Results for "plaques"

BIOC 503 - Lipoproteins

Chapitre 0: Topo sur la tectonique des plaques etc...

Unit 10 – Drugs for Central Nervous System (CNS) Problems (Comprehensive Study Guide – Nursing Pharmacology) ⸻ 🧩 Central Nervous System (CNS) Overview • CNS = Brain + Spinal Cord • Controls body movement, behavior, and cognitive function. • Neurotransmitters are chemicals that transmit signals between neurons. • Excitatory: Acetylcholine (ACh), epinephrine, norepinephrine • Inhibitory: Dopamine, serotonin, gamma-aminobutyric acid (GABA) ⚖️ Balance of dopamine and acetylcholine is critical for smooth movement. An imbalance leads to disorders like Parkinson’s Disease. ⸻ 🧍‍♂️ Parkinson’s Disease (PD) Cause • Progressive CNS disorder due to low dopamine production in the substantia nigra. • Too little dopamine → too much acetylcholine, causing impaired motor control. Key Symptoms Motor: • Tremors (“pill-rolling”) • Bradykinesia (slow movements) • Muscle rigidity, stiffness • Stooped posture, shuffling gait • Difficulty rising, “freezing in place” • Masklike facial expression Nonmotor: • Constipation, urinary frequency • Depression, anxiety, hallucinations • Sleep issues, fatigue • Memory problems ⸻ Drug Classes for PD Goal: Restore balance between dopamine and acetylcholine. 1️⃣ Dopamine Agonists Action: Mimic or increase dopamine. Improve movement, coordination, and muscle control. Examples: • carbidopa/levodopa (Sinemet, Rytary) • pramipexole (Mirapex ER) • ropinirole (Requip) • rotigotine (Neupro patch) Nursing Implications & Teaching: • Give 30–60 min before meals (empty stomach). • Avoid protein-rich foods (reduces absorption). • Monitor for orthostatic hypotension — rise slowly. • Don’t crush extended-release tablets. • Neupro patch: rotate sites, don’t reuse within 14 days. • Avoid vitamin B6 unless taken with carbidopa. • Takes 2–3 weeks for full effect. Side Effects: • Hypotension, headache, nausea, insomnia • Dyskinesia (abnormal movements) • “On/off effect” – medication wears off quickly • Long-term use → hallucinations, impulse control problems Adverse Effects: • Neuroleptic malignant syndrome: fever, rigidity, confusion • Psychosis, severe hypotension ⸻ 2️⃣ COMT Inhibitors Action: Block COMT enzyme → prolong dopamine activity. Examples: • entacapone (Comtan) • tolcapone (Tasmar) Nursing Implications: • Always give with carbidopa/levodopa. • Monitor liver function (q6 months) – risk of liver failure (especially tolcapone). • Harmless side effect: brown-orange urine. • Rise slowly to prevent hypotension. ⸻ 3️⃣ MAO-B Inhibitors Action: Inhibit MAO-B enzyme → prevents dopamine breakdown. Examples: • selegiline (Eldepryl) • rasagiline (Azilect) • safinamide (Xadago) Teaching: • Avoid foods high in tyramine → hypertensive crisis risk. (Aged cheese, wine, beer, cured meats, soy sauce, yogurt, avocados, bananas) • Monitor BP closely. • Avoid OTC decongestants or stimulants. • Can cause insomnia, dizziness, dry mouth, or constipation. ⸻ 🧠 Alzheimer’s Disease (AD) Cause • Progressive neurodegenerative disorder leading to memory loss, confusion, and poor judgment. • Loss of acetylcholine (ACh) and buildup of amyloid plaques and neurofibrillary tangles in the brain. Symptoms • Early: forgetfulness, confusion, mood changes. • Late: loss of reasoning, personality changes, inability to perform ADLs. ⸻ Drug Classes for AD 1️⃣ Cholinesterase Inhibitors Action: Block enzyme acetylcholinesterase (AChE) → increases ACh → improves memory and function. Examples: • donepezil (Aricept) • rivastigmine (Exelon) • galantamine (Razadyne) Side Effects: • Nausea, vomiting, diarrhea • Loss of appetite, GI discomfort • Drowsiness, headache, insomnia • Muscle cramps, bradycardia Adverse Effects: • Dysrhythmias, GI bleeding, hallucinations • Overstimulation of parasympathetic system (too much ACh) Nursing Implications: • Give at bedtime to reduce nausea. • Monitor weight, HR, and mental changes. • Report black/tarry stools or vomiting blood. • Avoid OTC anticholinergics (they reduce effectiveness). ⸻ 2️⃣ NMDA Blockers Action: Block NMDA receptor → decreases glutamate activity → prevents neuron death. Example: • memantine (Namenda) Used in: Moderate to severe AD (often combined with donepezil). ⸻ ⚡ Epilepsy / Seizure Drugs (AEDs) Purpose Reduce excessive electrical activity in the brain and prevent seizures. Common AEDs: • phenytoin (Dilantin) – prevents neuron excitation • topiramate (Topamax) – broad-spectrum seizure control Topiramate Key Points: • Side effects: dizziness, drowsiness, taste changes, paresthesias (“pins and needles”) • Adverse: metabolic acidosis, ↑ ammonia → confusion, lethargy, vomiting • Monitor: serum bicarbonate & ammonia levels • Teaching: stay hydrated, report mental status changes, don’t crush tablets • Contraindicated in pregnancy (teratogenic) ⸻ 💥 Multiple Sclerosis (MS) Pathophysiology • Autoimmune disease where the immune system attacks myelin (fatty sheath around neurons). • Leads to nerve signal disruption → muscle weakness and loss of coordination. • Common type: Relapsing-Remitting MS (RRMS) – periods of flare-ups and remission. Common Symptoms • Fatigue, weakness, difficulty walking • Double vision or blurred vision • Tingling or numbness • Bladder/bowel dysfunction • Depression, poor concentration ⸻ Drug Therapy for MS 1️⃣ Biological Response Modifiers (BRMs) Action: Modify immune system activity and slow disease progression. Examples: • beta-interferons (Avonex, Betaseron, Rebif, Extavia, Plegridy) • glatiramer (Copaxone) • fingolimod (Gilenya) • teriflunomide (Aubagio) Side Effects: • Flu-like symptoms, headache, fatigue • Elevated liver enzymes, slow HR • Thinning scalp hair Nursing Teaching: • Rotate injection sites. • Monitor liver enzymes, CBC, and heart rate. • Avoid live vaccines. ⸻ 2️⃣ Monoclonal Antibodies Action: Destroy lymphocytes that attack myelin. Examples: • alemtuzumab (Lemtrada) • natalizumab (Tysabri) • ocrelizumab (Ocrevus) Side Effects: • Increased risk of infection • Headache, rash, fatigue • GI upset Nursing Teaching: • Given IV every few months to yearly. • Monitor for infusion reactions and infection signs. ⸻ 3️⃣ Neurologic Drugs Examples: • dimethyl fumarate (Tecfidera) – reduces CNS inflammation • dalfampridine (Ampyra) – improves walking by increasing nerve conduction Teaching: • Take daily; don’t crush tablets. • Watch for GI symptoms and dizziness. ⸻ 💪 Amyotrophic Lateral Sclerosis (ALS) Description • Progressive, fatal disorder destroying motor neurons → paralysis. • Death usually occurs within 3–5 years of diagnosis. Drug Therapy Glutamate Antagonists Example: • riluzole (Rilutek, Tiglutik) Action: Inhibits glutamate release → slows neuron damage → prolongs life by months. Side Effects: • Weakness, nausea, dizziness • Liver toxicity (↑ liver enzymes) • Neutropenia, anemia Nursing Implications: • Monitor liver enzymes before and during therapy. • Report jaundice or dark urine. • Take on an empty stomach (1 hr before or 2 hrs after meals). • Avoid alcohol. • Don’t breastfeed while on this med. ⸻ ⚙️ Myasthenia Gravis (MG) Description • Autoimmune disease destroying acetylcholine receptors at neuromuscular junction. • Causes muscle weakness and fatigue, especially in eyes, mouth, throat. Symptoms • Ptosis (drooping eyelids) • Difficulty chewing/swallowing • Weakness in arms, legs, or respiratory muscles • Worsens with activity, improves with rest ⸻ Drug Therapy Acetylcholinesterase Inhibitors Action: Prevent breakdown of acetylcholine → improves nerve–muscle communication. Example: • pyridostigmine (Mestinon) Dosage: Usually every 4–6 hours, depending on patient response. Side Effects: • Nausea, vomiting, abdominal cramps, diarrhea • Increased salivation, sweating • Bradycardia, hypotension Adverse: • Cholinergic crisis (too much medication): → extreme weakness, bradycardia, bronchospasm, respiratory arrest. Nursing Implications: • Use with caution in asthma, COPD, bradycardia. • Give doses at same time each day to maintain muscle strength. • Monitor for myasthenic vs. cholinergic crisis. • Give meds 30–45 min before meals to prevent aspiration. Patient Teaching: • Take missed dose ASAP (but skip if close to next dose). • Don’t double dose. • Avoid alcohol and sedatives. • Report muscle weakness or breathing difficulty. • Keep atropine available (antidote for cholinergic crisis)

Hemodynamics Blood flow directly affects the stroke volume. Anything that affects blood flow, like resistance, affects stroke volume. Predict what would happen to stroke volume and blood flow if there was an increase in resistance. -> CO = HR x SV • CO = HR × SV • Resistance affects blood flow → affects SV If resistance increases: • It’s harder for blood to flow forward. • The heart must work harder to push the same amount of blood out. 👉 Prediction: • Stroke Volume ↓ (decreases) • Blood Flow ↓ (decreases) 2 | Recall from Activity 1 we used the equation for flow, F = (PA - Pv)/R, where F = Flow; PA = Arteriole Pressure, Pv = Venous Pressure, and R = Resistance. We can simplify the (PA - Pv) to change in pressure (AP). Therefore, we can solve for AP = F x R (Change in Pressure = Flow x Resistance). We can develop a mathematical equation substituting cardiac output for flow to get AP = HR x SV × R which means heart rate, stroke volume, and resistance all have an impact on the blood pressure in the body. To maintain a normal blood pressure, heart rate, stroke volume, and resistance can be altered. Predict what would happen to blood pressure if resistance was increased due to vasoconstriction of the arterioles. Flow equation: F = (PA - Pv)/R • Or rearranged: ∆P = F × R • CO = HR × SV, so ∆P = (HR × SV) × R 👉 Prediction: • If resistance increases due to vasoconstriction, then blood pressure ↑ (increases). 💡 Because narrowing arterioles make it harder for blood to flow, raising the pressure inside the vessels. 3 Afterload is the amount of resistance the left ventricle must overcome to force open the aortic semilunar valve, ejecting the blood into the ascending aorta. The greater the afterload, the harder it is to open the aortic semilunar valve, and less blood is ejected into the ascending aorta. Stroke volume is the amount of blood ejected into the ascending aorta during left ventricular systole. Stroke volume can be calculated by subtracting the End Systolic Volume (ESV) from the End Diastolic Volume (EDV). SV - EDV - ESV. EDY is the amount of blood in the ventrice when the ventricle is 100% filled. ESV is the amount of blood let in the ventrice after systole (contraction) ends. The greater the afterload, the larger the BSV. Resistance is generated from the body's arterioles pushing blood back towards the heart and is called peripheral vascular resistance. When there is an increase in peripheral vascular resistance, afterload is increased. a | Predict what would happen to the ESV If peripheral vascular resistance was increased. If peripheral vascular resistance increases: • Afterload (the pressure the left ventricle must overcome) increases. • The ventricle can’t eject as much blood. 👉 ESV ↑ (increases) — more blood stays in the ventricle after contraction. b | Predict what would happen to cardiac output if the ESV amount was increased. If ESV increases: • Stroke volume = EDV - ESV → less blood ejected per beat. • Therefore, stroke volume ↓, so cardiac output ↓. 💡 Because the heart is pumping against greater pressure, it empties less efficiently. 4 | Coronary artery disease is a form of atherosclerosis, where plaques form in the coronary arteries of the heart. This causes a decrease in the radius of the arteries due to the accumulation of plaque within the lumen of the arteries. Recall the right and left coronary arteries come off the ascending aorta, just above the aortic semilunar valve. a | Predict what will happen to the resistance in the coronary vessels that contain plaques. Resistance in coronary vessels: • Plaque narrows the lumen → resistance ↑ (increases). b | What will happen to the resistance on the aortic semilunar valve? How will this impact afterload? Explain. Resistance on the aortic semilunar valve & afterload: • The narrowing in coronary arteries doesn’t directly affect the valve, but overall, the heart faces increased resistance to blood flow leaving the aorta, so afterload ↑ (increases). c | How will this impact the ability of the heart to contract (with greater or less force)? Impact on heart contraction: • With increased afterload, the heart must contract with greater force to eject blood. • Over time, this strains the heart and can lead to weaker contractions and heart failure if untreated. 5| Calcium channel blockers like verapamil are used to help the smooth muscle of the arteries relax and is often a treatment for coronary artery disease. Explain how verapamil will affect resistance in the coronary arteries. How will this affect blood pressure in the body as a whole? How will this impact the ability of the heart to contract (with greater or less force)? What verapamil does: • Relaxes smooth muscle in arterial walls → vasodilation (arteries widen). Effects: • Resistance ↓ (decreases) in coronary arteries. • Blood pressure ↓ throughout the body (less vascular resistance). • The heart doesn’t have to work as hard → afterload ↓ → contracts with less force, but more efficiently. 💡 It eases the workload on the heart by widening the arteries and lowering overall pressure

Male and Female Pelvis Plaques: Urinary Structures

T1 Chpt.2 : La mobilité horizontale des plaques lithosphériques

Géo : Juin 2025 → Savoirs : La tectonique des plaques

Délais d'apparence et de fermeture des plaques de croissance (espèce canine)

tectonique des plaques

Geo: L'introduction à la dérive des continents et les plaques tectoniques

Infectious Disease: Nodules/Plaques

Géo mécanisme des plaques

EX 29 Viruses, bacteriophage plaques

Phage Typing Learning Objectives 1. Explain the purpose of phage typing. 2. Describe the phage typing method. 3. Explain what is occurring when plaques form in a bacterial lawn. 4. If both T4 and ΦX174 use LPS as their bacterial receptor, explain why wild-type phage T4 produces plaques, while wild-type ΦX174 does not infect E. coli K-12. Identification of Unknowns 1. Why is a streak plate important for a bacterial unknown analysis? What is an additional early analysis step? 2. Describe the Enterobacteriaceae and their major characteristics. 3. Describe the test series/battery typically used to distinguish between members of the Enterobacteriaceae. 4. Explain what the symbols (+) and (-) indicate regarding the outcome of various biochemical tests. 1. Identify the 3 groups of soil organisms isolated in the soil microbial count. Explain how these groups were separated for analysis. 2. Identify the major antibiotic-producing genera found in the soil, and, for each, identify the above group to which it belongs. 3. Explain why dilutions are necessary for microbial counts. 4. Starting with a culture containing 106 cells/ml, describe in detail how to set up a serial dilution scheme to result in a countable plate. 5. Evaluate and interpret the results of a plate count, including selecting the appropriate plate for counting, and calculating the original cell density (OCD). 6. Identify three bacterial pathogens transmitted through fecal contamination of water. 7. Explain the difference between coliform and non-coliform bacteria. Identify the coliform organisms used as indicator species for fecal contamination of water. 8. Describe in detail the technique commonly used to assess the presence of fecal coliforms in water. Specify what constitutes a countable plate. 9. Identify the selective medium used to enumerate fecal coliforms and the basis for its selectivity. Describe the appearance of coliforms on this medium. 10. Given a countable plate, calculate the coliform CFU per 100 mL. Specify the coliform count of potable water.

La théorie de la tectonique des plaques

Micro Exam 4 Virus - a genetic element that contains either RNA or DNA surrounded by a protein capsid and that replicate only inside host cells Obligate intracellular parasite - Cannot multiply unless they invade a specific host cell and instruct its genetic and metabolic machinery to make and release new viruses Capsid - the protein shell that surrounds the genome of a virus Nucleocapsid - nucleic acid + protein in enveloped viruses Envelope - viruses have an outer layer consisting of a phospholipid bilayer (from host cell membrane) and viral proteins – those without envelope are easier to kill Virion – inactive form of virus outside the host cell Capsomere - identical protein subunits that spontaneously self-assemble into a finished capsid icosahedron – one of 2 types of capsids (the other is helical) Genome - the sum total of the genetic information carried by an organism Bacteriophage - “bacteria eating” viruses that infect bacteria Temperate phage: Undergo adsorption and penetration, do not undergo replication or release immediately Viral DNA enters a Prophage state Inserted into bacterial chromosome → Copied during normal bacterial cell division Induction - prophage in a lysogenic cell becomes activated and progresses directly into viral replication and the lytic cycle lysogeny - a condition in which the host chromosome carries bacteriophage DNA lysogenic conversion - when a bacterium acquires a new trait from its temperate phage: Corynebacterium diphtheriae – diphtheria toxin Vibrio cholerae – cholera toxin Clostridium botulinum – botulinum toxin Monolayer - single, confluent sheet of cells that supports viral multiplication Plaques - areas where virus-infected cells have been destroyed show up as clear, well-defined patches in the cell sheet

Géo : 2. La tectonique des plaques

4 - dérive des continents et tectonique des plaques