MCQ of the Day

A  35 years old female had complaints of indigestion of food, pain abdomen and weight loss.  Serum amylase was raised.  Her CT scan reveals a pancreatic tumor.  Her serum calcium was raised and she had surgery in the neck to treat the cause.  Now she is having problem on seeing the things that are on the either side of her body.   Which of the following is the most probable cause of her vision problem?

 

1. Hypercalcemia
2. Hypocalcemia
3. Metastasis
4. Pancreatic tumor
5. Pituitary tumor
    
    
    

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Answer:e

Explanation: 

This patient is suffering from MEN-1 Neoplasia syndrome that comprises of Pituitary, parathyroid and pancreatic tumors.  The parathyroid tumor was causing hypercalcemia and was treated by neck surgery.  The vision symptoms are bitemporal hemianopia caused by a pituitary tumor.

(Choice a) Hypercalcemia is not the cause of such vision symptoms.  It was associated with the parathyroid tumor that was treated with neck surgery.

(Choice b) Hypocalcemia can be caused by extensive surgery for the parathyoids but is not the cause of her vision symptoms.

(Choice c) Pituitary is not the common site of Pancreatic metastasis.

(Choice d) Pancreatic  tumor cannot directly cause the vision symptoms.

 

Educational Objective: 

MEN-1 Neoplasia syndrome consists of Pituitary, Parathyroid and Pancreatic tumors.  Pituitary tumors when compressing the optic chiasm cause bitemporal hemianopia.  Parathyroid tumors cause hypercalcemia. Pancreatic tumors are diagnosed by CT scan.

 

 

MCQ of the Day

A  27 years old female was suffering from palpitations.  On echocardiography she was suffering from mitral regurgitation.  An artificial valve was placed.  She needs life long costeffective anticoagulation.  Which of the following agents is recommended in her case?

 

 

1. Aspirin
2. Debigatran
3. Rivaroxaban
4. Unfractionated Heparin
5. Vitamin K antagonist
    
    
    

 

 

 

 

 

 

 

 

Answer:e

Explanation:

Vitamin K antagonist i.e Warfarin is the traditional and cost effective long term anticoagulant used in these cases. A number of anticoagulants are available. The traditional ones are warfarin, other coumarins and heparins. There are a number of new agents  that are collectively called the novel oral anticoagulants (NOACs) or directly acting oral anticoagulants (DOACs). They include inhibitors of factor IIa (dabigatran) and factor Xa (rivaroxaban, apixaban and edoxaban).  They are possibly better than the coumarins with less serious side effects. They are more expensive than the traditional ones and should be used with care in patients with kidney diseasis. There is no antidote for the factor Xa inhibitors, so it is difficult to stop their effects in the body in cases of emergency (accidents, urgent surgery). Idarucizumab was FDA approved for the reversal of dabigatran.

 Debigatran and rivaroxaban are a lot costlier compared to warfarin, after having taken into consideration the cost of frequent blood testing associated with warfarin.

(Choice a) Aspirin can have added benefit but is not used for long term anticoagulation in cases of valvular surgery.

(Choice b) Explained

(Choice c) Explained

(Choice d) Unfractioned Heparin is not recommended for longterm anticoagulation.

 

Educational Objective: 

Warfarin is the drug of choice. Debigatran and rivaroxaban have a rapid onset action and relatively short half-lives.  They are more rapid and effective and allow for drugs to quickly reduce their anticoagulation effects. Routine monitoring and dose adjustments of Debigatran and rivaroxaban is less important than for warfarin, as they have better predictable anticoagulation activity. Both Debigatran and rivaroxaban  and warfarin are equivalent in effect, but Debigatran and rivaroxaban are less influenced by diet and medications compared to warfarin. There is  no antidote for most NOACs.

 

 

MCQ of the Day

A medical student becomes interested in genetic cloning.  He has to do Polymerase chain reaction during various investigations.  Almost all Polymerase reactions invlove a heat stable DNA polymerase which is an enzyme originally derived from the bacterium Thermus aquaticus.  What does this enzyme do?

1. Assembles a new DNA strand from nucleotides
2. DNA melting
3. Primers manufacture
4. Shorten the DNA strand
5. Thermal cycling
    

 

 

 

 

 

 

 

 

 

 

Answer:a

Explanation:

Taq Polymerase is the heatstable DNA Polymerase that assembles the new DNA strand from the nucleotides.

A basic PCR set up require these components: DNA template, two Primers, Taq Polymerase, dNTPs, Buffer solution, Mg2, Mn2, K+.  Thermal cycling and DNA melting are used during the procedure.

(Choice b)  In DNA melting the two strands of DNA are separated at a high temperature.

(Choice c) Primers are short DNA fragments containing sequences complementary to the target region along with a DNA polymerase.

(Choice d) Elongation of the DNA segments is done by the enzyme.

(Choice e) Thermal cycling consists of cycles of repeated heating and cooling of the reaction for DNA melting and enzymatic replication of the DNA.

Educational Objective: 

The polymerase chain reaction (PCR) is  used  to amplify a single copy or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence. It amplifies a focused segment of DNA, useful in the diagnosis and monitoring of genetic diseases, studying the function of targeted segment, DNA cloning for sequencing, DNA-based phylogeny, the identification of genetic fingerprints used in forensic sciences and DNA paternity testing and the diagnosis of infectious diseases.

 

MCQ of the Day

A 46 years old male had diarrrhea and fever for a period of one weak.  His stool culture showed the growth of Salmonella.  Now the patient have developed pain in left knee joint.  On examination the joint is swollen.  The culture of the joint aspirate did not show any growth.  The symtomatic treatment was effective. The most likely cause of his joint disease is?

1. HLA-B27
2. Osteoarthritis
3. Not related to diarrhea
4. Rheumatoid arthritis
5. Traumatic arthritis

 

 

 

 

 

 

 

 

 

 

 

Answer:a

Explanation:

The patient has reactive arthritis to Salmonella.  It is more common in patients with HLA-B27.  There is reactive arthritis and the joint aspirates are negative for any growth.  Other agents may also cuase a reactive arthritis e.g. Shigella, Compylobacter and Chlamydia.  Also seen in Reiter’s syndrome.

(Choice b) In Osteoarthritis there is usually a longer history and destruction of the cartilage with erosive changes in joints.

(Choice c) It is a reactive arthritis and is related to the cause as well as genetic antigen HLA-B27.

(Choice d) In Rheumatoid arthritis there is involvement of small joints of the hands and feet, ulnar deviation and other joint deformities. Rheumatoid factor is positive.

(Choice e) There is no history of trauma to the joint.

Educational Objective: 

HLA-B27  is associated with spondyloarthropathy that is associated with certain diarrheas e.g. due to Shigella, Salmonella, Compylobacter and Chlamydia.  Joint fluid aspirate does not show any growth in these cases.