MDS PREP
What is the significance of HLA class I antigens in the context of graft rejection and cell mediated cytolysis?
1) They are only involved in cell-to-cell recognition in the immune system.
2) They are the principal antigens that induce an immune response in the host against transplanted tissues.
3) They have no role in graft rejection or cell-mediated immunity.
4) They are only involved in the innate immune response.
HLA class I antigens are the principal antigens that induce an immune response in the host against transplanted tissues.
Pleomorphic adenoma arises from
1. Myoepithelial cells
2. Acinar cells
3. Connective tissue
4. Stem cells
Oral Pathology
Answer: 1
What is the primary effect of parathyroid hormone on serum calcium levels during pregnancy?
1) Decreases serum calcium levels
2) Increases serum calcium levels by mobilizing calcium from maternal bones
3) Has no effect on serum calcium levels
4) Increases serum calcium levels by enhancing calcium absorption in the gut
Answer: 2) The primary effect of parathyroid hormone during pregnancy is to increase serum calcium levels by mobilizing calcium from maternal bones for fetal use.
Widely accepted theory of dental caries
1) Proteolytic theory
2) Proteolytic chelation theory
3) Acidogenic theory
4) Autoimmune theory
Oral Pathology
Answer: 3
Hyperuricemia in Lesch-Nyhan syndrome is due to a defect in which of the following pathways?
1) Purine biosynthesis
2) Pyrimidine biosynthesis
3) Purine salvage
4) Pyrimidine salvage
Biochemistry Answer: 3
Uric acid is a purine derivative, increased by purine salvage reactions that convert purines, purine ribonucleosides, and purine deoxyribonucleoside to mononucleotides (incorrect answer 4).
Such salvage reactions require much less energy than de novo synthesis (incorrect answers 1, 2). The liver is the major site of purine nucleotide biosynthesis and provides excess purines for other tissues that cannot synthesize purines.
A defect in hypoxanthine-guanine phosphoribosyl transferase, one of the enzymes of purine salvage, is responsible for purine overproduction and subsequent hyperuricemia observed in Lesch-Nyhan syndrome.
In a case of parotid swelling the diagnostic procedure of choice
1) FNAC
2) Superticial parotidectomy
3) Enucleation
4) Excision biopsy
Oral medicine
Answer: 1
Cleft lip occurs due to non-union of
1) Maxillary process and frontonasal process
2) Maxillary process and mandibular process
3) Maxillary process and palatine process
4) Frontonasal and palatine process
Orthodontics
Answer: 2
The most potent narcotic analgesic is
1) Morphine
2) Pethidine
3) Methadone
4) Pentazocine
Pharmacology Answer: 3
Methadone is a synthetic narcotic analgesic The other major synthetic narcotic is meperidine (Demerol). Narcotic analgesics derived from opium are morphine, heroin (diacetylmorphine), and codeine.