Ketamine

Ketamine

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 technologyKetamine is a dissociative anesthetic. It is a type of drug that is commonly administered by physicians to induce anesthesia during surgery or medical procedures. Ketamine can also be used as a painkiller and as a bronchodilator, which facilitates easier airflow into the lungs.

Occasionally, ketamine use can lead to a specific type of hallucination that produces feelings of detachment from one's body and surroundings. This property has made it a popular recreational drug despite its potentially severe side effects. For this reason, ketamine is not typically available as an over-the-counter drug.

Medical Use

In clinical settings, ketamine is most commonly administered via injection into a vein (intravenous) or a muscle (intramuscular).

While ketamine is not the preferred anesthetic in many cases due to its hallucinogenic effects, it offers distinct advantages. Unlike most other anesthetics that suppress respiration and necessitate the use of mechanical ventilation, ketamine does not significantly inhibit breathing.

Ketamine is particularly valuable in situations where advanced medical equipment is unavailable, such as in war zones or emergency field medicine. ^{(December 2013)}

Side Effects

Short-Term Side Effects

Short-term side effects are experienced by approximately 40% of individuals and include:

• Dizziness
• Double vision
• Euphoria
• Blurred vision
• Difficulty expressing emotions
• High blood pressure
• Tachycardia (Fast heart rate)
• Nausea and vomiting
• Speech difficulties
• Nightmares
• Illusions
• Hallucinations
• Altered body image
• Memory and attention impairments.

Long-Term Side Effects

Long-term effects of ketamine are mostly observed in recreational users or from prolonged exposure in animal studies.

Urinary Tract Effects

Chronic ketamine use has been associated with urinary tract issues, including:

• Increased urgency to urinate
• Pain during urination with hematuria (blood in urine)
• Reduced bladder capacity

Neurological Effects

Frequent recreational use (more than 4 times a week) has been linked to impaired cognitive functions, including memory deficits and increased depression.

Mechanism of Action

Ketamine functions as an NMDA receptor antagonist in the central nervous system (CNS). By inhibiting these receptors, ketamine prevents excessive excitatory neurotransmission, resulting in an anesthetic effect. Additionally, it produces sympathomimetic effects that help maintain blood pressure and airway reflexes. These properties make it a critical option for patients with shock or requiring emergency surgery.

Research

Treating Addiction

Studies have explored ketamine's role in managing alcohol addiction and opioid use disorder.

Antidepressant Effects

Preliminary studies suggest that a single dose of ketamine can significantly alleviate symptoms of treatment-resistant depression within hours, with effects lasting up to a week.

Recreational Use

Recreational users typically consume ketamine at sub-anesthetic doses. The dissociative effects, often referred to as a "K-hole," include hallucinations and a profound sense of detachment. Chronic use, however, may lead to serious consequences such as bladder damage, cognitive decline, and psychological dependence.

References

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Ketamine

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  Ketamine 2D Structure

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  S-Ketamine 3D Structure