Gastrointestinal Flashcards
intussusception-def, pt pop, location, presentation (3)
invagination of a portion of intestine into lumen of the adjacent intestinal wall (like collapsed telescope)
-seen in children younger than 2 yrs
region of ileocecal valve
intermittent, sever, colicky abdominal pain, “currant jelly” stools and sometimes a palpable mass in right lower abdominal quadrant
poison/treatment
- arsenic
- lead/mercury
- cyanide
- iron
- methemobloginemia
- Dimercaperol
- CaNa2EDTA
- amyl nitrite
- deferoxamine
- methylene blue
symptoms of arsenic poison, mech, mech and name of treatment
- stomach pains, vomiting and delirium and garlic odor on breath*
- inactivates enzymes by binding to sulfhydryl groups
- treat with chelating agent dimercaprol
which cytokines are responsible for the down regulation of local cytokine production and inflammatory rxn?
TGF-beta (inhibits cells) and IL-10 (inhibits cytokines)
which cytokine can produce fever? (pyrexia)
Il-1
which cytokines are released by Th2 cells?
IL-4, IL-5, IL-10
name some pro-inflammatory cytokines?
IL-1, IL-4, IL-5, and IL-12
reperfusion injury leads to damage to what part of the cell?
cell membrane?
glutathione peroxidase
reduces cellular injury by catalyzing free radical breakdown
murmur in aortic regurg- 2 causes
early diastolic if mild and holodiastolic if severe
caused by aortic root dilation or a bicuspid aortic valve
aortic regurg murrmur due to aortic dilation is best heard
at right sternal border, vs left sternal board for normal aortic regurg
abnormal rotation and fixation of midgut early in fetal life results in- two main manifestations, location of cecum
- intestinal malrotation
- intestinal obstruction-due to compression by adhesive bands
- midgut volvulus-intestinal ischemia due to twisting around the blood vessels
- right upper quadrant fixed with Ladd’s bands (fibrous bands) to 2nd part of duodenum
MHC class II MCH class I B7 CD28 TCR
- expressed on surface of APCS
- expressed on surface of all nucleated cells except RBCs
- co-stimulation receptor in APC
- co-stimulation receptor in T-cell
- T-cell receptor that binds antigen MHC complex
failure to acidify lysosomes in antigen presenting cells (APCs) would prevent
removal of invariant chain on MHC II, decreased formation and expression of antigen-MHC complex, decreased interaction between APCs and Tcells
name 3 antigen presenting cells (APCs)
dendritic cells, macrophages, and B-lymphocytes
secretory vs inflammatory vs osmotic diarrhea
- no pus, blood. tea color and odorless (i.e VIPoma)
- pus and blood
- improves with dietary modification (i.e lactose intolerance)
VIPomas-hypersecretion of what from where? loss of which ions, inhibits which hormone, treatment?
non-beta pancreatic islet cell tumors hypersecrete VIP. VIP increases intestinal chloride loss in stool, leads to loss of water Na+, and K+. inhibits gastric acid secretion. WDHA (watery diarrhea, hypokalemia, and achlorhydria) treat with somatostatin
somatostatin decreases production of which GI hormones
aka octreotide. all of them- VIP, cholecystokinin, secretin, gastrin, and glucagon (not motilin or glucose-dependent insulinotropic peptide)
VIPomas vs gastrnoma, vs glucagonoma
- inhibits gastric acid release caused WDHA syndrome
- increases gastric acid release leading to intractable peptic ulcer disease (Zollinger-Ellison syndrome)
- can lead to secondary diabetes mellitus and necrolytic migratory erythema of skin (blistering rash lower abdomen, buttocks, perineum, and groin.)
imperforate anus results from? manifests when? most often associated with? can also be associated with what rarer syndrome?
abnormal development of anorectal structures.
- during 1st days of life by inability to pass meconium
- urogenital tract anomalies (i.e urorectal, urovesical, or urovaginal fistulas)
- VACTERL syndrome
VACTERL syndrome
Vertebral defects Anal atresia Cardiac anomalies Tracheoesophageal fistula Esophageal atresia Renal anomalies Limb anomalies
location of esophagus on CT
between trachea and vertebral bodies. typically collapsed with no visible lumen on CT images
migration of neural crest cells in intestinal wall plexi occurs in which direction? name of syndrome
- migrate caudally so rectum is always involved
- Hirschsprung disease
strain of E.coli that doesn’t ferment sorbitol or produce glucuronidase? mech of toxin produced?
enterohemorrhagic e. coli (EHEC), Siga-like toxin-inactivate ribosomal 60S
toxins produced by
- EHEC
- ETEC
- shiga-like toxin- inactivate ribosomal 60S
- LT (heat liable-activates adenylate cyclase and increass cAMP))/ST (heat stable- activates guanylate cyclase and increase cGMP)
lesser omentum-def, extends from where to where?, divided into which two structures? what structures (5) run in free right margin?
double layer of peritoneum.
- extends from liver to lesser curvature of stomach and beginning of duodenum
- divided into hepatogastic and hepatoduodenal ligamment
- right sided free margin contains portal triad (hepatic art, common bile duct, and portal vein) also contains lymphatics and hepatic plexus
define polycistronic mRNA? common in eukaryotes or prokaryotes? give GI related example? number of promoters, operators and regulatory elements involved?
one mRNA codes for several proteins
- more common in prokaryotes
- E. coli lac operon that codes from proteins needed for lactose metabolism.
- the transcription and translation of these bac proteins is regulated by a single promoter, operator, and set of regulatory elements
true vs false diverticulum- def and examples
- true contains all three layers (mucosa, submucosa, and muscular layers)=Meckel’s, normal appendix
- false contains 2 layers (mucosa and submucosa)=Zenker esophageal, common colon “ticks”
Rule of 2 for Meckel’s diverticulum
“2% population
2 feet from ileocecal valve, 2 inches in length, 2% symptomatic and males are 2X more likely to be affected, 2 yrs of age
in pancreas divisum which duct drains majority of pancreas?
normally major pancreatic duct (of wirsung) doesvia major papilla
-but in divisum the accessory duct of (Santorini) via the minor papilla does
ulcer in this GI location is less likely to develop into cancer.
duodenum
when should doctor administer life saving treatment against an adult’s wishes? against a parent’s wishes for their children?
adult pt who are competent or have their wishes in a living will have authority to refuse life saving treatment
- if there is any doubt in a clinician’s mind concerning the wishes of the pt the best thing is to treat.
- in am emergency physician should always provide potentially life-saving therapy to a minor
diagnose Meckel diverticulum
look for lower GI bleeding
-99mmTc-pertechnetate scan can be used to identify ectopic gastric epithelium found in M.D causing ulceration and bleeding.
Meckel’s vs acute appendicitis
both can cause acute right lower quad pain.
- meckel’s look for currant jelly, or intussesception
- migration of pain from center of umbilicus, acute
abnormal midgut rotation around superior mesenteric art vs abnormal hindgut descent along inferior mesenteric artery
- leads to intestinal malrotation, intestine is fixed by fibrous adhesive bands that can cause obstruction
- can lead to different degrees of anal ageneis of imperforate anus
E. coli strain associated with “stacked-brick” intestinal adhesion
EAEC enteroaggregatve e. coli. they adhere to jejunal, ileal and colonic mucosa in this pattern and do not invade.
-causes diarreha in children in developing coutries
periodic, non-peristaltic contractions of esophagus-disease, mech, presentation, appearance on barium esophagogram, mimics what serious disease that should be ruled out?
diffuse esophageal spasm- uncoordinated contractions of esophagus
- dsyphagia and chest pain
- “corkscrew” esophagus
- can mimic unstable angina
diffuse esophageal spasm (DES) vs GERD
- crampy pain
- burning pain
explain the process of base excision repair
is used to correct defects in single bases caused by spontaneous/toxic deamination.
1-glycoslyase recognizes altered base and creates AP site (apurinic/apyrimidinc)
2-endonuclease cleaves 5’ while lyase cleaves 3’ sugar phosphate
3-DNA polymerase-beta fills gap
4-ligase seals gap
base excision repair vs nucleotide excision repair
both utilize endonucleases, DNA polymerase, and ligase
- BER is used to correct defects in single bases, creates AP sites
- NER is used to repair bulky helix distorting lesions (endonuclease releases oligonucleotide-containing damaged bases)
deamination result of
cytosine
adenine
guanine
uracil
xanthine
hypoxanthine
two common bacteria in intra abdominal infections
e. coli
baxteroides fragilis
how to control for confounding vs how to control for selection bias?
- multiple repeated studies, crossover (subjects act as their own control) or matching (pts with similar race, age etc act are in control and treatment group)
- randomization, ensure choice of right comparison/reference group based on exposure not race, age etc…
describe pathogenesis of hepatic encephalopathy?
hyperammonemia results in depletion of alpha ketoglutarate, causing inhibition of Kreb’s cycle
-also excess ammonia depleted glutamate (an excitatory neurotransmitter) and causes accumulation of glutamine resulting in astrocyte swelling and dysfunction
name three types of adenomatous polyps
- tubular, villous, and tubulovillous
- villous are larger sessile and more severely dysplastic than tubular type. aka velvety or cauliflower-like projections
- tubular are dysplastic colonic mucosal cells that form tubular shaped glands
- tubulovillous is a combination of both
symptoms of villous adenoma
mc asymptomatic
-bleeding, secretory diarrhea, and partial intesting obstruction
colon/biopsy manifestations of
adenocarcinoma vs Kaposi’s sarcoma
- protuberant mass; dysplastic mucosal cells with variable degree of gland formation
- reddish/violet, flat maculopapular lesions or hemorrhagic nodules; spindle shaped tumor cells with small-vessel proliferation
colon/biopsy manifestations of
- cytomegalovirus
- crytosporidium
- entamoeba histolytica
- ulcerative colitis
- multiple ulcers and mucosal erosions; cytomegalic cells with inclusion bodies
- non-ulcerative inflammation; basophilic clusters seen on surface of intestinal mucosal cells
- numerous discrete, flask shaped ulcerative lesions; trophozoties containing red blood cells
- contigupuous area or erythematous friable, granular mucosa with possible pseudopolyps; inflammatory infiltrate involving mucosa and submucosa with crypt abscessses
histology of esophageal SCC. risk factors of SCC vs adenocarcinoma
- keratin nests and pearls
- alcohol use, tobacco smoke, consumption of N-nitroso-contianing foods, esp in Asian countries
- Barrett’s eso, GERD, obesity, and tobacco use
name three phases of ATN
initiation stage: ischemic injury to renal tubules, precipitated by hemorrhage, acute MI, sepsis, surgery
- maintenance: decreased urine output, fluid overload, increasing Cr/BUN hyperK
- recovery: increased urine output, electrolyte abnormalities (hypo K, Mg, PO4, and Ca) b/c of slow recovering tubular function
- factors need to progress from normal colon to adenoma
- genes needed to progress from adenoma to carcinoma
- APC- normal colonic mucosa to hyper proliferative epithelium
- methylation abnormalities and COX-2 overexpression (pts that take aspirin are protected). from hyperproliferative to small adenoma
- K-ras-unregulated cell proliferation. small to large adenomatous polyps
- DCC (“deleted in colon cancer”- large adenomatous polyps to adenocarcinoma)
- P53 (tumor supressor gene)-adenocarcinoma to carcinoma
MSH2 gene
responsible for DNA mismatch repair. leads to Lynch syndrome
how does glucose affect lac operon?
- glucose decreases the activity of adenylyl cyclase and leads to a reduction in intracellular cAMP
- decreased cAMP causes poor binding of catabolite activator protein (CAP) to the CAP-DNA binding domain leading to decreased expression of the structural genes of the lac operon.
lowering cut off point has what effect on sensitivity? FP, PPV and FN
-increase sensitivity, increase FP, and decrease PPV and FN
impetigo is caused by? not strep pneumoniae b/c
- caused by group A strep (strep pyogenes)
- strep p causes MOPS (meningitis, otitis media, pneumonia, and sinusitus)
difference b/t live attenuated vaccine for polio (Sabin) vs killed vaccine (Salk)
-live promotes synthesis and secretion of local mucosal IgA than does killed vaccine b/c oropharyngeal and intestinal are sites of entry
MTX mech of action, causes buildup of
- antimetabolite similar to folic acid
- inhibits dihydrofolate reductase synthesis of tetrahydrofolate
- causes buildup of dihydrofolic acid polyglutamate
two rxn mediated by dihydrofolate reductase. what does end product help create (3)
- folic acid to DHF and DHF to THF
- THF donates 1 Carbon group to produce amino acid, -purines, and thymidylic acid
- presentation of neonatal tetanus
- how to prevent?
- pt pop
- rigidity and spasms
- immunize mothers. IgG crosses placenta to protect baby
- developing countries b/c of no vaccines
mech of ribavarin
- lethal hypermutation
- inhibiting DNA polymerase
- inosine monophosphate dehygrodenase (depelted GTP), causing 5’cap on viral RNA transcipts
- modulating a more effective immune response (enhances Th1 which inhibiting Th2)
giardia on gram stain
-negative, pear-shaped bilaterally symmetric orangism with four pairs of flagella and two nuclei
gastroenteritis acquired from domestic animals. associated with what neurological disorder?
- campylobacter
- Guillain-Barre syndrome
leptin-produced where? mech? mutation causes?
- produced in adipocytes in proportion to quantity of fat stored
- acts on arcuate nucleus of hypothlaamus to inhibit produciton of neuropeptide U (decreasing appetitie) and stimulate productions of alpha MSH (increasing satiety)
- mutations cause hyperphagia and profound obesity
why are s. aureus and b. cereus able to cause rapid onset food poisioning?
- highly heat stable exotoxin is preformed prior to consumption
- s. aureus is found on mayonanaise containing products
- b. cereus is found in reheated fried rice
vitamin deficiencies
- decreased exposure to sunlight
- strict vegetarian diet
- biiliary obstruction
- vit D
- colbalamin
- fat soluble vitamins ADEK
dd for acquired nyctalopia
- although most common cause of night blindness id hereditary retinitis pigmentosa other causes of acquired night blindness are
- toxic retinopathy (phenothiazines or chloroquine)
- vit A def
- congenital rebella, syphillus, or other infections
- diabetic retinopathy
what are branches of splenic artery (3) name distribution. where does splenic art originate from? which branch is most susceptible to injury following splenic art blockage?
pancreatic branches (run posterior to upper border of pancreas supply body and tail)
- left gastroepiploic artery (supply middle part of greater curvature of stomach)
- short gastric (supplies upper part of greater curvature of stomach)
- celiac artery
- short gastric b/c of poor anastomoses
three risk factors for gallbladder disease
forty, faty, and female
secretin-produced from? action?
pancreas
promotes bicarbonate secretion
VIP-producede from? action?
pancreas
stimulates intestinal water secretion, counteract gastrin in stomach, and promote bicarb secretion
motilin-produced from? action
from small intestine, promotes intestinal motility
somatostatin-producted from? actitons? what inhibits it’s release?
numerous tissues (hypothalamus, stomach, intestine, and pancreas) in response to low pH
- inhibits release of GH and TSH and suppresses release of gastrin, CCK VIP, secretin, insulin, and glucagon
- vagal stimulation inhibits somatostatin release?
CCCK-produced where? action?
duodenum and jejunum in response to fatty acids and amino acids
gallbladder contraction
hereditary pancreatis
rare disorder that results from mutation involving trysingogen or SPINK1 genes
-trypsin is active and causes reoccurring attacks of acute pancreatitis
ways to inhibit trypsin
- self inhibition (trypsin cleaves itself into and inactive form)
- SPINK1 secreted by acinar cells to block trypsin that is prematurely activated
describe adenoma to carcinoma sequence in colon cancer. not over expression of cyclin D b/c?
APC mutation causes normal mucosa to small polyp
- k-ras mutation causes increase in size of polyp
- p53 and DCC mutations cause malignant transformation
- cyclin D over expression causes breast, lung, and esophageal cancers, and certain types of lymphomas
pathophysiology and presentation of drug induced biliary colic. drugs that can cause this?
- contraction of smooth muscles in spinchter of Oddi increased bile duct pressure and gallbladder leading to RUQ pain, cramping, jaundice in skin and eyes
- all mu agonists.
since all mu agonist cause biliary colic of them what is drug of choice in pts with bilary and pancreatic pain? what other drugs can be used?
meperidine (little evidence to support this but ppl use it), or NSAIDs (diclofenac, ketorolac)
gross, x-ray, histo of Crohn’s vs Ulcerative colitis
crohns: cobblestone, string sign, transmural inflammation and noncaseating granulomas
- UC: pseudopolyps, lead pipe, no granuolmas mucosal and submucosal inflammation only
which genes are involved in mismatch repair?
MSH2 and MLH1 which code for MutS and MutL homologs
which drugs can cause pill induced esophagitis?
tetracycline antibiotics and potassium chloride and bisphosphates
name two forms of IgA
- secretory form (dimer) has J chain and secretory component, in colostrum, tears, saliva, and mucus
- monomer form in serum
erosion vs ulcer
- do not fully penetrate muscular mucosa
- extend into submucosal layer and musclaris propria (inner circumferential and outer longitudinal smooth muscle layers)
using curves how do you define bioavailability? why not just area under curve?
- F=(area under the oral curve*IV dose)/ (area under the IV curve * oral dose)
- bioavailability is a fraction of the drug that reaches systemic system in unchanged form
- area under the curve is just total amt of drug absorbed and made available in systemic system before it was eliminated
name retroperitoneal structures
major vessels-abdoinal aorta, inferior vena cava, and branches
solid organs-pancreas (except tail), kidneys, and adrenal gland
hollow organs-parts 2, 3 and a part of 4 of the duodenum, ascending and descending colon (secondarily retroperitoneal), rectum, ureters, and bladder
vertebral column and muscles
- stool with mucus and some epithelial cells
- many leukocytes and neutrophils
- many erythrocytes and some leukocytes
- a bacteria that doesn’t invade just purely toxins that don’t cause cell death (v. cholera and ETEC
- a bac that invades (salmonella, EIEC), no hemorrhage needed
- a bac whose toxin causes cell death causing mucosal hemorrhage and necrosis, (EHEC) doesn’t have to invade
life cycle of strongyloides infection, diagnose how, live threatening complication, treatment?
- skin penetration, lungs, swallowed into GI tract
- diagnose by finding rhabitiform (non infectious) larvae in stool
- hyperinfection syndrome (maturation of rhadtiform in GI tract causing autoinfection)-multiorgan failure and shock
- ivermectin
- rhabditiform larve in stool
- parasite eggs in stool
- perianal egg deposition
- proglottids in stool
- trophozoites and cysts in stool
- stronglyoides stercoralis
- schistosomiasis
- enterobious vermicularis (pinworms)
- intestinal tapeworms (taenia solium, t saginata, diphyllobothrium latum)
- protozoal infections (giardia lamblia)
which bac have small inoculation threshold? (4)
shigella (10 cells) campylobacter jejuni (500) clostridium perfringens (500) entamoeba histolytica (1) giardia lamblia (1)
left side colon cancer vs right sided colon cancer
- left: partial intestinal obstruction (abdominal pain, distention, and nausea)
- right (large calliber so no obstruction): iron deficiency anemia and systemic symptoms
which disorders are benign
- essential fructosuria vs hereditary fructose intolerance
- galactokinase def vs classic galactosemia
- esstential fructosuria (missing fructokinase)
- galatokinase deficiency
risk factor of esophageal SCC vs adenocarcinoma
- smoking, alcohol, achalasia, plummer-vinson, nitrosamine containing foods
- barrett’s eso
energy in 1g of protein
1g of fat
1g of carbs
1g ethanol
- 4cal
- 9cal
- 4cal
- 7cal
diagnosis of toxic megacolon not abdominal ultrasounds b/c? not barium contrast or colonoscopy studies b/c?
- flat plain X ray
- US is not useful in this case
- these can cause perforation
diphenoxylate vs octreotide in treatment of diarrhea
- targets MOTILITY: opiate anti-diarrheal structurally related to meperidine. slows motility, use low dose and combine with atropine to prevent dependence and abuse
- targets OVERSECRECTION helpful for secretory diarrhea (so do bismuth subsalicylate, and probiotics)
are there any drugs used for diarrhea that increase absorption of water or electrolytes?
no
pancreatic juice ion concentration compared to plasma
-Na
-K
-Cl-
-HCO3-
what happens to concentrations in response to secretin?
- Na and K+ are isotonic
- HCO3 concentration is higher in pancreatic juice
- Cl- is lower in pancreatic juice
- secretin is released in response to high H+ and causes chloride content to decrease in proportion to increase in bicarb concentration (b/c chloride and bicarb are exchanged for each other at apical surface of ductal cells)
main source of fatty lipid digestion? absorption? effect of chlectystectomy
- duodenum
- jejunum
- it typically have little effect on lipid digestin and absorption though pt may find it difficult to eat a large fatty meal b/c bile acids are needed to absorb fatty acids
mech of polyethlyene glygol in constipation?
osmotic LAXATIVE
like magnesium hyroxide, magnesium citrate and other magnesium containing drugs
name three things that can increase gastric pH
achlorhydria, food ingestion and antacid ingestion
how to detect C. difflcile toxin
-look for genes in stool with PCR
causes of infectious diarrhea
- undercooked fish
- not taking vaccine before travel
- travel to mexico
- antibiotics
- v.cholera
- HAV and typhoid fever
- ETEC, campylobacter, salmonella and shigella or parasites (entamoeba and giardia)
- c. difficile
how to differentiate between no lactose fermenting oxidase negative bacteria?
these are salmonella proteus shigella and yersinia
- TSI agar
- no H2S production (Shigella)
- H2S production turn black (salmonella and proteus)
most significant viral factor for shigella? how does it enter host?
- mucosal invasion
- enters M cells in Peyer’s patches
name bac that can survive in blood
e. coli (sepsis) salmonella typhi (sepsis, typhoid fever) pseudomonas aeruginosa (sepsis, endocarditis and osteomyelitis) klebsiella (sepsis) proteus (sepsis)
which bac proliferate in lymph nodes
salmonella and yersinia entercolitica (reason why Y. enter can lead to lower right quad pain confused with appendicitis)
schilling test
- give intrinsic factor and see if vit B12 is absorbed
- determines cause of abnormal vit B12 absorption
- diagnose pernicious anemia
blunting of villi along a chonic inflammatory infiltrate in small intestine
celiac disease
mc location of tumor in zollinger-ellison syndrome
pancreas
chronic gastritis with antral sparing vs antral predominate gastritis
- autoimmune gastritis
- H.pylori
distal duodeunal ulcer vs proximal
distal-Zollinger Ellison
proximal-peptic ulcer disease
type A vs type B gastritis (causes, location, assocaitions)
type A- autoimmune, body of stomach, megaloblastic anemia (vit B 12 malabsorption)
type B-h. pylori, antrum, gastric adenocarcinoma and MALT lymphoma
granulomatous gastritis
idiopathic, intramucosal epithelioid granulomas that cause narrowing of antrum secondary to transmural inflammation
two types of gastric adenocarcinoma and ways to tell them apart?
intestinal type-looks like colonic adenocarcinoma
-diffuse type-signet ring cells
2 types of ulcers due severe trauma or burns? (location)
- Curling ulcers (proximal duodenum)
- Cushing ulcers due to high intracranial pressure (esophagus, stomach, duodenum, prone to perforation)
paneth cells-location, function (2)
- occur in small groups in base of intestinal cells
- phagocytic and secretory properties
- secrete lysozyme and defensins (polypeptide) both of these have antmicrobial and antiparasitic properties
M cells-location, func
- base of mucosal villi in Peyer’s patch
- sample contents of gut lumen and transfer antigens to basal lamina
mc location of anal fissure? why?
posterior midline distal fo dentate line
-b/c it’s poorly perfused
systemic mastocytosis define and effect on GI system
- abnormal proliferation of mast cells and increased histamine secretion
- increases production of gastric acid by parietal cells
tertodotoxin
puffer fish toxin
inhibits voltage gated Na+ channels
what keeps clostridium from causing infection? not gastric acid b/c?
- microbial flora
- c. difficile can form spores and survive gastric juices
presentation of circopharyngeal muscle dysfunction
- diminished relaxation of pharyngeal muscles during swallowing
- oropharyngeal dysphagia, couching, choking, and recurrent aspiration (recurrent pneumonia)
diverticulum in upper esophagus vs middle esophagus
- upper is usually due to circopharyngeal muscle dysfunction (posterior hypopharynx) leading to Zenker diverticulum
- lower is usually due to TB or fungal infections that cause scarring and traction leading to true diverticula
false vs true diverticulum
false has only mucosa
true has all layers of organ wall herniated
phases of swallowing aka
oral-voluntary
pharyngeal- involuntary pharyngeal muscle contractions to propel food forward
esophageal phase- peristalsis moves food downward until relaxation of LES allows food into stomach
amatoxins vs ricin
- found in various poisonous mushrooms (Amanita phalloides) and inhibits RNA polymerase II (halting mRNA synthesis)
- found in castor oil plant and inhibits rRNA protein synthesis by cleaving 60S
name art that supplies proximal lesser curvature vs distal lesser curvature of stomach. these are at risk of?
- proximal (left gastric from celiac)
- distal (right gastric from proper hepatic from common hepatic from celiac)
- at higher risk of perforation from ulcers which tend to occur on lesser curvature
name art that supplies proximal greater curvature above splenic art vs proximal greater curvature vs distal greater curvature
- prox above splenic (short gastric art from splenic from celiac)
- proximal (left gastroepiploic from splenic from celiac)
- distal (right gastroepiploic from gastroduodenal from common hepatic from celiac)
D-xylose-def, absorption, use
- monosaccharide
- doesn’t require pancreatic enzymes to be absorbed
- used to differentiate between malabsorption of pancreatic insufficiency vs gastrointestinal mucosal etiology
where is the antrum vs cardia vs fundus?
- pre-pyloric
- near esophagus
- above cardiac notch and body
structures near
- second part of the duodenum
- third part of duodenum
- peritoneal, courses inferiorly from L1-L3 (closely related to head of pancreas and ampulla of Vater is here*)
- retroperitoneal, courses horizontally (L1) across abdominal aorta and IVC at level of 3rd vertebra (closely related to SMA*)
olive sized mass felt on deep palpation? what causes this?
- congenital pyloric stenosis
- hypertrophy of pyloric muscularis mucosae
posterior ulcer in duodenal bulb vs anterior ulcer
- posterior can cause erosion and bleeding of gastroduodenal artery
- anterior ulcer can cause perforation
presentation/intestinal complications of Crohn’s vs UC
- Crohn’s abdominal pain/fistulas, strictures (lead to intestinal obstruction)
- UC blood diarrhea/toxic megacolon
presentation of mesenteric adenitis that allows you to tell it apart from everything else?
clinical manifestations are nonspecific
5-14 years old
whipple’s disease-def, symptoms, histo, pt pop
- infection with Tropheryma whippellii (gram positive)
- GI symptoms+ CNS+ ocular+ rheumatolotic (joint problems)
- intestine mucosa with enlarge foamy macs with both rod shapped bacilli and PAS-positive* diastase-resistance granules*
- middle age caucasian male
T cell vs neutrophil defense against candida
- T-cell defend against superficial infection (HIV pts)
- neutrophils protect against systemic infection (neutropenic pts)
cells recruited by C5a vs C3a
- C5a neutrophils, eosinophils all of them basically
- C3a no neutrophils just eosinophils and basophils
name 2 mc causes of acute pancreatitis
name the other causes
- alcohol and gallstones
- GET SMASHED (gallstones, ethanol, trauma, steroids, mumps, autoimmune, scorpion sting, mumps, hypercalcemia/hypertriglyceridemia, ERCP, Drugs (sulfa))
acute pancreatitis + megaloblastic anemia should make you think?
it’s due to alcohol b/c alcohols have poor diet and can have folate or cobalamin deficiency
measure AST:ALT >2=alcoholic
name 4 common non-neoplastic polyps
name 1 common neoplastic polyp, which shape is more likely to become cancerous?
hyperplastic (from glands or crypts), hamartomastous (Peutz-Jeghers or juvenile polyposis), inflammatory (Crohn’s or UC), lymphoid (children)
-adenomatous (villous is more likely than tubular to progress to adenocarcinoma)
when does a carcinoid tumor have symptoms?
when is metastasizes to liver to in extra-intestinal site (lung) then the liver cannot metabolize the secretory products
diarrhea, weight loss, epigastric pain with chronic alcoholism is? what causes calcifications on imaging? not bile salt deconjugation b/c?
- chronic pancreatitis
- alcohol causes protein precipitiation which calcify
- bile salt deconjugation occurs when bac have gained access to small intestine. this results in steatorrhea and failure of micelle formation
clinical presentation of nutrient deficiencies related to malabsorption -iron, folate, vit B12 -protein -vit K calcium/vit d -vit A -gross presentation of stool -how to screen for malabsorption?
- anemia
- muscle wasting and edema
- petechiae and easy bruising
- bone pain, muscle weakness, tetany
- hyperkeratosis and night blindness
- foul-smelly, bulky floating, greasy stool
- Sudan III stain which identifies fat
abetalipoproteinemia-def, histo on intestine and blood smear, gene involved
- inability to synthesize APO B needed for absorption of lipids
- enterocytes with clear or foamy cytoplasm
- acanthocytes
- MTP gene
how is lac operon regulated (positive and negative)
- negatively by binding of repressory protein to operator locus
- positively by cAMP-CAP binding upstream from promoter region
which drugs block gastric parietal cell at
- M3
- H2
- H/K ATP pump
- binds to base of mucosal ulcers?
- atropine
- cimetidine
- lansoprazole
- sucralfate
presentation of mets of gastric cancer?
Virchow’s triad (left supraclavicular sentinel node), Sister Mary Joseph nodule (periumbilical subcutaneous mass), Krukenberg (tumor in ovary)
clinical symps of lead vs iron posioning
- abdominal pain, constipation, HA, lead line, peripheral neuropathy, microcytic hypochromic anemia and basophillic stippling
- nausea, diarrhea, abdoinal pain, hemorrhage, hypovolemia, shock. stage 2 pt feels better. stage 3 metabolic acidosis, liver faliure, and hypoglycemia, stage 4 scaring of GI tract
watershed areas of Gi tract
splenic flexure and distal sigmoid colon
NF-kB protein is overexpressed in what GI disease? what is func ?
Crohn’s disease
-cytokine production
what layer are parietal cells found in? chief cells?
- superficial region of gastric glands
- secrete and synthesize pepsinogen and primary found in deeper region of gastric glands
acetyl-CoA carboxylase vs Acyl-CoA dehydrogenase
- fatty acid synthesis (1st rxn and rate limiting step)
- fatty acid breakdown (1st rxn)
acyl-CoA synthetase deficiency vs Acyl-CoA dehydrogenase deficicency
both involved in fatty acid breakdown and have hypoketonemia
- synthetase has carnitine deficiency
- dehydrogenase has normal carnitine levels
what is pantothenic acid? which rxn it is important for?
- non active form of coenzyme A
- binds with oxaloacetate in first step of TCA to form citrate
- also needed for synthesis of vit A, D, cholesterol, steroid, heme A, fatty acids, amino acids, and proteins
which biochemical processes occur in mito
- beta-oxidation of fatty acids
- TCA
- ketogenesis
- urea cycle (1st part)
location of fatty acid synthesis vs fatty acid oxidation?
- cytosol
- mito
which organ can use glycerol from TG breakdown (fatty acid+glycerol) for energy? enzyme needed?
-liver; glycerol kinase
earliest manifestation of systemic sclerosis aka?
CREST -esophageal hypomotiity -C-calcinosis R-aynaud syndrome Esophageal dsymotility Sclerdactyly Telangiectasia
mc location of colon adenocarcinoma?
rectosigmoid colon
colon adenocarinoma in multiple places vs ascending vs rectosigmoid colon
- Lynch syndrome
- large bulky, bleeding is major complication
- obstruction symptoms not bleeding b/c smaller caliber
gallbladder can lead to? not phospholipid stones b/c? not brown stones b/c? or black?
- biliary sludge (bile precipitation with cholesterol monohydrate crystals, calcium bilirubinate and mucus)
- phospholipids aren’t found in stones
- brown is seen in biliary tract infection
- black is seen in intravascular hemolysis
inhaled anesthetics such as halothane can be associated with what organ failure?
- acute liver injury (can’t distinguish from acute viral hepatitis)
- elevated aminotransferase levels
- look for prolonged PTT, eosinophilia, elevated aminotransferase
diffuse gallbladder calcification, aka. indicates?
- porcelain galbladder
- chronic cholecystitis
- remove b/c of risk of galbladder cancer
which comes first anti IgG or IgM?
-IgM
infectivity of hep B high vs low?
- high=HBeAg
- low=anti-HBe Ag
loops of small bowel at level of kidney is
jejunum
pancreas on abdominal CT
- head is closely associated with 2ns part of duodenum
- it’s body overlies left kidney, aorta, IVC and superior messenteric vessels
- tail is in splenorenal ligament
where is iron absorbed?
duodenum and proximal jejunum
7 alpha hydroxlyase
converts cholesterol into bile acids
risk factors for formation of cholesterol galstones
- caucasian race
- glucose intolerance
- female sex hormones
- malabsorption of bile acids
- obesity of rapid weight loss
- glucose intolerance
- pharmacotherapy with fibrates (inhbits 7 alpha hydroxylase)
- hypomotility of gall bladder ()
acute acalous cholecystitis vs acute calulous cholecystitis
- no gallstones, seen in hospitalized pts
- non obstructing pigment gallstones
DD for polyhydramnios in utero
- Gastrointestinal disorders, such as duodenal atresia, esophageal atresia, gastroschisis, and diaphragmatic hernia
- Brain and nervous system problems, such as anencephaly and myotonic dystrophy
- Achondroplasia
- Beckwith-Wiedemann syndrome
describe carcinoid tumor histology? where does it arise from?
- nest or sheets of uniform cells with eosinophilic cytoplasm and oval to round stippled nuclei
- derived from enterochromaffin cells
