Wednesday, February 28, 2007

New Medlineplus magazine issue

NLM has posted the latest issue of the MedlinePlus magazine.

In this issue:
- women's heart health
- a large section summarizing key strategies for aging well and staying healthy
- an interview with Elias Zerhouni, NIH Director, about the future of personalized medicine
- an overview of the NHLBI's new public awareness campaign about COPD
- descriptions of some of the Go Local projects (now covering 17 states)
- an article about Dr. Stephen Sherry of NLM who has developed software for use in identifying disaster victims using damaged DNA samples

Brief audio summary of the issue (mp3)
Form to mail in for a free subscription to the magazine (I sent one in for my mom and she loved her first issue)


Venter on the Colbert Report

Last night on the Colbert Report, Stephen Colbert interviewed Craig Venter about his work with the human genome and the potential future impact of related discoveries, including discussion of possible conflicts of interest associated with commercial development of genome-related initiatives (e.g. synthetic genomics).

A little history about controversy etc. surrounding Venter's work is available in this Time magazine article and this article from Wired magazine.

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Tuesday, February 27, 2007

Picking "random" numbers

Often in a report of a randomized clinical trial, you see description in the methods section of the paper indicating a bit more detail than just saying "patients were randomly assigned to treatment or control." Due to recognized (and unrecognized), internal (and possibly external) potential sources of bias, it's virtually impossible for a human to truly randomly pick numbers.

Dave of Cognitive Daily conducted an experiment earlier this month that illustrates this point very well -- he asked readers of his blog to pick any number between 1 and 20, and tabulated the responses. He reports the results in this post. Charting 347 responses from humans against 347 random picks made by a computer, it is clear that the distribution of the human selections are not randomly distributed -- humans were much more likely to select the number 17, far beyond what would be expected if the distribution was truly random.

(he also sums up reader comments on the experiment in this post and makes some inferences about why the number selection wasn't random)

So if we can't pick numbers randomly, how do researchers get random numbers for use in projects like randomized controlled trials?

There are a number of sources, including computer-based random number generators (e.g. the True Random Number Service, Microsoft Excel's random number generator) or a table of random numbers (e.g. the table on this page from the Partnership for Kentucky Schools -- the instructions provide a walk-through example for those who are interested in doing a little exercise about how you really use these numbers to randomly assign people to groups).

Researchers use these kinds of tools to randomize patients, and typically provide some explanation of their process for randomization in the Methods section, as noted above (e.g. the randomization section of the methodology in this article by Taha et al. in PLoS Clinical Trials).


Wednesday, February 21, 2007

Coughing and sneezing techniques

Very appropriate for this time of year, with increasing reports of influenza-like illness in Nashville and elsewhere -- a funny and informative instructional video about "better" ways to cough and sneeze to reduce how much you contaminate your hands and the air around you (via Bad Astronomy).

Friday, February 16, 2007

Animation of DNA wrapping and replication

"Molecular visualizations of DNA" is a 2003 video illustrating DNA wrapping and replication, credited to the Walter and Eliza Hall Institute of Medical Research, Howard Hughes Medical Institute, and the Dolan DNA Learning Center -- great animations and narration of both processes (found via Nobel Intent).

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Thursday, February 15, 2007

History blogging

If you're like me and you believe that librarians need to know at least a little bit of everything, check out some interesting history posts up in History Carnival #48, hosted this month by Martin at Aardvarchaeology. My favorites are the Caligula post and the consideration of why Planet of the Apes aired on the History Channel (comments on each post are just as interesting as the posts themselves).


Friday, February 09, 2007

Friday humor: a tribute to the heart

The group Hard 'N Phirm has video on YouTube for their song "El Corazón," a dramatic (and accurate) musical tribute to the heart and its functions, in Spanish with English subtitles (via BoingBoing).

(other songs, including a song about pi, are on the group's official site)


Thursday, February 08, 2007

The CAST trial: EBM and unexpected answers

The Houston Chronicle has started a new medicine column, and the first installment, "Evidence is key when it comes to your treatment by Dr. Howard Brody, discusses what evidence-based medicine means to the patient.

Dr. Brody uses very accessible, everyday language - he briefly describes the CAST trial, a large study with initial results published in 1990 - this study looked at drugs for suppressing a type of irregular heart beat, premature ventricular contractions (PVCs) and was terminated due to an interim analysis (a planned safety monitoring analysis conducted partway through the study) that indicate that drug therapy was actually associated with increased mortality, rather than reduced number of deaths as had been expected.

Dr. Brody summarizes the study:

So, allow me to tell you a story that goes back to 1989.

Scientists knew two things back then. First, older people who had a certain kind of irregular heartbeat were much more likely to die of coronary disease. Second, a class of drugs was very good at reducing the number of irregular beats.

So they designed a big research study, called CAST, to see whether giving those drugs to older, at-risk people saved lives.

Some would have said, "Why even bother to do the trial? You can already tell in advance these drugs will be a good thing. Why not just go ahead and prescribe them?"

CAST gave a clear-cut answer, all right, but it was the opposite of what everyone expected. They had to stop the study early because so many people getting the drugs were dying prematurely.
He further sums up how this illustrates EBM:

Some people beat up on EBM because they imagine it is just one more excuse for cutting costs...the more important use is to save people from worthless or harmful treatment. Imagine how many extra deaths would have occurred, had those heart-rhythm drugs studied in CAST been released for wide use...If you go to a good physician, it's very likely she thinks in EBM terms. If you know more about what she's thinking, you can get more involved in your own medical care and know a lot better what sorts of questions to ask. And more-involved patients stay healthier. The evidence shows it.
Additional information:
- the PubMed abstract for one of the initial reports of the unexpected mortality
- a broader PubMed search of articles reacting to this study, which is still being talked about today

- It's also worth noting that, though the study did not succeed in proving its primary hypothesis, that drug therapy to suppress PVCs would decrease the death rate in treated patients, it did lead to the creation of a rich dataset that has spawned numerous studies published since then, represented in the above PubMed search and the description of CAST (this record also has a list of studies that were based on this dataset, which is still maintained by the study investigators and available to other researchers for further analyses, managed by the National Heart, Lung, and Blood Institute.

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Monday, February 05, 2007

"Forgotten Genius" on PBS: Percy Julian's story

Tonight on PBS at 7pm Central, Nova is airing "Forgotten Genius," the story of Percy Julian, an African American chemist who made a number of ground-breaking discoveries during the early and mid 1900s.

The 2 hour long program will include "Archival footage, dramatic reenactments featuring Tony winner Ruben Santiago-Hudson and remarks from family and friends tell the story of organic chemist Percy Julian (1899-1975)."

The accompanying site has an interactive timeline of his many contributions, including work with alkaloids that had implications for therapy of heart disease symptoms and glaucoma, a discovery that helped launch the steroid industry, and developing scores of products from the soy bean including a foam that helped fight fires on US military vessels during WWII.

If you missed it or you just want to see it again, you can watch this episode of Nova online - they've divided it into 13 segments for easier viewing (available in QuickTime, Windows Media Player, or RealVideo formats).

Thursday, February 01, 2007

Observational and interventional studies

One of the editorials in this week's NEJM gives a great example of the relative roles of observational and interventional studies in clinical research. The editorial, "The healing power of listening in the ICU," discusses a randomized trial in the same issue that compares two different communication strategies for working with families who had a patient dying in the ICU.

The editorial by Lilly and Daly notes:

Recommendations to improve care for patients dying in ICUs are rooted in both observational and interventional studies. Observational studies confirm our own practical experience that nearly every American family will be affected by the loss of a loved one in an ICU and that the effect of this loss can be mitigated by high-quality care. The field has been advanced by interventional studies showing that proactive communication processes, including intensive communication as well as ethics and palliative care consultations, improve outcomes. Evidence that proactive multidisciplinary conferences in which care providers and family members address bereavement, with the provision of printed materials, is another important advance in the field of end-of-life care in the ICU. All providers of critical care should receive training that will allow them to offer the kind of support that they would want if they had a family member who was facing death in an ICU.
Observational studies begin to confirm that something that we believe to be true actually has some objective data to indicate that it really might be true. In this case, the observational data confirms that the question of communication with families during end-of-life care is an important part of the process. Observational studies provide data that aid investigators in developing hypotheses and ideas for feasible interventions, that can then be explored in future research.

Interventional studies then build on this experience - now that we have confirmed that the question is an important one, we can design interventions that attempt to address the issue. The trial in this NEJM looks at strategies for improving the communication experience of families with patients at the end of life in the ICU. These studies further explore the studies initiated and inspired by observational data, and move more toward the hypothesis-proving end of the clinical research spectrum.

While sometimes it can be easy to focus on looking for the randomized clinical trial that "answers" a clinical question, a trial on its own doesn't provide an adequate picture of the scope of a given clinical problem. Both kinds of studies provide essential pieces of the puzzle for understanding clinical issues, and the editorial commentary above highlights how the two kinds of evidence come together and provide actionable solutions for a real-world clinical challenge.

The full citation for the editorial: Lilly CM, Daly BJ. The healing power of listening in the ICU. New Engl J Med 2007;356:513-5. (full-text)

The study they're commenting on: Lautrette A, Darmon M, Megarbane B, et al. A communication strategy and brochure for relatives of patients dying in the ICU. N Engl J Med 2007;356:469-478. (full-text)