Biotechnology in Medicine

Biotechnology in Medicine

Biotechnology has made important contributions to medicine by helping scientists produce therapeutic proteins, vaccines, hormones, diagnostic molecules and other medical products.

Medical biotechnology में living organisms, cells, genes and recombinant DNA technology का उपयोग करके diseases की diagnosis, prevention और treatment के लिए useful products तैयार किए जाते हैं।

1. Major Applications of Biotechnology in Medicine

Important medical applications include:

• Production of recombinant therapeutic proteins
• Production of insulin
• Production of vaccines
• Gene therapy
• Molecular diagnosis of diseases
• Production of other biologically active molecules

2. Recombinant Therapeutic Products

A recombinant therapeutic product is a medical product produced using recombinant DNA technology.

A gene coding for a useful therapeutic protein can be inserted into a suitable host organism. The host then produces the required protein.

उदाहरण के लिए, human insulin को recombinant DNA technology की सहायता से microorganisms में produce किया जा सकता है।

3. Why Recombinant DNA Technology is Useful in Medicine

Traditional methods may not always be suitable for producing large quantities of pure human proteins.

Recombinant DNA technology allows the desired gene to be introduced into a suitable host so that the required protein can be produced in large quantities under controlled conditions.

4. Recombinant Human Insulin

Insulin is a peptide hormone produced by the β-cells of the islets of Langerhans in the pancreas.

Insulin plays an important role in maintaining blood glucose levels.

People suffering from diabetes may require insulin treatment when their body does not produce sufficient insulin or cannot use it effectively.

5. Structure of Human Insulin

Mature human insulin consists of two polypeptide chains:

• A-chain
• B-chain

These chains are linked by disulphide bonds.

Human insulin is initially synthesised as a precursor molecule called proinsulin.

Proinsulin contains an additional connecting segment called the C-peptide.

During maturation, the C-peptide is removed and mature insulin is formed.

Proinsulin
    ↓
Removal of C-peptide
    ↓
Mature insulin
    ↓
A-chain + B-chain
linked by disulphide bonds

6. Production of Recombinant Insulin

NCERT describes the production of human insulin using genetically modified Escherichia coli.

The DNA sequences corresponding to the insulin A and B chains were separately introduced into E. coli to produce the two chains.

The chains were then extracted and combined to form functional insulin.

इस approach का महत्व यह है कि insulin को large scale पर recombinant technology की सहायता से produce किया जा सकता है।

7. Insulin – Important Exam Points

• Human insulin consists of A and B chains.
• A and B chains are linked by disulphide bonds.
• Proinsulin contains an additional C-peptide.
• C-peptide is removed during maturation of insulin.
• Recombinant human insulin can be produced using genetically modified microorganisms.
• NCERT discusses the use of E. coli for production of recombinant insulin.

8. Recombinant Vaccines

Vaccines stimulate the immune system to develop protection against a particular pathogen or its components.

Biotechnology can be used to produce vaccines using recombinant DNA technology.

Instead of using the complete pathogen, a specific antigenic protein can be produced using a recombinant organism and used as part of a vaccine.

इससे vaccine production में specific antigen को controlled तरीके से obtain किया जा सकता है।

9. Hepatitis-B Vaccine

A well-known example of a recombinant vaccine is the Hepatitis-B vaccine.

The vaccine can be produced using recombinant DNA technology by expressing the gene encoding the Hepatitis-B surface antigen (HBsAg) in a suitable host.

The antigen is purified and used in vaccine preparation.

10. Molecular Diagnosis

Biotechnology has improved the diagnosis of diseases through techniques that detect specific molecules or genetic sequences.

Two important techniques discussed in biotechnology are:

• PCR
• ELISA

11. PCR in Disease Diagnosis

Polymerase Chain Reaction (PCR) amplifies a specific DNA sequence, making it easier to detect the presence of a particular genetic sequence.

If the genetic material of a pathogen is present in a very small amount, PCR can amplify the target sequence to a detectable level.

इसलिए PCR early or sensitive detection में useful हो सकती है, especially when the target nucleic acid is present in very low quantity.

Small amount of pathogen DNA
            ↓
           PCR
            ↓
Amplification of target sequence
            ↓
Detection of pathogen

12. PCR and Genetic Disorders

PCR can also be used to amplify DNA regions associated with genetic disorders.

After amplification, the DNA can be analysed using suitable molecular techniques.

Thus PCR can assist in the identification or study of certain inherited conditions.

13. ELISA

ELISA stands for Enzyme-Linked Immunosorbent Assay.

It is based on the principle of antigen-antibody interaction.

ELISA can be used to detect either a specific antigen or a specific antibody in a biological sample, depending on the test design.

यदि किसी disease के कारण body में specific antibody या antigen मौजूद है, तो appropriate ELISA उस molecule को detect करने में मदद कर सकता है।

14. PCR vs ELISA

PCR	ELISA
Detects/amplifies specific nucleic acid sequences	Based on antigen-antibody interaction
Uses DNA polymerase and primers	Uses antigen-antibody binding and enzyme-linked detection
Useful for detecting specific genetic material	Useful for detecting specific antigens or antibodies

15. Gene Therapy

Gene therapy is a technique in which a functional gene is introduced into a patient's cells to compensate for the effect of a defective or non-functional gene.

इसका उद्देश्य disease के genetic cause को target करना है, rather than treating only the symptoms.

16. First Clinical Gene Therapy

NCERT describes the first clinical gene therapy as being given in 1990 to a four-year-old girl suffering from adenosine deaminase (ADA) deficiency.

ADA deficiency is associated with severe immune-system dysfunction.

17. ADA Deficiency

Adenosine deaminase (ADA) is an enzyme involved in purine metabolism.

Deficiency of ADA can severely affect the immune system and may result in a form of severe combined immunodeficiency (SCID).

Gene therapy for ADA deficiency aims to provide cells with a functional copy of the ADA gene.

18. Approach Used in ADA Gene Therapy

In the approach described in NCERT, functional ADA cDNA is introduced into the patient's lymphocytes outside the body.

The genetically corrected lymphocytes are then returned to the patient.

Patient's lymphocytes
        ↓
Removed from body
        ↓
Functional ADA gene introduced
        ↓
Cells cultured
        ↓
Corrected cells returned to patient
        ↓
ADA function improved

यह treatment temporary benefit दे सकता है क्योंकि corrected lymphocytes have a limited lifespan. इसलिए repeated administration may be required.

19. Permanent Gene Therapy

A more permanent approach would involve introducing the functional gene into cells that can continuously produce corrected descendants, such as suitable stem cells.

इस approach का उद्देश्य ऐसी cells को correct करना है जो लंबे समय तक body में बनी रहें और corrected cells बनाती रहें।

20. Gene Therapy – Important Points

• Gene therapy aims to correct or compensate for a defective gene.
• ADA deficiency is a classic example discussed in NCERT.
• The first clinical gene therapy was performed in 1990.
• Functional ADA gene material can be introduced into patient cells.
• Corrected cells can be returned to the patient.

21. Genetically Engineered Organisms for Medicine

Genetically modified microorganisms can be used to produce medically useful proteins.

Examples include microorganisms engineered to produce:

• Insulin
• Vaccines or vaccine components
• Enzymes
• Other therapeutic proteins

22. Transgenic Animals in Medicine

Transgenic animals are animals whose genetic material has been modified by introducing a foreign gene or modifying an existing gene.

They can be used in medical research and in the production or study of biologically important substances.

Important applications include:

• Studying normal physiology and development
• Studying diseases
• Testing the safety of vaccines and medicines
• Producing useful biological products

23. Transgenic Animals for Disease Study

Transgenic animals can be developed to carry genes associated with particular diseases.

Researchers can then study how the disease develops and test potential treatments.

इससे human disease mechanisms को समझने और new therapeutic approaches को test करने में सहायता मिलती है।

24. Testing of Vaccine Safety

Transgenic animals can be used in research to evaluate the safety and biological effects of vaccines before further development and testing.

25. Testing of Chemical Safety

Transgenic animals can also be used for toxicity testing.

They may help researchers determine whether a chemical or drug has harmful biological effects.

26. Biological Products from Transgenic Animals

Some transgenic animals can be designed to produce useful human proteins in their milk or other biological materials.

NCERT gives the example of a transgenic cow named Rosie, whose milk contained the human protein alpha-lactalbumin.

यह protein human infants के लिए nutritionally important माना जाता है और इस example से transgenic animals की potential pharmaceutical applications को समझाया जाता है।

27. Important Medical Applications at a Glance

Application	Example / Purpose
Recombinant protein	Human insulin
Recombinant vaccine	Hepatitis-B vaccine
Molecular diagnosis	PCR, ELISA
Gene therapy	ADA deficiency
Transgenic animals	Disease research and biological product production
Transgenic cow	Rosie – alpha-lactalbumin in milk

28. Biotechnology and Cancer Diagnosis

Molecular techniques can help identify genetic changes associated with cancer.

PCR and other molecular methods can be used to analyse specific DNA sequences or genetic alterations.

इससे disease के molecular basis को समझने और certain diagnostic approaches विकसित करने में मदद मिलती है।

29. Biotechnology and Cancer Treatment Research

Biotechnology contributes to the development of targeted therapeutic approaches, recombinant proteins, antibodies and gene-based strategies.

इन approaches का उद्देश्य disease-causing molecular pathways को अधिक specifically target करना है।

30. Biotechnology and Personalised Medicine

Modern biotechnology can help identify genetic differences among individuals.

Such information may help doctors and researchers understand why different patients respond differently to particular treatments.

इस प्रकार molecular information के आधार पर treatment strategies को अधिक specific बनाने की possibility बढ़ती है।

31. Advantages of Biotechnology in Medicine

• Large-scale production of therapeutic proteins
• Production of specific vaccine components
• Improved molecular diagnosis
• Possibility of treating certain genetic disorders through gene therapy
• Better understanding of disease mechanisms
• Development and testing of new drugs
• Production of biologically important molecules

32. Limitations and Challenges

Medical biotechnology also involves several scientific and ethical challenges.

• Gene therapy may not always provide a permanent cure.
• Delivery of a functional gene to the correct cells can be difficult.
• Immune reactions may occur against introduced components.
• Safety and effectiveness must be carefully evaluated.
• Long-term effects of genetic interventions require monitoring.
• Ethical issues must be considered in genetic manipulation.

33. Important Terms

Term	Meaning
Recombinant DNA technology	Technology involving manipulation and combination of DNA molecules
Therapeutic protein	Protein used for prevention or treatment of disease
Proinsulin	Precursor of mature insulin
C-peptide	Connecting peptide removed during insulin maturation
PCR	Polymerase Chain Reaction
ELISA	Enzyme-Linked Immunosorbent Assay
Gene therapy	Use of genetic material to compensate for or correct a genetic defect
ADA	Adenosine deaminase
Transgenic animal	Animal whose genetic material has been genetically modified
HBsAg	Hepatitis-B surface antigen

34. Very Short Answer Questions

1. What is biotechnology in medicine?
2. What is recombinant insulin?
3. Name the two chains of mature human insulin.
4. What is proinsulin?
5. What is C-peptide?
6. What is the function of insulin?
7. What is the full form of PCR?
8. What is ELISA?
9. What is gene therapy?
10. What is ADA deficiency?
11. In which year was the first clinical gene therapy performed?
12. What is a transgenic animal?
13. What is HBsAg?
14. Name the transgenic cow mentioned in NCERT.

35. Short Answer Questions

1. Explain the importance of recombinant DNA technology in medicine.
2. Describe the structure of mature human insulin.
3. What is proinsulin? Why is C-peptide removed?
4. Explain the production of recombinant human insulin.
5. How is recombinant Hepatitis-B vaccine produced?
6. Explain the role of PCR in disease diagnosis.
7. What is ELISA? Explain its basic principle.
8. What is gene therapy? Explain its basic principle.
9. Explain the treatment approach for ADA deficiency discussed in NCERT.
10. What are the uses of transgenic animals in medicine?

36. Long Answer Questions

1. Explain the production of recombinant human insulin using genetic engineering.
2. Describe gene therapy with special reference to ADA deficiency.
3. Explain the major applications of biotechnology in medicine.
4. Explain the role of PCR and ELISA in molecular diagnosis.
5. Describe the applications of transgenic animals in medical research.

37. Multiple Choice Questions

1. Mature human insulin consists of:

   (A) One chain   (B) Two chains   (C) Three chains   (D) Four chains

   Answer: (B) Two chains

2. The two chains of insulin are:

   (A) A and B   (B) B and C   (C) A and C   (D) C and D

   Answer: (A) A and B

3. Proinsulin contains:

   (A) C-peptide   (B) DNA   (C) RNA   (D) Cellulose

   Answer: (A) C-peptide

4. C-peptide is:

   (A) Present in mature insulin   (B) Removed during insulin maturation   (C) A DNA molecule   (D) An antibody

   Answer: (B) Removed during insulin maturation

5. Recombinant insulin can be produced using genetically modified:

   (A) E. coli   (B) Virus only   (C) Human RBCs   (D) Plant chloroplasts only

   Answer: (A) E. coli

6. ELISA is based on:

   (A) Antigen-antibody interaction   (B) DNA replication   (C) Photosynthesis   (D) Translation only

   Answer: (A) Antigen-antibody interaction

7. PCR is mainly used to:

   (A) Amplify specific DNA sequences   (B) Digest proteins   (C) Produce antibodies directly   (D) Destroy chromosomes

   Answer: (A) Amplify specific DNA sequences

8. The first clinical gene therapy was performed for:

   (A) ADA deficiency   (B) Diabetes   (C) Malaria   (D) Cholera

   Answer: (A) ADA deficiency

9. ADA stands for:

   (A) Adenosine deaminase   (B) Adenine DNA acid   (C) Amino deaminase acid   (D) Adenosine DNA enzyme

   Answer: (A) Adenosine deaminase

10. The first clinical gene therapy was performed in:

    (A) 1980   (B) 1990   (C) 2000   (D) 2010

    Answer: (B) 1990

11. The recombinant Hepatitis-B vaccine is based on:

    (A) HBsAg   (B) Insulin   (C) ADA   (D) Haemoglobin

    Answer: (A) HBsAg

12. Rosie was a transgenic:

    (A) Cow   (B) Sheep   (C) Goat   (D) Mouse

    Answer: (A) Cow

38. Fill in the Blanks

1. Mature human insulin consists of ________ and ________ chains.
2. Proinsulin contains an additional ________ peptide.
3. The C-peptide is removed during the maturation of ________.
4. Recombinant insulin can be produced using genetically modified ________.
5. ELISA is based on ________-antibody interaction.
6. PCR stands for ________.
7. Gene therapy aims to compensate for a ________ gene.
8. ADA stands for ________.
9. The first clinical gene therapy was performed in the year ________.
10. Rosie was a transgenic ________.

39. Assertion and Reason

1. Assertion: Mature insulin consists of A and B chains.

   Reason: The C-peptide is removed during the maturation of proinsulin.

   Answer: Both Assertion and Reason are true, and Reason correctly explains the formation of mature insulin.

2. Assertion: PCR can help in detecting a pathogen present in very low quantity.

   Reason: PCR amplifies specific nucleic acid sequences.

   Answer: Both Assertion and Reason are true, and Reason correctly explains Assertion.

3. Assertion: ELISA is based on antigen-antibody interaction.

   Reason: Antibodies can specifically recognise particular antigens.

   Answer: Both Assertion and Reason are true, and Reason correctly explains Assertion.

4. Assertion: Gene therapy can be used to compensate for certain defective genes.

   Reason: A functional gene can be introduced into appropriate cells.

   Answer: Both Assertion and Reason are true, and Reason correctly explains Assertion.

40. Practice Set – Identify the Correct Technique

1. Amplification of a specific DNA sequence → ________
2. Detection based on antigen-antibody interaction → ________
3. Introduction of a functional gene into patient cells → ________
4. Production of recombinant insulin → ________ technology
5. Production of recombinant Hepatitis-B vaccine → ________ DNA technology

Answers:

1. PCR
2. ELISA
3. Gene therapy
4. Recombinant DNA
5. Recombinant DNA

41. Practice Set – Match the Following

Column A	Column B
1. PCR	a. ADA deficiency
2. ELISA	b. DNA amplification
3. Gene therapy	c. Antigen-antibody interaction
4. Golden example of recombinant insulin	d. E. coli
5. Rosie	e. Transgenic cow

Answers: 1-b, 2-c, 3-a, 4-d, 5-e

42. Quick Revision

43. One-Line Exam Facts

• Human insulin is composed of two polypeptide chains, A and B.
• A and B chains are connected by disulphide bonds.
• Proinsulin contains an additional C-peptide.
• C-peptide is removed during maturation of insulin.
• Recombinant human insulin can be produced using genetically modified E. coli.
• ELISA is based on antigen-antibody interaction.
• PCR is useful for amplification of specific DNA sequences.
• Gene therapy aims to compensate for defective genetic function.
• ADA deficiency is a classic example of gene therapy.
• The first clinical gene therapy was performed in 1990.
• Recombinant Hepatitis-B vaccine uses Hepatitis-B surface antigen.
• Transgenic animals are useful in medical research and biotechnology.
• Rosie was a transgenic cow mentioned in NCERT.