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Managing fever of unknown origin in adults – BMJ review

Posted: March 29, 2011 at 1:03 pm

Few clinical problems generate such a wide differential diagnosis as pyrexia (fever) of unknown origin. The initial definition proposed by Petersdorf and Beeson in 1961 was later revised. Essentially the term refers to a prolonged febrile illness without an obvious cause despite reasonable evaluation and diagnostic testing.

Definition

Classic adult fever of unknown origin (FUO) is fever of 38.3°C (101°F) or greater for at least 3 weeks with no identified cause after 3 days of hospital evaluation or 3 outpatient visits
Causes of FUO
Common causes of FUO are infections, neoplasms, and connective tissue disorders.

Investigations almost always include imaging studies. Serological tests may be indicated

Treatment of FUO

Empirical antibiotics are warranted only for individuals who are clinically unstable or neutropenic. In stable patients empirical treatment is discouraged, although NSAIDs may be used after investigations are complete. Empirical corticosteroid therapy is discouraged.

References:

Investigating and managing pyrexia of unknown origin in adults. BMJ 2010; 341:c5470 doi: 10.1136/bmj.c5470 (Published 15 October 2010).
Image source: Wikipedia, public domain.

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Recommendation and review posted by G. Smith

Diplomas Are Boring

Posted: March 29, 2011 at 11:46 am

Stephen dissertation heart

Click to view larger

I like people that break from the norm.  A long-time Street Anatomy fan and soon-to-be doctor, Stephen, recently sent in this image of an anatomical heart made up entirely of the words from his dissertation.  He put tons of effort into studying a particular cardiac arrhythmia, noted below the heart, and instead of hanging fancy diplomas on the wall, he chose to immortalize his time and efforts into a piece of anatomical art.

Well done Stephen!

 

Recommendation and review posted by G. Smith

We Age Because the World Changes

Posted: March 27, 2011 at 3:58 pm

Aging is an inevitability, or so we have to assume: the processes of evolution blindly but efficiently explore the space of possible living creatures, and have been doing so for a very, very long time. Surely a very long-lived or ageless species would have a great advantage in evolutionary competition, its individual members able to produce descendants for far longer than their competitors in a short-lived species that ages. Yet virtually all species - with only a very few exceptions - age in easily measured ways. The species that age are also the species that have won in evolutionary terms, and therefore prospered and spread. Why is this?

A recent open access paper (in PDF format) explores one of the approaches used to answer this question, and does so in a very readable fashion:

Living organisms shouldn't age, at least if that could be helped (many of use would certainly like that, but our wishes are not a valid argument). Evolution works in a way that any species whose representatives have any distinct disadvantage will be driven to extinction. It makes sense then to assume that, if aging could be avoided, species that showed senescence as the individuals grow older should be replaced by others where aging does not happen (or happens at a much slower rate). Senescence increases mortality and an individual who dies of old age will leave, in average, a smaller number of descendants than another individual that does not age and manages to live and reproduce for a longer time. And yet many known living organisms show senescence. The time it takes for an individual to show signs of old age varies greatly among species, but aging seems so natural that many people fail to realize there is an apparent contradiction between senescence and evolution.

...

Understanding why we age is a long-lived open problem in evolutionary biology. Aging is prejudicial to the individual and evolutionary forces should prevent it, but many species show signs of senescence as individuals age. Here, I will propose a model for aging based on assumptions that are compatible with evolutionary theory: i) competition is between individuals; ii) there is some degree of locality, so quite often competition will between parents and their progeny; iii) optimal conditions are not stationary, mutation helps each species to keep competitive.

When conditions change, a senescent species can drive immortal competitors to extinction. This counter-intuitive result arises from the pruning caused by the death of elder individuals. When there is change and mutation, each generation is slightly better adapted to the new conditions, but some older individuals survive by random chance. Senescence can eliminate those from the genetic pool. Even though individual selection forces always win over group selection ones, it is not exactly the individual that is selected, but its lineage. While senescence damages the individuals and has an evolutionary cost, it has a benefit of its own. It allows each lineage to adapt faster to changing conditions.

We age because the world changes.

And there is illustrated one of the present competing viewpoints on the origins of aging.

Recommendation and review posted by Fredricko

An Update on Germ Cells and Longevity

Posted: March 27, 2011 at 3:58 pm

Researchers continue to investigate the link between germ cells and longevity in lower animals. In this open access paper, changes to fat metabolism are implicated as an important mechanism: "Removing the germ line of Caenorhabditis elegans extends its lifespan by approximately 60%. Eliminating germ cells also increases the lifespan of Drosophila, suggesting that a conserved mechanism links the germ line to longevity ... Reproduction and aging are two processes that seem to be closely intertwined. Experiments in Caenorhabditis elegans and Drosophila have shown that depletion of the germ line increases lifespan and that this process depends on insulin and lipophilic-hormone signaling. Recently, it was demonstrated that when germline stem cells (GSCs) cease to proliferate, fat metabolism is altered and this affects longevity. In this study, we have identified a nuclear hormone receptor, NHR-80, that mediates longevity through depletion of the germ line by promoting fatty acid desaturation. ... Our results reinforce the notion that fat metabolism is profoundly altered in response to GSC proliferation, and the data contribute to a better understanding of the molecular relationship between reproduction, fat metabolism, and aging."

Link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3057950/

Recommendation and review posted by Fredricko

Immune Therapy Versus Pancreatic Cancer

Posted: March 27, 2011 at 3:58 pm

An example of the sort of immune system engineering that is presently taking place in the laboratory: "Until this research, we thought the immune system needed to attack the cancer directly in order to be effective. Now we know that isn't necessarily so. Attacking the dense tissues surrounding the cancer is another approach, similar to attacking a brick wall by dissolving the mortar in the wall. Ultimately, the immune system was able to eat away at this tissue surrounding the cancer, and the tumors fell apart as a result of that assault. These results provide fresh insight to build new immune therapies for cancer. ... pancreatic cancer patients received standard gemcitabine chemotherapy with an experimental antibody [that] binds and stimulates a cell surface receptor called CD40, which is a key regulator of T-cell activation. The team initially hypothesized that the CD40 antibodies would turn on the T cells and allow them to attack the tumor. The treatment appeared to work, with some patients' tumors shrinking substantially and the vast majority of tumors losing metabolic activity after therapy, although all of the responding patients eventually relapsed. When the researchers looked at post-treatment tumor samples, obtained via biopsy or surgical removal, there were no T cells to be seen. Instead, they saw an abundance of another white blood cell known as macrophages. ... When the investigators treated mice that developed pancreatic cancer with gemcitabine in combination with CD40 antibodies, the results looked like those of the human trial. Some mouse tumors shrank and were found to be loaded with macrophages but contained few or no T cells. Closer inspection showed that the macrophages were attacking what is known as the tumor stroma, the supporting tissue around the tumor. Pancreatic tumors secrete chemical signals that draw macrophages to the tumor site, but if left to their own devices, these macrophages would protect the tumor. However, treating the mice (or patients) with CD40 antibodies seemed to flip that system on its head. ... It is something of a Trojan horse approach. The tumor is still calling in macrophages, but now we've used the CD40 receptor to re-educate those macrophages to attack - not promote - the tumor."

Link: http://www.eurekalert.org/pub_releases/2011-03/uops-pru031611.php

Recommendation and review posted by Fredricko

An Approach to Step One of the Vegas Group: Bootstrapping the Codex

Posted: March 27, 2011 at 3:58 pm

The Vegas Group: a so far fictional community of the next ten years that will merge the longevity advocacy and open biotech communities in order to (a) reverse engineer the most promising life-span-enhancing techniques demonstrated in the laboratory, (b) translate that work into human rejuvenation biotechnologies, and (b) make these therapies available for use via medical tourism to Asia-Pacific region clinics.

So I have been pondering how best to make the vision of the Vegas Group a reality: what steps do we take so that we wake up six or seven years from now to an open source biotech community whose members are working on enabling the best longevity therapies produced by the formal research community - and who have the overseas connections to enable responsible use of resulting therapies in a clinical setting.

The path to this future involves networking and community building in a whole new and different direction from that taken by much of the longevity advocacy community - and the construction of a codex of information, a how-to manual of recipes for replicating specific products of the formal research community in longevity science. Networking makes the world go round, and that is the most important part of any attempt to create the Vegas Group, or indeed any human endeavor: making relationships and persuading people to join in. But this is not where I can be the most effective.

So any step one for me will involve considering the codex: what it is, and how it will be constructed, maintained, and made useful to the seeds of what will be the Vegas Group - however that organization ultimately comes about, and whatever form it ultimately takes. It is very clear to me that open biotechnology will grow into a massive semi-professional sphere of activity, exactly like the open source software community today. I want to take advantage of the wave that is coming, and produce a work that will both aid that wave and in turn be aided by it.

When thinking about the way in which contributions of content are made voluntarily to any given community or site - such as Wikipedia, or blogs such as this one, or the documentation repository at your workplace - it is self-evident that very, very few people step up to produce good content. Wikipedia works because a great many people each contribute just a little, a continual process of polishing, one grain of sand at a time, applied to the bulk outlines contributed by the motivated few. But for smaller groups, you don't get polishing, you just get next to nothing in the way of contributions.

So I'm fairly certain that for the Vegas Group codex, while a wiki model may be helpful as an adjunct to a motivated community further down the line, it isn't a way to get things written at the outset - it's not a way to provide the corpus of work that a community can later polish. There are few biotechnologists in the world in comparison to, say, football fans. Look at the number of science bloggers as compared with other topics, for example. Despite this, there are still initiatives out there, however, working on pulling together repositories of techniques and knowledge: OpenWetWare for example. So the concept of producing an open collection of techniques and recipies is not a foreign one to the biotechnology community - it's just not very advanced at this stage, at least not in comparison to the bodies of knowledge associated with larger communities.

Thus I think that a larger seed, a bigger online repository of freely available and reliable recipes for longevity-related biotechnology, would act as an attractor for people willing to tinker and help out. The same class of supporters and advocates who produced initiatives like OpenWetWare will contribute to help polish its contents. Overall, the concept of a codex seems to me to be where a comparatively small amount of money could be leveraged to good effect. Consider this:

  • Creating an initial repository website and content management system isn't a significant cost given the present state of open source content management software - it's almost something I could undertake myself.
  • People with significant knowledge of biotechnology are remarkable cheap to engage at the post-graduate level. Consider that a few thousand dollars of post-graduate time can net you a long and well-informed analysis, or detailed explanation of a specific methodology.
  • It wouldn't be a good piece of writing of course - no offense is intended when I say that few post-graduate scientists can write well. Writing well is hard, and just as much a specialty as is becoming a scientist; few people have the time and inclination to specialize in more than a few things, and why should one of them be writing?
  • Fortunately, people who can write well are always in supply, desperate for work, and inexpensive. It is a buyer's market.

So I can envisage a guiding council of advisors putting together a plan for the hierarchy of topics they would like to see in the Vegas Group codex, from basic methods in biotechnology through to best attempt reverse engineering of things we know to be possible and that have been published: such as Cuervo's work on restoring youthful levels of autophagy, or protofection to replace mitochondrial DNA. The end result of that process might look something like a distillation of Fight Aging! mixed with the very elegant materials produced by the Science for Life Extension Foundation.

Codex project volunteers would then run an ongoing process of hiring post-graduates and interested researchers to write, and passing the results to starving authors who improve the output to a quality suitable for the open biotechnology community. There would of course be some back and forth between the post-graduates and the starving authors in order to reduce the inevitable translation errors, but I see this as a viable way to produce a body of knowledge that is sufficiently good to begin with - not perfect, not even necessarily very good, but sufficient.

Since only a comparatively limited reach of biotechnology is under consideration, the cost of bootstrapping such a project might be less than a few hundred thousand dollars. The things I would need to understand before getting seriously underway on a Vegas Group codex are largely related to validating that price tag. A few hundred thousand dollars would mean that it is worth starting with ten thousand dollars, some volunteers, spare time, and raising funds as we go based on the quality of work exhibited. That would be true bootstrapping, but I'd have to give thought in advance to:

  • The actual cost of generating the materials - something that I suspect won't be clear until the project is at least twenty articles in. I have a fair grasp on the range of costs for writing for hire, in fields that range from very specialist (pricey) and completely generalist (a few cents a word), but I've no idea where this market falls in that spread of values, nor how much management and general cat-herding of writers would be required.
  • The predicted size of a sufficiently large body of information, as set out by guiding experts. Is it a hundred articles, a hundred videos, a thousand images, or half that, or ten times that?
  • How to make this project attractive to the existing open biotechnology community even in its earliest stages. There is no such thing as "build it and they will come" - if anything building in isolation guarantees that you'll have few visitors.

Which comes right back around to networking and relationships: as I said, they make the world go round. On that topic, I am sadly lacking in a knowledge of the current state of the open biotechnology community - something that will have to change as I give more thought to the Vegas Group idea. No sense in reinventing the wheel if there is a wheel out there already ... or even a half-built wheel, a project where lessons were learned.

Recommendation and review posted by Fredricko


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