#10 Vaya, parece que yo y otras 9 personas no hemos entendido nada. Yo sólo hablaba del sensacionalismo del titular, nada más. Deberías leerte mis comentarios antes de inventarte nada.
Desde que estoy aquí, y ya van casi seis años, he leído al menos quinientas noticias que decían haber encontrado una cura contra el cáncer.
¿Esta es la definitiva?
> In addition to being program director, Drisko has also been an ACAM board member. ACAM was formed chelation therapists and is primarily involved in promoting chelation therapy for cardiovascular disease, a procedure that has no scientific basis. Chelation therapy is the most-used and fraudulent physician-directed method in the United States. It has been condemned by the American Heart Association, the American Medical Association, the American College of Physicians, and several other major organizations. ACAM teaches physicians how to perform "chelation" and is the chelationists' main advocacy group.
> Drisko is a signatory to an anti-evolution statement promoted by the Discovery Institute, a stronghold of creation of creationist/intelligent design theorists I believe that her opposition to the most important theory in biology should cast doubt on her ability to judge what is important in the medical field, which is so heavily based on biology.
I couldn’t believe this when I read it. In a post a long time ago, I discussed a couple of studies that were represented by supporters of vitamin C therapy as a “vindication” of Linus Pauling. However, as I described at the time, it was totally a long run for a short slide, requiring huge doses of vitamin C to achieve equally huge concentrations of ascorbate in the blood, all with at best very modest effects in mouse xenograft models. Overall, it’s very unimpressive, needing huge osmotic loads even greater than that produced by Stanislaw Burzynski’s antineoplaston therapy to achieve even the modest effects that it achieves. Even if that effect is real and reproducible, it’s so unimpressive that even if vitamin C were a new, patentable drug no drug company would bother with it, so unimpressive have the results been whenever tested by reputable scientists. Yet still people keep testing it. Why the fascination with high dose vitamin C, I’ll never know, but apparently Dr. Drisko shares it.
What’s really scary, however, is this:
How do I know if the intravenous vitamin C therapy will work for my cancer? (-)
Each individual responds differently, and we can’t predict how different tumor types will react. A PET scan is usually a guidepost. If the PET is positive, the tumor usually responds to the vitamin C. If the PET is negative but there is active tumor present, the vitamin C is less effective in most cases. Vitamin C works best in the early stages of cancer when used in conjunction with chemotherapy or radiation. They will only consult patients who are also following along with a traditional oncologist.
And on what evidence does Dr. Drisko claim this? None that I can see. It’s even said that there is “no contraindications to giving intravenous vitamin C with any chemotherapy when proper protocol is followed” and that the only chemotherapy that intravenous vitamin C doesn’t work with is methotrexate. She states that at the doses used ascorbate is a pro-oxidant, not an antioxidant, and that it therefore increases the efficacy of chemotherapy and radiation therapy. On what evidence? Again, none is presented. It is mentioned that there are studies by Dr. Drisko looking at intravenous vitamin C in cancer, but no links are provided.
These are huge doses, consistent with previous experiments in mice with a xenograft from an ovarian cancer cell line (Ovcar5) in which 4 g/kg of ascorbate was administered twice daily for a total of 8 g/kg/day. The result was an inhibition of xenograft growth of around one-third after 30 days. Results for a pancreatic cancer cell line and a glioblastoma cell line were only marginally better.
The authors did several cell culture studies in which ovarian cancer cell lines were treated with ascorbate and various chemotherapeutic agents. The authors reported an IC50 of between 0.3 and 3.0 mM, which is still incredibly high for an anticancer drug. The authors blithely write that this is “easily achievable” with IV ascorbate. Maybe so, but given the quantities involved, if you’re going to use a drug that requires such high plasma concentrations to have activity, that activity had better be awesome. None of the activity shown in this paper can be characterized as being particularly impressive. Worse, the authors, despite testing several ovarian cancer cell lines, only tested one non-tumorigenic immortalized ovarian line, HIO-80, and, finding that the IC50 to kill HIO-80 cells was much higher than all but one of the other cell lines (SHIN3), proclaimed a high degree of specificity for cancer. Moreover, HIO-80 cells are hardly “normal.” They likely contain BRCA1 mutations. Finally, the authors only used one assay for proliferation, the MTT assay. This particular assay is very popular (I use it in my lab not infrequently) because it is faster and easier than counting viable cells and also allows for large experiments using 96-well plates. However, the MTT assay depends on the metabolism of cells to produce a dye that is detected. The amount of light absorbance due to the dye is assumed to be proportional to the number of viable cells. Usually, this assumption is reasonable accurate, but lots of things can interfere with this and render that assumption incorrect. For instance, one wonders if very high concentrations of ascorbate can interfere. I’d want to see a control demonstrating that the MTT results correspond to cell number.
In other words, if I were a reviewer for this paper, not so fast, I’d have said. I want to see the results for at least a couple of more non-tumorigenic cell lines and a control validating the MTT in the presence of so much ascorbate (even if just a reference) before I’ll let you conclude that the effects of ascorbate are highly specific for cancer over normal ovarian cells. At the very least, I wouldn’t have considered it unreasonable to ask for a couple more non-tumorigenic ovarian epithelial cell lines to be tested.
Yo pedí la megadosis de vitamina C como tratamiento compasivo para mi padre al que habían decidido no dar ningún tratamiento, pero me engañaron, me dijeron que sí el mismo día que dejaban de ponerle sangre y lo dejaban morir. Me pareció una opción ya que era un tratamiento barato, relativamente poco agresivo y estaba relacionado con algunos casos sorprendentes de reversión total de la enfermedad. Mi padre murió sin recibir ningún tratamiento, aunque tampoco se si hubiera sido peor de otro modo.
Comentarios
Linus Pauling ha resusitao?
¿Perdón? Menudo titular más sensacionalista y erróneo.
#1 #4 Si elimina células cancerosas sin dañar las células normales, "cura" en menor o mayor medida.
#5 Hace que la quimioterapia sea más efectiva; de ahí a que seis litros diarios de zumo de naranja (lo que sugiere el titular) curen el cáncer...
#7 Deberías leerte la noticia antes de inventarte nada.
Repite más de una vez que la vía digestiva no es viable, sólo la inyección intravenosa de grandes cantidades de vitamina C.
#10 Vaya, parece que yo y otras 9 personas no hemos entendido nada. Yo sólo hablaba del sensacionalismo del titular, nada más. Deberías leerte mis comentarios antes de inventarte nada.
Rajoy frotándose las manos. En vez de usar quimio, poniendo cartones de Don simón naranja
Desde que estoy aquí, y ya van casi seis años, he leído al menos quinientas noticias que decían haber encontrado una cura contra el cáncer.
¿Esta es la definitiva?
Jeanne Drisko en quackwatch:
http://www.quackwatch.com/11Ind/IOM/drisko.html
> In addition to being program director, Drisko has also been an ACAM board member. ACAM was formed chelation therapists and is primarily involved in promoting chelation therapy for cardiovascular disease, a procedure that has no scientific basis. Chelation therapy is the most-used and fraudulent physician-directed method in the United States. It has been condemned by the American Heart Association, the American Medical Association, the American College of Physicians, and several other major organizations. ACAM teaches physicians how to perform "chelation" and is the chelationists' main advocacy group.
> Drisko is a signatory to an anti-evolution statement promoted by the Discovery Institute, a stronghold of creation of creationist/intelligent design theorists I believe that her opposition to the most important theory in biology should cast doubt on her ability to judge what is important in the medical field, which is so heavily based on biology.
Algo más reciente:
http://scienceblogs.com/insolence/2013/04/16/quackademic-medicine-at-the-university-of-kansas/
I couldn’t believe this when I read it. In a post a long time ago, I discussed a couple of studies that were represented by supporters of vitamin C therapy as a “vindication” of Linus Pauling. However, as I described at the time, it was totally a long run for a short slide, requiring huge doses of vitamin C to achieve equally huge concentrations of ascorbate in the blood, all with at best very modest effects in mouse xenograft models. Overall, it’s very unimpressive, needing huge osmotic loads even greater than that produced by Stanislaw Burzynski’s antineoplaston therapy to achieve even the modest effects that it achieves. Even if that effect is real and reproducible, it’s so unimpressive that even if vitamin C were a new, patentable drug no drug company would bother with it, so unimpressive have the results been whenever tested by reputable scientists. Yet still people keep testing it. Why the fascination with high dose vitamin C, I’ll never know, but apparently Dr. Drisko shares it.
What’s really scary, however, is this:
How do I know if the intravenous vitamin C therapy will work for my cancer? (-)
Each individual responds differently, and we can’t predict how different tumor types will react. A PET scan is usually a guidepost. If the PET is positive, the tumor usually responds to the vitamin C. If the PET is negative but there is active tumor present, the vitamin C is less effective in most cases. Vitamin C works best in the early stages of cancer when used in conjunction with chemotherapy or radiation. They will only consult patients who are also following along with a traditional oncologist.
And on what evidence does Dr. Drisko claim this? None that I can see. It’s even said that there is “no contraindications to giving intravenous vitamin C with any chemotherapy when proper protocol is followed” and that the only chemotherapy that intravenous vitamin C doesn’t work with is methotrexate. She states that at the doses used ascorbate is a pro-oxidant, not an antioxidant, and that it therefore increases the efficacy of chemotherapy and radiation therapy. On what evidence? Again, none is presented. It is mentioned that there are studies by Dr. Drisko looking at intravenous vitamin C in cancer, but no links are provided.
Y otro enlace más:
http://www.sciencebasedmedicine.org/the-return-of-the-revenge-of-high-dose-vitamin-c-for-cancer/
These are huge doses, consistent with previous experiments in mice with a xenograft from an ovarian cancer cell line (Ovcar5) in which 4 g/kg of ascorbate was administered twice daily for a total of 8 g/kg/day. The result was an inhibition of xenograft growth of around one-third after 30 days. Results for a pancreatic cancer cell line and a glioblastoma cell line were only marginally better.
The authors did several cell culture studies in which ovarian cancer cell lines were treated with ascorbate and various chemotherapeutic agents. The authors reported an IC50 of between 0.3 and 3.0 mM, which is still incredibly high for an anticancer drug. The authors blithely write that this is “easily achievable” with IV ascorbate. Maybe so, but given the quantities involved, if you’re going to use a drug that requires such high plasma concentrations to have activity, that activity had better be awesome. None of the activity shown in this paper can be characterized as being particularly impressive. Worse, the authors, despite testing several ovarian cancer cell lines, only tested one non-tumorigenic immortalized ovarian line, HIO-80, and, finding that the IC50 to kill HIO-80 cells was much higher than all but one of the other cell lines (SHIN3), proclaimed a high degree of specificity for cancer. Moreover, HIO-80 cells are hardly “normal.” They likely contain BRCA1 mutations. Finally, the authors only used one assay for proliferation, the MTT assay. This particular assay is very popular (I use it in my lab not infrequently) because it is faster and easier than counting viable cells and also allows for large experiments using 96-well plates. However, the MTT assay depends on the metabolism of cells to produce a dye that is detected. The amount of light absorbance due to the dye is assumed to be proportional to the number of viable cells. Usually, this assumption is reasonable accurate, but lots of things can interfere with this and render that assumption incorrect. For instance, one wonders if very high concentrations of ascorbate can interfere. I’d want to see a control demonstrating that the MTT results correspond to cell number.
In other words, if I were a reviewer for this paper, not so fast, I’d have said. I want to see the results for at least a couple of more non-tumorigenic cell lines and a control validating the MTT in the presence of so much ascorbate (even if just a reference) before I’ll let you conclude that the effects of ascorbate are highly specific for cancer over normal ovarian cells. At the very least, I wouldn’t have considered it unreasonable to ask for a couple more non-tumorigenic ovarian epithelial cell lines to be tested.
joder, la anterior todavía pero esta..... manda webs
Yo pedí la megadosis de vitamina C como tratamiento compasivo para mi padre al que habían decidido no dar ningún tratamiento, pero me engañaron, me dijeron que sí el mismo día que dejaban de ponerle sangre y lo dejaban morir. Me pareció una opción ya que era un tratamiento barato, relativamente poco agresivo y estaba relacionado con algunos casos sorprendentes de reversión total de la enfermedad. Mi padre murió sin recibir ningún tratamiento, aunque tampoco se si hubiera sido peor de otro modo.