Signaling pathways Flashcards
cAMP
FLAT ChAMP FSH, LH, ACTH, TSH CRH, hCG, ADH (V2 receptor), MSH, PTH calcintonin GHRH glucagon PAF
cGMP
ANP
NO (EDRF)
IP3
GnRH, GHRG(minor) Oxytocin ADH (V1 receptor) TRH Histamin (H1) Angiotensin II Gastrin
Steroid receptor
Vitamin D Estrogen Testosterone T3/T4 Cortisol Aldosterone Progesterone
Instrinsic tyrosine kinase
Insulin IGF-1 FGF PDGF EGF
What pathway do instrinsic tyrosine kinases utilize?
MAP kinase pathway
Receptor assoc tyrosine kinases
Prolactin
Immunomodulators: cytokines IL-2, IL-6, IL-8, IFN
GH
What pathway do receptor assoc tyrposine kinases utilize?
JAK/STAT pathway
How does T3 increase CO?
binds to B1 receptors on the heart
how does T3/T4 increase BMR?
increase Na/K ATPase
What do you see elevated in the urine of a child w adrenal neuroblastoma?
HVA: homovanilic acid, a breakdown product of DA
what is the genetic mutation is neuroblastoma and what is the tumor marker>
overexpression of N-myc oncogene > rapid tumor progression
- tumor marker = Bombesin
- neurofilament stain
people with Hashimotos thyroiditis have an increased risk of what cancer?
Non-hodgkins lymphoma
very tender thyroid, increased ESR
subacute thyroiditis: self limited hypothyroidism often following a flu like illness
- see granulomatous inflammation on histo
fixed, rock hard and painless goider
Reidels thyroiditis: thyroid replaced by fibrous tissue
Jod-Basedow phenomenon- what is it? what can cause it?
when someone with iodine deficiecny is given iodine> hyyperthyroidism!
- seen when given contrast radio-iodine or amiodarone
what is the cause of death in thyroid storm?
death by arrhythmia
thyroid cancer w empty appearing nuclei, psammoma bodies, whats the cancer and assoc gene?
- Papillary carcnoma
- Ret gene mutation
thyroid cancer that produces calcitonin, sheets of cells in amyloid stroma, what is it and what is gene and associations?
- Medullary carcinoma
- ret gene mutation, assoc with MEN 2A and 2B
When do you see psammoma bodies? 4 instances
Papillary carcinoma of thyroid Serous cystadenocarcinoma of the ovary Meningioma Mesotheliam (PSMM)
hypocalcemia, shortened 4th/5th digits, short stature
Pseudohypoparathyrodism: Albright’s hereditary osteodystrophy
- AD kidney unresponsive to PTH
how do you diagnose Acromegaly?
- increase serum IGF-1
- failure to suppress serum GH following oral glucose tolerance test
what inhibits the release of GH?
glucose and somatostatin
What are the treatments for Nephrogenic diabetes insipidus?
- Hydrochlorothiazide
- Indomethacin
- Amiloride
What drugs can casue secondary nephrogenic DI?
- Lithium
- Demeclocycline
- Hypercalcemia
What drug can cause SIADH?
Cyclophosphamide
Treatment of SIADH?
- Demeclocycline
- Conivaptan
- Tolvaptan
how do you treat carcinoid syndrome?
somatostatin analog = Octreotide
what is the inheritance of MEN syndromes?
autosomal dominant
What amino acids stimulate the release of gastrin?
- Phenylalanine
2. Tryptophan
Why is oral glucose better than IV?
because you get the release of GIP with oral glucose which increases insulin
Somatostatin/prostaglandins/misoprostol act through what signaling cascade in parietal cells?
Gi -> decrease in cAMP
what is the most important mechanism in gastric acid release from parietal cells?
- activation of ECL cells by gastrin, causing release of Histamine that stimulate H2 receptors on gastric parietal cells
Jejunal ulcers are usually a sign of what?
Gastrinoma
What is the rate limiting step in carbohydrate digestion?
oligosaccharide hydrolases
How are glucose and galactose taken up by enterocytes?
via SGLT1 (Na dependent)
How is fructose taken up by enterocytes?
GLUT 5
How is trypsinogen activated?
via enterokinases and enteropeptidases secreted from duodenal mucosa
what is the rate limiting enzyme in bile acid synthesis?
cholesterol 7alpha hydroxylase
how is bilirubin removed?
- from blood by the liver and conjugated with glucuronate (via UDB glucuronosyl transferase)
salivary gland tumor- presents as a painless mobile mass composed of cartilage and epithelium and recurs frequently
pleomorphic adenoma
benign cyst within salivary gland with germinal centers
warthins tumor
malignant salivary gland tumor- painful mass
mucoepidermoid carcinoma
lye ingestion can cause what esophageal abnormality?
esophageal stricture
what can casue pill induced esophagitis?
tetracyclines
potassium chloride
bisphosphonates
in coffee ground emesis- why is blood brown?
oxidation of heme iron
what area of the stomach is most likely affected by celiac sprue?
distal duoedenum or proximal jejunum
which type of stomach cancer is not assoc with h pylori?
diffuse
which stomach cancer has signet ring cells?
diffuse
which GI ulcer increases your risk for carcinoma?
gastric ulcer! duodenal uclers usually dont
omphalomesenteric cyst
cystic dilation of vitelline duct
what virus is associated with intussusception?
adenovirus
what is the most common cause of small bowel obstruction?
adhesion- a fibrous band of scar tissue
inheritance of Peutz jeghers syndrome?
autosomal dominant
what part of the colon is involved in HNPCC?
proximal colon
how does CRC presentation differ in ascending vs descending colon?
Ascending: exophytic mass, iron deficiency anemia, weight loss
Descending: infiltrating mass, partial obstruction, colicky pain, hematochezia
2 molecular pathways that lead to CRC??
- Microsatellite instability: DNA mismatch repair gene mutation, seen in HNPCC
- APC/B catenin, chromosomal instability pathway: APC > K ras > p53
decresed ceruloplasmin =
wilsons disease!
what liver tumor is associated with exposure to arsenic, polyvinyl chloride?
angiosarcoma
waht liver tumor is common, benign, and can lead to hemorrhage if biopsied?
cavernous hemangioma
what liver tumor is assoc with OCP use?
hepatic adenoma
cirrhosis with PAS positive globules in liver
Alpha-1 antitrypsin deficiency
whats the mechanism behind wilsons disease?
-defective ATPase that transports copper into bile by hepatocyte for excretion
what is the result of hemochromotosis?
- CHF
- Testicular atrophy in males
- increased risk for HCC
what happens in iron poisoning?
- Cuases peroxidation of lipid membranes and damages cells by free radicals
starts: gastric bleeding/hypovolemic shock
60-70hrs: metabolic acidosis
2-8wks: scarring of GI tract
where does a pancreatic adenocarcinoma usually arise from?
the duct
