Friday 7 March 2014

DI-DCO Solved Exam Paper with Explanation (RAJASTHAN) . 2012 Part-4

Q.41 Which of the following drug is similar to Acarbose in classification
a) Tolbutamide        b) Glipizide   c) Miglitol      d) Pioglitazoneg
Ans 41. C Acarbose is an anti-diabetic drug used to treat type 2 diabetes mellitus. Acarbose inhibits enzymes (glycoside hydrolases) needed to digest carbohydrates, specifically, alpha-glucosidase enzymes in the brush border of the small intestines and pancreatic alpha-amylase. Pancreatic alpha-amylase hydrolyzes complex starches to oligosaccharides in the lumen of the small intestine, whereas the membrane-bound intestinal alpha-glucosidases hydrolyze oligosaccharides, trisaccharides, and disaccharides to glucose and other monosaccharides in the small intestine. Inhibition of these enzyme systems reduces the rate of digestion of complex carbohydrates.


Alpha-glucosidase inhibitors
  • Acarbose
  • Miglitol
  • Voglibose
 
Miglitol is an oral anti-diabetic drug that acts by inhibiting the ability of the patient to break down complex carbohydrates into glucose. It is primarily used in diabetes mellitus type 2 for establishing greater glycemic control by preventing the digestion of carbohydrates (such as disaccharides, oligosaccharides, and polysaccharides) into monosaccharides which can be absorbed by the body.






Q.42 Propyl thiouracil is similar to one of the following drug in pharmacological action?
a) Azothioprine   b) Chlormbucil c) Methimazole        d) Acyclovir
Ans 42. C  Propylthiouracil (PTU) or 6-n-propylthiouracil (PROP) is a thiouracil-derived drug used to treat hyperthyroidism (including Graves' disease) by decreasing the amount of thyroid hormone produced by the thyroid gland. Its notable side effects include a risk of agranulocytosis.

PTU inhibits the enzyme thyroperoxidase, which normally acts in thyroid hormone synthesis by oxidizing the anion iodide (I-) to iodine (I0), facilitating iodine's addition to tyrosine residues on the hormone precursor thyroglobulin. This is one of the essential steps in the formation of thyroxine (T4).

Methimazole (also known as Tapazole or Thiamazole or MMI) is an antithyroid drug, and part of the thioamide group. Like its counterpart propylthiouracil, a major side effect of treatment is agranulocytosis.

Methimazole inhibits the enzyme thyroperoxidase, which normally acts in thyroid hormone synthesis by oxidizing the anion iodide (I-) to iodine (I0), facilitating iodine's addition to tyrosine residues on the hormone precursor thyroglobulin, a necessary step in the synthesis of triiodothyronine (T3) and thyroxine (T4).

Q.43 Which of the following is pure opioid antagonist?
a) Butorphanol                        b) Nelbupine               c) Buprenorphine        d) Naloxone
Ans 43. Naloxone is an opioid antagonist drug. Naloxone is a drug used to counter the effects of opiate overdose, for example heroin or morphine overdose.

Q.44 Which of following drug causes maximum dependence?
a) Diethylmorphine                   b) Diacetylmorphine   
c) Dimethylmorphine                 d) Diphenoxylate
Ans 44. B Heroin (diacetylmorphine or morphine diacetate (INN)), also known as diamorphine (BAN). Under the chemical name diamorphine, diacetylmorphine is prescribed as a strong analgesic in the United Kingdom, where it is given via subcutaneous, intramuscular, intrathecal or intravenous route. Its use includes treatment for acute pain, such as in severe physical trauma, myocardial infarction, post-surgical pain, and chronic pain, including end-stage cancer and other terminal illnesses.

Like most opioids, unadulterated heroin does not cause many long-term complications other than dependence and constipation.

Q.45 Latanoprost has one of the following mechanism of action in glaucoma
a) Miosis          b) Prostaglandin analogues     c) Carbonic anhydrase inhibitor          d) Decrease formation of aqueous hamour.
Ans 45. B Latanoprost ophthalmic solution is a topical medication used for controlling the progression of glaucoma or ocular hypertension by reducing intraocular pressure. It is a prostaglandin analogue (more specifically an analogue of prostaglandin F) that works by increasing the outflow of aqueous fluid from the eyes (through the uvealsclearal tract).

Q.46 Lawsone  is obtained from
a) Gymnema           b) Liquorice       c) Dioscorea            d) Henna
Ans 46. D Lawsone (2-hydroxy-1,4-naphthoquinone), also known as hennotannic acid, is a red-orange dye present in the leaves of the henna plant (Lawsonia inermis) as well as jewelweed (Impatiens balsamina).
Henna, Lawsonia inermis, contains a red-orange pigment, lawsone, the molecule of which is also known as hennotannic acid. When henna leaves are crushed in an acidic medium and applied to skin, the lawsone molecules migrate from the henna paste, traverse the outermost layer of the hair, the cuticle and stain the hair. Prolonged applications of henna result in diffusion of the pigment deeply into the hair.

Chemically, the molecule of lawsone is 2-hydroxy-1, 4-naphthoquinone.

Q.47 Which one of the following is used as Osmatic purgative?
a) Milk of magnesia                b) Senna          c) Extract of rubarb     d) Aluminium hydroxide gel
Ans 47. A  Hydrating agents (osmotics) Site of Action: Small and large intestine
Onset of Action: 0.5–6 hours
Examples: sodium phosphate (and variants), potassium sodium tartrate, magnesium citrate, magnesium hydroxide (Milk of magnesia or Cream of magnesia), magnesium sulfate (a.k.a. Epsom salt).
Q.48 4 in 10, 000 is calculated as
a) 4 %        b) 0.04 %                     c) 0.4 %                       d) 40%
Ans 48. B   4/10000 x 100 =0.04%

Q.49 Sodium picrate is used for identification of
a) Cyanogenic glycoside                   b) Isocyanate glycoside       
c) Flavanol                                         d) Anthracene
Ans 49. A
The picrate method
For the picrate method, Egan et al. (1998) procedure was followed pouring a small amount of the cyanoglucoside or a portion of 25–100 mg of the finely ground powder or leaf. The procedure requires also 0.5 ml of phosphate buffer (pH 10). A picrate paper attached to a plastic backing strip is added and the vial immediately closed with a screw stopper. The paper was treated with sodium picrate in 2% Na2CO3 prior to use. The hydrolysis will normally take place within about 1 h if the flask is kept in a warm place. After about 16 h at 30 C, the picrate paper was removed and immersed in 5.0 ml water for at least 30 min. The absorbance of the obtained solution was measured at 510 nm and the liberated cyanide (CN-) was determined by the equation:
CN- =381 x absorbance x 100=g;
where g = weight (mg) of ground powder or leaf (adapted from Bradbury et al.,
1999).
To complete the interpretation of the determinations, a 200 lgml_1 solution of picric acid in 2% sodium carbonate was added to each sample containing cyanide resulted from the hydrolysis of the cyanogens. After heating the mixture for 30 min in a boiling water bath, the absorbance was measured at 510 nm and the concentration calculated using a standard with cyanide.

Q.50 Vapour pressure of propellant for aerosols are calculated from
a) Boyals law      b) Ficks law     c) Stokes law      d) Daltons law
Ans 50. D Dalton's law (also called Dalton's law of partial pressures) states that the total pressure exerted by the mixture of non-reactive gases is equal to the sum of the partial pressures of individual gases. This empirical law was observed by John Dalton in 1801 and is related to the ideal gas laws.

Boyle's law (sometimes referred to as the Boyle–Mariotte law, or Mariotte's law) is an experimental gas law which describes how the pressure of a gas tends to decrease as the volume of a gas increases. A modern statement of Boyle's law is:
The absolute pressure exerted by a given mass of an ideal gas is inversely proportional to the volume it occupies if the temperature and amount of gas remain unchanged within a closed system.

Fick's laws of diffusion describe diffusion and can be used to solve for the diffusion coefficient.

Stokes' law, for the frictional force – also called drag force – exerted on spherical objects with very small Reynolds numbers (e.g., very small particles) in a continuous viscous fluid. Stokes' law is derived by solving the Stokes flow limit for small Reynolds numbers of the Navier–Stokes equations:


where Fd is the frictional force – known as Stokes' drag – acting on the interface between the fluid and the particle (in N),μ is the dynamic viscosity (kg /m*s),R is the radius of the spherical object (in m), and v is the particle's velocity (in m/s).
Stokes' law makes the following assumptions for the behavior of a particle in a fluid:
·         Laminar Flow
·         Spherical particles
·         Homogeneous (uniform in composition) material
·         Smooth surfaces
·         Particles do not interfere with each other.
Note that for molecules Stokes' law is used to define their Stokes radius.
It is interesting to note the CGS unit of kinematic viscosity was named "stokes" after his work.
 

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