Archive for the Medicine Category

Immunological Horizons

Posted in Medicine, Science!, Things You Should Read with tags , , on November, 2011 by melendwyr

By now you’ve probably heard the news:  a team of researchers at MIT have developed a treatment which can target cells in which viruses are replicating and destroy them.  Which is pretty much the only way to deal with virus-infected cells, so it’s not as draconian a strategy as it sounds.

So far, it hasn’t been rigorously tested in human beings, and there are just tons of potential complications, obstacles to overcome, and hurdles to leap… but the potential is staggering.  This is the sort of thing which science fiction has only speculated about.  A few people have said this is like hearing about the initial research into penicillin.  They’re wrong.  This is way, way bigger.  Potentially.

There are some obvious possible drawbacks.  The therapy wouldn’t be all that useful for conditions in which the nervous system itself becomes infected, for example, not beyond perhaps the very earliest stages of infection.  And conditions in which immune cells are infected?  I don’t know that this would be useful for, say, HIV, once the infection is established.  The drug used has to diffuse throughout the body, which is going to require quite a dose, and I’m fairly sure it’s expensive.

But this could change the world substantially, in ways we can barely imagine.

It’s too soon to start breaking out the champagne and Nobel Prizes.  We should put a bottle on to chill, just in case.

Thoughts on Hospitalism

Posted in Medicine with tags , , , , on October, 2009 by melendwyr

A few people have commented on the similarity between puerperal fever, the cause of which was discovered by Ignaz Semmelweis, and hospitalism.

There are certain regions of overlap between the two examples. In both cases, a great deal of suffering and death was iatrogenic – that is, caused by doctors and their treatments. And in both cases, the problem was mostly resolved once the causes were generally understood. The differences are important, however: puerperal fever was considered a normal, if very serious, risk. Hospitalism deaths were always considered to be a morbid deviation from a healthy baseline. Of greater concern is nature of the relative causes: the high incidence of puerperal fever was the result of doctors not knowing about germ theory more than any particular thing they did; although midwives were far less likely to conduct internal investigations without pressing need, a large amount of direct physical contact is pretty inevitable. Hospitalism, in contrast, did not occur in anything approaching a ‘natural’ post-birth environment. It was caused entirely by the interventions of medical professionals. Thus, every attempt to improve things made them worse instead.

Failing to prevent harm, and actively inflicting harm, are distinctly separable.

Hospitalism: A Failure to Thrive

Posted in Doom, Medicine with tags , on October, 2009 by melendwyr

In medicine, it’s important to distinguish between a disease and a syndrome. Syndromes are collections of symptoms characteristically associated with each other – they don’t necessarily share the same causes.

One noteworthy syndrome of infancy and early childhood is called ‘failure to thrive’. The child’s development and growth fails to proceed normally, sometimes for obvious reasons such as inadequate nutrition or a major illness sapping resources. But sometimes the cause is less obvious.

Hospitalism was the name coined in 1895 to describe a phenomenon that often struck infants and young children who were hospitalized in the late 19th century. Despite receiving the highest standards of care, they were weak and sickly. They didn’t grow properly. They died at rates exceedingly high even for the norms of the time. And no one knew why.

Heroic measures were taken. Infants were isolated from their mothers, kept under constant supervision in specially-sealed incubators. It didn’t help. Children continued to die, and nothing anyone could do seemed effective at protecting them from the mysterious contagion that claimed their lives. It had been noted that Hospitalism struck at the most modern facilities and wealthiest parents but not at the children of the poor and isolated, but the significance of this fact was not recognized until the 1930’s. Then the common factor responsible for the failure to thrive was identified: the modern, up-to-date, sterile, and thoroughly unnatural treatment afforded the young was itself the cause.

It is not well-known why bonding and physical interaction between caregivers – particularly mothers – and infants is necessary for health and even survival, but it is thought to be the result of Darwinian calculations. Infants are cheap in terms of resources devoted to them – it would take many long years before they are capable of reproductive contributions. Mothers can produce more offspring relatively quickly. It follows that it is more important to preserve the life of a mother than the life of an infant if the lives of both are in jeopardy. Under conditions where a mother cannot spend time caring for a new infant, the principles of selection determine, it’s better for the infant to die so that the mother can focus on preserving her own life. So infants are programmed to self-terminate if they receive inadequate attention and stimulation.

Much as treating the weapon kept physicians from injuring their patients and was thus an ‘effective’ treatment, being poor meant that your parents had to take care of you and had no access to the ‘advanced’ standards of care that hurt the infants they were intended to keep safe. The doctors themselves were the problem – keeping them away from the infants was the solution.

An Idea Whose Time Has Come

Posted in Fantasy, Medicine on October, 2009 by melendwyr

Voodoo Acupuncture. Instead of having to stay still while people poke needles in you, they just take appropriate samples of hair, skin scrapings, and fingernails. Then those things are used to construct an effigy. Needles are then poked into the appropriate places on the doll in order to complete treatment.

The best part is, once the initial figurine is made, there’s no need for the patient to come into the offices! Treatment can be engaged in while the patient is elsewhere, living their life as normal. And they can be billed for a full visit, because the witchdoctor is ministering directly to them through the medium of voodoo.

Problems with Schizophrenia Comic

Posted in Medicine, Politics and Society, Science! on September, 2009 by melendwyr

See this comic.

What’s the problem? The claim that the schizophrenic aren’t more dangerous. Actually, people with delusions are significantly more likely than those without to engage in physical assault – and the problem is that it’s very difficult to predict when they’ll do so.

Obviously, given ‘sane’ individuals can be very violent too, and if a given schizophrenic has no history of violent reactions there’s really no reason to think they’ll suddenly start. But all else being equal, they’re a greater danger to others than they’d otherwise be.

I’m not even going to touch the discussion of what the causes of schizophrenia are – that topic requires more work than is suitable for this post.

Thoughts on Charles Bonnet Syndrome

Posted in GIGO, Medicine, Science! on September, 2009 by melendwyr

Possibly the most important lesson that should be taken from the story of Charles Bonnet Syndrome (CBS) is that correlation implies nothing about causation and even less about etiology.

Patients with general dementia, Alzheimer’s, or strokes were far more likely to communicate seeing things that weren’t there. So if you merely look at reported population statistics, visual hallucinations would seem to be associated very strongly with brain damage.

But the real problem was that such patients were much more likely to be uninhibited in talking about their hallucinations. Older people with loss of sight but properly-working minds feared the consequences of mentioning what they saw to anyone – at least partially because of the existing association in physicians’ minds between visual hallucinations and senility – and so said nothing. And so there was no awareness of the true rate of the phenomenon.

If you look at the actual statistics – the ones collected once the stigma of CBS was reduced, physician awareness increased, and elders gently but insistently questioned – then there’s no particular association between senility or brain disease and the hallucinations.

Remember – it took hundreds of years for the condition to even be mentioned in the English language, despite all of the people who must have experienced vision loss and CBS in that time. Despite all of the physicians who must have aged or had eye damage and suddenly experienced it themselves.

The Absence of Evidence

Posted in GIGO, Medicine with tags , , , , on September, 2009 by melendwyr

In 1769, the Swiss naturalist and philosopher Charles Bonnet noticed that his nearly-blind grandfather reported vivid hallucinations of things which he knew to be non-existent. As his own sight worsened with age, Bonnet began to experience similar visions: birds, men and women, strange plants, and architectural patterns came and went. As he was the first person to describe this phenomenon, it was named after him: Charles Bonnet Syndrome.

The syndrome did not enter the English medical literature until 1982. Most physicians and nurses had never heard of it, and there was little literature about it even in non-English journals. Millions of people had seriously-impaired vision without experiencing CBS, so clearly it must be a very rare and unusual condition. If elderly people reported seeing things, it was considered to be overwhelmingly likely to be a sign of dementia or psychosis.

Until doctors actually sat down and questioned patients as to whether they had seen peculiar things, with no suggestions that they were insane or demented. Then it was recognized that more than half of all people with impaired vision, particularly those whose loss of sight occurred suddenly, experienced CBS.

Most of them were afraid they’d be considered mad if they mentioned what they saw to people, only about a third revealed the hallucinations to anyone, roughly a third lived in terror that they were losing their minds, and the vast majority did not tell their physicians. Unless actively encouraged to be honest, and given assurances that seeing things wasn’t a sign of insanity, many people simply denied their experiences if asked.

People who had strokes, were developing Alzheimer’s, and so on were indeed more likely to report having visions. Not necessarily because the visions resulted from neurological impairment, but because they were less likely to possess the contextual awareness of others and their expectations and repress mention of them.

This is a superb example of how important it is to always keep in mind the distinction between reality and our knowledge of it. Absence of evidence is not evidence of absence. Relying upon our collective knowledge base is often useful, but it prevents us from checking that base against reality and correcting it when wrong.

If you assumed that CBS must be rare and unusual, because there was no recognition of it in the literature and doctors knew nothing about it, you’d have make the implicit assumption that physicians’ knowledge was valid and complete. In reality, it wouldn’t be – not through any fault of the doctors, mind you. But you’d be ruling out in advance the possibility that the system itself was lacking, and so wouldn’t have been able to notice the problem and correct it.

Only once physicians actively considered the possibility that they were missing something, and sought out evidence from the patients themselves instead of what the profession thought it knew, was the gap between understanding and reality closed.