| Learning Center | ||
- Overview Viruses aren’t considered living organisms, but they are very dependent on living cells to replicate. The structure of the virus includes the envelope which is constituted by proteins and the genetic material which can be DNA or RNA. All these components are thermo sensible. The genetic material and the proteins have complex structures that are involved in their function and the change of their arrangements may result in lost of function. This process is called denaturizing. There are two basic ways to achieve it: change PH or temperature. - Some examples: viruses and heat inactivation There are many studies focusing in the viruses’ inactivation by applying heat. For example, the HIV virus can be killed in blood when exposed only for a 0.006 seconds at 77 degrees C1. In another study, the authors discovered that exposure of parvovirus and phage phiX174 for 90 seconds at 103 degrees C completely inactivated those viruses2. In the case of the Herpes virus, high temperatures inhibit the release of proteins necessary for the success of the infection3. Airborne viruses aren’t different. One study with the respiratory sincytyal virus (the major cause of wheezing in children less than 2 years old) showed that when the virus is exposed to 65 degrees C for 45 minutes, the infection ability is affected and conformational proteins are changed, resulting in less release, by the host, of substances responsible for the inflammation, hyper responsiveness and damage of the airways4. The SARS virus (causative agent of severe acute respiratory syndrome) has thermo sensible proteins in its envelope, which can be totally denaturized at 55 degrees C, the same temperature where SARS virus was also reported to be inactivated5. The influenza virus (the meaning flu agent), has proteins necessary for the infection, that are sensible to variations of pH and temperature (variation between 55-70 degrees C)6. - Airfree and its HETD Ceramic Core internal temperature. Here, we have listed only few examples of viruses’ inactivation by heating and in all those cases, the temperatures were below the Airfree’s HETD ceramic core internal temperature of 200 degrees Celsius. Since 1977, studies have showed that the higher the temperature, the faster the proteins get denatured7. Therefore, we may infer that the Airfree purifier may be efficient in the inactivation of the virus proteins in most cases, resulting in the lost of the infection ability. Bibliography 1- Charm SE, Landau S, Williams B, Horowitz B, Prince AM, Pascual D. Hightemperature short-time heat inactivation of HIV and other viruses in human blood plasma. Vox Sang. 1992;62(1):12-20. 2- Lelie PN, Reesink HW, Lucas CJ. Inactivation of 12 viruses by heating steps applied during manufacture of a hepatitis B vaccine. J Med Virol. 1987 Nov;23(3):297-301. 3- Morrison EE, Wang YF, Meredith DM. Phosphorylation of structural components promotes dissociation of the herpes simplex virus type 1 tegument. J Virol. 1998 Sep;72(9):7108-14. 4- Jaovisidha P, Peeples ME, Brees AA, Carpenter LR, Moy JN. Respiratory syncytial virus stimulates neutrophil degranulation and chemokine release. J Immunol. 1999 Sep 1;163(5):2816-20. 5- Wang Y, Wu X, Wang Y, Li B, Zhou H, Yuan G, Fu Y, Luo Y. Low stability of nucleocapsid protein in SARS virus. Biochemistry. 2004 Aug 31;43(34):11103-8. 6- Epand RM, Epand RF. The Thermal Denaturation of Influenza Virus and its Relationship to Membrane Fusion. Biochemical Journal Immediate Publication. Published on 7 May 2002 as manuscript BJ20020290. 7- Palumbo SA, Smith JL, Kissinger JC. Destruction of Staphylococcus aureus During Frankfurter Processing. Applied and environmental micorbiology, 1977:740-744.
Back to Learning Center
|
||
© Copyright 2004 Airfree Products |
||
