Welcome to Our Blog
Thank you for visiting our website. We are a relatively small lab with big ideas. We are part of a much larger group of investigators known collectively as the LLUMC Molecular Radiation Biology Laboratories. It is our hope that this website will educate, communicate, and incite scientific debate. As the PI of our little group, I hope to post our data and discuss potential mechanisms, consequences, and countermeasures. With a bit of luck we'll all learn something. The links to the left include our merry band as well as collaborating investigators and laboratories. The links to the right include our archive and blogroll. The banner above will always bring you back to the main page page. Take a look around and please feel free to leave a comment on our blog (try to keep it civil and constructive) or shoot us an e-mail. - Michael " Ubertramp " Pecaut
Lab Update
Posted by: Ubertramp on 2009.07.06
Categories & Tags: Brookhaven National Laboratory,Gamma Radiation,Grant,Grant Proposal,Microgravity,New Publication
Comments: None
I seem to have a distinct lack of content, don’t I? Which is sad because quite a few things have been going on lately.
Most importantly, Farnaz graduated. Yeah, team! Her oral defense went well, despite her butterflies and the committee was impressed. She’s off studying for her MCAT over the summer, but she promises me that she’ll come back in the fall and convert two chapters of her dissertation into two manuscripts. She better because she put a ton of work into those studies and dataz must be published! Heh. She was also awarded a travel grant for the upcoming Radiation Research Meeting in Savannah, Georgia. In fact, they selected her abstract for an oral presentation so they must have thought she did something worth hearing. Read More..
Lab Update
Posted by: Ubertramp on 2009.04.12
Categories & Tags: Gamma Radiation,Grant,Low Dose Radiation,Microgravity,NASA,New Publication,Protons,Radiation,Space Shuttle,T cell
Comments: None
It’s been a couple of months since the last update, so it’s about time. We have some good news and some bad news. The bad news first. My NASA grant was turned down for funding. I haven’t seen the review yet, so I’m not sure why. Nor do I know who or what actually DID get funded. Guess we’ll have to see.
Ironically (or coincidentally, I haven’t decided which), we received the acceptance letter from JAP for our third immune publication from the last shuttle flight on the same day. The reviewers were pretty rough on us, though. It bounced back and forth three times before they finally accepted it. Farnaz was pretty excited as this was her first publication. Woot! Now all she has to do is finish her dissertation and graduate. Hahaha. It’s still an Epub ahead of print, so I don’t have a reprint. Give it a few weeks. Read More..
Lab Update
Posted by: Ubertramp on 2009.02.10
Categories & Tags: Department of Energy,Grant Proposal,High-Energy Iron Radiation,Immunity,Microgravity,Mouse,NASA,NIH,New Publication,Radiation,Space Shuttle
Comments: None
Well, I’ve been on and off vacation for the last month or so. But a lot has been going on since my last update.
First, the bad news. Both NIH and DOE have turned down my grant proposals. I will probably try to resubmit the NIH grant this summer once I figure out how to address some of the reviewer concerns. I gotta keep remembering that being a scientist requires a thick skin and a short memory when it comes to rejection. Good thing I’m showing signs of early onset Alzheimer’s. Hah!
I still haven’t heard back from NASA regarding my Mice In Space proposal. I’m not sure what is holding it up. My guess is the recent economic issues have made spaceflight an even more difficult prospect than usual. Plus, they may be trying to work out a way to blend two or more proposals together. Given the lack of funds for science in general, this is probably harder than it sounds.
We also haven’t heard from LLU regarding our NMTB grant proposal. Seems LLU got a lot more proposals than they expected and they are having a harder time deciding who gets what. They may also be debating cutting the funding cap in order to fund more individual projects. I have no idea.
On to the good news. Read More..
Protons, Secondary Neutrons, and Cancer
Posted by: Ubertramp on 2008.09.27
Categories & Tags: Cancer Risk,Neutrons,New Publication,Protons,Radiation,Radiotherapy,Secondary Radiation
Comments: None
There has been some controversy about secondary neutrons during proton therapy and the risk of cancer. Here’s a recent paper which suggests the risk is very small, but not negligible, and dependent on age.
Int J Radiat Oncol Biol Phys. 2008 Sep 1;72(1):228-35. Epub 2008 Jun 18.
Risk of developing second cancer from neutron dose in proton therapy as function of field characteristics, organ, and patient age.
Zacharatou Jarlskog C, Paganetti H.
Department of Radiation Oncology, Copenhagen University Hospital, Copenhagen, Denmark.
PURPOSE: To estimate the risk of a second malignancy after treatment of a primary brain cancer using passive scattered proton beam therapy. The focus was on the cancer risk caused by neutrons outside the treatment volume and the dependency on the patient’s age. METHODS AND MATERIALS: Organ-specific neutron-equivalent doses previously calculated for eight different proton therapy brain fields were considered. Organ-specific models were applied to assess the risk of developing solid cancers and leukemia. RESULTS: The main contributors (>80%) to the neutron-induced risk are neutrons generated in the treatment head. Treatment volume can influence the risk by up to a factor of approximately 2. Young patients are subject to significantly greater risks than are adult patients because of the geometric differences and age dependency of the risk models. Breast cancer should be the main concern for females. For males, the risks of lung cancer, leukemia, and thyroid cancer were significant for pediatric patients. In contrast, leukemia was the leading risk for an adult. Most lifetime risks were <1% (70-Gy treatment). The only exceptions were breast, thyroid, and lung cancer for females. For female thyroid cancer, the treatment risk can exceed the baseline risk. CONCLUSION: The risk of developing a second malignancy from neutrons from proton beam therapy of a brain lesion is small (i.e., presumably outweighed by the therapeutic benefit) but not negligible (i.e., potentially greater than the baseline risk). The patient’s age at treatment plays a major role.
Update from the Lab
Posted by: Ubertramp on 2008.09.06
Categories & Tags: BioServe Space Technologies,Brookhaven National Laboratory,Grant,International Space Station,NASA,New Publication,Politics,Russian Space Agency,Space Shuttle
Comments: 1
We’ve been pretty busy in the lab lately. We had yet another publication appear in PubMed, sent off multiple publications to journals for review, and ran a couple of big experiments. On top of that, I moved to a new house, so I’ve been less than useful in the lab for the last couple of months.
The publication in PubMed is from one of our earlier studies investigating the effects of radiation on the ability to respond to an immune challenge. In this case, it was a secondary challenge – meaning, we challenged the mice twice. Once immediately after irradiation. And once several weeks later. In essence, we were checking to see if radiation altered the development of basic immune memory. Here’s the abstract:
Woot! Another Publication in PubMed!
Posted by: Ubertramp on 2008.07.30
Categories & Tags: Brookhaven National Laboratory,Clemson,High-Energy Iron Radiation,Immunity,NASA,New Publication,Props,Rats
Comments: None
Yeay! We have another publication in PubMed. Its our fourth so far this year. And we’re expecting at least two more soon. We’re also about to send out 4 more to reviewers, too. This is a banner year for us in terms of publications. Woot! These animals were irradiated at the Brookhaven National Laboratory and the work was funded through NASA and LLU’s Radiation Medicine Department. We also collaborated with Clemson on this one. The bone paper from these animals has already been published.
Here’s the abstract.
Long-term changes in rat hematopoietic and other physiological systems after high-energy iron ion irradiation.
Gridley DS, Obenaus A, Bateman TA, Pecaut MJ.
Departments of Radiation Medicine.
Purpose: To assess the long-term consequences of high-linear energy transfer (LET) iron ion radiation on immune and other critical body systems in the context of assessing potential effects astronauts may experience during exploratory missions. Materials and methods: Sprague-Dawley rats were nearly whole-body irradiated with 56-Fe (5 GeV/n) to total doses of 0, 1, 2, and 4 Gray (Gy) and euthanized 9 months post-exposure for analyses. Results: Irradiated groups consistently had low body mass. Numbers of circulating white blood cells (WBC), lymphocytes and monocytes were lower in the 2 Gy group compared to 0 Gy (p < 0.05); a trend for low granulocytes was also noted. Red blood cell counts, hemoglobin, and hematocrit were decreased in irradiated animals (p < 0.05), whereas platelet counts and volume were unaffected. In the spleen, WBC counts and DNA synthesis by T cells were similar among groups and there were no differences in secreted interferon-gamma and interleukin-6. However, trends were noted for increased splenocyte capacity to secrete tumor necrosis factor-alpha and increased level of vascular endothelial cell growth factor in plasma. One or more of the irradiated groups had significant (p < 0.05) aberrations in several blood chemistry parameters associated with liver and kidney function. Conclusion: The data show that exposure to 56-Fe radiation induced pathological changes in important body systems long after exposure.
