GI Stuff Missed Flashcards
Primary Billiary Cirrhosis
chronic liver disease characterized by autoimmune destruction of INTRA-hepatic bile ducts and cholestasis
- common in middle aged women
- elevated alkaline phosphotase
- associated with severe pruritis at nice
Budd-Chiari Syndrome
secondary to thrombotic occlusion of hepatic veins and/or intra- or supra-hepatic IVC
- venous occlusion causes sinusoidal pressure to increase leading to portal hypertension, splenomegaly, ascites, hepatomegaly,
Elevated alkaline phosphotase of unknown etiology should be followed up what test
Gamma-glutamyl transpeptidase - enzyme predominantly found in hepatocytes and biliary epithelial.
Elevated alk phosphatase + elevated gamma=glutamyl transpeptidase = liver disease
Discuss presence of bi-modal distribution of drug plasma concentration
- presence of two distinct groups within population and suggests polymorphism in drug metabolism
- one rapidly converts drug to metabolite and other drug converts drug slowly leading to accumulation of original drug
Isoniazid metabolism
metabolized by acetylation to N-acetyl isoniazid.
- genetically, people are fast “acetylators” thus metabolize drug quickly or slow “acetylators” and thus metabolize drug slowly.
- Slow metabolizers are at increased risk of side effects
Methylation in drug metabolism
- used in azathioprine and 6-mercaptopurine
Ulcerative Collitis complications
- Toxic megacolon
- Malutrition
- Sclerosing cholangitis
- Colorectal carcnimoa (worse with right sided colitis or pancolitis)
Sx: Patient diagnosed with UC but poorly controlled is presenting with abdominal pain and distention, fever, diarrhea, and shock. What’s the next step in work up?
Flat plain abdominal X- ray to identify toxic megacolon
- Barrium enema and colonoscopy are contraindicated because it may cause perforation
Ulcerative Collitis
- autoimmune disease
- continuous colonic lesions, always with rectal involvement
- MUCOSAL and SUBMUCOSAL involvement only
- Friable mucosal “pseudopolyps”
- Loss of haustra “lead pipe appearance”
Crohn’s Disease
- disordered response to intestinal bacteria
- any part of GI, usually terminal ileum and colon
- Skip lesions and rectal sparing
- TRANSMURAL inflammation
- “Cobblestone” mucosa, creeping, bowel wall thckening, linear ulcers, fissures, and FISTULAS
Pathogenesis of hepatic steatosis
- due to decrease in fatty acid oxidation to excess NADH production by alcohol dehydrogenase and aldehyde dehydrogenase
Sx: 5 month old presenting with poor feeding, weakness, and complete loss of extremity muscle tone. Aside from formula, fed with juice and honey. Likely diagnosis”
“Floppy baby syndrome” - from C. botilinum
- infant botulinism results form eating C. botulinum spores found in spores due to honey consumption.
- Don’t give honey to babies under 1
To reduce likelihood of cholesterol precription and gallstone formation, what should be the balance between bile acid and cholesterol
Cholesterol levels should be kept LOW
Bile acid levels should be help HIGH
- High levels of phosphatidylcholine, will render cholesterol more soluble
Liver: embryological origins and arterial supply
Endoderm derived foregut
- arterial supply is celiac trunk derived from proper hepatic artery
Kidneys: embryological origins and arterial supply
- retroperitoneal and derived from mesoderm
- renal arteries
Transverse Colon: embryological origin and arterial supply
Proximal 2/3 of transverse colon: derived from MIDgut and supplied by SMA via middle colic artery
Distal 1/3: derived from HINDgut and supplied by IMA via left colic artery
Pancreas: embryological origin and arterial supply
Endoderm derived structure of FOREgut and MIDgut
- receives blood from superior and inferior pancreaticduodenal arteries as well as other arterial branches of celiac artery
VIPomas
non-beta cell pancreatic islet cell tumors that hypersecrete VIP
VIP
- increases intestinal Cl- loss into stool which creates excess loss of water, sodium, and potassium
- relaxes GI smooth muscle
- inhibits gastric acid secretion
- Somatostatin inhibits VIP secretion
WDHA syndrome
- Watery Diarrhea Hypokalemia Achlorydia
- due to excess secretion of VIP
Gastrin
- produced by G cells in stomach mucosa
- stimulates gastric acid production and growth of gastric mucosa
- excess secretion of gastrin cause Zollinger-Ellison synrom (intractable peptic ulcer diseae)
Metoclopramide
- dopamine antagonist with both central and peripheral effects
- has prokinetic and anti-emetic effects
- used to treat gastroparesis, no real effect on PUD
Erosions
- mucosal defects that don’t fully extend through muscularis mucosa
- acute erosive gastropaty can cause upper GI bleeds –> tarry stools
Gastric ulcers
- extend into submucoal layer and muscularis propria (inner circular layer and outer longitudinal smooth muscle layers)
Common causes of gastric ulcers
- H. pylori (most common cause)
- NSAID use, due to inhibition of prostaglandins
Kaposi’s sarcoma (on colonoscopy)
- derived from HHV-8
- in colonoscopy: reddish/flat maculopapular lesions and hemorrhagic nodules
- spindle-shaped tumor cells with small vessel proliferation
Ulcerative Colitis (on colonoscopy)
Colonoscopy: continuous areas of erythematous, fribable, granular mucosa with possible pseudopolyps
Biopsy: inflammatory infiltrate involving mucosa and submucoda
Entamoeba histolytica (on colonoscopy)
Colonoscopy: numerous discrete, flash-shaped ulcerative lesions
Biopsy: Trophozoits containing RBCs
Cryptosporidium (on colonoscopy:
Nonulcerative inflammation
- basophilic clusters een on surface of intestinal mucosal cells
Signs of metastasis of gastric cancer (hint: 3)
Virchow’s node (supraclavicular node)
St. Mary Joseph nodule (nodule bulging into umbilicus)
Krukenberg tumor of ovary (usually bilateral mucin-producing, “signet” ring cells in ovaries)
Adenoma to Carcinoma sequence
- APC mutation: progression from normal mucosa to small polyp
- K-ras mutation: increased size of polyps
- p53 and DCC mutation: malignant transformation
Ulcerative Colitis
- Rectum is always involved
- Inflammation limited to submucosa and mucosa
- Mucosal damage is continuous
Mallory Weiss Syndrome
- longitudinal mucosal tears at esophagogatric-squamocolumnar junction
- secondary to increased intraabdominal pressure and gastric pressure due to repeated retching and vomiting
- seen in alcoholics and bulimics
Useful marker in evaluation of cirrhotic patients for hepatocellular carcinoma
Alpha-fetoprotein
CEA
serum marker associated with colorectal cancer
- not useful for screening but used in staging and determining prognosis
CA-125
serum marker elevated in majority of women with ovarian cancer
- not effective screening tool for ovarian cancer but helpful in determining recurrence of disease
Acute acalculous cholecystitis
commonly seen in hospitalized patients who are :
- septic
- immunocompromised
- on Total parental nutrition
- major trauma
secondary to gallbladder stasis and ischemia which cause injury and inflammation to gallbladder BUT WITHOUT GALLSTONES
Porcelain gallbladder
seen on abdominal radiograph as rim of Ca deposits that outline gallbladder
- associated with gallbladder carcinoma
Fluke infection of biliary tree
associated with formation of brown pigment stones
Formula for drug half live (using clearance and volume distribution)
t 1/2 = (Vd X ln 2) / CL
Vd = volume distribution CL = drug clearance
** Ln 2 = .7
Mesenteric adenitis
occurs in children 5-14 years old
- may be associated with Yersinia Enterocolitica
- non specific signs: abdominal pain in right lower quandrant
Ulcerative Colitis: Clinical Manifestations
BLOODY DIARRHEA, abdominal comfort
“Toxic megacolon” is complication
Crohn’s Disease: Clinical Manifestation
ABDOMINAL PAIN, diarrhea
“Fistulas, strictures (leading to intestinal obstructino)
Crigler-Najjar Syndrome
autosomal recessive disorder of bilirubin metabolism by lack of UGT enzyme need to catalyze bile glucuronidation
- uncojugated bilirubinemia develops causing kernicterus (bilirubin encephalopathy) and death
Sx: One month old with hx of persistent jaundice experiences muscle rigidity, lethargy and seizures. Presents with hyperbilirubinemia
Crigler-Najjar Syndrome
Dubin-Johnson syndrome
autosomal recessive disorder
- absent biliary transport protein (MRP2), used in hepatocellular excretion of conjugated bile in bile canaliculi
- liver appears dark but patients are assymptomatic
Rotor syndrome
autosomal recessive disorder
- assymptomatic hyperbilirubinme results from defects in hepatic uptake and excretion of bilirubin pigments
- patients are often jaundiced but have normal life expectancies
Discuss gut deconjugation of bilirubin
S. aureus and lots of anaerobes can decojugate bile in gut (removing glycine and taurine) of bile acids making them less soluble and unable to form micells
- no neuro symptoms associated with this
Campylobacter
- common cause inflammatory gastroenteritis and can be acquired frrom domestic animals or contaminated food
- inflammatory diarrhea accompanied by fever, abdominal pain, and tenesmus
- associated with Guillain Barre syndrome
Traveler’s diarrhea
- self contained, watery diarrhea
related to ETEC - produces heat labile (LT, cholera-like) and heat stable (ST) enterotoxins
LT - activates adenylate cyclase and increases cAMP
ST- activates guanylate cyclase and increases gGMP
- both cause water loss and watery diarrhea
EHEC
produces Shiga-like toxin, like Shiga toxin, inactivates 60S ribosomal subunit in human cells thus inhibiting cell protein production and eventually cell death
C. difficile
- pseudomembranous colitis (yellow/white membranous plaque in colon
- secondary to antibiotic use which disturb gut flora and lead to overgrowth of C. difficile
- treated by metrodinazole
Discuss opioid use and right upper quadrant pain
Opioid analgesics can lead to biliary colic
Sx: 2 y.o presents with black tarry stool. Radioactive labeled accumulation in right lower abdominal quadrant.
Failed embryo process?
- symptomatic of Merkel’s diverticulum
- contains ectopic gastric mucosa which produces acid causing possible uleration and bleding
- 99mm Tc-pertechenate scan identidies ectopic gastric epithelium an
Merkel’s diverticulum
- derived from vitelline duct (yolk sac)
- present in first 2 years of life, usually with lower GI bleeding (red stools)
- true diverticulum (involves all three layers of bowl)
- may contain acid-secreting gastric mucosa and/or pancreatic tissue
- ## may lead to intussusception or volvulus
Hirschsprung disease
- caused by failure of neural crest migration into bowel wall
- absence of ganglion cells of Auerbach and Meissner plexi
- manifests with obstruction in the first few days of life
- unable to pass meconium, bilious vomiting, abdominal distention
Pancreatic pseudocyst
common complication of acute pancreatitis.
- commonly found in lesser peritoneal sac, bordered by stomach, duodenum, and pancreas
- collection of fluid rich in enzymes and inflammatory debris
- walls consist of granulation tissue and fibrosis.
- NOT lined by epithelium like true cysts
Major side effects of statins
- Myopathy
- Liver toxicity
** careful monitoring of liver function is useful with treatment with hypolidemic drus
Common causes of esophagitis in HIV patients
- Candida albicans (most common)
- CMV
- HSV-1
- patients present with dysphagia and pain upon swallowing
Microscopic findings of Crohn’s disease
- Chronic inflammation that involves ENTIRE thickness of intestinal wall
- NONCASEATING GRANULOMAS that may be present in all tissue layers
Hepatitis B virus infection (hint: 2 phases)
- PROLIFERATIVE phase - entire virion and related antigens of episomal HBV DNA are present. HBsAg and HBcAg w/ MHC class molecules activate CD8+ T lymphocytes which destroy infected hepatocytes.
- INTEGRATIVE phase - HBV DNA is incorporated into hepatocytes that survived immune response. Those re-infectivity remains low, patients still at risk for hepatocellular carcinoma.
Hepatitis D virus
replication defective RNA virus that is only capable of causing infection when encapsulated by HBsAg
- or superinfection of chronic carrier
Discuss aflatoxins and cancer risk
Aspergillus flavus and Aspergillus parasiticus make AFLATOXINs which associated with a G:C –> T:A transversion in p53 gene that increases risk of HEPATOCELLULAR CARCINOMA
Diverticula
- abnormal pouches that protrude from wall of GI tract
- most commonly affected part is sigmoid colon (> 60 years old)
- attributed to increased luminal pressure, commonly due constipation
- may be assymptomatic, acute diverticulitis, or painless bleeding
- PULSION, by mechanism and FALSE, but nature
Traction diverticula
occur to inflammation and subsquent scarrings
- are TRUE diverticulaw
Pathogenesis of acute necrotizing pancreatitis
- caused by abnormal activation of TRYPSIN which activate ALL proteolytic pancreatic enzymes
- also proteolytic enzymes lead to activation of other proteolytic enzymes and autodigestion
Positive Predictive Value
TP / FP + TP
- depends on prevalence of a disease
- more common a disease is in the population, the more likely the person tested positive HAS the disease
Discuss negative predictive value and disease prevalence
NPV = TN / FN + TN
- as prevalence increases, NPV becomes lower
- more common a disease is within a population, the probability of a true negative result for a person who doesn’t have the test is low
Calories per gram
- in protein
- in carbs
- in fat
Protein: 1g produces 4 calories
Fat: 1g produces 9 calories
Carbohydrate: 1 g produces 4 calories
Which part of GI tract is always affected by Hirschsprung’s disease?
- Rectum
- Hirschsprung’s is abnormal migration of neural crest cells as they are supposed to migrate caudally
- in proximal colon by 8th week
- in rectum by 12th week
Natural Killer cells
- express CD16 and CD56
- don’t require thymus for maturation and are present in athymic patients
- have no antigen-specific activities, and don’t require antigen exposure or process antigen memory
- are activated by IFN-gamma and IL-12
Natural Killer Cells are activated by which cytokines?
IFN-gamma and IL-12
Which immune effector cell kill cells with decreased MCH class I antigen cell surface expression?
NK cells
- they’re like bouncers at a club
- they periodically check the IDs (MHC I) of cells to determine if they belong there.
- Virus-infected cells and tumor cells are killed by NK cells
Gallstone ileus
mechanical bowel obstruction caused when a large gallstone erodes intestinal lumen
- air in biliary tract is suggestive for this
Lesser omentum
- double layer of perinteum that extends from liver to lesser curvature of stomach and beginning of duodenum
- composed of hepatogastric and hepatoduodenal ligaments
Greater omentum
- peritoneum that extends form greater curvature of stomach, travels inferiorly over small intestine and then reflects on itself and ascends to encompass transverse colon
- gastrocolic ligament extends from greature curvature of stomach to transverse colon
Main side effects of all protease inhibitors
Lipodystrophy: increased deposition of fat on back and abdomen but less fat on extremities
Hyperlglycemia: results from increased insulin resistance form protease inhibitors may lead to diabetes
Inhibition of P450 -
Whipple disease
- caused by gram + actinomycete, Tropheryma whippelli
- involves small intestines, joints, and CNS
- proliferates within macrophages of tissues, thus no inflammatory response
Histological signs of Whipple’s disease-
- caused by Topheryma whippelli
- findings in small intestine mucosa containing foamy macrophages packed with rod-shaped bacilli and PAS-positive, diastase-resistant granules
Identifying pancreas on abdominal CT
head of panceas is in close association with second part of duodenum
- body overlies left kidney, aorta, IVC and superior mesenteric vessels
- tail lies in splenorenal ligament
Sx: young man coming back from India presents with low-grade fever, dark urine, nausea, anorexia and mild right upper abdominal quandrant tenderness
Acute viral hepatitis
- likely caused by Hepatitis A, virus endemic in INdia
Histological features of viral hepatitis
Diffuse ballooning degeneration (hepatocyte swelling)
Mononuclear cell infiltrates
Councilman bodies (eosinophillic apoptotic hepatocytes
Carcinoid tumors
made from enterochromaffin cells of intestinal mucosa
- produce vasoactive substances, such as %-HT, bradykinin, prostaglandins, and others
- when confined to intestine, secretory products go to portal system and are metabolized by liver
- if they metastasize to liver, then they enter systemic circulation
Sx of Carcinoid tumors
- Vasomotor instability: cutaneous flushing, dizziness
- GI symptoms: secretory diarrhea, crampy abdominal pain
- Bronchoconstriction: dyspnea with wheezing
- Right sided (pulmonary, triscuspid) valvular heart disease
Celiac sprue
- malabsorption disease characterized by IgA antibodies to gliadin
- patients present with diarrhea, steatorhea, weight loss, fat-dependent vitamins (A,D,E,K)
- small intestinal biopsy shows severe atrophy and blunting of villi
Alpha-1 trypsin deficiency
- often young mailes
- protein reduces tissue damage caused by inflammation through the inhibition of neutrophil elastase
- histologically associated with reddish-pink, periodic acid-Schiff-positive granules of unsecreted, polymerized A1AT in periportal hepatocytes
80% of acute pancreatitis is caused by what two things?
- Gallstones
- Chronic alcoholism
** One should measure hypertriglyceride levels
Appearance of intestinal mucosa for someone with lactase deficiency
Appears normal on histological examinatino
Whipple disease on histological exam
Distended macrophags in intestinal lamina propria
Th1 cells
- mediated release of IL-2 and IFN-gamma and activate macrophages to synthesize TNF (tumor necrosis factor)
- key factor for development of granulomas
Echinococcus granulosus
tapeworm that is most common cause of hyatid cysts in humans
- endemic regions are in Middle East, South America, Iceland, Oceania
- initially assymptomatic.
- Liver is most affected, including lung, muscle, or bone
- cysts look like egg-cell cal
Gallstone hypomotility
- slow response to cholecystokinin
- risk factors: pregnancy, rapid weight loss, prolonged TPN, octeotride, or high spinal cord injuries
- results in biliary sludge
Brown pigment stones
arise in cases of biliary tract infection
Black pigment stones
seen in intravascular hemolysis
Initial presentation of Hep B
“serum sickness-like” with patients experiencing malaise, fever, skin rash, pruritis, lymphadenpathy and joint pain
- may see elevations in ALT and AST (ALT > AST) followed by rise in bilirubin and alkaline phosphatase
Cholecystokinin (CCK)
hormone responsible for gallbladder contraction
- made in duodenum and jejunum in response to fatty acids
Secretin
promotes HCO2 secretion from pancreatic ductal epithelium
Imperforate anus
result of abnormal development of anorectal structures
- manifests during 1st days life by inability to pass meconium
- if fistula is present, may pass meconium through umbilicus or urethra
- often seen with urogenital tract abnormalities
Pus
thin, protein-rich fluid is composed of dead leukocytes (mostly neutrophils)
IL-8
secreted by macrophages and surrounding epithelial cells to attract neutrophils
IL-10
antinflammatory cytokine secreted by macrophages and TH2.
limited production of pro-inflammatory cytokines (IFN-gamma, IL-2, IL-3, TNF-alpha)
C3a
part of complement system
- along with C4a, C5a are anaphylotoxins that trigger histamine release from mast cells, resulting in vasodilation and enhanced vascular permeability
IL-3
cytokine produced by activated T-cells, stimulated growth of cells in bone marrow
Vibrio cholerae
- along with ETEC cause toxin-mediated watery diarrhea
- toxins don’t cause cell desth
- activate adenylate cyclase to increase cAMP and increase efflux of Na and Cl
Discuss UC and colon cancer
Long-standing UC is associated with increased risk of colorectal cancer
- unlike sporadic colon cancer, UC carcinomas are more likely arise from:
- non-polypoid dysplastic lesions
- be multifocal
- early p53 mutations and late APC mutations
- higher histological grade
Causes of malabsorption
- Pancreatic exocrine insufficiency
- Intestinal mucosal defects
- Bacterial proliferation
First step after suspected malabsorption
Sudan III stain of stool
- identifies fecal fat and can be used to identify malabsorption
Tubular adenomas
- ## composed of dysplastic colonic mucosal cells that form tubular-shaped glands
Villus adenomas
dysplastic epithelial cells form villi-like projections (“cauliflower-like”) that extend from polyp surfaces to stroma
- cause bleeding, secretory diarrhea, and partial intestinal obstruction
Discuss estrogen and gallstone formation
Estrogen facilitates gallstone synthesis by increasing hepatic HMG-CoA reductase activity.
- Suppressing 7-alpha hydroxylase (by medications such as fibrates) reduces conversion of cholesterol to bile acids, resulting in excess cholesterol secretiion
Fibrates
inhibit 7-alpha hydroxylase - which reduces conversion of cholesterol to bile acids, resullting in increased secretion of cholesterol in bile
Most likely outcome for someone infected with Hepatitis C
- stable chronic hepatitis
- chronic hepatitis progressing to cirrhosis
Appearance of Hep B histologically
hepatocyte cytoplasm is filled with spheres and tubules of HBsAg and the cytoplasm takes on granular, eosinophilic appearance described as “ground glass”
Superior mesenteric artery syndrome
when transverse portion of duodenum is entrapped between SMA and aorta, causing symptoms of partial intestinal obstruction
- aorticmesenteric angle lessens, secondary to diminished mesenteric fat, pronounced lordois, or surgical correction of scoliosis
Most common malignant neoplasm of the liver
Metastasis
- major site for metastatic spread because of its size, dual blood supply, high perfusion rate, and filtration function of Kupffer cells
- appears as multiple nodules in the liver with marked hepatomegaly
- more common than hepatocellular carcinoma
Hepatic angiosarcomas
associated with recent or remote exposure to vinyl chloride, arsenic, or Thorostate
- commonly aggressive
When is the omphalomesenteric (vitilline duct) obliterated during gestation?
7th week of embryonic development
Crohn’s disease is associated with what type of kidney stones
Oxalate kidney stones
Impaired bile acid absorption in terminal ileum leads to loss of bile acids in feces with subsequent fat malabsorption.
- Lipids then bind Ca ions and resulting soap complex forms
- Free oxalate (which is normally bound by calcium to form unabsorbable complex) is absorbed and forms urinary calculi
HNPCC
aka Lynch Syndrome
- leads to occurrence of colon adenocarcinomas at young age (< 50 years old), along with extraintestinal malignancies
- due to mutations of DNA mismatch repair genes (MLH1 and MSH2)
Greatest markers of alcoholic liver injury
Serum albumin and prothrombrin time reflect liver dunction and are greastest determiners of prognosis
- increased AST and ALT indicate hepatocellular amage
Patient is drunk and/or intoxicated and demands to leave with no treatment. What do you do?
Patients who are temporarily intoxicated are not allowed to make medical conditions.
He is not allowed to leave until he is sober
Chronic mesenteric anemia
- often caused by atherosclerotic narrowing of celiac trunk, SMA, and IMA
- these changes diminish blood flow, they cause postprandial abdominal pain, weight loss, and pain out proportion with physical findings
Splenic artery
originates from celiac artery and gives off branches to stomach and pancreas (pancreatic, short gastric, left gastroepiploic arteries) before getting to spleen
- if splenic artery is blocked, gastric tissues supplied by these arteries will be ischemic
APC mutation
most common mutation required for emergence of adenomatous polyps from normal mucosa
Diphenyloxate
opiate anti-diarrheal related to meriperdine
- binds to mu opiooids in GI tract and slows motility
Rapid urease tests are used to diagnose what?
H. pylori
* pink color indicates alkaline solution or pH increase
urease will convert urea to carbon dioxide and ammonia and cause pH increase
Triad of hemochromatosis
- Hyperpigmentation
- Diabetes Mellitus
- Pigment Cirrhosis
“Bronze Diabetes”
Most common outcome for someone infected with Hepatitis B
Acute hepatitis or subclinical symptoms that eventually resolve
What type of ectopic tissue is usually present in Meckel’s diverticulum?
Gastric mucosa
- gastric acid production leads to ulceration and subsequent bleeding
Dorsal pancreatic bud
forms majority of pancreatic tissue (body, tail, and most of head)
Ventral pancreatic pu
precursor for uncinate process, inferior/posterior potion of head, and major pancreatic duct
Pancreas divisim
- failure of pancreatic buds to fuse
- pancreatic ductal systems remain separate with accessory duct draining majority of pancreas
Secretin
secreted by duodenal S cells in response to increased H+ concentrations
- Chloride content of pancreatic secretions decrease as Bicarb concentration increases
Risk factors for squamous cell esophageal cancer
Alcohol use
Tobacco smoking
Consumption of N-nitroso-containing foods (smoked) foods
Risk factors for esophageal adenocarcinoma
Barrett’s esophagus
GERD
Obesity
Tobacco use
In situations in which patient is unable to make decisions for themselves and there is no written directive stating their intentions for end of life care, who is responsible for making decisions.
Next of kin.
If married: spouse is next of kin followed by adult children
Reye syndrome
occurs in children with febrile illness treated with salicylates
- consists of hepatic failure and encephalopathy
- associated with microvesicular steatosis of hepatocytes without inflammation and cerebral edema
PPIs (“prazoles”)
acts on H+/K+/ATP inhibits gastric secretion from parietal cells from 3 pathways:
- ACh (resists vagal stimulation)
- Histamine
- Gastrin
common environmental risk factors for pancreatic cancer
Smoking (MOST IMPORTANT) > 50 chronic pancreatitis diabetes mellitus genetic predisposition
Cephalic phase of gastric secretion
mediated by cholinergic and vagal mechanisms
- triggered by thought, sight, smell, and taste of food
Gastric phase of gastric secretion
- mediated by presence of gastrin (which stimulates histamine secretion)
Intestinal influences
- initiated when protein containing food enters duodenum
- can influence gastric secretion, but more importantly DOWNGRADES gastric secretion
Parietal cells
secrete HCl and intrinsic factors
- found in superficial region of gastric glands
- autoimmune destruction leads to pernicious anemia
Chief cells
synthesize and secrete pepsinogen
primarily found in deeper region of gastric glands
Vancomycin resistance in VRE
substitution of D-lactate in place of D-alanine during peptioglycan cell wall synthesis.
-prevents binding of vancomycin to usual D-alanyl-D-alanine
Abetalipoproteinemia
inherited inability to synthesize apolipoprotein B, important component of chylomicrons
- lipids absorb in small intestine cannot be transported and therefore accumulate in intestinal epithelium
- lack of lipids in cell membrane cause abnormal blood cells (acanthocytes) and neurological deficits
Curling ulcers
ulcers arising in proximal duodenum in association with severe trauma or burns
Cushing ulcers
ulcers arising in esophagus, stomach, or duodenum in patients with high ICP are particularly prone to perforation
Markers of active Hep B viral infection
- HBsAg
- HBeAg
- HBV DNA
Discuss the changes in HBcAg overtime
Initially starts as HBcAg IgM and then changes to HBcAg IgG
H. pylori infection
associated with duodenal ulcers caused by decrease in somastatin- secretin cells in gastric mucosa leading to unchecked gastrin production
