laetrile


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Related to laetrile: Vitamin B17

laetrile

(lā`ətrĭl'), name given to the chemical amygdalin, a substance derived from an extract of the kernels of many fruits, notably apricots, bitter almonds, and peaches. The idea that laetrile might selectively destroy cancer cells was developed by Dr. Ernst T. Krebs, Sr., a German immigrant to the United States, in the 1920s and was later refined by his son Ernst T. Krebs, Jr., who used the name "vitamin B17" for amygdalin and the derivatives of amygdalin that he developed. The Krebses had hypothesized that an enzyme that was more abundant in tumor cells than normal cells acted on laetrile to produce cytotoxic cyanide. (Cyanide is naturally produced in the intestines when laetrile is acted upon by intestinal bacteria.) This hypothesis and several refinements of it were proved to be untrue, as was the younger Krebs's later classification of the substance as a vitamin.

The subject of controversy for many years, laetrile was subjected to much scientific scrutiny in the 1970s. Investigations showed that anecdotal reports of improvement with laetrile were insufficient proof of effectiveness. Clinical trials showed no effectiveness in shrinking tumors, prolonging survival, or improving the quality of the patient's life. Toxicity from cyanide poisoning in some patients, coupled with the drug's ineffectiveness, led the Food and Drug Administration to label laetrile a fraud. Interstate shipment and shipment from other countries are illegal, but it is still legal in some states and in Mexico.

References in periodicals archive ?
Moss, a man with a background in the classics and awareness of the political issues of the day, found himself with an insider's view of research and testing of the controversial laetrile through his ability to interview administrators and researchers.
A form of laetrile was definitely tested in the Moertel trial.
I have much to say on each of the scientific issues involved in this controversy, but right now I would like to address the question of whether laetrile can be considered a vitamin.
This is actually the true laetrile, according to Krebs, and it differs from the original amygdalin, which has two glucose molecules instead of the glucuronic acid.
In the late 1970s, over 70,000 US patients crossed the border to obtain cancer treatments that were unavailable back home, mostly laetrile.
However, when she and her husband returned to San Diego, her family physician was advised by his attorney not to treat her with laetrile, because it was not approved by the government.
After extra therapies with laetrile, a questionable apricot-pit-based shot, McQueen discussed he was in recovery, yet he passed away in a while after that, pursuing surgical procedure to delete cancer from his tummy and neck.
After added treatments with laetrile, a controversial apricot-pit-based injection, McQueen mentioned he remained in recuperation, yet he died in a while after that, going after surgery to erase cancer from his belly and neck.
In the 1950 s, a semi-synthetic, injectable form of amygdalin was developed and patented as Laetrile (LAEvorotatory mandeloniTRlLE) by Ernst T.
The people of Sloan-Kettering, excited about the findings of their research, proceeded twice in 1974 and 1975 to Washington, arguing their points of view on laetrile and literally begging from the government for funds to continue the research and allow them to do clinical trials, as laetrile showed positive results on lab animals.
Social movements: Laetrile / Finally, during the past few decades, the lay population has assumed a greater role in pressuring the FDA to make drugs accessible to the seriously ill more quickly and more broadly.
In the United States, a doctor who would risk treating a patient with laetrile and vegetarian diet would be ostracized by the profession.