Class Notes (890,996)
CA (533,010)
UTSG (45,589)
LMP (74)
LMP301H1 (8)
all (8)
Lecture 1

LMP301H1 Lecture 1: Lab Tests, Cases, Water and Electrolytes, Acid-Base Disorders, Renal Disease, Lipids and Cardiac Diseases

9 Pages

Laboratory Medicine and Pathobiology
Course Code

This preview shows pages 1-2 and half of page 3. Sign up to view the full 9 pages of the document.

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.

Leah — University of Toronto

OneClass has been such a huge help in my studies at UofT especially since I am a transfer student. OneClass is the study buddy I never had before and definitely gives me the extra push to get from a B to an A!

Leah — University of Toronto
Saarim — University of Michigan

Balancing social life With academics can be difficult, that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes. Now I can be the all-star student I want to be.

Saarim — University of Michigan
Jenna — University of Wisconsin

As a college student living on a college budget, I love how easy it is to earn gift cards just by submitting my notes.

Jenna — University of Wisconsin
Anne — University of California

OneClass has allowed me to catch up with my most difficult course! #lifesaver

Anne — University of California
LMP301 Introduction to the Biochemistry of Human Disease Lecture 1 - Introduction Disease - sickness with characteristic symptoms; response to injury A diagnosis of disease requires objective evidence Biochemical tests use body fluids, are relatively non-invasive, safe, and fast and accurate Objectives of laboratory medicine 1. Define (diagnosis) 2. Predict (prognosis) 3. Monitoring 4. Find cause (etiology) 5. Screening Mortality: causing death or reducing lifespan Morbidity: impairs quality of life Prevalence: number of cases of disease in a population Incidence: number of new cases/unit time in a population Endemic: most of the population has the disease Epidemic: widespread occurrence of disease in a population where it’s rare Classifications of disease:  Hereditary – genetic etiology  Congenital - from birth  Injury – physical or chemical stress  Infections – often bacterial or viral  Inflammation  Vascular  Nutritional – caused by diet  Metabolic – abnormal production of enzymes/other molecules  Tumors  Iatrogenic  Psychological  Idiopathic Purpose of testing:  Diagnostic testing  Screening for risk of a disease (e.g. heart disease, cancer)  Exclusion test  Monitoring  Others… Lecture 2 – Lab Tests Labs in Ontario are funded by MOHLTC. Labs are divided into different areas. Turn-around time, cost, technical expertise, and clinical need are things to consider. Types of markers: 1. Physiological (normal range in a healthy person, tightly regulated by body) 2. Disease markers (not normally present or only in minute amounts, not regulated by body, normally excreted) Patient self-testing and point-of-care (POC) testing is convenient, but often costly and lacking in QC. Testing process: 1. Pre-analytical – patient preparation (e.g. fasting or diet, medications, patient factors such as age, sex, race, pregnancy, stress), sample collecting, transporting, processing 2. Analytical – sample analysis 3. Post-analytical – interpretation and communication of result Specimen type:  Red cap: serum  Green: plasma + heparin  Grey: plasma + sodium oxalate  Purple: plasma + EDTA Sampling errors include technique, errors in timing, incorrect sampling site, etc. + Case 1: woman on diuretics shows high serum K , but physician is not concerned This is normal range for patients on diuretic medication. Precise: values agree with each other, but not necessarily close to true value (usually more important) Accurate: values close to true value Interferences may decrease precision and accuracy Lecture 3 – Cases The normal interval is the central 95% of a distribution from a healthy sample of 120+ individuals. However, factors such as age, sex, and race may differ – the best healthy range is the patient’s own. This 95% interval = 2.8 x √ [(analytical variance) +(biological variance) ] Test interpretation:  True positive  True negative  False positive  False negative o Where true/false determines whether the test was right and positive/negative determine the test result. Clinical sensitivity = TP/(TP+FN) Detects a disease when it is actually present SnNout = SeNsitivity test, Negative result, rule OUT disease Clinical specificity = TN/(TN+FP) Detects absence when the disease is not present SpPin = SPecificity test, Positive result, rule IN disease Predictive value of + test = TP/(TP+FP) Probability of test detecting a disease when it’s present Predictive value of – test = TN/(TN+FN) Probability of test detecting absence when it’s absent Efficiency = TP+TN/(TP+TN+FP+FN) Accurately make a conclusion Receiver operator characteristic (ROC) curves balance sensitivity and specificity y-axis = true positive rate (sensitivity) x-axis = false positive rate (1-specificity) upper left corner is best Lecture 4 – Water and Electrolytes The total body water in an average person is 42L, divided into intracellular fluid (ICF), extracellular fluid (ECF), which includes the plasma and interstitial fluid (ISF) Concentration – amount of solute in volume of solvent Osmolality – amount of solute particles (i.e. if solute dissociates) in weight of solvent Osmolarity – osmolality, but solvent is water Oncotic pressure – proteins (e.g. albumin) draw out water from ISF into plasma Polyuria – lots of dilute urine Oliguria – few quantity of concentrated urine Polydipsia – drinking too much Dehydration – increased pulse (to compensate for decreased BP), dry mucous membranes, decreased + skin turgor, and decreased urine output; increased plasma Na , blood urea, hematocrit Overhydration – most features normal, edema possible; Na and other stuff become less concentrated Water regulation  Hypothalamus is the sensor  Pituitary gland secretes ADH (vasopressin) which increases resorption and constricts vessels  Renin (from kidney) and ACE convert angiotensin  angiotensin I  angiotensin II  + vasoconstriction, Na resorption, and aldosterone secretion  Aldosterone stimulates Na resorption at the expense of H and K +  Na+ is critical because as it is re-absorbed, so is water Sodium (135-145 mmol/L is normal)  Mostly stored in ECF (also bones and tissues)  Aldosterone (from adrenals) resorb Na from kidney  ANP (from atria of heart) excretes Na+  Hypernatremia is too high [Na ] o Loss of solutes drags water along with it – dehydration o Hyperaldosterone - Conn’s, Cushing’s – too much Na resorption +  Hyponatremia is too low [Na ] o Renal failure – not eliminating enough water o Adrenal insufficiency – Addison’s  Edema – too much water in ISF o Body increases ADH and aldosterone as it thinks it’s low in circulating water o Volume overload – heart failure and hypoalbuminemeia  Approach is to identify Na status, water status, input/output of Na , and organ functions  Treatment is infusion of isotonic solution (5% dextrose, 0.9% saline, or plasma) Potassium  Mostly stored in ICF  Hyperkalemia o Acidosis o Cell lysis/damage (remember majority is in ICF) o Kidney failure + o Excess K intake o Aldosterone (mineralocorticoid) deficiency  Hypokalemia o Alkalosis o Aldosterone excess + o Certain drugs that cause excess K secretion  Pseudokyperkalemia o Cell rupture during sample extraction o White blood cells/platelets (e.g. coagulation is currently happening) Lecture 5 – Acid-base Disorders + [H ] is normally 35-45 nmol/L or pH = 7.35-7.45 PCO i2 normally 40 mmHg - [HCO ]3is normally 25 mmol/L Outside this range usually indicates something wrong (e.g. hypoxia, ketoacidosis, alkalosis, poisoning, lung and/or kidney failure) H is produced from metabolism, especially S-containing proteins. + + + Excess H is removed via lungs (CO ) and 2idney (H and NH ) 4 Either system can compensate if the other fails The body’s main buffers are HCO , plasma proteins and hemoglobin, intracellular proteins. + -
More Less
Unlock Document
Subscribers Only

Only pages 1-2 and half of page 3 are available for preview. Some parts have been intentionally blurred.

Unlock Document
Subscribers Only
You're Reading a Preview

Unlock to view full version

Unlock Document
Subscribers Only

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.