Sys Path Trivia Flashcards
Phylloerythrins
Phylloerythrins are green photoactive catabolites of plant porphyrins that are normally excreted in bile. Retention of phylloerythrins = photosensitive dermatitis.
iii) Inherited: abnormalities in porphyrin metabolism
Glucuronic acid
Conjugated by the enzyme UDP-glucuronyl transferase to substances such as drugs, pollutants, bilirubin, androgens, estrogens, mineralocorticoids, glucocorticoids, fatty acid derivatives, retinoids, and bile acids - conjugation (acts like a detergent to make toxic substances soluble so they can be excreted by the kidneys).
Superficial necrolytic dermatitis
unique cutaneous manifestation of some forms of chronic liver dx (hepatocutaneous syndrome) in dogs. Crusting, ulceration and necrosis of epidermis. Mechanism is thought to be related to an abnormal metabolic state due to hepatic insufficiency.
Liver colour changes White/pale yellow Yellow-orange Black (diffuse focal) Red (diffuse focal) Pale tan/brown
white or pale yellow =fat; necrosis; cellular infiltrate; fibrosis
- yellow-orange (turns green in formalin) = BILE
- Black – diffuse = hemosiderin or melanin-like pigments
- focal = melanosis or liver fluke
- red- diffuse = congestion
- focal = telangiectasis(capillary dilation) or hemorrhage - pale tan/brown = diffuse inflammatory or neoplastic infiltrate; amyloid
cytochrome P450
enzyme that metabolizes lipids, drugs etc
cytochrome reductase
It catalyzes the reduction of cytochrome c by oxidation of coenzyme Q (CoQ) and the concomitant pumping of 4 protons from the mitochondrial matrix to the intermembrane space
Hepatic glycogenosis
buildup of glycogen in hepatocytes (?)
(glucocorticoid-induce or “steroid” hepatopathy): Common in dogs, associated with exposure to glucocorticoids (hyperadrenocorticism).
Cirrhosis pathogenesis - Process
Pathogenesis: initiated by “reparative” processes following episodes of hepatocellular necrosis and inflammation
Space of Disse
The space of Disse (or perisinusoidal space) is a location in the liver between a hepatocyte and a sinusoid. It contains the blood plasma. Microvilli of hepatocytes extend into this space, allowing proteins and other plasma components from the sinusoids to be absorbed by the hepatocytes.
periacinar
Zone 3,hepatocytes are furthest from the portal triad (afferent oxygen rich blood) & nearest the outflow
Intrahepatic arterivenous fistula
= usually multiple, dilated vessels on capsular surface, atrophy of adjacent parenchyma.
Amanita mushrooms
toxic cyclopeptides; dogs; massive hepatic necrosis
Alsike clover
Consumption as pasture or hay is associated with biliary fibrosis/cholangiohepatitis. Pathogenesis unknown.
Pathogenesis for chronic copper toxicosis in the liver of a Bedlington terrier
- accumulation of Cu in hepatocyte lysosomes; cytoplasmic Cu overflow toxic to cell
- leads to the production of free-radicals
- diffuse single cell necrosis over time → chronic hepatitis
- icterus, ascites, weight loss
- occasional copper release and haemolytic crisis
Primary liver neoplasms
⇒ Hepatocellular adenoma (benign), hepatocellular carcinoma (malignant): often solitary. Carcinoma = local invasion; may metastasize to local LNs, lung, peritoneal cavity.
⇒ Bile duct adenoma, bile duct carcinoma: uncommon (older dogs) = locally invasive, may metastasize widely. Must be differentiated from metastatic carcinomas of extrahepatic origin
⇒ Primary mesenchymal tumors –RARE
Most common cardiac anomalies
- DOG: PDA, pulmonic stenosis, aortic/subaortic stenosis
- CAT: left AV valvular dysplasia
- CATTLE: VSD, aortic transposition
Viral/bacterial/protozoal causes of heart disease
Viral causes: Parvo, Distemper, Foot & mouth
Protozoal: Toxoplasma, Neospora, Trypanosoma cruzi (Chaga’s disease)
Bacterial:
1. H. somni (cattle: animals partially immune don’t have pneumonia or encephalitic form – instead myocaridis)
Bacteremic/septicaemia – localized in left interventricular septum (in papillary muscle) → septic infarct and arrhythmia and death; vasculitis w/ infarction
2. Clostridium chauvoei (blackleg)
Only a couple significant bacterial causes – keep in mind at PM
3. Immune mediated causes -> Human – rheumatic fever
Vascular disease
Cattle
Cats
Horses
- Infectious agents (direct: H. somni)
- Cattle: Acute BVD, MCF
- Cats: FIP (wet form: fibrinoid necrosis & vasculitis)
- Horses: African horse sickness (ddx: equine viral arteritis)
- Direct attack of vascular endo cells via the virus (not a true 1˚ vasculitis)
Causes of arterial mineralization
- Metabolic: VitD toxicity, Johne’s disease
• HyperCa states ↑ VitD (which → ↑ Ca) - ‘Dystrophic’: vascular injury of many causes -> 2˚ to necrosis of tissue e.g. Strongyles valargearis in horses
Neoplasia
Hemangiosarcoma - dogs
Lymphangiosarcoma - cats
What cells do detox in the lungs?
Clara cells & type II pneumocytes convert drugs into highly reactive intermediates, which are detoxified and excreted.
Pulmonary IV macrophages – present in alveolar septal wall – w/n capillaries in what species?
• Mo in blood vessels of cat, horse, ruminants, pigs; NOT in dogs, rodents, humans
Innate factors in the lungs
o Surfactant pr A & D
o Defensins (host-defense peptides)
o Lactoferrin – binds iron away from pathogens
o Lactoperoxidase (natural antibacterial agent)
Examples of failure of lung defences (6 examples)
o Overwhelm defences – VERY large amt of agents introduced
o Viral and mycoplasma infection → impair function of cilia, secretory epithelium, PAM
o Stress impairs macrophage function and impairs immune response
o Neutropenia: parvoV, BVDV, chemotherapy etc
o Air-borne pollutants → may ↓ m-a-c
o Genetic disorders: ciliary dyskinesia (congenital; seen in some breeds of dog, cats, pigs) → chronic resp disease etc
3 examples of pathogens in bronchitis
Bacterial (heaves), viral (influenza), allergy
Exception to the cranio-ventral broncho-alveolar pattern
- Actinobacillus pleuropneumoniae (middle/caudal) -> pigs
- In small animals may look patchy
- BRSV- viral bronchopneumonia