Search found 81 matches

by claudepa
Tue Aug 02, 2016 2:30 pm
Forum: Genetics
Topic: CpG methylation
Replies: 1
Views: 2778

Re: CpG methylation

I see only phosphorothioates in chemically modified DNA oligonucleotides used as antisense oligonucleotides. Phosphorothioate render DNA oligonucleotides less subject to degradation by nucleases and still allow RNAse H to cleave mRNA hybridized to the phosphorothioate DNA oligonucleotide. CpG sequen...
by claudepa
Tue Aug 02, 2016 2:24 pm
Forum: Molecular Biology
Topic: Why cancer cells change Gln metabolism?
Replies: 1
Views: 2187

Re: Why cancer cells change Gln metabolism?

Can you graft human colon cancer cells to nude or PDX mice and feed the mice without glutamine ? will the mice survive? will the tumor shrink? A leukemia, I do not remember which one, depends on asparagine and tumor cells are not able to synthetize asparagine. So it is efficiently treated in patient...
by claudepa
Tue Aug 02, 2016 2:11 pm
Forum: Cell Biology
Topic: Does chemiosmosis pump protons or hydronium ions?
Replies: 3
Views: 4621

Re: Does chemiosmosis pump protons or hydronium ions?

Hi. It is indeed written in all books that it is protons. I do not know what is the evidence for proton against hydronium. If there is a channel made by the inner membrane enzymes which translocate the protons into the inter membrane space it could be interesting to know the channel diameter since I...
by claudepa
Tue Aug 02, 2016 1:56 pm
Forum: General Discussion
Topic: Ribozyme synthesis?
Replies: 2
Views: 1984

Re: Ribozyme synthesis?

I do not know precisely the response for ribozymes. However I do not see any other possibility for synthesis of a RNA than being transcribed from DNA. It is true for rRNA, as you say, but also for instance for other RNAs with are not translated in peptides, tRNA, siRNA, miRNA and other regulating RN...
by claudepa
Fri Jul 01, 2016 5:19 pm
Forum: Molecular Biology
Topic: endocytosis and clathrin
Replies: 3
Views: 3569

Re: endocytosis and clathrin

The figure 6 of this review article indicates that aptamer conjugates can follow the clathrin independent pathway. However I do not know the precise references on this point: E.W. Orawa et al. Biochemica et Biophysica Acta (2010) 1798, 2190-220
by claudepa
Sat Jun 25, 2016 8:18 pm
Forum: Cell Biology
Topic: Cells of the human vein
Replies: 3
Views: 3492

Re: Cells of the human vein

Did you look for endothelial cells ?
by claudepa
Mon May 30, 2016 9:04 am
Forum: General Discussion
Topic: Is life only a system of evolving chemical reactions?
Replies: 23
Views: 11265

Re: Is life only a system of evolving chemical reactions?

The actual view is that uncontrolled cell proliferation in tumors is due to mutations in DNA. These mutations can affect proliferation and death of cells. Mutated oncogene proteins, such as RAS for instance, can then send constantly signals of proliferation to the nucleus instead of doing it only wh...
by claudepa
Thu May 05, 2016 6:04 pm
Forum: Genetics
Topic: genetic witches in evo devo
Replies: 1
Views: 2664

Re: genetic witches in evo devo

I have some answers not all. I am reading Sean Carroll's "Endless forms most beautiful" and trying to understand genetic switches. I have trouble seeing the big picture -- how to put it all together. I will explain my current perception of the process in the hope you can either correct my ...
by claudepa
Tue May 03, 2016 9:40 am
Forum: General Discussion
Topic: Question about cell membranes and oocyte development
Replies: 1
Views: 1566

Hi
Question 1: The right answer is D and E. B alone is OK but is not, as alone, in the possible answers. So the test is not wrong.
by claudepa
Sat Apr 30, 2016 8:54 am
Forum: Physiology
Topic: nervous system crossover (hard question!)
Replies: 13
Views: 26043

Re: nervous system crossover (hard question!)

Hi I discovered by chance (because of a temporary injury at the right arm) that for some activities I am ambidextrous. For instance I play with both hands in tennis (not only the now very general two hands backhand) . In competition this is even an advantage since it is a problem for some opponents ...
by claudepa
Thu Apr 28, 2016 7:08 am
Forum: General Discussion
Topic: Is life only a system of evolving chemical reactions?
Replies: 23
Views: 11265

Re: Is life only a system of evolving chemical reactions?

When first cells (or the first cell) were formed either there was no so many available organic molecules or a very small minority of available molecules was fitted for life. 2 examples: 1) Adenine is a molecule used by cells for different purposes: information, energy, neurotransmission, redox react...
by claudepa
Thu Apr 21, 2016 8:31 am
Forum: Human Biology
Topic: Assisting the human immune system by injecting antibodies
Replies: 2
Views: 2258

Re: Assisting the human immune system by injecting antibodie

Hi, I am not an immunologist and immunology is a complex science. However I know that a major progress in cancer therapy in the last 10 years is the injection of monoclonal antibodies recognizing with specificity cancer cells. This recognition triggers their apoptosis by complex mechanisms which inv...