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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[@dafneelpypitsiori5147]

Perfect for students who study from Mohan's! Thank you so much!!

[@venkateshwarlugangishetty8853]

Sir plsssssssss make vedios on Every topic ..

[@rahulshetty5067]

It's worth for med students referring harsh Mohan book.
Good job sir.

[@ilovepathologyVijayPatho]

Thank you Rahul

[@randajameel6913]

The best lecture ever!!

[@Artsylove4]

The topic was super easy to understand sir!! Thank you so much!!

[@olivialin9704]

It’s easy to understand. Thank u sir!

[@rimplekour3882]

Can u provide pdf files of ur vdo sir

[@meghanabandaru9955]

Your lectures are really good sir. Why don't you make more videos?

[@tejasjoshi798]

Please make videos

[@alishashashasha6909]

Tysm sir!! You're explanation helped alot!

[@sanjidaalammitu4939]

Thanks a lot sir! It was very easy to understand ames test!It was so helpful fr me. :)

[@krishnavaswani7147]

🙏🏻🙏🏻🙏🏻❤️🧿🥺u made this super easy , thankyou so much god bless you sir

[@abhishekmukherji2332]

Thank you so much ❤️ especially the AMES test!!

[@varunkaraju7872]

Sir please make more videos on pathology.. Your videos are really good and useful..

[@rashim.jbajaj]

Easy to understand video

[@janhavikulkarni3440]

very helpful video
what is the difference between metastasis and carcinogenesis

[@shamsperwez9220]

it was very helpful sir. please keep adding videos whenever u get time

[@user-fj9mz3vy8k]

excellent video

[@gopalkhodve]

Thank you so much sir very informative

[@debigdogk9563]

Awesome teaching. Thank you ❤❤❤❤

[@Gege_TUMUSHIME]

This is extremely helpful, thank you sir!

[@s.kselimofficial8838]

Sir plz tell me
The examples of physical carcinogens

[@bramhanioza3009]

Thank you!

[@peace6951]

Very useful video

[@sulemankhanvirologist5015]

Thanks sir... i got now 100% long live sir

[@nicky5366]

thanks!

[@hello_nasa786]

Thank you

[@shamsuddeenharuna8657]

Highly educative

[@hubasyed5546]

Brilliant sir hoping for more videos like this

[@bhanusharma4744]

Great explanation
Thank you😊

[@jasmeenkaur1380]

Thankyou sir

[@nitinkshirsagar5464]

a very bright attempt. good

[@atulmishra9813]

One question sir....... In Ames test why did it contain the defective gene of S. Typhimurium? ?

[@sonalprabhu3825]

very helpful sir! thankyou so much ☺

[@ilovepathologyVijayPatho]

Thanks:-)

[@rhymedozen9119]

ur videos are the best

[@AlimaAktar]

Such a nice explanation

[@RK-Ravindra.]

Very gud explanation
👍👍👍👍👍👍

[@hafsahoumairi2121]

Thanks it was so easy to understand.

[@smg3555]

Great video sir 😀😊😀

[@kavyadas9340]

Good video,really helpful

[@mansvisharma808]

why aren't you uploading newer videos?

[@ilovepathologyVijayPatho]

Thanks. Shall be uploading shortly :-)

[@solosoul8961]

Really helpful...thanx a lot nd please provide more videos

[@lonelydreamer5085]

It is a very helpfull video.

[@rhymedozen9119]

do u have a video on grading and staging of cancer?

[@husainapoonawala9735]

Thank you so much sir!!! 🥺

[@zeelparmar406]

Nicely explained. Can you put video on biological carcinoma

[@atulmishra9813]

Why can't we use functioning gene contain S. Typhimurium

[@PrabhatKumar-mu1nr]

Thank You Sir.

[@osseipaulsampene4866]

Please anyone knows how to get the transcript?

[@krutisavani4328]

Good one ☝️

[@bhoomibagadia5637]

Sir please make a video on microbial carcinogenesis.

[@shashank20able]

It was brilliant sir. one question sir as for inoculation is there any time frame eequired?

[@ilovepathologyVijayPatho]

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!

[@hello_nasa786]

It's helped lots of

[@rhymedozen9119]

please keep uploading

[@rhymedozen9119]

awesome!

[@shwetaanand9957]

Fabulous

[@user-ms8nj6sz3z]

It is very useful sir. We need more videos❤

[@bithis-kitchen]

good ✌

[@rajusinghharipuria2119]

❤

[@ankushanand5931]

awsm

[@shingiezengeni7034]

Thank you