Inactivation of viruses

The minimum residuals required for cyst destruction and inactivation of viruses are much greater. Although chlorine residuals in Table 4 are generally adequate, surface waters from polluted waterways are usually treated with much heavier chlorine dosages. Ordinary chlorination will destroy all strains of coli, aerogenes, pyocyaneae, typhsa, and dysenteria. 

Kasermann F, Kempf C (1998) Buckminsterfullerene and photodynamic inactivation of viruses. Rev Med Virol 8 143-151. 

Currently, all donors and blood preparations undergo multistage and expensive control to ensure the absence of viral contamination In this respect, the development of affordable methods of inactivation of viruses could be an important step toward safety in hemotransfusion. Currently used treatments such as UV irradiation damage therapeutic components of the blood (Williamson and Cardigan, 2003), so alternative selective approaches are needed for this purpose. Among them, chemotherapy, photochemotherapy (PCT), and photodynamic antibacterial therapy should be noted (Mohr, 2000). 

Mohr H (2000) Inactivation of viruses in human plasma. Methods Enzymol. 319 207-216. Wainwright M (2002) The emerging chemistry of blood product disinfection. Chem Soc Rev. 31 128-136. 

Burleson, G. R., T. M. Murray, and M. Pollard. Inactivation of viruses and bacteria by ozone, with and without sonication. Appl. Microbiol. 29 340-344, 1975. 

Brown, E, Review of accidents caused by incomplete inactivation of viruses. Dev Biol Stand, 1993. 81 103-7. 

An interesting property of DBBF—hemoglobin is its thermal stability. This property has been used to achieve both a partial purification of the cmde reaction mixture after cross-linking and inactivation of viruses in the final product (101,102). 

Horovitz B, Williams B, Rywkin S, et al. Inactivation of viruses in blood with aluminum phthalocyanine derivatives. Transfusion 1991 31 102-8. 

Reduction in viral infectivity occurs by inactivation of virus or by removal of virus particles. During removal steps, virus is not inactivated but is separated from the protein of interest using methods such as precipitation, chromatography, or filtration. For example, during an ethanol precipitation step, ethanol is added to a suspension to precipitate unwanted contaminating proteins and viruses. The ethanol-containing suspension is then centrifuged so that the contaminants in the precipitated paste fraction can be separated from the product in the effluent fraction. 

Gellis, S.S. Neefe, J.R. Stoks, J. Strong, L.E. Janeway, C.A. Scatchard, G. Chemical, clinical and immunological studies on products of human plasma fractionation inactivation of virus of homologous serum albumin by means of heat. J. Clin. Invest. 1948, 27, 239-244. 

Horowitz, B. Wiee, M.E. Lippin, A. Vandersande, J. Stryker, M.H. Inactivation of viruses in labile blood derivatives II physical methods. Transfusion 1985, 25, 523-527. 

Disease Therapy. Inactivation of viruses by L-ascorbic acid was reported in 1935 to occur rather quickly under in vitro conditions (220) and somewhat later by Jungeblut (221) with limited confirmation in vivo. 

In order to find new sources of antiviral agents with different mechanisms of action, extracts of marine algae from all over the world were assayed for anti-HSV activity. The first screening of 89 types of seaweed collected from British Columbia, Canada and Korea for antiviral activity was reported by Kim et al. [66]. Analipus japonicus was the most potent anti-herpes algae. Extracts from 13 types of Korean seaweed previously shown to contain antiviral activity were investigated in more detail in order to learn their mechanism of action [14]. Four species, Enteromorpha linza, Colpomenia bullosa, Scytosiphon lomentaria and Undaria pinnatifida were active against HSV. In experiments to determine the site of action of these antiviral extracts, the predominant activity was virucidal (i.e., direct inactivation of virus particles) rather than inhibition of virus replication. 

UV can cause permanent inactivation of virus, bacteria, spores, fungi and other pathogens. UV irradiation disinfection requires no additional chemicals. Unlike chlorination disinfection, it does not produce odor it is usually deemed as the best choice with very low or no DBFs and no residual toxicity. In addition, it is able to kill some chlorine-resistant pathogens such as Cryptosporidium and Giardia. Compared with other disinfection alternatives, UV is a cost-effective, clean, and simple approach. UV disinfection system does not require the transportation, storage, and handling of regulated chemicals such as chlorine. 

In accordance with the US Environmental Protection Agency, the CT Values for inactivation of viruses by UV radiation is independent of temperature, as shown in Table 4. 

For the UV facility at Ft. Benton, the initial UV dosage of 41 mW s/cm provides in excess of 3-log inactivation of viruses. However, after 4500 h of UV tube operation, the... 

No MCLGs were set for turbidity and heterotrophic plate count (HPC). Treatment requirements also were established in lieu of MCLs for Giardia, viruses, HPC, Legionella, and turbidity. Treatment must reliably achieve at least 99.9% removal/inactivation of Giardia lamblia cysts and 99.99% removal/inactivation of viruses (1,4,5). 

Appendix B gives CT values for inactivation of Giardia lamblia cysts with free chlorine (2.0 mg/L). At any given concentration of chlorine, the CT values increase rapidly as the pH rises above 7.0. This is also true at each temperature listed. Appendix C presents the CT values for inactivation of viruses by free chlorination. Figure 1 shows the relationship between pH and the concentration of hypochlorous acid. Effective pH... 

When direct filtration is included in the water treatment process, disinfection credit can be taken by the filtration step for a 2-log inactivation of Giardia cysts and a 1-log inactivation of viruses. This means that the primary disinfectant must provide an additional 1-log inactivation of Giardia cysts and 3-log inactivation of viruses. In the specific instance of a conventional treatment process that includes coagulation, flocculation, sedimentation, and filtration, an inactivation credit of 2.5-logs for Giardia cysts and 2-logs for viruses may be taken. This means that the primary disinfectant must provide an additional 0.5-log inactivation of Giardia cysts but a 2-log inactivation of viruses. 

Adansonia digitata root-bark and leaf methanol extracts have shown high antiviral activity (against Herpes simplex, Sindbis and Polio), together with viricidal (direct inactivation of virus particles) and also intracellular antiviral activity, which could indicate the presence of multiple antiviral compounds, or a single compound with multiple actions (17, 27). Whether such studies will show... 

Removal and Inactivation of Viruses by a Surface-Bonded Quaternary Ammonium Chloride... 

Inactivation of Viruses bv Surface-Bonded QAC. The attachment of this Si-QAC to surfaces involves a rapid ion-exchange process which coats as a monolayer on the bead surface. Then, the immobilization is further strengthen by the polymerization reactions (24). Table 2 shows the effects of dried alginate beads treated by various Si-QAC concentrations. Zero percent means untreated beads and served as controls. When the titer was very low (4.7 x 10 ), viruses were eliminated completely in all cases including the control. This was due to non-specific adsorption. When the titer was raised to 4.0 x 10, the adsorption capacities of treated beads were distinctly better them the control. For a titer as high as 2.0 x 10 , it seems that the beads were nearly saturated with viruses in all cases. 

Treatment with near-critical or supercritical fluids has also been proposed for the inactivation of virus particles in biological systems, especially blood products (65). SCF N2O at 40°C and 17-27 MPa was contacted with Murine-C retrovirus in culture medium and in serum for 5 30 min. Upon... 

Castor T, Lander A. Method and apparatus for the inactivation of viruses. US patent 6465168 Bl, 2002. 

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