Test 11 Flashcards
What is the main toxin produced by C. perfringens? What is it’s function?
Alpha toxin (lecithinase= phospholipase C)
Lecithinase degrades lecithin (component of cell phospholipid membranes) that leads to cell destruction NECROSIS (gas gangrene) and hemolysis.
PERFringens PERForates a gangenous leg with alpha toxin.
Why does c. perfringens produce gas?
It uses carbs for energy–the rapid metabolism of muscle tissue produces gas that can be seen on xray or CT.
What are the three plasminogen activators?
streptokinase (Exotoxin released by S. Pygoenes)
urokinase
TPA
What is one of the most common reasons for elevated AFP levels?
underestimation of gestational age, confirmed by fetal US
*fetal liver, GI tract and yolk sac= source
What are other reasons for elevated AFP?
- Neural tube defects
- Anterior abdominal wall defects (omphalocele, gastroschisis)
- Multiple gestation
- Down Syndrome
What are decreased estriol levels indicative of?
Placental insufficiency
What are INCREASED levels of hCG (synth from trophoblastic tissue) associated with?
multiple gestation
hydatiform mole
choriocarcinoma
What is a mitochondrial enzyme that activates caspases and indirectly brings about cell death through intrinsic pathway apoptosis?
Cyt C
What is Edwards Syndrome?
47 xx +18 (nondisjunction)
Small jaws small eyes low formed ears rocker bottom feet (also in Patau) CLENCHED HANDS W/ OVERLAPPING FINGERS**
Flat face, abnormal ears, slanted palpebral fissures, redundant neck skin, single transverse palmar crease are associated with what genetic disorder?
Down syndrome
Cleft lip and palate, polydactyly and omphalocele are associated with what genetic disorder?
Patau syndrome
Tall male w/ gynecomastia and infertility is indicative of…
Klinefelter syndrome (47XXY)
An inability to normally metabolize fat is indicative of…
exocrine pancreatic insufficiency
Often from alcholism
What cytokines down regulate local inflammation?
TGF-B
IL-10
Do advance directives take precedence over wishes of family members?
Yes
Physicians should adhere to patient’s wishes outlined in advance directives
What is the most prevalent collagen in the human body?
Type I
Bone
Skin
Tendon
LATE wound repair
What type of collagen is associated w/ osteogenesis imperfecta?
type I
easily fracturable bones
What is made of type II collagen?
carTWOLage (hyaline) vitreous body (jelly in eye) nuclous pulposus (jelly in spine)
What is made of type III collagen?
Reticulin skin blood vessels uterus fetal tissue granulation tissue
What is deficient in ED syndrome?
type III collagen
What is made of type IV collagen?
Basement membranes
basal lamina
lens
What is defective in alport syndrome?
type IV collagen
What is targeted by autoantibodies in Good pasture syndrome?
type IV collagen
Pain sensation from the mediastinal/diaphragmatic parietal pleura is carried by what nerve?
phrenic
C3, 4, 5
Damage to what nerve causes a winged scapula?
long thoracic
serratus anterior
What is the CFTR protein?
Transmembrane ATP gated Cl channel
What causes CF?
Mutation in the CFTR gene on chromosome 7
AR disease
What is the agent of choice for prevention and tx of post-MI arrythmias?
Lidocaine
Binds depolarizing and depolarized cells–> ISCHEMIC myocardium is depolarized tissue
What are class IB antiarrythmics?
Little Mexican w/ an M
Lidocaine
MEXiletine
Decreases AP
What antiarrythmic is used to treat re-entrant or ectopic SVT/VT?
Class IA
QDP:
Quinidine
Procainamide
Disopyramide
Increases AP/ERP/QT
What antiarrythmic causes cinchonism?
1A: QDP
What antiarrythmics are often used to treat SVTs like a. fib?
1C: FP
Flecainide
Propafenone
Increase ERP in AV node and accessory bypass tracts
doesn’t affect AP duration
What drugs are CONtraindicated in isCHEMIC heart disease?
1C: Flecainide, Propafenone
What drugs help control ventricular rate and are used for a. fib and a flutter?
Class I (Beta blockers)
Decrease SA/AV nod by decreasing cAMP /Ca currents
*decrease the slope of phase 4
What drug is especially good for v. TAch?
Class II (AIDS)
Amiodarone (specifically)
Ibutilide
Dofetilide
Sotalol
Increased AP, ERP, QT–> prolonged repolarization
What beta blockers are good for TDPs?
Sotalol
Ibuitilide
What class III antiarrythmic can affect the lung, liver and thyroid and lead to blue/gray skin deposits?
Amiodarone
What drugs are used to prevent nodal arrhythmias (SVT)?
Class IV: Verapamil, diltiazem
Decrease conduction velocity, increase ERP, PR
Blocks Ca channels> slows depol in phase 0 and latter part of phase 4> slows rate of SA node firing and AV node conduction
What antiarrythmic causes constipation, flushing , edema, HF?
IV: VP
What is the drug of choice for supraventricular tachycardia?
Adenosine (increases K out of cell> hyperpolarizing cell> decraese Ca)
What is digoxin used for?
A. Fib
slows conduction through AV node
What electrolyte abnormalities are seen in a pts with primary adrenal insufficiency (Addisons)?
Decreased aldosterone> decreased reabsorption Na> decreased excretion of K and H
- Hyponatremia
- Hyperkalemia
- Met acidosis> low serum bicarb> compensatory incrase in Cl
- Hypercholremia
What is the most effective way to provide long term relief to pts with PUD?
Eradicate H. pylori using Antibiotics
Ranitidine
H2 blockers> decreased H secretion by parietal cells
Sucralfate
Binds to base of mucosal ulcers and protectsa gainst gastric acid allwoing ulcers to heal
Metoclopramide
DA antagonist> increases resting tone, LES tone, motility
Diabetic and postsurgery gastroparesis
Antiemetic
Misoprostol
PGE1 analog
Prevents NSAID induced ulcer disease
How does CO affect O2 binding on heme iron?
CO binds to Hb w/ 220 times the affinity of O2 for Hb leading to Carboxyhemoglobin. This causes a left shift and a decreased in O2 binding capacity as well as deficient unloading of O2.
tx: 100 O2 and hyperbaric O2
Night blindness, xeropthalmia, vulnerability to infection (measoles)
vit A
Cheilosis, corneal vascularization
Vit B2
Cheilosis and periopheral neuorpathy
B6
Pellagra
Niacin (dermatitis, dementia, diarrhea)
Scurvy, impaired wound healing
Vit C
Pernicious anemia
B 12
What syndrome is characterized by low plasma Na and osmolality, concentrated urine and increased urine Na volume, but NORMAL extracellular fluid volume?
SIADH
What is an important cause of SIADH?
paraneoplastic effect secondary to small cell lung cancer
What is the power of a study?
The ability of a study to detect a difference between groups when a difference really exists. Related to type II error (not an effect when one exists)
P= 1-B (B is type II error rate)
Where are receptors for cortisol located?
In the cytoplasm, then translocate to the nucleus
Receptor for insulin?
cell surface receptor> activation TK> suppression gluconeogenesis
Receptor for GH?
memberane bound Jak/STAT> increased gluconeogenesis
Receptor for NE/EPI/Glucagon?
GPCR membrane receptors> increases cAMP> AC> increase glycogenolysis
What causes meningoencephalitis in HIV + patients?
Cryptococcus neoformas
Inhalation> hematogneous dissemination to meninges
What is used for dx of c. neoformas?
latex agglutination detects the polysaccharide capsule Ag of Cryptoccus
INDIA INK shows ROUND/OVAL unequal budding yeast
Nonspetate hyphae that branch at wide angles
Mucor and Rhizopus
cause infection of paranasal sinuses in immunosuppressed
Germ tubes (sprouts of true hyphae from yeast cells)
Candida
Spherules
Tissue form of Coccidiomycosis
What is the neurotoxin released by C. Tetani?
Tetanospasm> exotoxin> tetanus
Block release of inhibitory interneurons in spinal cord that use GABA and glycine as their NT> prevents release of NT> spastic paralysis
What causes flaccid paralysis?
C. Botulinum> releases pre-formed heat labile toxin that inhibits ACh at NM jxn> flaccid paralysis
What is the mechanism of penicillins and cephalosporins?
Irreversibly bind to PBPs (transpeptidases)
Where does Vancomycin bind
Terminal D alanine residues of CELL WALL glycoproteins preventing transpeptidases from forming cross links
What is the mechanism of fluoroquinolones?
bind to proteins like DNA gyrase > interfere w/ DNA replication
What is a mechanism of resistance to ceophalosporins?
Change in PBP structure
How do corticosteroids affect a CBC?
Corticosteroids lead to dermarginalization of neutrophils that were previously attached to a vessel wall> increased neutrophils
Decreased: lymphocyte, monocyte, basophil and eosinophil
