United Imaging does not produce drugs. The provided text discusses various drugs and their mechanisms of action, but none are specifically linked to United Imaging. United Imaging is a medical technology company that develops and manufactures diagnostic imaging equipment. Therefore, the question of what mechanisms of action their drugs use is not applicable.

Instead, the text provides information on the mechanisms of action of a wide range of drugs used for various conditions, including:

Cancer Treatment:

• Alkylating agents: These drugs, like melphalan and cyclophosphamide, work by attaching alkyl groups to DNA, disrupting its function and leading to cell death. Resistance can develop through cellular and extracellular factors.
• Anthracyclines: Doxorubicin and daunorubicin work through multiple mechanisms, including free radical formation and interactions with DNA and topoisomerase II. Drug concentration plays a role in which mechanisms are active. Cardiotoxicity is a significant side effect.
• Antiangiogenic agents: These drugs, such as bevacizumab, target tumor blood vessel formation. They work by inhibiting new vessel growth, causing regression of existing vessels, and altering vascular function.
• Cisplatin: This drug forms DNA adducts, inhibiting DNA synthesis and leading to apoptosis. Side effects and drug resistance are limitations.
• Monoclonal antibodies: These drugs, like trastuzumab and rituximab, target specific antigens on cancer cells. Their mechanisms involve stimulating immune responses, complement activation, and direct effects on cell signaling.
• PARP inhibitors: These drugs target the DNA damage response and are particularly effective in cancers with BRCA mutations.
• Targeted therapies: These drugs target specific genetic biomarkers in cancer cells. Examples include trastuzumab and pertuzumab, which target HER2 in breast cancer.

Neurological and Psychiatric Disorders:

• Antiepileptic drugs: These drugs work through various mechanisms, including modulation of ion channels, enhancing GABAergic inhibition, and reducing glutamatergic excitation. Examples include phenytoin, carbamazepine, and benzodiazepines.
• Antipsychotics: These drugs primarily antagonize dopamine D2 receptors. Atypical antipsychotics also modulate serotonin, norepinephrine, and histamine neurotransmission. Examples include clozapine and risperidone.
• Ketamine: This drug has rapid antidepressant effects. Its mechanisms involve NMDAR modulation, GABAergic interneuron disinhibition, and actions of its metabolites.
• Mood stabilizers: These drugs, such as lithium, are used to treat bipolar disorder. Their mechanisms are complex and involve multiple molecular and cellular targets.
• SSRIs: These drugs, like fluoxetine and sertraline, inhibit serotonin reuptake. Their therapeutic effects are thought to be due to delayed neurochemical adaptations, such as desensitization of serotonin 1A autoreceptors.

Other Conditions:

• Antibiotics: These drugs target various bacterial processes, including cell wall synthesis, protein synthesis, and DNA replication. Examples include beta-lactams, quinolones, and tetracyclines.
• Antifungals: These drugs target fungal cell membranes or cell walls. Examples include amphotericin B and echinocandins.
• Anti-inflammatory drugs: These drugs, such as NSAIDs and glucocorticoids, work by inhibiting prostaglandin synthesis and other inflammatory pathways.
• Bisphosphonates: These drugs inhibit bone resorption and are used to treat osteoporosis and other bone diseases. They work by inhibiting the mevalonate pathway in osteoclasts.
• Diuretics: These drugs increase urine output and are used to treat hypertension and edema. They work by impairing sodium reabsorption in the kidneys.
• Opioids: These drugs, such as tramadol and heroin, activate opioid receptors in the brain and spinal cord to relieve pain.

This is not an exhaustive list, and the text provides more detailed information on the specific mechanisms of each drug. It is important to consult the original articles for a complete understanding of the complex mechanisms involved.