LMP299Y1 Lecture Notes - Lecture 1: Transfusion Medicine, Differential Diagnosis, Blood Transfusion

317 views5 pages
Published on 19 Jan 2015
LMP301 Lecture 1
Introduction to the Biochemistry of Human Disease
-societal role of laboratory medicine
-disease states and classifications
-reason that laboratory tests are ordered
-testing process and variables which affect lab tests and results
How to Determine Sick vs. Healthy
-initial assessment
family history
recent events
physical signs and symptopms
diagnostic testing (lab and imaging)
-this assessment can determine a working diagnosis that can then be narrowed down
-most initial assessment does not include diagnostic testing – this is usually after a working diagnosis has
been determines (to obtain a differential diagnosis)
-differential diagnosis – narrowing of possibilities down to a single one (which is then usually treated)
What is Disease?
-multiple definitions
characteristic train of symptoms
pattern of response to a living organism to some form of injury
injury – starvation, poisoning, infection, stress, depression, trauma, etc.
Definitive Diagnosis
-usually requires objective evidence of pathologic process
-objective evidence
often takes the form of, or involves, diagnostic testing
has to tie back to the history, complaints, etc. of the patient (recorded during the initial assessment)
-to have a definitive diagnosis there must be 100% certainty that it is the correct diagnosis
-examples of objective evidence
demonstration of a specific biochemical abnormality
visualization of a tumour by ultrasound imaging
finding an inflamed appendix at surgery
isolation of a bacillus or virus
location of a lesion in the tissue by biopsy
Medical Laboratory Services
-pathology (anatomic)
histology (tissues)
cytology (cells)
blood transfusion medicine
mycology (fungus)
Unlock document

This preview shows pages 1-2 of the document.
Unlock all 5 pages and 3 million more documents.

Already have an account? Log in
-biochemistry (clinical chemistry)
molecular diagnostics
Reasons for Biochemical Testing
-about 70% of medical decisions are based on lab tests
-about 70% of the lab testing done falls under biochemistry (biochemical testing)
-biochemistry analyzes chemical markers found in cells and fluids (like blood, serum, urine, etc.)
-relatively non-invasive and safe
-small sample size/amount is usually enough to perform analysis – dozens of tests can be done on a single
10 cc tube of blood
-many tests (assays) have been developed to a high degree of
speed of analysis
-example – high turnover for blood tests (about 30 minutes in a hospital) whereas a biopsy may take days
Objectives of Laboratory Medicine
-diagnosis – help define as objectively as possible health and disease
-prognosis – help predict the course of a disease
-monitoring – monitor the effectiveness of treatment
-etiology – seek the underlying causes of disease
-screening – to screen for unsuspected disease
Use of Biochemical Testing
-using the objectives, examples in biochemistry are
diagnosis – does the glucose level indicate diabetes
prognosis – is the caner curable (predict course)
monitoring – has enough medication been given (test the same thing again and again over time)
etiology – what is the cause of the kidney disease (underlying issue)
screening – what is the risk of having a heart attack in CVD (underlying disease that has already
started by is unaware – cholesterol levels for heart disease)
Societal Role of Laboratories
-mortality and morbidity mean very different things from a disease standpoint
-often the mortality/morbidity rate is measured predicting the course of the disease (prognosis)
-mortality – disease that causes death or reduces life expectancy
-morbidity – disease that impairs the wellbeing of an individual
Worldwide Mortality
-leading causes of death (worldwide)
ischemic heart disease
cerebrovascular disease (stroke)
lower respiratory infections
chronic obstructive lung disease
diarrheal diseases
cancer of trachea/lung/bronchus
prematurity and low birth weight
diabetes mellitus
Unlock document

This preview shows pages 1-2 of the document.
Unlock all 5 pages and 3 million more documents.

Already have an account? Log in

Get OneClass Notes+

Unlimited access to class notes and textbook notes.

YearlyBest Value
75% OFF
$8 USD/m
$30 USD/m
You will be charged $96 USD upfront and auto renewed at the end of each cycle. You may cancel anytime under Payment Settings. For more information, see our Terms and Privacy.
Payments are encrypted using 256-bit SSL. Powered by Stripe.