Clinical Chemistry and Enzyme Functions

Standard Deviation

Measure of dispersion of values from the mean. Most frequently used measure of variation.

Coefficient of Variation

Mean expression in percentile. Index of precision.

Quality

Feature/characteristic of a product meeting expected criteria of a consumer.

Variance

Square of Standard Deviation. V=SD^2.

T-test

Used to assess statistical difference between means of 2 groups of data.

Control

Solution resembling a human sample used for Quality Control purposes only.

Standard

Colorless solution with known concentration of substances used for calibration.

F-test

Used to assess statistical difference between Standard Deviation of 2 groups of data.

Specificity

Ability of a method to measure the analyte of interest only.

Sensitivity

Ability of a method to measure analytes even at their lowest concentration.

Shewhart Levey-Jennings Chart

Most widely used Quality Control chart.

Trend

Six or more consecutive values that either increase or decrease gradually, crossing the mean.

Shift

Six or more consecutive values distributed on one side of the mean, not crossing it.

Accuracy

Nearness of measured value to the target value.

Precision

Nearness of measured values to each other.

Diagnostic Specificity

Ability of a method to detect a population absent of a disease process.

Diagnostic Sensitivity

Ability of a method to detect a population having the presence of disease.

Delta check

Used to check significant differences between present and past values on the same individual sample.

Six Sigma

Method of improving product processing to eliminate defects.

Mean

Average of a set of values. Mean = Σx/n. Measures central tendency.

Median

Midpoint of a set of values.

Mode

Most frequent value among all data.

Range

Simplest expression of spread or distribution.

Energy

Entity transmitted by electromagnetic waves.

Wavelength

Distance between two successive peaks of a wave.

Nanometer

Unit expression of wavelength.

Frequency

Number of waves passing a point per unit of time.

Potentiometry

Measures electric potential

Carbohydrates

Composed of carbon, hydrogen, and oxygen; water-soluble; important source of energy for the body's mechanisms

Monosaccharides

Classified as glucose, fructose, and galactose

Disaccharides

Classified as maltose (glucose + glucose), lactose (galactose + glucose), and sucrose (fructose + glucose)

Electrophoresis

Separation of proteins aided by an electric current

Glucose

Primary sugar found circulating in the body; involved in carbohydrate metabolism

Ions

Positively charged cations (anode) and negatively charged anions (cathode)

Hormones for glucose regulation

Insulin, glucagon, and somatostatin

Electrophoretic pattern of certain conditions

Different patterns seen in conditions like hypoglycemia and hyperglycemia

Neocuproine

Inhibits the action of inulin, growth hormone, and glucagon

Alkaline ferric reduction method

Method for glucose determination using ferricyanide reduction

Condensation Method

Method for glucose determination using O-toluidine and glacial acetic acid

Enzymatic methods

Methods for glucose determination involving enzymes like glucose oxidase

Oxidation reduction method

Includes alkaline copper reduction method and hexokinase enzymatic method

Glycogen storage diseases

Various types of diseases related to defects in enzymes like glucose-6-phosphatase and glycogen debranching enzyme

Hyperglycemia

Condition characterized by increased glucose levels in the body

Lipids and lipoproteins

Major forms include fatty acids, phospholipids, triglycerides, and lipoproteins like cholesterol

Insulin-dependent DM

Type 1 diabetes characterized by the body's inability to produce insulin.

Non-insulin dependent DM

Type 2 diabetes characterized by insulin resistance.

Juvenile-onset DM

Type 1 diabetes diagnosed in childhood or adolescence.

Adult-onset DM

Type 2 diabetes diagnosed in adulthood.

Oral Glucose Tolerance Test

A series of glucose tests used to diagnose diabetes.

Hypoglycemia

Condition with low blood glucose levels, characterized by Whipple's triad.

Gestational DM

Diabetes occurring during pregnancy due to hormonal imbalance.

Glycogen Storage Diseases

Inherited disorders affecting glycogen metabolism.

Von Gierke

Glycogen storage disease type Ia involving glucose-6-phosphatase deficiency.

Pompe

Glycogen storage disease type II involving lysosomal acid alpha glucosidase deficiency.

Cori-Forbes

Glycogen storage disease type III involving glycogen debranching enzyme deficiency.

Andersen

Glycogen storage disease type IV involving glycogen branching enzyme deficiency.

McArdle

Glycogen storage disease type V involving muscle phosphorylase deficiency.

Hers

Glycogen storage disease type VI involving glycogen phosphorylase deficiency.

Tarui

Glycogen storage disease type VII involving phosphofructokinase deficiency.

Fanconi-Bickel

Glycogen storage disease type XI involving glycogen transporter 2 deficiency.

Lipids and Lipoproteins

Fats and their carrier proteins in the bloodstream.

Fatty Acids

Lipids with esterified and free cholesterol forms, crucial in CAD management.

Phospholipids

Simplest lipids serving as building blocks, with saturated and unsaturated forms.

Triglycerides

Lipids with a structure of 2 fatty acids and a glycerol, abundant in the body.

Cholesterol

Lipid with a four-ringed structure, a cell membrane component, and a hormone precursor.

Lipoproteins

Carrier proteins for lipids, including major forms like chylomicrons, VLDL, LDL, and HDL.

Apolipoproteins

Proteins associated with lipoproteins, with roles in lipid metabolism and transport.

IDL

Intermediate-density lipoprotein subclass with Apo B-100 as a major component.

Lp(a)

Lipoprotein linked to atherosclerosis, also known as sinking pre-beta lipoprotein.

Abell-Kendall Method

Cholesterol extraction method using Zeolite and L-B reaction.

Enzymatic Method

Lipid quantitation method utilizing enzymatic reactions for measurement.

Liebermann Burchardt Reaction

Dehydration and Oxidation of cholesterol to form a colored compound using Acetic anhydride-sulfuric acid, resulting in Cholestadienyl monosulfonic acid - GREEN

Salkowski Reaction

A method involving the extraction of cholesterol by Bloor's, L-B reaction

LDL-Cholesterol (LDL-C)

Formula: total cholesterol - HDL- VLDL

HDL-C

Levels: 40 mg/dL

LDL-C

Levels: <130 mg/dL, 130-159 mg/dL, 160-189 mg/dL

Total Cholesterol

Levels: <200 mg/dL, 200-239 mg/dL, >240 mg/dL

Age (in years)

Moderate Risk (mg/dL), High Risk (mg/dL): 2-19 (>170, >185), 20-29 (>200, >220), 30-39 (>220, >240), 40-above (>240, >260)

Types of Hyperlipoproteinemia

Fredrickson and Levy's Classification: Type I, Type IIa, Type IIb, Type III, Type IV, Type V

Lipid Storage Diseases

Fabry's disease, Gaucher, Krabbe, Metachromatic Leukodystrophy, Niemann Pick, Sandhoff, Tay Sach

Proteins

Macromolecules composed of carbon, hydrogen, oxygen, and nitrogen, most abundant in the body, amphoteric in nature, synthesized in the liver except for immunoglobulins

Globulin

Measurement: TP - A = G, increased in early cirrhosis

Plasma Proteins Fractions

Include Prealbumin, Albumin, Alpha1 globulin, AFP, Alpha-1-acid-glycoprotein, Alpha1-antichymotrypsin, Gc-globulin, Alpha-1-lipoprotein, Fibrinogen, Hemopexin, Transferrin/Siderophilin, Alpha2 globulin, Ceruloplasmin, Haptoglobin, Alpha2 macroglobulin, Gamma globulin

Myoglobin

Protein that carries oxygen in muscles, acts as a nephrotoxin, and is a marker for chest pain and early detection of AMI

Troponin (cTnI)

A protein marker for acute coronary syndrome and AMI

Beta globulin

Includes Pre-beta-lipoprotein, Beta-lipoprotein, Beta2 microglobulin

Complement System

Part of the immune response, increased in inflammation and decreased in DIC, hemolytic anemia, and malnutrition

Lowry (Folin-Ciocalteu) method

A method based on the digestion of protein and measurement of nitrogen content, used to regulate actin and myosin

BNP

A dye-binding method used to detect ventricular dysfunction and congestive heart failure

Cystatin C

A marker for kidney function (GFR) and an endogenous renal marker

CSF Oligoclonal Banding

Includes Beta-trace protein, Amyloid, and various bands associated with different diseases

Coagulates at 40-60°C and dissolves at 100°C

Unique feature of aminoacidopathies

Immunofixation

Method for measurement in aminoacidopathies

"Tall spike" or "monoclonal peak"

Electrophoretic pattern in aminoacidopathies

Absence of homogentisate oxidase in tyrosine pathway

Method for albumin quantitation

Ochronosis: tissue pigmentation

Characteristic of albumin quantitation

Darkening of urine upon standing

Observed effect in albumin quantitation

Measurement of at least 2 peptide bonds and formation of a violet colored chelate

Principle of biuret method

Impaired activity of cystathionine B-synthetase

Characteristic of homocystinuria

Elevated homocysteine and methionine in blood and urine

Clinical presentation in homocystinuria