Research in Medicine and Healthcare Lecture 3
Research in Medicine and Healthcare - Overview
Key Areas:
Experimental Models in Health Research (Non-clinical, Clinical)
These models range from basic laboratory experiments to studies involving human participants, designed to understand biological processes and test interventions.
Human Studies, Basic Experimental Designs
This involves research directly on human subjects, categorized by whether an intervention is applied or not.
Evidence-based Medicine (EBM)
A systematic approach to clinical decision-making that integrates the best available research evidence with clinical expertise and patient values.
New Dimensions in Medicine and Healthcare
Encompasses emerging technologies, personalized medicine, and broader healthcare system considerations.
Evidence-Based Medicine (EBM)
Core Principle: Applying scientific evidence directly to clinical decisions.
This involves a rigorous process of finding, appraising, and incorporating evidence from research into routine medical practice to optimize patient care.
Cochrane Reviews:
A significant database containing systematic reviews and meta-analyses.
Purpose: To summarize and interpret the aggregated results of medical research from multiple studies, providing a comprehensive overview of effectiveness for interventions.
Relevance: Highly relevant to the clinical setting, providing synthesized evidence for practitioners to make informed decisions for patient treatment and management through high-quality, reliable, and up-to-date evidence.
Origin of Information (Basic Research):
Includes in vitro ("in glass") and ex vivo ("out of the living") experiments.
In vitro research is conducted in test tubes, culture dishes, or other controlled environments outside of a living organism, often focusing on cells or molecules.
Ex vivo research involves tissue or cells taken from an organism and studied in an external environment, maintaining some of the original biological context.
Utilizes animal models, serving as essential steps before human trials to understand disease mechanisms and test potential therapies in a living system.
Human Studies (Non-intervention):
These are observational studies where researchers observe participants without actively intervening or administering any treatment.
Examples: Cohort studies (tracking a group over time to see who develops a condition) and case-control studies (comparing individuals with a condition to those without).
Key Characteristic: No intervention (e.g., medicinal or lifestyle treatment) is given to participants, meaning researchers only observe and collect data.
Human Studies (Controlled Interventions):
These studies involve actively administering an intervention (like a new drug or therapy) to a group of participants and comparing its effects against a control group.
Examples: Randomized Controlled Trials (RCTs), where participants are randomly assigned to an intervention or control group.
Key Characteristic: Involve controlled interventions; these studies should ideally be blinded (e.g., double-blind where neither the participants nor the researchers know who is receiving the treatment) to reduce bias and ensure objectivity in results.
Experimental Models for Human Medical and Health Research
These models progress from simulations to direct human involvement to understand health and disease mechanisms, each with unique advantages and limitations.
Simulations with Mathematical Models/Computer (In silico):
Utilizes computational methods and mathematical equations to model biological systems and processes.
Description: Performed on a computer or via computer simulation. This approach can simulate complex biological interactions, predict drug effects, or model disease progression based on existing data and algorithms.
Allows for predictions and hypothesis generation without direct biological experimentation, saving time and resources in initial research stages.
In Vitro ("in glass") and Ex Vivo ("out of the living") Models:
Description: Conducted in a controlled environment outside a living organism. These models offer a high degree of experimental control over specific variables.
Examples:
Culturing transformed (cancer) cells or normal cells in a laboratory to study cellular growth, metabolism, or drug responses.
Maintaining an isolated perfused (and even beating!) heart specimen to study cardiac function or the effects of drugs on heart muscle.
Growing skin (epidermis) in a dish to study dermatological conditions or test topical treatments.
Isolating specific tissues, such as rat soleus muscle, for incubations and metabolic studies to understand energy pathways in muscle.
Main Purposes:
Allows for extremely controlled experimental conditions, isolating specific variables to understand their direct impact without confounding factors from the whole organism.
Crucial for understanding fundamental mechanisms at cellular and molecular levels, providing foundational knowledge for advanced research.
Reductionist Approach: These models exemplify a reductionist approach by studying isolated components or processes in simplified systems, breaking down complex biological systems into smaller, manageable parts.
Self-assessment Application: Both an in vitro cell culturing study and studying an isolated liver ex vivo are examples of a reductionist approach because they focus on specific components outside the complexity of the a whole organism.
Animal Models:
C. Elegans (Nematode):
Genetic Homology (to human): Approximately . This means a substantial portion of their genes have counterparts in humans.
Advantages: Easy and inexpensive to study due to their small size and simple maintenance.
Key Characteristics: Short life cycle (around days), self-fertilizes (producing genetically identical offspring), can be frozen, thawed, and remain viable (allowing for long-term storage of genetic lines), transparent body (facilitates the study of cell differentiation and internal processes in living animals).
Research Examples: Used to study embryonic metabolism (turning genes and pathways "on" and "off" to observe developmental effects), tracking nutrient digestion, protein synthesis, or cholesterol using fluorescent tags to visualize these processes in real-time.
Primary Use: Extensively used for genetic research, especially in understanding gene function and developmental biology due to their simple genetics and ease of manipulation.
Drosophila Melanogaster (Fruit Fly):
Genetic Homology (to human): Approximately . This higher homology makes them valuable for studying complex human diseases.
Key Characteristics: Life cycle and development are very sensitive to environmental conditions, making them ideal for studying environmental impacts on biology. They also have well-characterized genetics.
Research Examples: Widely used in neuropharmacology research to study the effects of drugs and alcohol on the nervous system, as their neural pathways share similarities with humans. Also used to model neurodegenerative diseases like Alzheimer's and Parkinson's.
Primary Use: Extensively used for genetic research and understanding developmental processes, as well as disease modeling.
Laboratory Rats (Various Strains):
Characteristics: Very social and intelligent, making them suitable for behavioral studies. They have a larger body size than mice, which is advantageous for certain physiological measurements and sample collection.
Research Uses: Frequently used to study lifestyle effects on metabolism (e.g., diets, exercise, drugs) and chronic diseases like hypertension and diabetes. Researchers often use more extreme conditions than with humans (e.g., fat diets to induce obesity quickly, hours/week of intense exercise to gauge physiological limits).
Limitations: Not a very good model for human infant nutrition