GI dysfunction PPQ Flashcards
You are carrying out a study investigating Wnt signalling in breast cancer tumourigenesis. You create a transgenic mouse that overexpresses Wnt in mammary tissue, and regulation of WNT binding to its receptor. Which protein is subsequently recruited to the ligand-receptor complex? Abc Axin Beta–catenin Dishevelled SK3beta
Dishevelled
The Adenomatous Polyposis Coli (APC) gene, so named because mutations in this gene lead to form a hereditary form of bowel cancer, that prevents excessive activation of mitotic signalling pathways. As part of the destruction complex, ABC binds to target proteins, leading to their ubiquitnation and proteasomal degradation. Which protein is a target for this destruction complex? Beta–catenin Frizzled Patched Smoothened Wnt
Beta–catenin
Retinoblastoma protein (Rb) is an important tumour suppression protein, and the gene encoding this protein is commonly mutated in cancer. Rb inhibits cell division by preventing progression from G1 to S phase of the cell cycle activity by blocking a key transcription factor involved in cell cycle progression. Which transcription factor does this protein block?
E2F
Gli
HIF (hypoxia-inducible factor)
Nuclear factor kappa (NF-kB)
p53
E2F
Humans express several cyclin dependent kinases (CDKs). CKs4 and 6 have a role in cell cycle progression based on their ability to phosphorylate a restriction point target. What is it key target for the CDKs?
Raf
Ras
Reininoblastoma protein (Rb)
Protein kinase C (PKC)
Phosatidylinositol(4,5) bisphosaphate
Phosatidylinositol(4,5) bisphosphate
Cyclin-dependent kinases(CDKs) constitutively present in cells, but become activated by the cell cycle stage dependent transcription such as cyclins. Which CDK is activated by then?
CDK1
CDK2
CDK3
CDK4
CDK5
CDK2
Explanation
Mitogen independent in late G1
A man undergoes continuous ambulatory peritoneal dialysis. He develops peritonitis as a result of biofilm development on the indwelling catheter used for delivery of exchange fluid into the peritoneal cavity. This is identified as a coagulase negative staphylococcal infection caused by commensal bacteria that usually exist harmlessly as part of normal human flora. Where is easily found?
Bladder
Blood
Skin
Colon
Duodenum
Skin
You are beginning your professional training you research project in the microbiology laboratory investigating the rise of antibiotic resistance in commensal bacteria in the general population. One of the first steps is to culture and identify commencing bacterial samples taken from the study participants. From which part of the body with the greatest range of microorganisms be obtained?
Stomach
Terminal ileum
Hand
Duodenum
Blood
Terminal ileum4
A new drug for hypertension is being investigated including the calculation of its bioavailability after oral administration. When given orally some drugs can be extensively broken down into inactive metabolites after absorption from the GI system (known as a first pass metabolism), making them largely unavailable for therapeutic activity. Where does this metabolism occur?
Gall bladder
Kidney
Liver
Pancreas
Spleen
Liver
You are working in research and create a transgenic mouse model characterised by defective uptake of glucose into pancreatic beta cells. To achieve this you would need to alter the gene encoding which protein?
GLUT-2
GLUT-4
Insulin receptor
Sodium-glucose antiporter
Sodium-glucose co-transporter
GLUT-2
You want to produce polypeptide analogues. Why might you choose to use a eukaryotic cell line rather than a bacterial system?
Culture, transformation and polypeptide expression is cheaper.
More extensive post translational modification is possible.
Purification of transformed DNA is easier.
The potential polypeptide yield is higher.
Transformation of DNA is easier.
More expensive house is possible. Purification of transformed DNA is easier. The potential polypeptide yield is higher. Transformation of DNA is easier.
More extensive post translational modification is possible.4
You are conducting a concentration response experiment should human cells. You want to measure histamine release in response to increasing concentration. What type of cells should you use in your experiment?
Delta (D) cell
Enterochromaffin-like(ECL) cell
G cell
Parasympathetic neuron
Parietal cell
Enterochromaffin-like(ECL) cell
Cyclooxygenase(COX) inhibitor drugs have been used as anti-inflammatory agents for many years. However some of these drugscarry a risk of CVA or myocardial infarction due to inappropriate clotting resulting from non-specific in inhibition of arachnidonic acid metabolism. Which other enzyme in this pathway could be specifically inhibited to reduce the risk of clotting?
Lipoxygenase
Phospholipase C
Prostacyclin synthetase
Prostaglandin E synthetase
Thromoxane synthetase
Thromoxane synthetase
A pharmaceutical company is interested in developing novel drugs for gastrointestinal ulcers. Peptic ulceration can occur due to inhibition of prostaglandin production. NSAIDs produce this effect by preventing breakdown which precursor?
Prostacyclin
Thromboxae A2
Arachidonic acid
Phosphatidylinositol (4,5) biphosphate
Phosphatidylinositol (3,4,5) triphosphate
Arachidonic acid
A 24-year-old man is prescribed sulphasalzine for ulcerative colitis (UC). The tablets have a waxy coating resulting in drug release been delayed so that the active ingredient is released at its target site of action. What other purpose does this coating serve?
Improves absorption of the drug
Improve bioavailability of the drug
Improve potency of the drug
Reduces first part pass metabolism of the drug
Reduces effects of the drug
Reduces effects of the drug
Ras is a signalling molecule activated following binding of factors such as epidermal growth factor (EGF) to its receptor. Activity of the signalling pathway is dependent upon the net balance of a number of signalling and regulatory components. What change to the signalling pathway would promote cell proliferation?
Decreased rasGAP activity
Decreased rasGEF actvitiy
Decreased ras activity
Increased cytoplasmic GDP/GTP ratio
Increased protein tyrosine phosphtase activity
Decreased rasGAP activity
A single tumour cell has detached from a primary tumour but has failed to undergo detachment mediated cell death. It is not yet entered the blood or lymph-nodes. What potential therapeutic strategies could target the next step in the metastatic process?
Inhibition of cyclin-dependent kinases CDKs
Inhibition of matrix metalloproteinases (MMPs)
Inhibition of regulatory T cells (Tregs)
Inhibition of vascularcell cell adhesion molecule 1 (VCAM-1)
Inhibition of vascular endothelial growth factor (VEGF)
Inhibition of matrix metalloproteinases (MMPs)
