Specific agents

The discovery of several classes of opioid receptors that cause different effects and side effects has important pharmacologic implications. Research in this area continues to expand our knowledge about the structural and functional aspects of these receptor classes. Drug developers will hopefully capitalize on the unique aspects of opioid receptor classes, and new agents will be produced that are even more specific in relieving pain without provoking excessive side effects. 

SECTION 4 Drugs Used to Treat Pain and Inflammation 

A new addition to this category is buprenorphine (Buprenex). This drug partially activates mu receptors but is an antagonist at kappa receptors. Because of these selective effects, buprenorphine has been advocated not only as an analgesic, but also as a treatment for opioid dependence and withdrawal.26 84 The use of this drug in treating opioid addiction is discussed in more detail later in this chapter. 

Examples of mixed agonist-antagonists include the following  

---

Flame-Retardant Treatments For Wool. Although wool is regarded as a naturally flame-resistant fiber, for certain appHcations, such as use in aircraft, it is necessary to meet more stringent requirements. The Zirpro process, developed for this purpose (122,123), is based on the exhaustion of negatively charged zirconium and titanium complexes on wool fiber under acidic conditions. Specific agents used for this purpose are potassium hexafluoro zirconate [16923-95-8] [16923-95-8] K ZrF, and potassium hexafluoro titanate [16919-27-0], K TiF. Various modifications of this process have been... 

Cumulative organ toxicity also presents a significant obstacle for effective chemotherapy. In many cases, the severity of the toxicity impedes the broader use of an agent. Other specific toxicities are associated with specific agents, for example cardiotoxicity with adriamycin (32), renal toxicity with i7j -platinum (28), and neurotoxicity with vincristine (49). 

The payoff of an agent-based approach is a radically new way of looking at fundamental issues of land combat. Models such as these are emphatically not to be used for prediction rather they are best used to enhance understanding. Specifically, agent-based models of combat are designed to help military theorists... 

Vinca alkaloids are derived from the Madagascar periwinkle plant, Catharanthus roseus. The main alkaloids are vincristine, vinblastine and vindesine. Vinca alkaloids are cell-cycle-specific agents and block cells in mitosis. This cellular activity is due to their ability to bind specifically to tubulin and to block the ability of the protein to polymerize into microtubules. This prevents spindle formation in mitosing cells and causes arrest at metaphase. Vinca alkaloids also inhibit other cellular activities that involve microtubules, such as leukocyte phagocytosis and chemotaxis as well as axonal transport in neurons. Side effects of the vinca alkaloids such as their neurotoxicity may be due to disruption of these functions. 

There is now little doubt that ROMs are produced in excess in patients with aaive IBD. That, at least in experimental colitis, they are rather more than irrelevant epiphenomena is indicated by the anti-inflammatory effect of specific antioxidants. Proof that this is also the case in human disease awaits the outcome of further controlled trials of specific agents interfering with ROM production. Whilst induction of NO production has been shown to occur in association with inflammation and tissue damage in both humans and in animal models, the significance of this is as yet unclear. 

What specific agent(s) would you consider for prophylactic use in this patient ... 

Hepatocyte-specific agents (infections disease especially viruses)... 

Scheme 13. Self-immolative degradation of the enzyme-specific agents.

The answer is d. (Hardman, p 12362) Celbcycle-specific agents such as 6-MP, 5-FU, bleomycin, and vincristine have proved to be the most... 

Depending on the properties of the specific agent, unmodified G-series agents are classified as either nonpersistent or moderately persistent by the military. Evaporation rates range from near that of water down to that of light machine oil. 

The amount of contamination and the distance an agent cloud will travel is based primarily on the physical/chemical properties of the specific agent, method of release, local terrain, and weather conditions. 

Depending on the specific agent and the concentration of vapor or aerosol, the effects begin to appear in seconds or may be delayed up to several hours. 

Laboratory grade agents are typically colorless liquids or solids. Depending on the specific agent, liquids may be mobile, viscous, or even waxy in nature. Many solids are salts of the free-base liquid that are colorless to white to beige crystalline materials. In either state, these materials typically have little or no odor when pure. 

Military-specific agents are stable even under tropical conditions and can be stored in glass, aluminum, or steel. Stabilizers are not required. Some potentially dual use agents are sensitive to heat and light and may require stabilizers for long-term storage. 

Varies depending on the specific agent but may include various complex alkaloids and organic acids. 

---