VPTAC Sample Paper for Pharmacy competitive examination, MCQ (With Explanation )-5

Q 1. Treated soda lime glass chemical resistances is evaluated by following test?
A) Fused glass test B) Water attack test C) H2SO4 attack test D)Powdered glass test

Ans = B, Treated sodalime glass (Type-II) used for Buffered Aqueous solution with pH below 7, Dry powders & Oligogenic Substance.

Powdered glass test for = Brosilicate (Type-I), Regular Sodalime Type-III), General purpose (Type-NP)

Q 2. Cab-O-sil used as
a) Lubricant b) Antiadherent c) Glidant d) Disintegrant

Ans = C, Cab-O-Sil fumed silica is a white, free-flowing powder of extremely high purity. It is widely used as a glidant in tablet and capsule formulations.

Q 3. Type I hypersensitivity mediated by immunoglobulins is
A). IgE B). IgD C). IgM D). IgA

Ans= A, In type-I reaction IgE antibody involve, degranulation of mast cell, reaction occur with in 30 minutes, Ex.= anaphylactic shock, hey fever, asthma.

Q 4. which of the following mediate secondary response?
A) IgA B) IgD C) IgE D) IgG

Ans = D, In type-II reaction IgM and IgG antibody involve, reaction occur with in 5-12 hrs. Ex.= Rh incompatability

Q 5. Toxic features of atropine include the following, except:
A). Tachycardia B). Blurred vision C). Urinary retention D). Hypothermia

Ans = D , Atropine inhibits sweating and stimulates the temperature-regulating center of the hypothalamus hence the body temperature rises. Larger doses of atropine block the vagal effects on M2 muscarinic receptors on the SA nodal pace maker hence there is tachycardia. It has a relaxant action on the ureter and the urinary bladder hence urinary retention may occur in old males with prostatic hypertrophy. The lenss is fixed for far vision hence near objects appear blurred.

Q 6. Cyclosporine :
A). Is excreted unchanged from the body.
B). Is derived from a bacterium.
C). Has a selective inhibitory effect on T-lymphocytes.
D). Is not absorbed orally.

Ans = C, Cyclosporine is obtained from a soil fungus Tolypocladium inflatum gams. It has a selective inhibitory effect on T-lymphocytes, suppressing the early cellular response to antigenic stimuli. It can be administered both orally as well as intravenously. It gets metabolized extensively in the liver and various drugs, which affect cytochrome P450, affect its clearance.

Q 7. Choose the antimicrobial which acts by interfering with DNA function in the bacteria:

A. Chloramphenicol

B. Ciprofloxacin

C. Streptomycin

D. Vancomycin

Ans. B. Chloramphenicol is a bacteriostatic broad-spectrum antibiotic, alongside the tetracyclines . Chloramphenicol, also known as chlornitromycin, is effective against a wide variety of Gram-positive and Gram-negative bacteria, including most anaerobic organisms.  Chloramphenicol is a bacteriostatic drug that stops bacterial growth by inhibiting protein synthesis. Chloramphenicol prevents protein chain elongation by inhibiting the peptidyl transferase activity of the bacterial ribosome.

Ciprofloxacin is second-generation quinolones are a family of synthetic broad-spectrum antibacterial drugs. Quinolones exert their antibacterial effect by preventing bacterial DNA from unwinding and duplicating.

Streptomycin is an antibiotic (antimycobacterial) drug, the first of a class of drugs called aminoglycosides. It is derived from the actinobacterium Streptomyces griseus. Streptomycin is a protein synthesis inhibitor. It binds to the small 16S rRNA of the 30S subunit of the bacterial ribosome, interfering with the binding of formyl-methionyl-tRNA to the 30S subunit. This leads to codon misreading, eventual inhibition of protein synthesis and ultimately death of microbial cells through mechanisms that are still not understood. Speculation on this mechanism indicates that the binding of the molecule to the 30S subunit interferes with 50S subunit association with the mRNA strand. This results in an unstable ribosomal-mRNA complex, leading to a frameshift mutation and defective protein synthesis; leading to cell death. 

Vancomycin is of the glycopeptide antibiotic class and is effective mostly against Gram-positive bacteria. Vancomycin acts by inhibiting proper cell wall synthesis in Gram-positive bacteria. The large hydrophilic molecule is able to form hydrogen bond interactions with the terminal D-alanyl-D-alanine moieties of the NAM/NAG-peptides. Under normal circumstances, this is a five-point interaction.

 

Q 8. Absorption of oral iron preparation can be facilitated by co-administering:

A. Antacids

B. Tetracyclines

C. Phosphates

D. Ascorbic Acid

Ans. D.   A higher bioavailability of the dietary iron can be achieved by increasing the content of food components enhancing iron absorption (ascorbic acid, meat/fish) or by decreasing the content of inhibitors (e.g., phytates, tannins). The key role of ascorbic acid for the absorption of dietary nonheme iron is generally accepted. The reasons for its action are twofold: (1) the prevention of the formation of insoluble and unabsorbable iron compounds and (2) the reduction of ferric to ferrous iron, which seems to be a requirement for the uptake of iron into the mucosal cells.

It is often recommended to individuals who have iron deficiency (anemia) that they take their iron supplements with orange juice. This is because the vitamin C in the orange juice aids in iron absorption. When vitamin C, also known as ascorbic acid, enters the stomach it mixes with the iron supplement that contains non-heme iron. The ascorbic acid is able to reduce iron from its non-heme form to a form called ferric iron. The ferric iron then leaves the stomach and enters the small intestine. Iron absorption in the small intestine is able to occur because the iron is in this ferric form. Ferric iron has a low pH, which enables the mucous cells of the small intestine lining to take up the iron. If it wasn't for the vitamin C converting non-heme iron into ferric iron, the iron would pass through the body and not be absorbed.

Q 9. Interferon is used in :

A. Hepatitis B

B. AIDS

C. Both A and B

D. None

Ans. C, Interferons (IFNs) are proteins made and released by host cells in response to the presence of pathogens such as viruses, bacteria, parasites or tumor cells. They allow for communication between cells to trigger the protective defenses of the immune system that help eradicate pathogens.

IFNs belong to the large class of glycoproteins known as cytokines. Interferons are named after their ability to "interfere" with viral replication by protecting cells from virus infection. IFNs have other functions: they activate immune cells, such as natural killer cells and macrophages; they increase host defenses by up-regulating antigen presentation by virtue of increasing the expression of major histocompatibility complex (MHC) antigens. Certain symptoms of infections, such as fever, muscle pain and "flu-like symptoms", are also caused by the production of IFNs and other cytokines.

More than twenty distinct IFN genes and proteins have been identified in animals, including humans. They are typically divided among three classes: Type I IFN, Type II IFN, and Type III IFN. IFNs belonging to all IFN classes are important for fighting viral infections and for the regulation of the immune system.

Q 10. Foscarnate inhibits viral:

A. DNA polymerase

B. Revese transcriptase

C. Both A and B

D. None

Ans. C, Foscarnet is the conjugate base of the chemical compound with the formula HO₂CPO₃H₂.

This phosphonic acid derivativeis an antiviral medication used to treat herpes viruses, including drug-resistant cytomegalovirus (CMV) and herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2). It is particularly used to treat CMV retinitis. Foscarnet can be used to treat highly treatment-experienced patients with HIV as part of salvage therapy.

Foscarnet is a structural mimic of the anion pyrophosphate   that selectively inhibits the pyrophosphate binding site  on viral DNA polymerases at concentrations that do not affect human DNA polymerases.

MOA: inhibits viral DNA polymerase, RNA polymerase and HIV reverse transcriptase directly without requiring activation by phosphorylation -IV use only -large nephrotoxicity -very good against CMV, herpes simplex and pts w/ acute flairs of HIV -second-line drug for CMV retinitis, colitis, pneumonitis, esophagitis, as well as acyclovir resistant VZV and HSV infections in immunocompromised pts