Gastro Flashcards
Which vitamin deficiency?
Macrocytic anaemia, elevated homocysteine, peripheral neuropathy, memory loss, cognitive defects
Causes?
B12 cobalamin
Animal source - strict vegans (Inc breastfed)
Ileal resection
Crohn’s
Pernicious anaemia
Deficiency in Vit B9
Folate
Macrocytic anaemia, elevated homocysteine, deficiency in pregnancy women causes birth defects
Which vitamin deficiency?
Pellagra.
Aggression, dermatitis, insomnia, weakness, mental confusion, diarrhoea
Sources?
Causes?
Niacin B3
Three Ds” - dermatitis, diarrhoea, dementia
In advanced cases pellagra causes dementia and death
Milk and eggs
Malabsorptive diseases, anorexia nervosa
Alcoholism, prolonged Isoniazid therapy
Which vitamin deficiency?
Ariboflavinosis
Cheilosis, high sensitivity to sunlight, angular cheilitis, glossitis, dermatitis or pseudo syphilis or pharyngitis
Source?
Causes/prevelance
Riboflavin B2
Meat, Fish, eggs, milk, yeast, vegetables
Prolonged phototherapy in Prems
High prevalence in adolescent females
Low socioeconomic status
Which vitamin deficiency?
Beriberi (what is it?)
Wright loss, emotional disturbances, Wernicke’s encephalopathy (impaired sensory perception), weakness and pain in limbs, arrythmias, oedema
Source?
Thiamin B1
Infantile Beriberi - congestive heart failure, neuritis, hoarseness or aphonia, absence of deep tendon reflexes anorexia
Yeast, legumes, meat, milk, Vegetables
Treatment of Wilson’s disease
Common first line - D penicillamine
Penicillamine can chelate heavy metals such as lead, copper, and mercury and form a soluble complex that is renally excreted in the urine.
It is an α-amino acid metabolite of penicillin, although it has no antibiotic properties.
Trientene is an alternative option.
Zinc salts may also be used to bind intestinal copper
First line induction therapy of Crohn’s with pancolitis and terminal ileitis without perianal disease
Exclusive enteral nutrition
Shown to have high mucosal healing rates than steroids with comparable rates of clinical remission
EEN required dedicated patient and family
Steroids used if EEN not feasible
First line therapy for mild Crohn’s disease after successful induction therapy
Methotrexate or azathioprine
Mtx is generally avoided in post pubertal girls as it is a folate antagonist
Mechanism of absorption of Fructose
Absorbed directly via the brush border of the small intestine, after absorption it enters the hepatic portal vein and is directed toward the liver
Transport across into cell by GLUT5 in apical membrane and out of cell by GLUT2 via basement membrane into blood vessel (Na independent facilitated diffusion)
Note: as sucrose comes into contact with small intestine the enzyme sucrase catalyses the cleavge of sucrose into 1 X glucose and 1x fructose
Mechanised of absorption of glucose/galactose in small intestine
SGLT 1 Na/K ATPase transporters in intestine and exits cell via GLUT2
SGLT = sodium glucose linked transporter
Complications of Hep A infection
Uncommon - pancreatitis, acute liver failure (older patients), prolonged cholestatic syndrome with fat malabsorption for months
Type 1 autoimmune hepatitis
Symptoms
Bloods
10-20yo, 78% F
Hepatic encephalopathy, coagulopathy, jaundice
Anti SMA, ANA, pANCA
Pronounced IgG increase, IgA normal
Associations HLA B8, DR3, DR4
Good prognosis
Type 2 autoimmune hepatitis
Age
SX
Bloods
Associations
2-14yo, 89% F
antiLKM1 antibodies
Moderate IgG increase, occasional IgA decrease
HLA B14, DR3
IgA deficiency
More aggressive and higher relapse rates that classical type 1
Ix for Meckel’s diverticulum
99mTachnetium pertechnetate scan
Mucous secreting cells of the ectopic gastric mucosa take up pertechnetate, permitting visualisation of Meckel diverticulum
Sensitivity 85% specificity 95%
RET gene
Hirshsrpungs disease
Also associated with EDNRB, andEDN3genes
DG551D
Cystic fibrosis
Less common than F508
JAG1
Alagille syndrome
Also associated with NOTCH2
ATP7B gene
Wilson’s disease
Congenital sucrase-isomaltase deficiency
- gene, inheritance
- pathophysiology
- presentation
- Ix
SI gene, autosomal recessive
Unable to break down disaccharides: sucrose (fruit/table sugar) and maltose (grains)
Sx appear after infant begins consuming fruit/juice/grains
After consumption -> stomach cramps, bloating, excessive gas production, diarrhoea.
Can have explosive watery diarrhoea leading to dehydration
Can have malnutrition and FTT
Tissue Bx: disaccharidase assay
Sucrose hydrogen breath test
Stool - increase total sugars. Low reducing sugars (monosaccharides)
Helicobacter pyloriincreases risk of which malignancies
Epidemiology studies have shown that individuals infected withH. pylorihave an increased risk of gastric adenocarcinoma. Studies have also shown that individuals infected withH. pylorihave an increased risk of gastric mucosa-associated lymphoid tissue (MALT) lymphoma, a rare cancer of the stomach. Gastric MALT lymphoma is frequently associated (72-98%) with chronic inflammationas a result of the presence ofH.pylori.
Conversely, risk of oesophageal adenocarcinoma may be reduced inH. pylori-infected individuals.
acute hepatic GVHD
LFTs/Bili?
Timeline
aminotransferase levels may rise markedly in the absence of elevated bilirubin, ALP, and GGT levels, mimicking viral hepatitis.
Acute hepatic GVHD can present both early (days 14–21) and late (>day 70) after allogeneic SCT.
Chronic hepatic GVHD blood picture
In chronic hepatic GVHD, serum aminotransferase levels are not as markedly elevated and cholestasis is more prominent with marked rises in serum conjugated bilirubin, GGT, and ALP levels.
Veno-occlusive disease clinical picture
VOD or SOSsecondary to sinusoidal endothelial damage and subsequent thrombotic/fibrotic occlusion of hepatic sinusoids and venules. There is a clinical syndrome of:
Jaundice and hyperbilirubinaemia
Right upper quadrant pain, generally with tender hepatomegaly.
Weight gain and ascites
What is absorbed in the Duodenum and proximal jejunum
Ca, Mg, PO4, iron, folic acid.
What is absorbed in Proximal 100-200cm of small intestine
carbohydrates, protein, water soluble vitamins.
What is absorbed Throughout small intestine
monoglycerides and fatty acids as miceller complexes, medium chain triglycerides directly into portal circulation.
What is absorbed in Distal ileum
vit B12, bile salts.
What is absorbed in the colon
water, electrolytes.
Marasmus
"non oedematous malnutrition" Severe energy and protein malnutrition Weight loss - severe muscle wasting, hypotonia, visible intestinal pattern, emaciation, wrinkled skin, shrunken wizened face Listlessness Subnormal temperature Slow pulse
Kwashiorkor
Severe protein malnutrition "Oedematous malnutrition" Loss of muscle tissue oedema Hepatomegaly Increased susceptibility to infections vomiting and diarrhoea
Anorexia
Lethargy, apathy, irritability
Patchy hyper and hypopigmentation
Sparse and thin hair, streaky red or grey in dark skin kids
Pyridoxine deficiency
Which vitamin?
Causes
Presentation
(B6)
classically associated with isoniazid
Breast fed by Vit B6 deficent mother
Homocystinuria
Microcytic anaemia
Refractory seizures in infancy
Sensory neuropathy
Dermatitis
Hydatid cyst
Organism?
Symptoms?
Ix?
Rx?
Echinococcosis “tapeworm”
Treatment - if cyst is simple and accessible, percutaneous injection of hypertonic saline can be done. Medical treatment is withalbendazole, response occurs in 40-60%, can cause mild GIT upset, elevated transaminases.
Liver – many cysts never become symptomatic and regress spontaneously or produce non-specific symptoms; symptoms can include increased abdo girth, hepatomegaly, vomiting, abdominal pain.
Lung – chest pain, cough, haemoptysis.
Diagnosis is viaUSS; serological tests can be done but there is afalse negative rate of 50%
In the presence of insulin, the liver converts glucose to which forms for storage?
Glycogen and triglycerides are both stored in the liver, for later release during periods of fasting.
Kasai procedure
Complications
for biliary atresia
aims to restore bile flow from the liver to the proximal small bowel by creating a roux-en-Y loop of bowel directly anastomosed to the liver.
Even if successful, most patients develop slowly progressive liver disease and almost all patients with biliary atresia require liver transplant.
Portal hypertension
Ascending cholangitis is a common complication, particularly in patients following successful Kasai procedure with an incidence between 40-90%. Most patients have at least one episode by two years of age. Patients following Kasai procedure are at risk of ascending cholangitis due to the nature of the anatomy and bacterial stasis in the roux limb.
Wilson disease
Clinical features
Wilson disease which usually presents with hepatic dysfunction in children. In teenagers and adults, neurological and psychiatric problems are the more common presenting complaint. Kaiser-fleischer rings are seen in 50% of patients with liver disease and nearly 100% of patients with neurological involvement. A less well known clinical feature of Wilson disease is that is can lead to distal renal tubular acidosis which results in kidney stones.
PRSS1
80% of autosomal dominant hereditary pancreatitis
serine protease 1
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PRSS1 gene
serine protease 1
Normal Function
ThePRSS1gene provides instructions for making an enzyme called cationic trypsinogen. This enzyme is a serine peptidase, which is a type of enzyme that cuts (cleaves) other proteins into smaller pieces. Cationic trypsinogen is produced in the pancreas and helps with the digestion of food. Cationic trypsinogen is secreted by the pancreas and transported to the small intestine, where it is cleaved to form trypsinogen. When the enzyme is needed, trypsinogen is cleaved again into its working (active) form called trypsin. Trypsin aids in digestion by cutting protein chains at the protein building blocks (amino acids) arginine or lysine, which breaks down the protein. Trypsin also turns on (activates) other digestive enzymes that are produced in the pancreas to further facilitate digestion.
A particular region of trypsin is attached (bound) to a calcium molecule. As long as trypsin is bound to calcium, the enzyme is protected from being broken down. When digestion is complete and trypsin is no longer needed, the calcium molecule is removed from the enzyme, which allows trypsin to be broken down.
Related Information
What is DNA?
What is a gene?
How do genes direct the production of proteins?
More aboutHow Genes Work
Health Conditions Related to Genetic Changes
Hereditary pancreatitis
More than 40 mutations in thePRSS1gene have been found to cause hereditary pancreatitis, a condition characterized by recurrent episodes of inflammation of the pancreas (pancreatitis), which can lead to a loss of pancreatic function. Most of these mutations change single protein building blocks (amino acids) in cationic trypsinogen. SomePRSS1gene mutations result in the production of a cationic trypsinogen enzyme that is prematurely converted to trypsin while it is still in the pancreas. Other mutations prevent trypsin from being broken down. The most commonPRSS1gene mutation that causes hereditary pancreatitis replaces the amino acid arginine with the amino acid histidine at position 122 in the enzyme (written Arg122His or R122H). As a result of this mutation, the enzyme is not able to be broken down, even when it is no longer bound to calcium.
Trypsin activity in the pancreas can damage pancreatic tissue and can also trigger an immune response, causing inflammation in the pancreas and leading to episodes of pancreatitis.
SPINK1
Autosomal recessive hereditary pancreatitis
Heterozygotes have 12 fold risk of chronic pancreatitis but majority are asymptomatic
serine peptidase inhibitor Kazal type 1
The protein encoded by this gene is a trypsin inhibitor, which is secreted from pancreatic acinar cells into pancreatic juice. It is thought to function in the prevention of trypsin-catalyzed premature activation of zymogens within the pancreas and the pancreatic duct. Mutations in this gene are associated with hereditary pancreatitis and tropical calcific pancreatitis.
Sclerosing cholangitis
Sclerosing cholangitis is acommon hepatobiliary disease associated with IBD. It is usually diagnosed in the second decade in paediatric patients. There is progressive inflammation and fibrosis of segments of intra and extrahepatic bile ducts, and thiscan progress to complete obliteration.
Most patients areasymptomatic, and SC isfound on routine LFT’s: elevated ALP, GGT, antinuclear or smooth-muscle antibodies can be present.10-15% of adult patients present with: anorexia, wt loss, fatigue, RUQ pain, jaundice, intermittent acute cholangitis with fevers.
Alpha 1 anti-trypsan phenotypes
M - normal
S - moderately low
Z - very low
Null
ZZ = neonatal cholestasis and emphysema Null = no liver disease but severe lung disease
Associations with H pylori
Helicobacter pylori is a gram-negative bacillus associated closely with antral gastritis.
Epidemiology studies have shown that individuals infected withH. pylorihave an increased risk of gastric adenocarcinoma. Studies have also shown that individuals infected withH. pylorihave an increased risk of gastric mucosa-associated lymphoid tissue (MALT) lymphoma, a rare cancer of the stomach. Gastric MALT lymphoma is frequently associated (72-98%) with chronic inflammationas a result of the presence ofH.pylori.
Conversely, risk of oesophageal adenocarcinoma may be reduced inH. pylori-infected individuals.
Most likely location for a swallow foreign body to become impacted
Thoracic inlet
Differentiate PFIC 1, 2, 3
PFIC 1 &2 low GGT
- impaired bile salt secretion, present with intrahepatic cholestasis in infancy
- PFIC 2 more severe with higher bile salts, more puritis, earli liver failure and risk of hepatocellular carcinoma
PFIC 3 high GGT
- reduced biliary phospholipid secretion
- late infancy to early adulthood
