Medical Laboratory Science

Bone marrow is the primary site of platelet (thrombocyte) production.

White blood cells variation

White Blood Cells
Granulocytes

The peripheral blood is composed of cellular elements (red blood cells, white blood cells, and platelets) and plasma (water, electrolytes, and proteins). Peripheral blood smears can be made by a variety of methods: coverslip, push-wedge, automated wedge, automated centrifugal.

Red blood cells have a biconcave shape with peripheral hemoglobinization and a central clear zone of pallor.. this shape allows for erythrocyte movement through even the smallest capillaries, while hemoglobin carries oxygen for delivery to tissues.

Erythrocyte maturation occurs on a continuum that has been divided into six stages for morphologic identification.

Red blood cells decrease in size and increase in hemoglobin content as they mature.

The red blood cell nucleus decreases in size until it is extruded during maturation.

The red blood cell cytoplasm increases in amount relative to the nucleus during maturation
Red blood cell maturation stages in the picture below:

Red blood cells( erythrocytes) , shapes and inclusions

Hormones
Hormones in clinical chemistry
Pituitary hormones: (Anterior pituitary);
ACTH: regulates production of adrenocortical hormones by adrenal cortex. it is regulated by corticotropin-releasing hormone(CRH) from hypothalamus. Diurnal variation; highest levels in early am, lowest in late afternoon. increases in Cushing's disease. collect on ice. store frozen
FSH: regulates s***m and egg production. it is regulated by gonadotropin-releasing hormone(GnRH)from hypothalamus. sharp increase just before ovulation.
Growth Hormone(GH): regulates protein synthesis, cell growth and division. it is regulated by growth-hormone-releasing hormone (GHRH) and somatostatin from hypothalamus. it is increased in gigantism, acromegaly, and decrease in dwarfism.
LH: regulates maturation of follicles, ovulation, production of estrogen, progesterone, testosterone. it is regulated by GnRH form hypothalamus. sharp increase just before ovulation. home ELISA kils to detect ovulation
Prolactin(PRL): regulates lactation. it is regulated by prolactin-releasing factor (PRF) and prolactin-inhibiting factor(PIF) from hypothalamus.
TSH: regulates production of T3 and T4 by thyroid. it is regulated by thyrotropin-releasing hormone(TRH) from hypothalamus. Increase in hypothyroidism and decrease in hyperthyroidism.
Posterior pituitary:
ADH: regulates reabsorption of water in distal renal tubules. it is produced in hypothalamus. stored in posterior pituitary. Release stimulated by inrease osmolality, decrease blood volume or blood pressure, decrease in diapetes insipidus.
Oxytocin: regulates uterine contractions during childbirth, lactation. It is produced in hypothalamus. stored in posterior pituitary.

Hormones:
The main function of endocrine glands is to secrete hormones directly into the bloodstream. Hormones are chemical substances that affect the activity of another part of the body (target site). In essence, hormones serve as messengers, controlling and coordinating activities throughout the body.
Hormones can be grouped into three main types:
amines, these are simple molecules.
proteins and peptides which are made from chains of amino acids.

Summary of Diagnostic Enzymology
Skeletal muscle Disorders :AST , LD, aldolase and Creatine Kinase (CK) found in cardiac muscle, skeletal muscle, and brain. It increases with AMI.
Hepatic Disorders: hepatocellular disorders:( Aspartate aminotransferase (AST) which increase with liver disease and AMI. Alanine aminotransferase (ALT) found in liver tissue . Lactate Dehydrogenase (LD) increase with AMI, liver disease and pernicious anemia). Biliary tract obstruction:( Alkaline phosphatase (ALP) increase in liver and bone disease. Gamma glutamyl transferase (GGT) increase in liver disease and chronic alcoholism).
Cardiac disorders: CK-MB
Bone Disorders: ALP
Acute Pancreatitis: Amylase(AMS) found in salivary glands and pancreas, it breaks down starch to simple sugars, it increases in acute pancreatitis at first hours peak at 24 hr and return normal in 3-5 days. Lipase(LPS) found in pancreas, it breaks down triglycerides into fatty acids and glycerol, increase in acute pancreatitis.
other enzyme like Glucose-6-phosphate dehydrogenase(G6PD) found in red blood cell. Inherited deficiency can lead to drug-induced hemolytic anemia.

Other indirect cardiac markers:
Cholesterol has long been used to assess the risk of heart disease. High levels of total cholesterol and LDL-C, and low levels of HDL-C are important risk factors for cardiac disease risk.
C-Reactive Protein (CRP) is an acute phase reactant made in the liver. CRP rapidly rises and falls in response to acute inflammation and tissue damage, and reference ranges are gender specific.
Lipoprotein (a) Lp(a), is a lipoprotein subclass. Though the mechanism and sites of Lp(a) are still unknown, it has been identified as a possible independent risk factor for heart disease.
Apolipoprotein A (Apo A), binds to fat (lipids) to form lipoproteins, which transport dietary fats through the bloodstream. It helps protect the arteries, and in large concentrations, can reverse the build up of plaque deposits resulting from atherosclerosis which can lead to coronary artery disease. The concentration of Apo A reflects the amount of HDL in serum.
Apolipoprotein B (Apo B) , is the primary apolipoprotein of low density lipoproteins (LDL), which transport water-insoluble lipids such as cholesterol and triglycerides. The cholesterol that LDL and Apo B transport is vital to cell membrane integrity. However, high levels can lead to plaque build up in artery walls which increases the risk of MI.
Homocysteine is an amino acid in the blood, produced by the breakdown of proteins
Fibrinogen is a protein produced by the liver and is involved in platelet aggregation and coagulation. Since most AMI’s are due to acute thrombosis at the site of an atherosclerotic plaque, studies have indicated that increases in fibrinogen levels over time may be associated with an increased AMI risk.
D-dimer is the end product of active clot formation and dissolution. In conditions that cause thrombosis, D-dimer levels can be elevated for days prior to thrombosis

Cardiac Markers:
Troponin, CK-MB, and myoglobin are normally present in cardiac tissue and are released into the blood after an MI. Elevated blood levels of CK-MB and myoglobin may be found in the presence of skeletal muscle injury or disease. Troponin is the preferred marker for the diagnosis of MI as it is cardiac specific.
CK-MB is not as specific as troponin and is generally not needed. However, CK-MB is sometimes used as a confirmatory test or if there is reason to believe that the troponin is inaccurate due to an interference. Myoglobin is an early indicator of myocardial necrosis and is usually ordered along with troponin to help diagnose cardiac injury or an AMI when the onset of chest pain occurred within 6 hours.
BNP (B-type, or brain natriuretic peptide) is a small polypeptide hormone used as a biomarker to diagnose and evaluate heart failure. In healthy patients, BNP is produced by the left ventricle of the heart and becomes elevated in response to tension increases in the ventricular walls due to volume expansion and pressure overload.

In patients with heart failure, BNP is produced throughout the myocardium. BNP acts on the renal glomeruli to increase the urinary flow rate and the excretion of sodium, without increasing the glomerular filtration rate, renal blood flow, or blood pressure.

An electrocardiogram (ECG) is a display of the electrical activity produced by the heart. The waves of electrical signals show a different part of the heartbeat. Changes in the pattern of a standard ECG may indicate cardiac injury.
Cardiovascular Disease (CVD) or heart disease:
Coronary Artery Disease (CAD) is the most common type of heart disease. CAD, also called atherosclerosis, occurs when plaque builds up in the inner walls of the coronary arteries.
Ischemia is defined as deficient oxygenated blood flow to an organ. Cardiac ischemia occurs when a coronary artery is partially or completely obstructed, as in the case of coronary artery disease. Cardiac ischemia can cause an abnormal heart rhythm, which may cause fainting or sudden death.
Angina is the most common symptom of cardiac ischemia. Angina causes chest pain or discomfort when the heart is not receiving enough oxygenated blood, due to a partial or severe arterAcute myocardial infarction (AMI), also known as a heart attack, is defined as the death or necrosis of myocardial cells due to prolonged ischemia, often the result of a sudden or severe blockage of blood flow to the heart. for diagnosis check ischemia, ECG and cardiac markers
Heart failure, often called congestive heart failure, occurs when the heart cannot pump blood effectively to the body’s organs and tissues. If left untreated, a backup of blood in the body can cause fluid accumulation in the lungs and, over time, throughout the body.
A congenital heart defect is a problem with the structure of the heart present at birth, and occurs in about 8% of all live births.

The heart is divided into four separate chambers (2 atrium and 2 ventrical).
Arteries are blood vessels that carry blood away from the heart. Most arteries contain oxygenated blood. Veins are blood vessels that carry the flow of blood to the heart. Most veins contain deoxygenated blood. The exception to this rule is the pulmonary artery and pulmonary vein, which carry deoxygenated blood from the heart to the lungs and oxygenated blood from the lungs to the heart, respectively. The oxygen and nutrient rich blood is delivered to the heart from the aorta by the coronary arteries.
An electrical system regulates the contraction of the heart through a mass of nervous tissue called the sinoatrial node (SA Node), causes simultaneous contraction of the left and right atria at about 70 to 80 beats per minute. The atrioventricular node (AV node) lies near the right atrium. After the atria completely contract and empty, the AV node passes the electrical impulses from the atria to the walls of the ventricles causing simultaneous ventricular contraction. Graph B
Systole is the phase of the heartbeat when the heart contracts, pumping blood from the chambers into the vessels. Diastole is the phase of the heartbeat when the muscles relax and the chambers fill with blood.

Protein electrophoresis 5:
Monoclonal gammopathy of undetermined significance (MGUS) describes patients with a monoclonal gammopathy in serum or urine, but without a specific diagnosis (e.g., myeloma) related to the monoclonal gammopathy.

Protein electrophoresis 4:
Amyloidosis is a term used for conditions in which proteins depositing abnormally in tissues have a characteristic microscopic appearance and staining pattern.
Deposition of monoclonal light chains in tissues may lead to a form of amyloidosis called AL-amyloidosis (for Amyloid Light chains) or primary amyloidosis.
The clinical presentation of amyloidosis varies with the organs involved and can include the following: carpal tunnel syndrome, nephrotic syndrome, congestive heart failure, hepatomegaly, and neuropathy.

Protein electrophoresis 3:
Waldenström's macroglobulinemia (WM), also known as lymphoplasmacytic lymphoma, is a type of cancer affecting two types of B cells, lymphoplasmacytoid cells and plasma cells. Both cell types are white blood cells. WM is characterized by having high levels of a circulating antibody, immunoglobulin M (IgM), which is made and secreted by the cells involved in the disease.

Protein electrophoresis 2:
Multiple myeloma is a cancer that forms in a type of white blood cell called a plasma cell. Plasma cells help you fight infections by making antibodies that recognize and attack germs.

Multiple myeloma causes cancer cells to accumulate in the bone marrow, where they crowd out healthy blood cells. Rather than produce helpful antibodies, the cancer cells produce abnormal proteins that can cause kidney problems.

Protein electrophoresis 1:

Protein electrophoresis:
Electrophoresis is the process of using an electric field to separate molecules based on charge and size.
Electrophoresis of serum and urine proteins in an agarose gel can help diagnose plasma cell disorders such as multiple myeloma, Waldenstrom's macroglobulinemia, amyloidosis, some forms of lymphoma, and other disorders.
Urine and CSF must be concentrated because of low protein concentration. Bence Jones proteins migrate to gamma region in urine electrophoresis. CSF has a prealbumin band.

Albumin: Albumin is the most abundant serum protein.
Alpha-1: The alpha-1 zone consists mainly of alpha-1-antitrypsin, alpha-1-acid glycoprotein, and alpha-1-lipoprotein.
Alpha-2: The alpha-2 zone consists mainly of 3 bands: alpha-2 macroglobulin (most anodal), haptoglobin, and beta-lipoprotein (most cathodal). Sometimes, because of genetic variability in haptoglobin, haptoglobin and alpha-2 macroglobulin migrate in the same broad band rather than in distinct bands. Beta-lipoprotein has a distinct ruffled pattern and variable mobility. It is also acceptable to include beta-lipoprotein in the beta zone.
Beta: The beta zone consists mainly of 2 bands: transferrin (more anodal) and complement (predominantly C3). C3 is heat labile and decreases as serum is stored at room temperature.
Gamma: The gamma region is quite broad and consists mainly of the immunoglobulins.

Proteins
Proteins are a large class of biological molecules consisting of chains of amino acids called polypeptides. A single polypeptide can make a protein, although many proteins consists of multiple polypeptide subunits.
proteins funtion:
Protein is termed the building block of the body
Protein is a major source of energy.
Enzymes are proteins that increase the rate of chemical reactions in the body.
Protein is a major element in transportation of certain molecules. Protein forms antibodies that help prevent infection, illness and disease.
The total protein test measures the total amount of two classes of proteins found in the fluid portion of your blood. These are albumin and globulin. Albumin helps prevent fluid from leaking out of blood vessels. Globulins are an important part of your immune system. The normal range is 6.0 to 8.3 gm/dL (grams per deciliter) or 60 to 83 g/L
The biuret test uses an alkaline mixture, or reagent, composed of potassium hydroxide and copper sulfate. The normal color of biuret reagent is blue. The reagent turns violet in the presence of peptide bonds -- the chemical bonds that hold amino acids together.
Albumin: it constitutes about half of serum protein. It is produced in the liver. It is soluble and monomeric. Albumin transports hormones, fatty acids, and other compounds, buffers pH, and maintains oncotic pressure, among other functions.it can be used to assess the concentration of proteins
normal range: 3.5-5g/dl
low can indicate malnutrition, liver disease, nephrotic syndrome
high can indicate dehydration

Microalbumin in urine. 50-200mg/24 hr predictive of diabetic nephropathy.

Medical Laboratory Science education about the general health and tips

Lipids
Lipids are naturally occurring organic compounds, commonly known as oils and fats. Lipids occur through out the living world in microorganisms, higher plants and animals and also in all cell types. Lipids contribute to cell structure, provide stored fuel and also take part in many biological processes.
Lipids are relatively insoluble in water. They are soluble in non-polar solvents, like ether, chloroform, methanol. They include fats, oils, waxes, phospholipids, etc.
Cholesterol is an essential component of cell membranes, brain and nerve cells, and bile, which helps the body absorb fats and fat-soluble vitamins.
Fats, such as cholesterol and triglycerides, cannot circulate freely in the blood, because blood is mostly water. To be able to circulate in blood, cholesterol and triglycerides are packaged with proteins and other substances to form particles called lipoproteins.
There are different types of lipoproteins. Each type has a different purpose and is broken down and excreted in a slightly different way. Lipoproteins include chylomicrons, very low density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL). Cholesterol transported by LDL is called LDL cholesterol, and cholesterol transported by HDL is called HDL cholesterol.
- HDL cholesterol : inversely related to risk of Coronary Artery Disease(CAD). low levels are risk factors. desirable:>= 60 mg/dl, use homogeneous assays
- LDL cholesterol: major cause of CAD. primary target of therapy. best : 400 mg/dl
- total cholesterol: limited value of predicting risk of CAD by itself. used in conjuction with HDL and LDL cholesterol. desirable:

Tests for Diabetes Mellitus
-random plasma glucose: collected any time of day. diabetes >=200mg/dl
-fasting plasma glucose: fast of at least 8 hours. diabetes >= 126mg/dl on 2 occasions
-2-hr plasma glucose: 75 g glucose load. diabetes >= 200 mg/dl on 2 occasions
-oral glucose torlerance test: only for diagnosis of gestational diabetes, it is performed at 24-48 wk of gestation. fast at least 8 hr. 75 g glucose load. diabetes , fasting >= 92 mg/dl or 1-hr >=180
-hemoglobin A1C: it gives estimate of glucose control over previous 2-3 months. fasting not required. diabetes >=6.5%

Carbohydrates:
major source of cellular energy. Glucose, fasting( 70-99 mg/dl). use sodium fluoride to prevent glycolysis. glucose oxidase and hexokinase are most common methods.
Regulation of glucose:
-decreases glucose levels: insulin
_inreases glucose levels: glucagon, cortisol, epinephrine, growth hormone, and thyroxine.
Diabetes Mellitus:
-type 1 diabetes( insulin-dependent diabetes mellitus, juvenile-onset diabetes) caused by autoimmune destruction of beta cells and absolute insulin deficiency.
type 2 diabetes( non-insulin-dependent diabetes mellitus, adult-onset diabetes) caused by insulin resistance in peripheral tissue and insulin secretory defect of beta cells. it is the most common type.
-gestational diabetes mellitus (GDM) caused by placental lactogen when it inhibits action of insulin. it is usually diagnosed during latter half of pregnancy.

Chemistry Panels
-basic metabolic panel: Na+, K+, Cl-, CO2, glucose, creatinine, BUN, Ca2+
-comprehensive metabolic panel: Na+, K+, Cl-, CO2, glucose, BUN, creatinine, albumin, total protein, ALP, AST, bilirubin, Ca2+
-electrolyte panel: Na+, K+, Cl-, CO2
-hepatic function panel: albumin, ALT, AST, ALP, bilirubin(total and direct), total protein
-lipid panel: total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides
-renal funcion panel: Na+, K+, CO2, glucose, creatinine, BUN, Ca2+, albumin, phosphate

Clinical chemistry

Other urine chemistry tests:
-Microalbumin detects albumin in low concentration
-Sulfosalicyclic acid detects all proteins including Bence Jones proteins
-Clinitest detects reducing substances
-Acetest detects ketones
-Ictotest detects bilirubin

Other fluids:
-Semen fluid: collected in sterile container, after 3-day abstinence. deliver to lab within 1hr of collection. don't analyze until specimen is liquified.
-Serous fluid: fluid contained in pericardial, peritoneal, and pleural cavities.
In a pleural effusion, different fluids can enter the pleural cavity. Transudate(clear, yellow, pale , 1000micrl of wbc, and >3g/dl of protein) is fluid that leaks around the cells of the capillaries caused by inflammation.
-Synovial fluid: fluid in joints.

Body fluids:
Cerebrospinal fluid (CSF) is a clear, colorless body fluid found in the brain and spine. It is produced in the choroid plexuses of the ventricles of the brain. It acts as a cushion or buffer for the brain's cortex, providing basic mechanical and immunological protection to the brain inside the skull. CSF is usually obtained by lumbar puncture. The specimen is collected into multiple sterile tubes, labeled sequentially, and transported to the laboratory.
The diagnosis of CSF infection is of critical clinical importance.
Bacterial infection is characterized by a markedly increased white blood cell count consisting primarily of neutrophils. CSF glucose is generally low and the protein concentration increased.
In contrast, viral infection is characterized by an increased white blood cell count consisting primarily of lymphocytes and few macrophages with relatively few neutrophils. CSF glucose levels are generally normal.
The table lists CSF lab tests that help diagnose various infections of the central nervous system.

Body fluids (1):
amniotic fluidAmniocentesis (also referred to as amniotic fluid test or AFT) is a medical procedure[1] used in prenatal diagnosis of chromosomal abnormalities and fetal infections,[2] and also used for s*x determination in which a small amount of amniotic fluid, which contains fetal tissues, is sampled from the amniotic sac surrounding a developing fetus, and the fetal DNA is examined for genetic abnormalities. It is performed at 16-18 weeks of gestation.
During pregnancy, the fetus is surrounded by amniotic fluid, a substance much like water. Amniotic fluid contains live fetal cells and other substances, such as alpha-fetoprotein (AFP). These substances provide important information about your baby's health before birth. Normal amniotic fluid appearance is clear, pale yellow.
other amniotic fluids tests are:
-lecithin-to-sphingomyelin (L/S) ratio: for fetal lung maturity
-phosphatidyglycerol(PG) : fetal lung maturity
-foam stability index( shake test) : for fetal lung maturity
-lamellar body count: fetal lung maturity
-amniotic fluid bilirubin: hemolytic disease of the newborn/ fetus

Kidney Conditions:
Kidney stones (nephrolithiasis): Minerals in urine form crystals (stones), which may grow large enough to block urine flow. It's considered one of the most painful conditions. Most kidney stones pass on their own but some are too large and need to be treated. urinary findings are RBCs and crystals (calcium oxalate, cystine,uric acid, etc..).

Nephrotic syndrome: Damage to the kidneys causes them to spill large amounts of protein into the urine. Leg swelling (edema) may be a symptom, laboratory findings are: large positive biochemical protein test ,free fat and oval fat bodies, and all kinds of cast ( renal , waxy and fatty)

Polycystic kidney disease: A genetic condition resulting in large cysts in both kidneys that impair their function.

Acute renal failure (kidney failure): A sudden worsening in kidney function. Dehydration, a blockage in the urinary tract, or kidney damage can cause acute renal failure, which may be reversible.

Chronic renal failure: A permanent partial loss of kidney function. Diabetes and high blood pressure are the most common causes.Urinary findings;fixed specific gravity at 1.01, positive biochemical test for protein, RBC, all type of casts (waxy and broad casts).

End stage renal disease (ESRD): Complete loss of kidney function, usually due to progressive chronic kidney disease. People with ESRD require regular dialysis for survival.

Papillary necrosis: Severe damage to the kidneys can cause chunks of kidney tissue to break off internally and clog the kidneys. If untreated, the resulting damage can lead to total kidney failure.

Diabetic nephropathy: High blood sugar from diabetes progressively damages the kidneys, eventually causing chronic kidney disease. Protein in the urine (nephrotic syndrome) may also result.

Kidney Conditions:
Acute tubular necrosis is a disease of the renal tubules. it is characterized by destruction of the renal tubular epithelial cells due to reduced blood flow or a toxic insult. Urinary findings; renal tubular epithelial cells often in clumps. RTE, waxy and granular casts.

Pyelonephritis (infection of kidney pelvis): Bacteria may infect the kidney, usually causing back pain and fever. A spread of bacteria from an untreated bladder infection is the most common cause of pyelonephritis. Positive protein test, leukocyte esterase and nitrite. WBCs, RBCs, and bacteria and WBC cast.

Glomerulonephritis: An overactive immune system may attack the kidney, causing inflammation and some damage. Blood and protein in the urine are common problems that occur with glomerulonephritis. It can also result in kidney failure.it can be acute or chronic.In acute glomerulonephritis u can find positive biochemical tests for protein and blood. RBCs and WBCs, RBC and Hemoglobin casts, and hyaline and granular cast. in chronic granular and fatty cast are found.