Search found 81 matches

by claudepa
Thu Apr 21, 2016 8:19 am
Forum: General Discussion
Topic: Books about famous experiments in biology - 'methods of inve
Replies: 1
Views: 2605

Re: Books about famous experiments in biology - 'methods of

Hi I like very much Essential Cell Biology by Alberts and co-authors. My edition is the third one. May be now there is a more recent one. The great experiments of biology are described in special inserts. It is historically very interesting. For instance I read about Griffith experiment: "This ...
by claudepa
Wed Mar 30, 2016 2:33 pm
Forum: General Discussion
Topic: Why do mutations occur, and what are possible mutations?
Replies: 8
Views: 6973

Re: Why do mutations occur, and what are possible mutations?

Hi Gagarin I never heard of these on purpose mutations. But I do not know everything. What I know is that the genome of cancer cells becomes unstable and they can accumulate mutations because at some steps regulation mechanisms are damaged. For instance normally a DNA damage is repaired or if not th...
by claudepa
Wed Mar 16, 2016 8:34 am
Forum: General Discussion
Topic: Why do mutations occur, and what are possible mutations?
Replies: 8
Views: 6973

Re: Why do mutations occur, and what are possible mutations?

Hi. Thank you. My pleasure is only to communicate in the field of cell biology with anyone interested in this field. And this forum is a very good place to do it. In this line I also give online free teaching in cell biology. I believe there are people who would like to know more about how work the ...
by claudepa
Thu Mar 03, 2016 8:26 am
Forum: Molecular Biology
Topic: When do mutations occur?
Replies: 24
Views: 79827

Re: When do mutations occur?

I am a cell biologist, however not a specialist of mutations. Nevertheless my feeling is the following: There are 2 types of mutations. Mutations of germ cells (spermatozoïds and ovules) and mutations of somatic cells (the other ones). Mutations of germ cells are in the genetic program because they ...
by claudepa
Wed Mar 02, 2016 2:56 pm
Forum: General Discussion
Topic: Why do mutations occur, and what are possible mutations?
Replies: 8
Views: 6973

Re: Why do mutations occur, and what are possible mutations?

In the reply that vanished I added that generally speaking mutations occur at random on the genome. Most of them have no serious consequences. But sometimes they occur statistically in sensitive genes and can trigger diseases such as cancers. Human genome has 23000 genes and most part of the genome ...
by claudepa
Tue Mar 01, 2016 12:32 pm
Forum: General Discussion
Topic: Why do mutations occur, and what are possible mutations?
Replies: 8
Views: 6973

Re: Why do mutations occur, and what are possible mutations?

my reply of last week has vanished. So to summarize mutations happen essentialy during DNA replication and by the action of deficient DNA repair systems. They therefore cannot happen during translation. Chemical modifications of bases either due to oxygen or to toxic compounds can cause errors in DN...
by claudepa
Mon Feb 15, 2016 5:48 pm
Forum: Genetics
Topic: Hepatocyte Nuclear Factor HNF4a
Replies: 1
Views: 4147

Re: Hepatocyte Nuclear Factor HNF4a

Hi. Only by curiosity could it be also the opposite ? HNF4 could be dephosphorylated during inflamation ? I believe it is not the phosphate by itself which modifies the affinity for the promotor but the structural change of the transcription factor due to phosphorylation or dephosphorylation which m...
by claudepa
Sun Feb 14, 2016 10:04 am
Forum: General Discussion
Topic: How does a Virus survive
Replies: 3
Views: 4172

Re: How does a Virus survive

Hi, I cannot answer all your questions. But to the question of is a virus a living entity my feeling is: It is a question a the definition of what is life. For some life is where are nucleic acids which contain the genetic information. According to this definition a virus can be considered as a livi...
by claudepa
Wed Feb 03, 2016 10:03 pm
Forum: Human Biology
Topic: Find how many times blood is filtered in the kidney?
Replies: 4
Views: 5435

Re: Find how many times blood is filtered in the kidney?

is the question how many times in 24 hours ? or is it how many times ?
by claudepa
Wed Feb 03, 2016 9:45 pm
Forum: Cell Biology
Topic: Are cells on agar or in agar?
Replies: 7
Views: 7539

Re: Are cells on agar or in agar?

tumorigenic eukaryotic cell form colonies in soft agar. However I do not believe that non tumorigenic (and even tumorigenic) do it in more solid agar. If cells grow on or inside solid agar why are we all using culture medium ? Bacteria grow inside soft agar and on solid agar. Am I wrong ?
by claudepa
Wed Feb 03, 2016 8:41 am
Forum: Cell Biology
Topic: Cancer more than animals animals
Replies: 9
Views: 19003

Re: Cancer more than animals animals

plants are indeed a great source for anticancer drugs. However I believe that these alkaloids have mostly an antibacterial or antiparasitic role in the plant. I used to do research on ellipticine which has anticancer activity. It originates from Ochrosia Elliptica. We have many examples of anticance...
by claudepa
Sun Jan 31, 2016 9:15 am
Forum: Human Biology
Topic: Looking for Answers about a recent ECHO
Replies: 1
Views: 2912

Re: Looking for Answers about a recent ECHO

I have no competence for heart. May be you are right to be worried, may be your doctor is right not to be. The best would be then to make an other echo with an other doctor. In fact the more new types of examinations are done the more news things about us are discovered that were completly unknown 2...