Metabolic Information and Courses from MediaLab, Inc.

Due to the wide range in urine pH values in healthy individuals, pH results must be evaluated in conjunction with the patient's medical condition. Factors to be considered include: respiratory or metabolic acidosis respiratory or metabolic alkalosis renal function crystal or calculi formation urinary tract status diet

Although glucose is the sugar most commonly tested for in urine, normal human urine can contain small amounts of galactose, lactose, fructose, xylose, and other pentoses. Galactosuria, an abnormal amount of galactose in the urine, occurs in infants with a congenital metabolic defect. Lactose may be found in the urine of nursing women and during late pregnancy. All of these sugars, including glucose, are reducing substances.

As we will discover later in the course, there are other variables which impact the effectiveness of hemostatic mechanisms as well, such as acquired disease states, and inborn metabolic pathway defects. For now, however, our focus will be on the mechanisms, processes, and components which work together to achieve coagulation, or the cessation of blood flow from a damaged vessel. Note: The terms coagulation and hemostasis are used interchangeably throughout this course.

When discussing PGx, we classify a person according to his/her phenotype (metabolic capacity for a given enzyme).A poor metabolizer (PM) is a person who lacks the functional enzyme and therefore exhibits decreased metabolism of drugs. This person would require lower doses of a drug that is metabolized by that enzyme. A PM who receives a standard dose is more likely to experience unwanted side effects or toxicity. A PM can also experience diminished effects with drugs that need to be metabolized to active compounds by the enzyme in question.An ultrarapid metabolizer (UM) will require a higher dose than usual since he/she will eliminate the drug more quickly. A UM may be resistant to standard treatments, and it may take some time to adjust the dosage before therapy is achieved.An intermediate metabolizer (IM) has one wild-type (normal) copy of the gene and one absent or dysfunctional copy. The IM group is very heterogeneous.A person with normal enzyme activity is referred to as an extensive metabolizer (EM). This person should respond to standard dosages of a drug. Most people are EM's. This is the population in which most dosing regimens have been worked out in clinical trials.

Phenotyping involves measuring the metabolism of a probe drug. For example, with CYP2D6, dextromethorphan or debrisoquine can be given to a patient to see how well the drug is metabolized. Both these drugs are safe and extensively metabolized by CYP2D6. By measuring the parent drug and the metabolite in urine, the metabolic capacity of a CYP450 enzyme can be estimated. Such testing is complex and tedious, however, and has not become routine in clinical laboratories. Therefore, genotyping is likely to be the main tool that is used for assessing the PGx of a patient.

Consists of an electrolyte panel, plus: Blood urea nitrogen (BUN), which a measure of renal function. Creatinine (Creat), which also measures renal function Glucose, the most important blood sugar, and Calcium. Run on serum or plasma

These are some of the panels you will frequently encounter: Hemogram (CBC)Electrolytes (Lytes) Basic Metabolic Profile (BMP)Comprehensive Metabolic Profile (CMP)

Echinocyte comes from the Greek word meaning “sea urchin,” which relates to its shell-like appearance. Echinocytes are reversible, meaning that this alteration can be the result of the cell’s environment, pH of the medium (including the glass slides on which blood smears are made), the metabolic state of the cell and the use of some chemical substances. An example of an echinocyte can be seen in the center of this slide. Notice the projections (10-30 can be seen) are rounded and evenly spaced around the cell. Acanthocytes have irregularly spaced thorn-like projections. An echinocyte is shown left of the B in this photomicrograph. A polychromatophilic cell is seen just above the echinocyte.

Crystals are not usually present in freshly voided urine, but can appear in urine left at room temperature for several hours. Most crystals form due to changes in urine pH and temperature after collection. Diagnostically significant crystals may indicate the presence of a metabolic disorder, renal calculi formation, or provide information that can be used to regulate medications.