I'm doing research on UV damage to human skin cells. The research uses
the Comet Assay method to quantify cell damage.
I need to know (from other scientific studies / research papers that
used the Comet Assay method)
1. The UVA and UVB dosages used on HaCat (Human skin) cells.
2. The UV Lamps that were used.
3. The highest possible UVA and UVB doses, that can be given, before
the cells are damaged beyond repair.
I would prefer an answer (see below) and the relevant links.
Study, UVA doses used, UVB doses used, UV Lamps used.
Note:
1. I am interested only in human skin cells, not other types of cells.
2. I am not interested in non-scientific information, miracle cures, sunscreens etc. |
Request for Question Clarification by
bobbie7-ga
on
12 Nov 2005 14:58 PST
Hello Jessyabc,
Please let me know if the material below is the kind of information
you're looking for. If it is, I can provide you with a few more
studies as the answer to your question.
--Bobbie7
J Photochem Photobiol B. 2003 Dec 5;72(1-3):55-60.
N-acetyl-L-cysteine prevents DNA damage induced by UVA, UVB and
visible radiation in human fibroblasts.
In this study the effects of NAC were examined in cultured human
fibroblasts during prolonged exposure to ultraviolet B (UVB),
ultraviolet A (UVA) and visible irradiation (280-700 nm), delivered by
a 150 W xenon-arc lamp. The alkaline comet assay was used to assess
the DNA damage in individual cells.
----------------------------------
Interexperimental and Interindividual Variations of DNA Repair
Capacities After UV-B and UV-C Irradiations of Human Keratinocytes and
Fibroblasts
Photochemistry and Photobiology, Mar 2004
In this work we have studied the response of skin cells (i.e.
fibroblasts and keratinocytes) from the same or from different
individuals after both ultraviolet-15 (UV-B) and ultraviolet-C (UV-C)
irradiations using the comet assay to characterize the specific
cellular response to UV-induced DNA damage. Cells were irradiated with
increasing doses of UV-B or UV-C. To study the UV dose dependency of
initial steps of DNA repair, namely recognition and incision at DNA
damage level, the comet assay was performed, under alkaline
conditions, 60 min after UV irradiation to allow detection of DNA
strand breaks.
Skin cells are directly exposed to UV irradiation, which induces DNA
lesions, potentially leading to their transformation if they are not
repaired. Ultraviolet-B (UV-B, 290-320 nm) is considered as the major
wavelength range involved in skin carcinogenesis, although
ultraviolet-A (320-400 nm) is also implicated.
UV sources. A germicidal lamp was used for UV-C (254 nm) irradiation
(Philips, Suresnes, France), and fluence was established using a
Vilbert Lnurmat (Marne La Vallee, France) dosimeter. The dose rate for
the experiments was 0.3 J/m^sup 2^/s. The UV-B source was a Vilbert
Lourmat TFX-35M, 6 × 15 W lamp with a [lambda]^sub max^ at 312 nm.
This UV-B table emits less than 2% of the spectrum with wavelength
between 270 and 290 nm . Fluence rate at the site of cell irradiation
was 10.25 J/m^sup 2^/s as determined by Parker chemical actinometric
method.
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Clarification of Question by
jessyabc-ga
on
13 Nov 2005 00:36 PST
Hi Bobbie
Thanks for the quick response
Yes, this is similar to what I'm looking for.
1.But it should be specific for HaCat calls (Keratinocytes).
2.The experiment should be in vitro, not in vivo.
3. I need to know the maximum dosage. (see above)
Do these papers describe the extent of damage done to the cells?
Jessy
|
Request for Question Clarification by
bobbie7-ga
on
13 Nov 2005 07:18 PST
Hello again Jessy,
Here are four more studies. Please review them and let me know if they
meet your requirements. If they don't I will continue my search.
Inhibitory effect of polypeptides from Chlamys farreri on UVB-induced
apoptosis and DNA damage in normal human dermal fibroblasts in vitro1
http://www.chinaphar.com/1671-4083/24/1006.htm
Ultraviolet Radiation Increases the Toxicity of Pyrene, 1-Aminopyrene
and 1-Hydroxypyrene to Human Keratinocytes
http://www.mdpi.net/ijerph/papers/ijerph2005010058.pdf
UV-induced DNA damage in human keratinocytes: quantitation and
correlation with long-term survival.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15854128&query_hl=7
PREVENTION Effect of eicosapentaenoic acid, an omega-3 polyunsaturated
fatty acid, on UVR-related cancer risk in humans.
http://carcin.oxfordjournals.org/cgi/content/full/24/5/919
Here are the direct links to the two studies I mentioned previously.
N-acetyl-L-cysteine prevents DNA damage induced by UVA, UVB and
visible radiation in human fibroblasts.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14644566&dopt=Abstract
Interexperimental and Interindividual Variations of DNA Repair
Capacities After UV-B and UV-C Irradiations of Human Keratinocytes and
Fibroblasts
Photochemistry and Photobiology,
http://www.findarticles.com/p/articles/mi_qa3931/is_200403/ai_n9406868
I look forward to your clarification.
Thanks,
Bobbie7
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Request for Question Clarification by
bobbie7-ga
on
14 Nov 2005 06:15 PST
Hi Jessy!
Did you have a chance to review the additional studies I provided?
Do they meet your requirements?
Thanks, Bobbie7
|
Clarification of Question by
jessyabc-ga
on
14 Nov 2005 14:39 PST
Hi Bobbie
Yes. This is what I was looking for.
Thanks.
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