Pulm Flashcards
What path does fetal blood take from the placenta to the heart?
Umbilical vein - liver - ductus venosus - IVC - heart
T-test versus analysis of variance (ANOVA)
A t-test is used to compare the difference between the means of (2) groups. ANOVA compares bbetween the means of 2 or more groups.
Deletions or additions of a number of base pairs which are not a multiple of three, indicate that a ___________ mutation has occured.
Frameshift
What type of drug is ipratropium and what type of bronchoconstriction is affected by it?
It is an antimuscarinic agent
Only reverses vagally-mediated bronchoconstriction
What kind of drug are theophylline and aminophylline? What is their MOA?
They are Methylxanthines
They cause bronchial dilatation by decreasing phosphodiesterase enzyme activity, thereby increasing intracellular camp.
What are Hamartomas? How do they present? What are they composed of?
The most common benign lung tumor
Present as asymptomatic peripherally located “coin lesion” in patients 50-60 y/o
Composed of disorganized cartilage, fibrous and adipose tissue
What are the (2) key functions of type II pneumocytes?
- Regeneration of the alveolar lining
- Surfactant production
What is responsible for the green discolortion of pus or sputum during bacterial infections?
Myeloperoxidase (MPO) from neutrophil azurophilic granules. MPO is a heme-containing pigmented molecule.
Omalizumab MOA/ indication
Anti-IgE antibody
Add-on therapy for patients with severe allergic asthma
What are the (4) major causes of hypoxemia? Which has a normal A-a gradient?
- Alveolar hypotension (normal A-a gradient)
- V/Q mismatch
- Diffusion impairment
- Right-to-left shunting
Main potential AE of neonatal oxygen therapy?
Retinal damage
What are the structural differences between MHC Class I and Class II?
MHC Class I: Heavy chain and B2-microglobulin
MHC Class II: Alpha and beta polypeptide chains
Describe Type IV Hypersensitivity
How are antibodies involved?
What are the (4) T’s of this hypersensitivity?
Aka delayed (T-cell mediated) type
Sensitized T cells encounter antigen and then release cytokines (leading to macrophage activation)
No antibodies involved
4 T’s:
T cells
Transplant rejections
TB skin tests
Touching (contact dermatitis)
Interstitial lung disease has what effect on lung volumes? Lung elastic recoil?
How does this affect expiratory flow rates?
Decreased lung volumes
Increased lung elastic recoil
The increased recoil leads to radial traction (outward pulling) of airways, leading to increased corrected expiratory flow rates.
When amniocentesis is performed to check phospholipids, what are we really checking for?
Fetal lung maturity
Phospholipids (such as lecithin aka phosphatidylcholine) are a majory component of pulmonary surfactant
What is the negative predictive value and how do we calculate it?
NPV represents the probability of not having a disease given a negative test result. NPV = true negatives/total negative tests
Sensitivity vs Specificity
Sensitivity = true-positive rate
(the probability that a test detects disease when a disease is present)
Specificity= true-negative rate
(Probability that a test indicates no disease when disease is absent)
What type of epithelium makes up the true vocal cords?
Stratified squamous
What is hypocapnia and what does it imply for a patient?
A state of reduced CO2 in the blood. Always implies alveolar hyperventilation.
Describe the common presentation for sarcoidosis
- Hilar adenopathy
- Pulmonary infiltrates
- Non-caseating granuloma
- AA Woman
Describe the pathogenesis of Sarcoidosis
Granuloma formation as a manifestation of cell-mediated immunity driven by products of Th1 type CD4 helper T-cells, particularly IL-2 and IFN-y, which stimulate Th1 type cell proliferation and macrophage activation, respectively.
Th1 vs Th2
What do they secrete? What do they recruit/activate? How are they activated? How are they inhibited?
Both are CD4+ Helper T-cells
Th1
- Secretes IFN-y
- Activates macrophages and cytotoxic T cells
- Activated by INF-y and IL-12
- Inhibited by IL-4 and IL-10 (from Th2)
Th2
- Secretes IL-4, 5, 10, and 13
- Recruits eosinophils for parasite defense and promotes IgE production by B cells
- Activated by IL-4
- Inhibited by IFN-y (from Th1 cells)
What is the most common CFTR mutation associated w/ CF?
F508 mutation. This causes impaired postranslational processing (improper folding and glycosylation) of the CFTR. As a result, the abnomormal protein is targeted for degradation.
What are the classic sputum findings for Extrinsic Allergic Asthma
Eosinophils and Charcot-Leyden crystals (crystalloid bodies containing eosinophil membrane proteins).
What key interleukin/cytokines are responsible for converting a helper T-cell into a Th1 cell? Th2 cell? Th17 cell?
Helper T to…
Th1 (via IL-12)
Th2 (via IL-4)
Th17 (via TGF-B and IL-6)
Describe the main roles for IL-1 through IL-6 when secreted by macrophages
Hot T-Bone stEAK
IL-1: fever (hot)
IL-2: stimulates T cells
IL-3: stimulates bone marrow
IL-4: stimulates IgE production
IL-5: stimulates IgA production
IL-6: stimulates aKute-phase protein production
Stimulation of the vagus nerve would have what effect on the lungs?
It would cause bronchoconstriction and increased bronchial mucus secretion via Ach binding to M3 receptors. This ultimately increases the work of breathing.
What is the MOA and Indication for both Cromolyn and Nedocromil? How effective are they compared to drugs with a similar indication?
They are mast cell stabilizing agents which inhibit mast cell degranulation independent of stimuli.
They are a second-line treatment for allergic rhinitis and bronchial asthma. Glucocorticoids are the first line prophylactic and are a superior drug.
What is a pancoast tumor? Where is the most likely location for a pancoast tumor to occur? What is the most common presentation?
Carcinoma in the apex of the lung. These usually arise in the superior sulcus (groove fromed by the subcalvian vessels)
Common presentation:
- Pt. w/ extensive smoking history
- Shoulder pain- most common symptom
- Horner syndrome
- Pain in distribution of C8-T2 roots (spinal cord compression)
Idiopathic Pulmonary Artery Hypertension
Pathogenesis/pathophys?
Presentation?
Treatment?
Pathogenesis: If familial form, result of inactivation of the pro-apoptotic BMPR2 gene. Results in increased endothelial and smooth muscle cell proliferation and vascular remodeling
Presentation: Dyspnea, excercise intolerance in women 20-40
Treatment: Lung transplant and bosentan (endothelin-receptor antagonist) in the meantime
What virus is the pictured biopsy associated with?
What is the normal type of patient who has this virus?
Describe the virus?
This biopsy is associated with cytomegalovirus (CMV).
This is particuarly common among patients who have recently had lung transplants or are generally immunocompromised.
It is an enveloped double-stranded DNA virus
Ghon Complex and TB reactivation (who is it in and what characterizes it?)
This complex characterizes the initial stages of M. tuberculosis infection. It consists of a lower lobe lung lesion (Ghon focus) and ipsilateral hilar adenopathy.
Reactivation of TB occurs most often in immunosuppressed patients and is characterized by apical cavitary lesions and hemoptysis.
X-linked agammaglobulinemia
Pathogenesis?
Diagnostics?
Presentation?
- A mutation in Bruton tyrosine kinase gene causes failure of BM pre-B cells to mature.
- These patients have:
- low B-cells in peripheral blood (CD19+, CD20+, CD21+)
- pan-hypogammaglobulinemia (low Ig’s)
- Increased risk of infection w/ encapsulated bugs and certain viruses and parasites
Mechanisms of bacterial transfer: Transformation vs Conjugation vs Transduction
Transformation: Direct uptake of naked DNA form the environment
Conjugation: One way transfer of chromosomal or plasmid DNA between bacteria via direct physical contact (one of them must have F factor which codes for a sex pilus).
Transduction: Transfer via bacteriophage
Name the key characteristics of which distinguish Slicosis from other forms of pneumoconiosis (2)
How can silicosis impair immune function?
- Eggshell calcification at the hilar nodes
- Birefringent silica particles surround by fibrous tissue on histology
Silicosis impairs the macrophages, by disrupting them with internalized silica particles
Klebsiella
Encapsulated or not?
Lactose-fermenting or not?
Usual presentation/ patients affected/characteristics?
- Encapsulated
- Lactose fermenting (grows pink on MacConkey agar)
- It causes pneumonia in subjects with impaired host defenses, especially alcoholics
- Characterized by tissue necrosis, early abscess formation and currant jelly sputum
What is the relationship between CO2 and cerebral perfusion?
CO2 is a potent cerebral vasodilator and therefore a drop in CO2 (due to hyperventilation and subsequent hypocapnia for example), causes a linear decrease in cerebral perfusion.
At the FRC, the airway pressure is? alveolar pressure is? Intrapleural pressure is?
Airway pressure = 0
Alveolar pressure = 0
Intrapleural pressure = Negative, with a value of -5cm H2O (prevents pneumothorax)
Mesothelioma
What is it?
Risk factor(s)?
Presentation?
Dx factors? (3)
- Rare malignant neoplasm of mesothelial cells.
- Primary risk factor is consistent Asbestos exposure
- Symptoms include: dyspnea and chest pain
- Dx tests will show:
- Hemorrhagic pleural effusion
- Pleural thickening on radiographic study
- Long slender microvilli and abundunt tonofilaments on histo.
You see a large cell with multiple nuclei in the shape of a horshoe. What is it called and what disease process is it associated with?
Langhans Giant Cells. Formed from macrophages which are activated in response to pulmonary TB.
Name the potential sequelae of Obstructive Sleep Apnea (3)
Systemic and Pulmonary HTN, and right heart failure
Sarcoidosis
Pathophys?
Presentation?
Dx?
Treatment?
- Path:Immune mediated, widespread noncaseating granulomas
- Pres: Black women w/ possible erythema nodusum, arthralgia, elevated ACE levels, etc.
- Dx: Bilateral hilar adenopathy on CXR
- Tx: Steroids
What are the (4) stages associated with Lobar Pneumonia? Describe the exudate.
- Congestion (first 24 hours): Vascular dilation; exudate contains bacteria
- Red hepatization (days 2-3): erythrocytes, PMNs and fibrin in exudate
- Gray hepatization (days 4-6): RBCs disintegrate. Exudate contains PMNs and fibrin
- Resolution: Enzymatic digestion of exudate
Chronic Granulomatous Disease
- Pathogenesis?
- Clinical Manifestations?
- Dx?
- Pathogenesis: Inactivating mutation affecting NADPH oxidase. Impaired respiratory burst inhibits phagocytic intracellular killing
- Clinical Manifestation: Recurrent infections in child w/ catalase (+) bacteria/fungi (commonly in lungs, skin, LNs and liver). Diffuse granuloma formation
- Diagnosis: DHR flow cytometry (prefered); Nitroblue tetrazolium (NBT) testing
Describe the pathogenesis of centriacinar emphysema
- Oxidative injury to the respiratory bronchioles by smoking
- Macrophage activation
- Inflammatory recruitment of neutrophils
- Release of proteases by neutrophils and macrophages
What is the common clinical presentation for a pneumothorax?
What is often the cause of spontaneous pneumothorax?
- Sudden unilateral chest pain
- Hyperresonance
- Absent breath sounds
- Often seen in tall, thin males around age 20
Can be the spontaneous result of the rupture of an apical subpleural bleb