Question

40. Titanium, a hapten, is now being used frequently in human joint replacement. In terms of an immune response to titanium, you would expect

     a.   an innate immune response.

     b.   no immune response because titanium is not a large enough, complex molecule.

     c.   an allergic response because titanium is a metal

     d. no immune response because titanium is not part of any microorganisms

     e.   an adaptive immune response because titanium is foreign to the body.

                       

41. Which of the following best characterizes antigens?

     a. Antigens may be proteins, polysaccharides, glycolipids, or glycoproteins that stimulate an immune response.

      b. Antigens come only from foreign microorganisms.

      c. Antigens are proteins called antibodies.

      d. Antigens are immunoglobulins the body produces in response to exposure to foreign

            organisms.

      e.   Both A and C

22.   Mrs. Jones titer shows high level antibodies but she has never had Chagus disease. Mrs. Jones is scared, although she has had no sign of illness, even after being exposed to this contagious disease. She is exhibiting:  

a.         natural acquired active immunity.

b.         natural acquired passive immunity.

c.         an allergic reaction.

d.         innate immunity.

            e.         artificial acquired passive immunity.

18. All of the following are benefits of fever, EXCEPT:

        a.   mobilizes defenses by promoting chemotaxis

        b.   inhibit bacterial growth and reproduction

        c.   catalyses metabolic reactions

        d.    increase metabolic rates

        e.   accelerates tissue repair

Answer 1

40. Haptens are small molecules, that can illicit immune response only when attached to large carrier molecules, like some proteins. Titanium based alloys (TiAIV) are used for Total knee arthroplasty (TKA) processes, as haptens may not illicit immune response and cause reaction.

Answer: b

41. Antigens are substances that can stimulate immune response, which may be associated with microorganisms, their parts, or sometime part of the host components. Antigens may include proteins, polysaccharides, glycoproteins, glycolipids that elicit immune cells, generate immune responses like producing antibodies or immunoglubulins.

Answer: a

22. Chagas disease is caused by protozoan parasite Trypanosoma cruzi. In chronic stage of the disease, due to presence of circulating parasites, antibody levels become high and present in high titers.

The individual does not exhibit symptoms of the disease, but show high levels of antibodies, on being exposed to antigens of the disease. Since the individual has not suffered from the disease, even on being exposed to the organism, it indicates a prior presence of immune cells, which may have been obtained from birth from the individual’s mother.

Thus, the individual exhibit natural acquired passive immunity.

Answer: b

18. Fever has following benefits:

1. Prevents the growth and multiplication of microorganism, as they require optimum temperature for growth ad reproduction.

2. Increase metabolism, to produce energy, as elevated temperatures cause consumption of stored energy reserves.

3. Cause vasodilation, resulting in better blood flow, to increase immune response, inflammation, chemotaxis of cells, and tissue repair.

But fever may result in elevated temperature that decrease catalytic function of body enzymes. So, they cannot catalyze metabolic reactions.

Answer: c