Use against viruses

MAJOR USES Used in vaccines, tissue grafts, enzymes and surgical instmments sterilize blood plasma, water, milk and nutrient broth used against viruses. 

Reverse transcriptase inhibitors are also used against certain viruses which although they are not retroviruses do require re verse transcriptase to repro duce The virus that causes heptatitis B is an example... 

Ozone has proven to be effeetive against viruses. Franee has adopted a standard for the use of ozone to inaetivate viruses. When an ozone residual of 0.4 mg/I ean be measured 4 minutes after the initial ozone demand has been met, viral inaetivation is satisfied. This property plus ozone s freedom from residual formation are important eonsiderations in the publie health aspects of ozonation. When ozonation is eombined with aetivated earbon filtration, a high degree of organie removal ean be aehieved. Coneerning the toxieity of oxidation produets of ozone and the removal of speeifie eompounds via ozonation, available evidenee does not indieate any major health hazards assoeiated with the use of ozone in wastewater treatment. 

However, acyclic nucleotide analogs (acyclic nucleoside phosphonates) have been developed, which carry one phosphonate moiety and require only the two subsequent phosphorylation steps (De Clercq et al. 1978). Independent of virus-encoded kinases, they display a broader spectrum of efficacy. This class comprises important drugs against HIV (tenofovir) and HBV (adefovir, tenofovir), as well as cidofovir, which is approved for use against CMV retinitis, but also displays an exceptionally broad efficacy profile against many herpesviruses, adenovirus, poxviruses, and papillomaviruses (De Clercq and Holy 2005). 

Viruses that contain hpid are inactivated by organic solvents such as chloroform and ether. Those without hpid are resistant to these agents. This distinction has been used to classify virases. Many of the chemical disinfectants used against bacteria, e.g. phenols, alcohols and quaternary ammonium compounds (Chapter 10), have minimal virucidal activity. The most generally active agents are chlorine, the hypochlorites, iodine, aldehydes and ethylene oxide. 

Isopropyl alcohol (isopropanol, CH3CHOH.CH3) has slightly greater bactericidal activity than that of ethanol but is also about twice as toxic. It is less active against viruses, particularly non-enveloped viruses, and should be considered a limited-spectrum virucide. Used at concentrations of 60-70%, it is an acceptable alternative to ethanol for preoperative skin treatment and is also employed as a preservative for cosmetics. 

Rift Valley fever occurs primarily in sub-Saharan Africa where it is transmitted by mosquitoes. If a terrorist were to use Rift Valley fever, it would be dispersed as an aerosol. One troubling thing about a terrorist attack using this virus is that humans and domestic animals can become infected by aerosol means and a resident mosquito population can continue the assault. Defense against Rift Valley fever must include mosquito control. 

Considerable effort has gone into investigating compounds from tunicates over the past two decades. For unknown reasons these chemicals are often potent antiviral agents, whereas clinicians have few drugs active against viruses. Didemnin B was the first of these candidate compounds to be examined and initially it showed promise against a broad spectrum of viruses. After lengthy clinical trials, however, it was finally abandoned as too toxic for safe human use. 

The salts of heterylbiguanides are generally active 8) against viruses, and are of unusually low toxicity. They appear to be useful against influenza, herpes zoster, smallpox, Newcastle disease and canine distemper. Xylylbiguanides are also active (7/2) against influenza, and isopropylbiguanide hydrochloride inhibits Lee influenza virus in chick embryos [740). 

In addition to this, the potential of producing a plant-made vaccine against a papillomavirus using a virus-based vector has been explored. In this case, the LI capsid protein of control rabbit papillomavirus (CRPV), a model system for the study of papillomavirus-host interactions, was... 

Ng, C. R. A. 1997. Polysaccharopeptide from Coriolus versicolor has potential for use against human immunodeficiency virus type I infection. Life Sci. 60 383-387. 

At the present time, there is no accepted chelating agent which can be used against common influenza viruses in humans. A virus has a core of either DNA or RNA and a protective coat of many identical protein units. All viruses are either rods or spheres, that is the protein coats are cylindrical shells having helical symmetry or spherical shells having icosahedral symmetry. Viruses reproduce inside living cells, where each viral nucleic acid directs the synthesis of about 1000 fresh viruses. These are then released and the host cell may die. 

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