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CASE FILES: BIOCHEMISTRY
A N SW E R S TO C A SE 2: RIBA V IR IN A N D IN F L U E N Z A
Summary:
A college student complains of the sudden onset of fever, chills,
malaise, nonproductive cough, and numerous sick contacts in the fall season.
Likely diagnosis:
Acute influenza infection
Biochemical mechanism of action of ribavirin:
A nucleoside
analogue with activity against a variety of viral infections
Genetic makeup of organism:
Ribonucleic acid (RNA) respiratory virus
C L IN IC A L C O R R E L A T IO N
This 21-year-old college student has the clinical clues suggestive of acute
influenza. Typically, the illness occurs in the winter months with an acute onset
of fever, myalgias (muscle aches), headache, cough, and sore throat. Usually,
there are outbreaks with many individuals with the same symptoms. This patient
is young and healthy, and antiviral therapy is not mandatory. The best way to pre-
vent the infection is by influenza vaccination, usually given in October or
November of each year. Because of the antigenic changes of the virus, a new vac-
cine must be given each year. Patients who are at especially high risk for severe
complications or death should receive the vaccine each year. These include the
elderly and people with asthma, chronic lung disease, human immunodeficiency
virus (HIV) infection, diabetes, or chronic renal insufficiency.
APPR O A CH TO TH E U SE O F RIBAVIRIN IN IN FLU EN ZA
O bjectives
1.
Know the structure of deoxyribonucleic acid (DNA) and RNA.
2.
Understand the processes of denaturation, renaturation, and hybridiza-
tion of DNA.
3.
Know the differences between RNA and DNA.
4.
Be familiar with the differences between human and viral/bacterial
DNA and RNA.
D efinitions
Base pairing:
The hydrogen bonds formed between complementary bases
that are part of the polynucleotide chains of nucleic acids. The base pair-
ing is specific in that adenine will base pair with thymine (uracil in
RNA) and guanine will pair with cytosine.
Chargaff rule:
the amount of adenine and thymine in DNA is equal; the
amount of cytosine and guanine are equal. (A = T, C = G). The amount
of purines equals the amount of pyrimidines.
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