NEOPLASIA 7: CHEMICAL CARCINOGENESIS & Ames test
A series of video tutorials discussing the topics for undergraduates in Pathology
In this tutorial , i have discussed Chemical Carcinogenesis.
Carcinogenesis
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• Oncogenesis
Mechanism of induction of tumors
Carcinogen
• A substance or agent which can induce cancer.
• Types:
1.Chemical carcinogen
2.Physical carcinogen
3.Biological carcinogen
History
1761 - Dr John Hill, London Physician Observed the association of nasal cancer among tobacco snuff users in men.
1775 - Percivall Pott, an English surgeon : increased Incidence of scrotal cancer in chimney sweepers in London.
1915 - Yamagiwa and Ichikawa, Japanese Pathologists: Multiple topical applications of coal tar to rabbit ears produced squamous cell carcinomas.
First demonstration that a chemical could produce cancer in animals.
1930’s - Kennaway, a british Pathologist : showed for the first time that polycyclic aromatic hydrocarbons , such as dibenzanthracene, are tumorigenic in mouse skin
1940’s - James and Elizabeth Miller, Oncologists : first to find the relationship between metabolic activation, and tumorigenesis.
Experiments demonstrating the initiation & promotion
Tests For Chemical Carcinogenicity
• Experimental induction
• Tests for Mutagenecity( AMES’ TEST)
• The Ames Test is an easy and inexpensive way to measure the MUTAGENICITY of a chemical.
• Ames test does not determine if chemical is carcinogenic!!!
• Rationale of test is that greater than 90% of all chemical mutagens have been shown to be carcinogenic in subsequent animal tests
• The bacterium used in the test is a strain of Salmonella typhimurium that caries a defective (mutant) gene making it unable to synthesize the amino acid histidine from the ingredients in its culture medium.
• However, some types of mutations (including this one) can be reversed, a back mutation, with the gene regaining its function.
• These revertants are able to grow on a medium lacking histidine.
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Please watch: "WARBURG EFFECT: Hallmark of CANCER. What, Why & How?"
• NEOPLASIA 6: WARBURG E...
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Пікірлер: 65
Perfect for students who study from Mohan's! Thank you so much!!
Sir plsssssssss make vedios on Every topic ..
It's worth for med students referring harsh Mohan book. Good job sir.
@ilovepathologyVijayPatho
7 жыл бұрын
Thank you Rahul
The topic was super easy to understand sir!! Thank you so much!!
Thank you so much ❤️ especially the AMES test!!
The best lecture ever!!
Thanks a lot sir! It was very easy to understand ames test!It was so helpful fr me. :)
This is extremely helpful, thank you sir!
Sir please make more videos on pathology.. Your videos are really good and useful..
very helpful video what is the difference between metastasis and carcinogenesis
Brilliant sir hoping for more videos like this
it was very helpful sir. please keep adding videos whenever u get time
a very bright attempt. good
It’s easy to understand. Thank u sir!
Thanks it was so easy to understand.
Your lectures are really good sir. Why don't you make more videos?
@tejasjoshi798
6 ай бұрын
Please make videos
Such a nice explanation
Can u provide pdf files of ur vdo sir
do u have a video on grading and staging of cancer?
Tysm sir!! You're explanation helped alot!
Great explanation Thank you😊
Awesome teaching. Thank you ❤❤❤❤
Really helpful...thanx a lot nd please provide more videos
Thank you so much sir very informative
Sir plz tell me The examples of physical carcinogens
Thank You Sir.
Good video,really helpful
ur videos are the best
excellent video
Very useful video
Thanks sir... i got now 100% long live sir
🙏🏻🙏🏻🙏🏻❤️🧿🥺u made this super easy , thankyou so much god bless you sir
Please anyone knows how to get the transcript?
Thank you so much sir!!! 🥺
Great video sir 😀😊😀
very helpful sir! thankyou so much ☺
@ilovepathologyVijayPatho
7 жыл бұрын
Thanks:-)
It is a very helpfull video.
Nicely explained. Can you put video on biological carcinoma
thanks!
Highly educative
Good one ☝️
why aren't you uploading newer videos?
@ilovepathologyVijayPatho
7 жыл бұрын
Thanks. Shall be uploading shortly :-)
Very gud explanation 👍👍👍👍👍👍
One question sir....... In Ames test why did it contain the defective gene of S. Typhimurium? ?
Thank you!
Why can't we use functioning gene contain S. Typhimurium
awesome!
Easy to understand video
Sir please make a video on microbial carcinogenesis.
please keep uploading
Thank you
It was brilliant sir. one question sir as for inoculation is there any time frame eequired?
@ilovepathologyVijayPatho
7 жыл бұрын
Thanks for asking. Well, the inoculation has to be done immediately on to the growth plates.. there should be no delay because, if delayed, the results will be difficult to interpret.. Well note that the incubation time is usually overnight or sometimes 48 hrs at 35-37 degrees. There has been many modifications of this test over the years. the one described above is the original Ames test!
It's helped lots of
Thankyou sir
Fabulous
good ✌
awsm
❤
It is very useful sir. We need more videos❤
Thank you