Question

1. What was the first virus used to battle Ca, in 1910?
2. How are the viruses altered, in order to make them only attack Ca cells?
3. How did the pediatric patient, Emily Whitehead respond to the therapy?
4. Towards the end, what was the percentage of the 39 children, who had complete remission?
5. 
   

Answer 1

Vaccinia virus

This was the first demonstration ofviral oncolysis in the laboratory. the scientific study of viruses and the infections they cause – began in the closing years of the 19th century. Although Louis Pasteur and Edward Jennerdeveloped the first vaccines to protect against viral infections, they did not know that viruses existed. The first evidence of the existence of viruses came from experiments with filters that had pores small enough to retain bacteria. In 1892, Dmitri Ivanovsky used one of these filters to show that sap from a diseased tobacco plant remained infectious to healthy tobacco plants despite having been filtered. Martinus Beijerinck called the filtered, infectious substance a "virus" and this discovery is considered to be the beginning of virology.The subsequent discovery and partial characterization of bacteriophages by Frederick Twort and Félix d'Herelle further catalyzed the field, and by the early 20th century many viruses had been discovered. In 1926, Thomas Milton Rivers defined viruses as obligate parasites. Viruses were demonstrated to be particles, rather than a fluid, by Wendell Meredith Stanley, and the invention of the electron microscope in 1931 allowed their complex structures to be visualised.

Oncolytic viruses (OVs) are able to target and kill tumor cells by selecting some strains in nature with weak pathogenicity, and certainviruses can be genetically modified.It may seem unlikely that viruses could a key tool for fighting cancer. Viruses are known for causing human suffering and death – from the common cold to HIV and influenza. Because viruses are so good at invading and taking over cells they have great potential as cancer killers. The following section gives some background on cancer killing (oncolytic; onco=tumor lysis=breaking down) viruses and describes some of the most promising ones.

The 7-year-old girl had been fighting the most common childhood cancer, acute lymphoblastic leukemia (ALL), for more than a year.

Eighty-five percent of children with ALL are cured after a two-year process of standard chemotherapy, but 15 percent have a type of disease that is resistant to even the most intense chemotherapy regimens.

While Emily’s local oncologist at first thought she had “a garden-variety leukemia,” the relapse proved she was up against the type of disease that was more resistant to treatment.