GASTROINTESTINAL FUNCTION TESTS

GASTROINTESTINAL FUNCTION TESTS

Indications:

Diagnosis of:

• Gastric-ulcer/ Peptic-ulcer
• Pernicious anaemia
• Zollinger Ellison Syndrome
• Completion of surgical vagotomy

Classification:

Examination of

• resting juice content.
• fractional gastric juice.
• gastric juice after stimulation.

alcohol stimulation

caffeine

histamine

insulin/ pantagastrin

• Tubeless gastric analysis (Azure-A-resin)/ cation exchange resin - excreted into urine (H+ conc) 

Sample collection: Ryle’s Tube

ABNORMALITIES OF GASTRIC FUNCTION:

Increased Gastric HCl: 

1. Zollinger – Ellison Syndrome (a tumor of gastrin secreting cells of the pancreas)
2. Chronic duodenal ulcer
3. Excessive histamine production 

Decreased Gastric HCl:  Gastritis, gastric carcinoma, pernicious anaemia.

 TESTS FOR INTESTINAL FUNCTION:

Lactose Tolerance Test –

• 50 gm lactose in 200 ml of water
• Blood specimen at Fasting, 30, 60 and 120 minutes.
• Normal : More than 30mg/dL.
• 20-30mg/dL borderline and <20mg/dL - lactase deficiency

D-Xylose absorption test –

• 25 gm (0.5 gm/kg body weight in children) in 250ml  water
• blood level after 30’, 1 hr and 2 hrs.      (<25 mg/dL abnormal).
• urine for 5 hrs (normally 4 gm excretion) (> 20%)
• normal blood concentration with decreased urinary excretion ---> renal impairment/ incomplete urine collection

To differentiate pancreatic steatorrhoea and malabsorption steatorrhoea

Serum carotenoids –

e.g. lycopene, xanthophyll and carotene malabsorption  

carotenoids  (normal ranges 50 - 250mg/dL)

Fecal fat analysis –

• normally 1 - 4gm/ 24 hrs (lipid free diet)
• < 7gm / (lipid rich diet)
• excretion in biliary obstruction
• exocrine pancreatic insufficiency
• diseases of small intestine

Qualitative screening test –

• Sudan staining for fecal fat
• Normally 40 to 50 small neutral lipid droplets/ high power

Quantitative fecal fat analysis –

• 72 hrs stool collection
• lipid rich diet for 2 days prior to test
• 50 – 100 gm of lipid each day
• reference range – 1 to 7gm/ 24 hrs 

Glycolysis Mnemonics

Glycolysis: Metabolic Pathways

"Goodness Gracious, Father Franklin Did Go By Picking Pumpkins(to) Prepare Pies"

Glucose
Glu-6-P
Fru-6-P
Fru-1,6-diP
Dihydroxyacetone-P
Glyceraldehyde 3-P
1,3-Bisphosphoglycerate
3-Phosphoglycerate
2-Phosphoglycerate
Phosphoenolpyruvate(PEP)
Pyruvate

"Did", "By" and "Pies" reminds you the first part of those three: di-, bi- and py- and "PrEPare" reminds you PEP.

Na+/K+ pump

Remember the characters present in those.

Eg. "K+" and "in", each contains 2 characters, so 2 K+ molecules are pumped in.
whereas in "Na+" and "out", each contains 3 characters, so 3 Na+ are pumped out.

Purines and Pyrimidines:

Remember "Pure as Silver(Ag)"
So Purine is Adenine and Guanine.

and for Pyrimidines, Remember "CUT the py(Pie)"
Cytosine, Uracil and Thiamine.

Also you can remember by structurewise.
Short name (Purine) has bigger structure
and Long name (Pyrimidine) has smaller structure.

So Think, " Pyrimidines can be CUT out from Purines".

Site of Metabolism:

"Use both arms to HUG"

Heme synthesis
Urea Cycle
Gluconeogenesis

These reactions occurs in both cytoplasm and mitochondria.

Galactosemia: deficiency enzyme

Remember "GALIPUT"

Galactose 1 Phosphate Uridyl Transferase

Live attenuated vaccines:

Remember "ROME Is My Best Place To go Yet !"

Rubella
Oral Polio vaccine
Measles
Epidemic typhus
Influenza
Mumps
BCG
Plague
Typhoid oral vaccine
Yellow fever


Killed Vaccines:

Remember "RIP A" (Rest in peace always)
Rabies
Influenza
Polio (Salk type)
A Hepatitis

What is Apoptosis and Necrosis ?

Apoptosis – What is it ?

• Form of cell death, also known as programmed cell death, in which a ‘suicide’ program is activated within the cell leading DNA fragmentation, cytoplasm shrinkage, membrane changes and cell death without lysis or damage to neighboring cells.   
• 
  
• It is a normal phenomenon of multicellular organisms.
• 
  

 Necrosis: What is it ?

• Necrosis is un-programmed cell death; it is less orderly than apoptosis. Injury, infection, cancer, infarction, and inflammation cause necrosis. 
• 
  
• Enzymes released from the lysosomes digest cellular components in an unorganized chain reaction.
• 
  
• Also harmful digestive enzymes released from cells damage neighboring cells.
• 
  
• Without apoptosis we would be at much greater risk of developing cancer, since apoptotic mechanisms destroy cells that have taken the first steps toward tumor formation.

Mnemonics made easy

5: Alkalosis: Metabolic changes

Remember,
"Al-K-loss and Al-Ca-loss"

So, in alkalotic states,
Loss of K+ Causing, Hypokalemia and
Loss of Ca++ causing Hypocalcemia

6: Anion Gap: Metabolic acidosis causes

Remember "A MUDPILE CAT"

Alcohol
Methanol
Uremia
Diabetic ketoacidosis
Paraldehyde
Iron/Isoniazid
Lactic acidosis
Ethylene glycol
Carbamazepine
Aspirine
Toluene

7: Blotting Methods

For this, you can remember Indian dishes

South Indian dish: Dosa--> Southern blotting for DNA
North Indian dish: Roti--> Nothern blotting for RNA
West Indian dish: Pizza--> Western blotting for Proteins

8: Citric acid cycle steps:

"Oh ! Citric Acid Is Ofcourse A Silly Stupid Funny Molecule"

Oxaloacetate
Citrate
Aconitate
Isocitrate
Oxalosuccinate
Alpha-ketoglutarate
Succinyl-CoA
Succinate
Fumerate
Malate

Here, Silly and Stupid helps to differentiate Succinyl-CoA and Succinate.

9: Enzyme Kinetics: Competitive Vs. Non-Competitive

With Kompetitive inhibition: Km Increases (no change in Vmax.)
With Non-Kompetitive inhibition: No change in Km (Vmax decreases)

There is Cross in the Graph in competitive but not in non-competitive.

"Competition is hard because we have to travel more Kilometers (Kms) with the same velocity" So in competitive inhibitors, velocity remains same but Km increases.


10: Essential Amino acids

"PVT TIM HALL" Always Argues, Never Tires"

Phe, Val, Thr
Trp, Ile, Met
His, Arg, Leu

Here "A" is for always Arginine and "T" is never for Tyrosine.

Mnemonics for Biochemistry

1: Glycogen Storage Disease

Von Physics Chemistry AND Maths mei Hoshiyar Thha. (Useful for those who understand Hindi language)

Von gierke’s
Pompe’s
Cori/forbe’s
Anderson
Mc. ardle
Hers
Tauri

Regarding branching and debranching enzyme deficiencies:

Remember,
ABCD
Anderson's has Branching enzyme deficiency
Cori's has Debranching enzyme deficiency

2: Conjugated hyperbilirubinemia

DR. B.N. Singh
D-Dubin-Johnson Syndrome
R-Rotor Syndrome
B-Biliary Atresia
N-Neonatal hepatitis
S-Sepsis

3: Hemboglobin binding curve: Causes of Shift to Right

"CADET, face right !":

CO2
Acid
2,3 -DPG (k/a 2,3 BPG also)
Exercise
Temperature

4: Zinc dependent Enzyme

a Clas

A- Alcohol dehydrogenase
C- Carbonic anhydrase
L- Lactase dehydrogenase
A- Alakaline phosphatase
S- Superoxide dismutase