Quinine

An article about the use of quinine in medicine

Engineered Monoclonal Antibodies

Diagram of engineered monoclonal antibodies

Engineered monoclonal antibodies are a class of biological therapies that are designed to target specific antigens on the surface of cells. These antibodies are produced using recombinant DNA technologies and are used in the treatment of various diseases, including cancer, autoimmune disorders, and infectious diseases.

Structure and Function

Monoclonal antibodies are composed of two identical heavy chains and two identical light chains, forming a Y-shaped molecule. The tips of the "Y" contain the antigen-binding sites, which are highly specific to the target antigen. This specificity allows monoclonal antibodies to bind to their target with high affinity, blocking or modulating the function of the antigen.

Types of Engineered Monoclonal Antibodies

There are several types of engineered monoclonal antibodies, each designed for specific therapeutic purposes:

• Chimeric antibodies: These antibodies are composed of murine (mouse) variable regions and human constant regions. They are less immunogenic than fully murine antibodies.

• Humanized antibodies: These antibodies are mostly human, with only the antigen-binding sites derived from murine sources. This reduces the risk of immune reactions.

• Fully human antibodies: These are entirely human in origin, produced using transgenic mice or phage display technologies.

• Bispecific antibodies: These antibodies are engineered to bind two different antigens simultaneously, offering unique therapeutic mechanisms.

Applications in Medicine

Engineered monoclonal antibodies have revolutionized the treatment of many diseases:

• Cancer therapy: Monoclonal antibodies can target specific tumor antigens, leading to direct tumor cell killing or recruitment of immune cells to attack the tumor.

• Autoimmune diseases: By targeting specific components of the immune system, monoclonal antibodies can reduce inflammation and tissue damage in diseases such as rheumatoid arthritis and multiple sclerosis.

• Infectious diseases: Monoclonal antibodies can neutralize pathogens or their toxins, providing passive immunity or enhancing the host's immune response.

Production

The production of engineered monoclonal antibodies involves several steps:

1. Antigen identification: The target antigen is identified and characterized. 2. Hybridoma technology: B cells from immunized animals are fused with myeloma cells to create hybridomas that produce the desired antibody. 3. Recombinant DNA technology: Genes encoding the antibody are cloned and expressed in suitable host cells, such as Chinese hamster ovary cells. 4. Purification and formulation: The antibodies are purified and formulated for clinical use.

Challenges and Future Directions

While engineered monoclonal antibodies have shown great promise, there are challenges such as high production costs, potential for immune reactions, and the development of resistance. Ongoing research aims to improve antibody design, reduce immunogenicity, and enhance therapeutic efficacy.

Related Pages

• Monoclonal antibody therapy
• Biopharmaceutical
• Immunotherapy
• Hybridoma technology

Quinine is a medication used to treat malaria and babesiosis. It is a naturally occurring alkaloid derived from the bark of the Cinchona tree. Quinine has been used for centuries as an effective treatment for malaria, a disease caused by Plasmodium parasites transmitted through the bites of infected Anopheles mosquitoes.

History

The use of quinine dates back to the early 17th century when it was first introduced to Europe by Jesuit missionaries. The bark of the Cinchona tree, native to the Andean forests of South America, was used by indigenous people to treat fevers. The active ingredient, quinine, was isolated in 1820 by French researchers Pierre Joseph Pelletier and Joseph Bienaimé Caventou.

Mechanism of Action

Quinine works by interfering with the growth and reproduction of the malaria parasite in the red blood cells. It inhibits the parasite's ability to digest hemoglobin, leading to the accumulation of toxic heme molecules, which ultimately kills the parasite.

Medical Uses

Quinine is primarily used to treat uncomplicated Plasmodium falciparum malaria. It is often used in combination with other antimalarial drugs to enhance efficacy and reduce the risk of resistance. Quinine is also used off-label to treat nocturnal leg cramps, although this use is controversial due to potential side effects.

Side Effects

Common side effects of quinine include cinchonism, which is characterized by symptoms such as tinnitus, headache, nausea, and visual disturbances. More severe side effects can include thrombocytopenia, hemolytic anemia, and arrhythmias. Due to these potential adverse effects, quinine use is generally limited to cases where other treatments are not available or suitable.

Biosynthesis

Biosynthesis of quinine

Quinine is biosynthesized in the Cinchona tree through a complex pathway involving several enzymatic steps. The process begins with the amino acid tryptophan and involves the formation of several intermediate compounds before the final quinine molecule is produced.

Cultural and Other Uses

Quinine is also known for its use in tonic water, where it is responsible for the drink's distinctive bitter taste. Under ultraviolet light, tonic water fluoresces due to the presence of quinine, as shown in the image above.

Also see

• Malaria treatment
• Cinchona
• Antimalarial medication
• Cinchonism