Pathology - part 2 Respiratory, GI, etc Flashcards
PH (pulmonary hypertension)
cause, mechanism, patho,
mean PA pressue > 25/30 mm Hg at rest/exercise
mechanism 2° PH: respiratory acidosis/hypoxemia → vasoconstriction PAs
MCC 2° PH: left-sided valvular disease
Patho: atherosclerosis in main PAs
MC sym: exertional dyspnea
tapering PAs/RVH (right ventricular hypertrophy) on chest X-ray: cor pulmonale (= PH + RVH, 肺心病)
Goodpasture syn
cause? presentation?
Ab attack basement membrane in pulmonary cap and glomerular cap (type II hypersensitivity)
hemoptysis (咯血)followed by renal failure
RLD (restrictive lung disease)
defination? cause? 表现?
defination: ↓ TLC (total lung capacity)
cause: chest wall disorders (ie: kyphoscoliosis, mesothelioma, obesity, acute/chronic ILDs - interstitial lung diseases. ILD的一种,idiopathic pulmonary fibrosis: most MCC of RLD; sarcoidosis)
dry cough, inspiratory crackles (湿罗音)in lower lung fields, exertional dyspea
favor shallow, fast breath to ↓ work of breathing
Pathogenesis of interstitial fibrosis? Dx?
earlist manifestation: alveolitis [leukocytes release cytokines → fibrosis] → interstitial fibrosis
↓ compliance (↓ expansion during inspiration)
↑ elasticity (↑ recoil during expiration
Pulmonary function test: all volumes and capacities are equally ↓; normal to ↑ FEV1/FVC ratio (normal is 80% = 4L/5L), respiratory alkalosis (PCO2 < 33 mmHg), ↓PaO2
X-ray: diffuse bilateral reticulonodular infiltrates
silicosis: X-ray特征改变?
胸片见egg-shell calcification in hilar nodes
MC occupational disease
opacities contain collagen and quartz (highly fibrogenic)
↑ risk for lung cancer/TB [differentiate: CWP (coal worker’s pneumoconiosis): no risk for lung cancer/TB]
if lung is encased, likely Rx?
mesothelioma (arise from pleura serosa)
no relationship with smoking
sarcoidosis:
etio? patho? Dx?
immune regulation disorder: CD4 Th cells interact with unknown Ag
noncaseating granulomas: Dx is exclusion (rule out other granulomas diseases)
lung is the target organ: dyspnea is the MC sym [patho: granulomas contain multinucleated giant cells]
UW case: 35-yr black woman, arthralgias+tender, deep nodules on legs, hepatomegaly (scattered granulomas), chest X-ray: enlarged hilar lymph nodes, serum ACE ↑[note: important lab for sarcoidosis]
Caplan syn?
cavitating rheumatoid nodules in the lung + pneumoconiosis
emphysema 肺气肿
patho?
how can smoking produce emphysema?
MCC: smoking; α1-AAT (α1 antitrypsin: antielastase) deficiency
patho: ↑ compliance, ↓ elasticity (能张开,但是无法recoil)
inbalance between elastase vs. antielastases; free radicals vs. GSH
cigarette smoke: chemotactic to neutrophils and macrophages ➞ release free radicals ➞ inactivate AAT/GSH
分为centriacinar vs. panacinar:
centriacinar: destruction of distal terminal bronchioles /upper lobe; panacinar: entire respiratory unit, lower lobe, no α1-globulin peak on serum protein electrophoresis
early dyspnea + late hypoxia (take time to destruct respiratory unit)
X-ray: ↑ hyperlucency, ↑ anterior-posterior diameter, vertically oriented heart, depressed diaphraghms
↑ TLC, RV; ↓ FEV1/FVC
↓ PaO2, normal to ↓ arterial PCO2 (pink buffer)
bronchial asthma
extrinsic (most, autoimmune) vs intrinsic (nonautoimmune)
extrinsic: type I HSR: allergen stimulates CD4 TH2 cells ➞ release IL4, IL-5 ➞ IL-4 stimulates isotype switching to IgE (release histamine, etc from mast cells), IL-5 stimulates production and activation of eosinophils (major basic protein and cationic proteins to damage epithelial cells)
other mediators: leukotrienes (LTC-D-4, acetylcholine)
intrinsic (ie, viral infection, etc): normal IgE, negative skin tests to allergens
Bronchial asthma: alkalosis or acidosis?
initially: respiratory alkalosis (work hard to expell air, 过度通气)
If bronchospasm is not relieved, progress into respiratory acidosis
[normal pH or acidosis: indicates need for intubation !!!!]
FEV1 is the best measure of severity
MCC of bronchiectasis?
In US: CF
worldwide: TB
CF: cause? symptoms?
AR, MC fatal heretidary disorders in whites in US
3-nucleotide deletion in chr#7, coding for Phenylalanine: mutation causes defective protein folding in CFTR (CF transmembrane conductance regulator)➞ degraded in Golgi
CFTR is regulated by cAMP/ATP
CF: loss of NaCL in sweat (for Dx) /luminal secretion (dehydrated, thickened secretion)
nasal polyps in children, respiratory infections (MCC death in CF), chronic pancreatitis producing malabsorption, type I DM), infertility in males,
3 (patho/histological) types of pneumomia?
- bronchopneumonia: locally, involve lower or right middle lobe; pathy areas of consolidation
- interstitial pneumonia: inflammatory infiltration is confined to the alveolar walls
- lobar pneumonia: involve an entire lung lobe
stages and patho characteristics of lobar pneumonia?
- congestion (充血):< 24 hrs [vascular dilation, alveolar exudate contains mostly bacteria], affected lobe is red, heavy and boggy
- red hepatization: 2-3 days [alveolar exudate contains RBCs, neutrophils and fibrin]; red, firm lobe, liver-lie consistency
- grey hepatization: 4-6 days [RBCs distegrate, alveolar exudate contains neutrophils and fibrin]
- resolution: enzymatic digestion of the exudate, restore the normal architecture
work of breathing change in obstructive vs. restrictive pulmonary disease?
obstructive (asthema, COPD): compliance ↓, airflow resistance ↑: favor lower rate/higher TV (tidal volumes): show, deep breath
restrictive (fibrosis, asbestosis): elasticity ↓, elastic resistance ↑: favor faster rate/low TV: fast, shallow breath
most sensitive test to rule out asthma?
Bronchial challenge test: test bronchial hypersensitivity. Give an aerosolized bronchoconstrictive substance required to produce a 20% ↓ in FEV1
usually use Methacholine
this test is sensitive but not specific. Used to exclude asthma
complication of give premature newborns concentrated O2?
retinopathy of prematurity: concentrated O2 ⇒ VEGF ↑ ⇒ abnormal retinal neovascularization
asbestosis: sym? light microscope? cancer related?
formation of fibrocalcific plaques on the parietal pleura, Subsequent diffuse pleural thickening and fibrosis of the lower lung lobes,
clinic: dyspnea, ↓ lung volumes (restrictive lung disease)
light microscope: interstitial fibrosis, asbestos bodies (ferruginous bodies, 铁锈色体): asbestos fibers coated with protein-iron matrix
risk for bronchogenic carcinoma ↑↑↑, MC cause of death; the 2nd leading cause of death is mesothelioma
TB: 病原体隐藏在what kind of cells? virulence factor? 肺部病理表现(分为primary vs, reactivation TB)?
organisms reside in phagasomes of alveolar macrophage! Produce ‘cord factor” (a protein to prevent fusion of lysosomes with phagosomes)
[note: humoral immunity plays no role in TB, because TB is an intracellular parasite in macrophages!】
TB特征:strict aerobe (like to be in upper /apex lobe), acid-fast 抗酸
primary TB: upper part of lower lobes, or lower parts of upper lobes; Ghon focus (= casecous necrosis: yellow-tan subpleural granuloma); Ghon complex (冈氏病灶):caseous necrosis in hilar nodes
secondary (reactivation) TB: in immunosuppressed patients (HIV, corticoids, etc): upper lobe cavitary lesions (due to release of cytokines from memory T cells)
cough, hemoptysis, weight loss;
acid-fast bacillion a sputum culture, cavitary upper love pulmonary lesion on X-ray:
Dx?
reactivation TB
lung cancer histology: ovoid cells smaller than resting lymphocytes, immunostaining positive for chromogranin: Dx?
small cell carcinoma
strongly associated with smoking, centrally located;
round or oval cells with scant cytoplasm and large hyperchromatic nuclei; resemble lymphocytes, but smaller
Goodpasture syn?
IgG directed against basement mem. in pulmonary cap and glomerular ca. (type II HSR)
clinic: hemoptysis followed by renal failure
Churg-strauss syn?
autoimmune medium and small vessel vasculitis.
It usually (but not always) manifests in three stages. The prodromal stage is marked by airway inflammation: almost all patients experience asthma and/or allergic rhinitis; the second stage is characterized by hypereosinophilia: abnormally high numbers of eosinophils, which causes tissue damage — most commonly to the lungs and the digestive tract. The third and final stage consists of vasculitis, which can eventually lead to necrosis and is potentially life-threatening.