excess, the body responds by retaining water so that the excess salt would become diluted. The extra amount of water would also increase the volume of blood, which would add more workload on the heart and the kidneys.

Hypertension’s effect on kidneys

The excess salt could cause then hypertension, congestive heart failure and other unhealthy conditions.  Sodium may cause also the constriction of the blood vessels that could cause hypertension.

When a person has constant hypertension, vascular stress is exerted on the kidney cells, which would then be destroyed, and excretory function of the kidneys is compromised. If the kidneys are dysfunctional, they would not be able to discard toxic products of metabolism. These products of metabolism could amass in the body causing toxic poisoning. Formation of urine crystals in the kidneys

When the kidneys become dysfunctional because of excess salt, urinary sediments may be retained to form stones and calculi. These renal stones could amass in the kidneys and block urinary ducts or passages.

The most common causes of kidney stone formation are uric acid and calcium oxalate crystals. Inability of the kidneys to eliminate these stones could result to kidney stones, which may have to be surgically removed. The formation of stones in the kidneys is called nephrolithiasis.

Increased salt causes decreased blood supply to the kidneys

This effect results from the hormonal function of the kidneys, in which it would prompt the secretion of hormones to help regulate the electrolyte. This is stimulated by the hypothalamus in order to retain more water in an attempt to increase blood going to the kidneys.

This does not happen, though. Instead, water accumulates in the heart and other organs causing congestive heart failure.

Dysfunctional kidneys could affect the whole body’s ability to function well because of the accumulation of waste products, which the kidneys could not excrete. To ensure good health, people avoid taking in excess salt.

All about FPIA Fluorescence Polarization Immunoassay

• Fluorescein-labeled drug competes with unlabeled drug for antibody

•Sample excited with plane polarized light (490 nm)

•Fluorescein emits plane polarized light (520 nm)

•Small, free drug-fluorescein, rotates faster leading to less emission

•Larger, antibody-drug-fluorescein, rotates slower and emits plane polarized light (520 nm)

Principle: Drug in sample competes for antibody with fluorescein bound drug

•More drug in the sample; less fluorescein labeled drug bound to antibody; lower

emission of plane polarized light.

•Higher drug concentration results in lower light emission values.

FPIA

•Available for a variety of drugs

Advantages

Rapid turnaround times, sensitivity, ease of operation

Disadvantages

Background interference in serum sample (requires blank measurement).