The Biology of Ultrasound by Emily L. Williams,molecular biologist

[proximity1]

The Biology of Ultrasound

 

January 10, 2013 by Emily L. Williams

 

posted here with the kind permission of the author, Emily L. Williams, a developmental and molecular biologist engaged in laboratory research, written on recommendation of Dr. Michael F. Casanova, M.D. Both Ms. Williams and Dr. Casanova are at the University of Louisville. Both host a science blog. The following was originally posted at E. Williams' blog.

 

This is opened here for the dual purposes of discussion and to heighten awareness by bringing this to the attention of readers, their friends and families who are susceptible to being advised to submit to ultrasound technology.

 

 

 

Proposing that prenatal ultrasound is a potential teratogen sounds like pseudoscience to most people, I realize this. Hell, when my partner came to me with the idea even I thought he’d gone round the bend. But he really wanted us to review the literature and see if this crazy notion could have any foundation at all. Prenatal ultrasound is after all a growing clinical epidemic and the Rakic team out of Yale had published a paper back in 2006 that found changes in the brains of prenatally exposed mice, so why not? [1]

 

With my reservations in hand, I started scanning the literature. At first all the early safety studies from the ’70s and ’80s seemed to say the same thing: “No deleterious changes following exposure.” Again and again I came across the same types of studies, many epidemiological. After awhile and in frustration, I set the searches aside because the literature at first glance really seemed to suggest that ultrasound was relatively safe, and the occasions in which differences did arise, such as low birth weight, they eventually righted themselves. So not much to go on.

 

After a nice hiatus investigating other things, I ran across an article that showed that when osteoblasts, fibroblasts, and monocytes were subjected to ultrasound in vitro (in a petri dish), exposure stimulated the production of interleukin-8, basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF), each of which acts as growth factors on these and nearby cells [2]. That same group later found that osteoblasts under similar levels of exposure release nitric oxide and prostaglandin E2, both of which are known to have growth-inducing effects on bone [3].

 

Even though we’re talking bone and not my primary focus, brain, these results truly intrigued me. Unfortunately, one can’t be certain from such an experiment that the same would be found in vivo (in life) as opposed to a petri dish and whether such effects occur across cell types. But the fact that the effect was real ignited my curiosity and I was primed to continue my searches into the biophysical mechanisms of ultrasound. It hasn’t been easy because the research is spread across numerous professional disciplines, but here’s a basic rundown of my literary travels:

 

Ultrasound is exactly that, “ultra” and “sound”. It’s an auditory waveform that occurs above the upper limit for human hearing. Like all sounds– and as is implied by the term “waveform”– this flow of sound pressure occurs in waves, called compression and expansion half-cycles. All that simply means is that the materials that are hit by this sound undergo alternations of a compression of their materials followed by an expansion, kind of like an accordion. This is one of the things that makes ultrasound potentially dangerous, dependent on the level of intensity of the soundwave and the duration of exposure.

 

The act of bubble or cavity formation within a liquid upon ultrasound exposure is called cavitation. The term cavitation is particularly used to refer to the implosion of a gaseous bubble under pressure within a liquid, although this is more specifically known as transient cavitation. Stable cavitation is the formation of bubbles which remain relatively stable in the liquid medium. In pure water, bubbles form at more than 1,000 atmospheres of pressure, which is to say that if you were to take pure water and subject it to even the highest intensities of diagnostic or prenatal ultrasound, bubbles would not form because the intensity is far too low. But not so for biological tissues. As occurs with almost every solid within a liquid (e.g., cells), small gaseous pockets hide within crevices. The pre-existence of such bubbles essentially lowers the threshold for cavitation within biologic tissue compared to pure water because gaseous cavities, though extremely small, are already present. When subjected to the force of ultrasound, these bubbles undergo expansion with the expansion half cycles and compression with the compression half cycles. Just picture taking a balloon, blowing it up, then sucking in a little of the air and seeing it contract a little bit, and repeat this procedure over and over again. In this analogy you are the ultrasound wave, the force driving expansion and contraction. The main problem is that with each subsequent cycle, the bubble compresses less and less, so over time the size of it grows until at which point, much like when that balloon is filled till it pops, the surface area of the bubble can no longer withstand the pressure. In the case of a bubble in liquid, it implodes and the surrounding water rushes in, meets with the gases once trapped in the bubble, triggering a violent chemical reaction which produces an extraordinary local rise in temperature– a temperature close to that of the surface of the sun [4]. Thankfully, the rapid cooling rates of the surrounding medium (on the order of 109 ⁰C·s-1) virtually assure that for a single occurrence the temperature of surrounding tissues rises insignificantly. The problem arises when transient cavitation occurs more frequently in a local tissue such that the rapidity of cooling is not as efficient which can cause thermally-induced tissue damage.

 

These little bubbles can also cause other problems aside from temperature increase. As you might imagine, when a bubble implodes it can create a considerable force of pressure in the surrounding medium such that nearby cells may be hit with high pressure water jets. This can also occur, though in a gentler fashion, by stable cavitation in which the bubble doesn’t implode but merely oscillates next to or within a cell, creating a variety of forces and pressures against the outer membrane and within the cell itself. In a worst case scenario, the jets of water may fatally damage the membrane and internal structures of cells, leading to cell death. In a less deadly scenario, the water jet may poke transient holes through the outer membrane of the cell which allows into the cell many communicating molecules such as sodium, calcium, and various proteins. This inward rush of calcium, for instance, can activate many downstream pathways involved in cell repair, cell growth, and even alter cell-to-cell communication, such as in the case of neurons. Did you know in fact that ultrasound is used transcranially (across the skull) to elicit activity of target neurons? [5]

 

So what harm can a little calcium do? Well, if it doesn’t kill off the cell through calcium cytotoxicity, the fact that many of these extracellular molecules are normally used in a controlled way for cell-to-cell communication essentially feeds cells the wrong messages and could feasibly alter the development of cells permanently, especially concerning stem cells, progenitors, or immature cells which may pass down these alterations through further generations.

 

Previous in vitro studies have also found that ultrasound is capable of promoting chromosomal breakages in DNA, although there isn’t currently evidence to suggest the same severity is found in vivo within diagnostic and prenatal intensity ranges so this may be an effect particular to cell cultures [6]. But it does beg the question what ultrasound exposure may be doing to the cellular contents within exposed cells. Poking transient holes through membranes, jostling the cell’s internal contents, disturbing its general physiology, and if exposure occurs for a long enough duration, the greater the likelihood of cavitation, deadly jets of water, and thermally-induced damage.

 

Think of it: You subject cells to increased water pressure, and if the duration is long enough the threshold for transient cavitation may be reached. The potential for ultrasound’s teratogenicity is considerable and, in this scientist’s opinion, research has not been thorough enough to rule out possible dangers. Consider the ultrasound parties which are becoming all the rage or the keepsake ultrasounds parents are having done to “start the family photo album early”,– or what about the doppler ultrasound fetal heart rate monitors that parents can use unsupervised in their own homes on a daily basis? And that’s not even addressing the issues of poor technician education or the staggeringly high rates of malfunctioning ultrasound equipment used in everyday clinical practice [7, 8]. Ultrasound regulations are dismal in this country and may unknowingly be turning a useful tool into a teratogen.

 

I want you to think about this: The image below is a pump which has been degraded by transient cavitation stimulated by ultrasonic waves. If you have enough force, this is what occurs to metal. Just think what could be happening to a developing fetus. Admittedly, this image is meant to scare you. And while the intensity levels and duration of exposure which a fetus endures are by no means comparable to what this water pump has gone through, it’s the same basic physics based upon cavitational and noncavitational effects.

 

 

We truly need to temper our enthusiasm for ultrasound photos of our babies and reassess whether this tool is as safe as we think it is. As a clinical tool it is extraordinarily useful, and not unlike X-rays, it has its purposes. But it isn’t just a photograph.

As a parting gift, below is a list of some of the many uses of ultrasound in medicine, manufacturing, and research. It’s been borrowed from one of our in-press publications (Williams & Casanova, 2013). I hope it might start the cogwheels turning.

1. Diagnostic sonography providing structural imaging, including prenatal ultrasound;
2. The ablation of target tissue, i.e., during neurosurgery or tumor removal, and the breakdown of calculi i.e. kidney stones or gallstones;
3. Transcranial ultrasonic stimulation, similar to transcranial magnetic stimulation (TMS);
4. Vasodilation, providing better visualization of the vasculature during cardiovascular procedures;
5. Targeted drug delivery, utilizing focused ultrasound to stimulate greater tissue more permeability, e.g., the blood-brain barrier, skin, etc.;
6. Wound healing;, e.g., bone fractures and ulcers;
7. Bactericidal properties when synergized with antibiotics;
8. Elastography, in which ultrasound is used to determine the elasticity of a given organ which can help discern the overall health of that organ;
9. Transmembrane delivery of products into target cells, e.g., nonviral genes or nutrients;
10. Acoustophoresis: the use of ultrasound on an ionic medium to create an electric charge;
11. The purification of agricultural products;
12. Heat transfer in liquids for production of substances such as ethanol;
13. The purification of metals;
14. Manipulation and characterization of particles in the bio- and physical sciences;
15. The testing of metals, plastics, aerospace composites, wood, concrete, cement, etc. in manufacturing in order to measure thickness and locate flaws within the material.

link to original text: https://insolemexumbra.wordpress.com/2013/01/10/the-biology-of-ultrasound/comment-page-1/#comment-106

Edited January 12, 2013 by proximity1

[John Cuthber]

They didn't do ultrasound scans before they invented them (obviously).

Nowadays, practically every baby in the Western world is scanned.

If ultrasound caused birth defects then the number of such defects would have risen and people would have noticed and stopped scanning babies.

There was no jump in the number of birth defects to correspond with the jump in the number of babies scanned.

So you can conclude (on the basis of a truly massive scale experiment) that the effect is either very small or non existent.

 

Why do people come up with this sort of stuff?

In particular why say things like "As occurs with almost every solid within a liquid (e.g., cells), small gaseous pockets hide within crevices." without some sort of evidence?

After all, these cells have never been exposed to air- where would the gas in the crevices have come from?

 

Why put in a picture of a damaged lump of metal?

It's got nothing to do with the situation in utero.

 

Are people like Emily Williams just trying to attract attention to themselves?

[proximity1]

"After all, these cells have never been exposed to air- where would the gas in the crevices have come from?"

 

 

Do red blood cells carry oxygen? Why? Is oxygen a "gas"? Do cells respire, consume oxygen as a vital function? Is there ever any H₂O within a cell? Within the tissue composed by cells?

 

Please, as a non-specialist, I'd like to be better informed on these points. Could you help? And, yes, I wonder: why would a medical doctor and research specialist in molecular biology and another associated researcher bother to rasie such concerns unless they were sincerely concerned about the potential dangers? I wonder! Perhaps you could suggest an ulterior motive on their parts--because that is exactly what you are insinuating. Personally, given what I've read already by Emily Williams, I can't think of any plausible ulterior motive on her part or that of Dr. Casanova.

 

So, please, have you a good idea or, indeed, any idea at all why they'd bother to raise or attempt to raise concern in the public under false pretenses?

 

I'll wait for your explanations. Thank you.

[John Cuthber]

That's like saying my cup of coffee is solid because it has sugar dissolved in it and sugar is a solid.

As something dissolves it changes phase.

 

I asked a question. Do you have an alternative explanation for the observed behaviour?

Why do people write this sort of thing?

Is it just attention seeking?

If not, what is it?

[proximity1]

That's like saying my cup of coffee is solid because it has sugar dissolved in it and sugar is a solid.

As something dissolves it changes phase.

 

I asked a question. Do you have an alternative explanation for the observed behaviour?

Why do people write this sort of thing?

Is it just attention seeking?

If not, what is it?

 

Yes, you asked a question --and I answered it :

 

" I can't think of any plausible ulterior motive on her part or that of Dr. Casanova."

 

If you can reason logically, then that leaves only motives which are other than ulterior--those that are disinterested, open, above-board, all of which are what I see as the antonyms of "ulterior."

 

I think the motives are right there in front of your nose: a plain honest concern, based on reasoned facts concerning the physics of cells and the soft tissues (to say nothing of hard tissues, such as bone, etc.) and the potential for serious harm to patients' internal tissues, but, most of all, to the health and safety of fetuses in utero--- harm as a consequence of ultrasound technology as used in routine medical practice.

 

By the way, I can add, as for clarification of motives all there is to know about how Ms. Williams' commentary came to be posted here. I, on my sole initiative, without the slightest influence in any form or fashion on the part of the author, Ms. Williams, proposed to re-post her views here, and I did that with the sole intention of bringing attention to a topic which I believe, as a completely disinterested observer, is worthy of wide notice and discussion, in order, especially, to allow the general public to give due consideration to a range of technologies used in medical practice in ways that there is valid reason to suspect are potentially seriously harmful.

 

I have no personal interests whatsoever in the authors, their blogs, their professional or personal lives--just as, in posting here, I am acting solely on my own personal initiative without the slightest interest in or prospect for any gain of any kind whatsoever.

 

I don't see how I could state a clearer or more complete position of disinterest on my part in this matter. Nor have I any reason to think that Williams or Casanova are acting on anything other than the best and most public-spirited intentions to serve the interests of the public to be informed.

 

So, that's my view of "why".

 

What are your interests, if any in the issue? please.

Edited January 12, 2013 by proximity1

[John Cuthber]

My only interest is in trying to ensure that stuff posted on this site is actually scientific.

 

Incidentally, while "I don't know" is a valid answer to the question "why do people write stuff like this?", it doesn't move the discussion forward.

 

I'm not terribly concerned about why you copied it here, but I'd like to know what it was written for in the first place. If it's a genuine concern then why not put in real evidence rather than claims about bubbles in cells and scaremongering pictures of damaged metal?

Above all, they need to explain why the widespread use of ultrasound didn't bring about an epidemic of birth defects (or if it did, how come we didn't notice like we did with thalidomide).

Otherwise it's not really science.

Here's an idea of what the scientific version would look like.

Based on the fact that high intensity ultrasound can damage things I hypothesis that the low intensity ultrasound used in scanning babies is harmful.

From that hypothesis I make a prediction.

If ultrasound produced damage then, when the technique became widespread, the number of birth defects would rise.

Further, if the number of defects rose, then people would notice (based on the observation that they noticed thalidomide).

No such rise has been observed.

Therefore the original hypothesis is wrong.

 

That piece by Emily Williams isn't science.

The deliberate scaremongering isn't helpful either.

 

If there is actually any substance to this then it's important- far too important to be dealt with as badly as that quote which started this thread.

Edited January 12, 2013 by John Cuthber

[proximity1]

My only interest is in trying to ensure that stuff posted on this site is actually scientific.

 

Incidentally, while "I don't know" is a valid answer to the question "why do people write stuff like this?", it doesn't move the discussion forward.

 

I'm not terribly concerned about why you copied it here, but I'd like to know what it was written for in the first place. If it's a genuine concern then why not put in real evidence rather than claims about bubbles in cells and scaremongering pictures of damaged metal?

Above all, they need to explain why the widespread use of ultrasound didn't bring about an epidemic of birth defects (or if it did, how come we didn't notice like we did with thalidomide).

Otherwise it's not really science.

Here's an idea of what the scientific version would look like.

Based on the fact that high intensity ultrasound can damage things I hypothesis that the low intensity ultrasound used in scanning babies is harmful.

From that hypothesis I make a prediction.

If ultrasound produced damage then, when the technique became widespread, the number of birth defects would rise.

Further, if the number of defects rose, then people would notice (based on the observation that they noticed thalidomide).

No such rise has been observed.

Therefore the original hypothesis is wrong.

 

That piece by Emily Williams isn't science.

The deliberate scaremongering isn't helpful either.

 

RE : " That piece by Emily Williams isn't science."

 

True. And who has claimed otherwise? You're trying to present a straw-man, there. Her article is an opinion piece--but it's an opinion piece by a professional research scientist (or two) who are by all outward indications entirely competent to write and comment knowledgably on the topic.

 

Your own posts here aren't "science" either. It's interesting how you allow yourself here the very same scope and freedom to comment --not "practice science"--that you reproach E. L. Williams for doing in her blog. Nowhere do you present us with the grounded reasons why your objections to her article are at all better founded or reasoned than what she has written--with supporting references.

 

 

RE:

 

"

No such rise has been observed.

Therefore the original hypothesis is wrong."

 

As a matter of logic, that is flatly false.

 

The premise, that no such rise has been observed, is your unsupported assertion and, even if that were in fact true, it does not logically follow that the original hypothesis, or, namely, (as you have put it),

 

"Based on the fact that high intensity(*) ultrasound can damage things I hypothesis that the low intensity(*) ultrasound used in scanning babies is harmful." ----that this is false.

 

It's entirely consistent with Williams' article to reason that, contrary to your claim here,

 

"If ultrasound produced damage then, when the technique became widespread, the number of birth defects would rise. ... if the number of defects rose, then people would notice"

 

a consequent rise in birth defects could be inadvertently misattributed to other causes, and the potential involvement of ultrasound ignored, down-played, discounted--just as you discount it here. In that case, the original hypothesis --stated tendentiously in your terms--could be valid at the same time that the relationship in birth-defects is missed or ignored. Nowhere does Williams indicate that medical ultrasound is, as you put it, "low-intensity". "High" or "low" intensity are arbitrary concepts with no particular significance other than in relation to the fragility of the substances to which these are applied.

 

As to your own interests, you haven't had a word in response to offer to my previous queries. But you aren't slow to impugn the integrity and sincerity, by insinuation, of others. Why is that?

 

When it comes to the physics, you don't offer us the reasoned arguments why the intensities practiced in medical fetal scans are, with regard to the tissue matter being subjected to the scan, are fairly or correctly described as "low-intensity", nor why, in the case where, in relation to soft tissues, they are not low intensity, the concerns expressed by E.L. Williams are not entirely reasonable ones.

 

Got "science" ? --as you're implicitly demanding that Williams present in what is an opinion article, based on her professional knowledge of the subject or just your unsupported assertions to offer?

 

------------------------

 

Note: bold (*) : indicates your tendentious phrasing, above, not the author, Williams', arguments or assertions.

Edited January 12, 2013 by proximity1

[John Cuthber]

So, no real evidence of an effect then?

 

Can you explain why you have described my words, but not those of the original quote, as tendentious?

Do you not see that it is "Expressing or intending to promote a particular cause or point of view"

And, by extension your choice to highlight my words is "Expressing or intending to promote a particular cause or point of view".

 

It seems we are all at it.

 

Re "As to your own interests, you haven't had a word in response to offer to my previous queries. "

Yes I have.

Specifically, you asked "Do red blood cells carry oxygen? Why? Is oxygen a "gas"? Do cells respire, consume oxygen as a vital function? Is there ever any H₂Owithin a cell? Within the tissue composed by cells?"

and I pointed out the change in phase that occurs on dissolution.

 

You asked

"Please, as a non-specialist, I'd like to be better informed on these points. Could you help? And, yes, I wonder: why would a medical doctor and research specialist in molecular biology and another associated researcher bother to rasie such concerns unless they were sincerely concerned about the potential dangers? "

and

"So, please, have you a good idea or, indeed, any idea at all why they'd bother to raise or attempt to raise concern in the public under false pretenses?"

and I repeated my suspicion that it might be attention seeking.

(I remind you that you have not presented any evidence to refute the suggestion or any alternative.)

 

And you asked " What are your interests, if any in the issue?"

And I explained my interest; that I want the site to be based on science rather than scaremongering.

 

 

So it seems that I have responded to your questions.

Why did you say I hadn't?

Edited January 13, 2013 by John Cuthber

[proximity1]

So, no real evidence of an effect then?

 

Can you explain why you have described my words, but not those of the original quote, as tendentious?

Do you not see that it is "Expressing or intending to promote a particular cause or point of view"

And, by extension your choice to highlight my words is "Expressing or intending to promote a particular cause or point of view".

 

It seems we are all at it.

 

Re "As to your own interests, you haven't had a word in response to offer to my previous queries. "

Yes I have.

Specifically, you asked "Do red blood cells carry oxygen? Why? Is oxygen a "gas"? Do cells respire, consume oxygen as a vital function? Is there ever any H₂Owithin a cell? Within the tissue composed by cells?"

and I pointed out the change in phase that occurs on dissolution.

 

You asked

"Please, as a non-specialist, I'd like to be better informed on these points. Could you help? And, yes, I wonder: why would a medical doctor and research specialist in molecular biology and another associated researcher bother to rasie such concerns unless they were sincerely concerned about the potential dangers? "

and

"So, please, have you a good idea or, indeed, any idea at all why they'd bother to raise or attempt to raise concern in the public under false pretenses?"

and I repeated my suspicion that it might be attention seeking.

(I remind you that you have not presented any evidence to refute the suggestion or any alternative.)

 

And you asked " What are your interests, if any in the issue?"

And I explained my interest; that I want the site to be based on science rather than scaremongering.

 

 

So it seems that I have responded to your questions.

Why did you say I hadn't?

 

 

RE :

 

“So, no real evidence of an effect then?”

 

The effects of ultrasound technology, particularly as concerns effects on soft tissues in fetuses in utero, are quite reasonably liable to be at the cellular level, and not, as you’ve confined the “search-area” to be—in obvious defects in internal or external organs of the new-born. Therefore, unless doctors are looking for indications of actual cell-damage or malfunctions in cells in the new-born, there is no particular reason to suppose that, in the hypothesis that ultrasound technology can disrupt and damage cells, the doctors would detect anything amiss.

 

In addition, “birth-defects” are phenomena we associate with the hours, days, weeks or a few months following birth. Your unstated assumption, explicit in your chain of reasoning, is that if the ultrasound technology were harmful, then it shall have produced an observed increase in birth defects. But, in fact, that doesn’t by any means exhaust the possibilities for potential harm, does it? Instead, the cellular damage could be such as is not noticeable until much later. Since newborns are still in developmental stages in their anatomy, damage to their internal soft tissue could have much delayed consequences. Imagine, for example, that the ultrasound technology disrupts the cells, in the fetus’s still-developing testes? That’s not something that doctors would likely look for or see evidence of soon after birth. But the foundations for later testicular malfunctions or low-sperm production could conceivably been laid from the time that the fetus was subjected to ultrasound. Years later, when considering male fertility, how many doctors are going to put ultrasound technology on the suspect-list?

 

There is simply no good reason to assume, as you do, that all that medical scientists have to consider is the incidence of observed birth-defects in determining whether or not there is a question as to the safety of ultrasound technology. Very simply, in this circumstance, doctors don’t necessarily know what “they’re looking for” as indications of potential harm—no more than they are aware of what they may be overlooking.

 

RE:

 

“Can you explain why you have described my words, but not those of the original quote, as tendentious?”

 

In what I call a tendentious recapitulation of the reasoning-chain –as you imagine it to be--in the mind of the author, Ms. Williams, your comments give us a specious comparison, never found in her text; a comparison in which, on one hand, you refer to levels of ultrasound as “high-intensity”, as being “harmful”—(viz: “Based on the fact that high intensity ultrasound can damage things...”) and then, tendentiously proceed to define, as by implication, that a different level, which you, not Williams; refer to as “low-intensity”, is a level, by virtue of which label “low,” is not to be taken seriously as a potentially harmful factor, (viz: ridiculing the idea as follows, (in your recap of Williams’ supposed reasoning according to you), “I hypothesis (sic) that the low intensity ultrasound used in scanning babies is harmful.”)

 

That is, you resort to a contrived comparison, one which the author never states or assumes in her article; you attribute this comparison to our author as being an integral part of her line of reasoning, you then indicate that what is somehow supposed to be by definition (never specified) “high-intensity” (whatever that means) is liable to produce harm, while“low-intensity”(whatever that means) is not so liable to produce harm.

All of that in order to invite the reader to regard as preposterous such a contrived comparison, and, indeed, it is preposterous.

 

The fact is, however, that, contrary to what you suggest by implication, both “high-intensity” and “low-intensity” are simply arbitrary labels and they become meaningful only when they are seen in the context of some actual case where the material subjected to ultrasound can be considered for its fragile character. ( I have already explained this above and you have completely ignored that explanation.) That, taken together, constitutes what I call a case-book example of a tendentious argumentation—it works via insinuation and innuendo. Those are your tools here, as I’ll show in still another example (*).

 

RE:

 

“Do you not see that it is "Expressing or intending to promote a particular cause or point of view. And, by extension your choice to highlight my words is "Expressing or intending to promote a particular cause or point of view".

 

No more so that Einstein’s special or general theories of relativity “intend to promote a particular cause or point of view,” no, I do not.

 

RE:

 

“It seems we are all at it.”

 

But we are not “all at it” in the same way or with the same good-faith. It seems to me that you are singularly lacking in that latter in this thread.

 

RE:

 

 

Re "As to your own interests, you haven't had a word in response to offer to my previous queries."

Yes I have.

Specifically, you asked "Do red blood cells carry oxygen? Why? Is oxygen a "gas"? Do cells respire, consume oxygen as a vital function? Is there ever any H₂Owithin a cell? Within the tissue composed by cells?"

and I pointed out the change in phase that occurs on dissolution.

 

You asked

"Please, as a non-specialist, I'd like to be better informed on these points. Could you help? And, yes, I wonder: why would a medical doctor and research specialist in molecular biology and another associated researcher bother to raise such concerns unless they were sincerely concerned about the potential dangers? "

 

and

"So, please, have you a good idea or, indeed, any idea at all why they'd bother to raise or attempt to raise concern in the public under false pretenses?"

and I repeated my suspicion that it might be attention seeking.

(I remind you that you have not presented any evidence to refute the suggestion or any alternative.)

 

 

Nonsense. I’ve expressly stated that an alternative to a motive of “attention seeking” is, as I see it, to be found in (from my post N° 5, quote) “...a plain honest concern, based on reasoned facts concerning the physics of cells and the soft tissues (to say nothing of hard tissues, such as bone, etc.) and the potential for serious harm to patients' internal tissues, but, most of all, to the health and safety of fetuses in utero--- harm as a consequence of ultrasound technology as used in routine medical practice.”

 

(* ref. above : "as I’ll show in still another example (*)" ) this example:

 

On the contrary, you have presented absolutely nothing in evidence of the base motive of “attention seeking”— failing to conceive of any other possibility. Your imagination is manifestly lacking something which comes without strain or effort to my imagination: the possibility that the author(s) are motivated by a good-faith and soundly-reasoned concern for the welfare of the general public. This, again, is the second time I have expressly spelled that out to you and the second time you’ve ignored it, claiming, flatly falsely, that I’ve “not presented...any alternative (motive)” to the base one you assert, without the slightest evidence for it offered on your part.

 

RE:

 

 

“ And you asked ’What are your interests, if any in the issue?’ And I explained my interest; that I want the site to be based on science rather than scaremongering. So it seems that I have responded to your questions. Why did you say I hadn't?”

 

 

Because, until this, (just above), where you claim that your motives in participating here in this thread are, “I want the site to be based on science rather than scaremongering.” You’d offered none.

 

But you’re ignoring in that another aspect of my query to you—one which I see I have to state expressly concerning your “interests”—as in your potential conflicts in considering the issues here without personal and corrupting influence on your positions; about that sort of “interest” you’ve given us no information at all. While I’ve stated categorically that as a disinterested layman, I have absolutely nothing “at stake” in the question, no potential gain or loss to color my views.

 

What about you? Are you a medical professional or otherwise professionally interested (i.e. “involved” ) in the use or the promotion of ultrasound technology in medicine or have you any gainful interest in the good-standing in the view of the public or the medical professions of the use of ultrasound technologies in some manner?

 

That is what I mean by your “interests” or lack of such in the topic. You’ve still completely ignored that factor. Now that I’ve put it in the plainest terms, are you going to continue to skirt that question?

 

 

 

 

 

 

That's like saying my cup of coffee is solid because it has sugar dissolved in it and sugar is a solid.

As something dissolves it changes phase.

 

I asked a question. Do you have an alternative explanation for the observed behaviour?

Why do people write this sort of thing?

Is it just attention seeking?

If not, what is it?

 

 

 

As I've been given to understand, oxygen, a gas, may be disolved in liquids. I don't know whether oxygen molecules in solution are physically distinct from their character in a gaseous state, but perhaps you do.

 

In the article, Williams refers (with a hyperlink) to the presence of nitric oxide ( symbol ; "NO" ) as a very important factor in cells' activity.

 

from Wikipedia:

 

 

"Nitric oxide, or nitrogen oxide,^[2] also known as nitrogen monoxide, is a molecule with chemical formula NO. It is a free radical^[3] and is an important intermediate in the chemical industry. Nitric oxide is a by-product of combustion of substances in the air, as in automobile engines, fossil fuel power plants, and is produced naturally during the electrical discharges of lightning in thunderstorms.

In mammals including humans, NO is an important cellular signaling molecule involved in many physiological and pathological processes.^[4] It is a powerful vasodilator with a short half-life of a few seconds in the blood. Long-known pharmaceuticals like nitroglycerine and amyl nitrite were discovered, more than a century after their first use in medicine, to be active through the mechanism of being precursors to nitric oxide.

Low levels of nitric oxide production are important in protecting organs such as the liver from ischemic damage."

 

http://en.wikipedia.org/wiki/Nitric_oxide

 

 

 

I gather that the nitric oxide is also disolved in the cells' liquid components, but maybe I'm mistaken about that. I doubt very much that E.L. Williams is mistaken about the significance of NO in cells and its potentials when subject to ultrasound.

 

About the sugar in your coffee. You've written, mockingly,

 

 

 

"That's like saying my cup of coffee is solid because it has sugar dissolved in it and sugar is a solid.

As something dissolves it changes phase."

 

 

But my point was that oxygen, in whatever phase, is in the body and is used by cells. So, like sugar, the fact that it's typically in a solid granular form when you dip a spoon into it, and then, when disolved in coffee drinks, it's a component of the resulting solution, doesn't alter the fact that, once introduced into your coffee, the "solid" sugar, typically a variant of C_nH_2nO_n, is nonetheless in your coffee, and the oxygen, once inhaled in human respiration, is nonetheless in the body via the lungs and the bloodstream, and carried by red blood cells. You may mock that as much as you wish; The essential facts are that in each case, the substances are introduced into a "system"--the sugar (C_nH_2nO_n) in you coffee, and the oxygen (O), in the bloodstream.

 

Once present (disolved) in liquids, gases, I gather, are susceptible to being released in bubble forms. Try a different beverage. Take, instead of coffee, a can or a bottle of beer. open it and pour it into a glass. After allowing the beer to settle, notice that from the bottom of the (inside of the) glass, tiny bubbles appear spontaneously in the liquid and float to the top of the liquid. That would be disolved carbon dioxide in the beer, as it is released from its soluable bonds in the liquid, right?

 

My point was that, disolved or not, within liquids molecules of a gas--oxygen, nitric oxide, nitrogen--can be present and can be acted upon by external conditions or effects applied to the solution in question, whether that is a glass of beer or the liquid contents of a cell in the body's tissues.

 

What part of that general view is wrong in the context of this thread's points?

Edited January 13, 2013 by proximity1

[John Cuthber]

" The effects of ultrasound technology, particularly as concerns effects on soft tissues in fetuses in utero, are quite reasonably liable to be at the cellular level, and not, as you’ve confined the “search-area” to be—in obvious defects in internal or external organs of the new-born."

 

I remind you that the original text you quoted is the one which introduces the idea of teratogenicity

So the search area I chose was the one that you chose for me.

 

While birth defects are often apparent at birth, they sometimes only show up later- for example the "hole in the heart" problem.

If scanning produced these then they too would have become more common and people would have noticed that..

The time-scale for diagnosis doesn't affect my reasoning. If scanning was harmful we would have noticed the harm.

We have't so it isn't (unless there's evidence that the incidence of birth defects has risen in line with ultrasound.)

 

Let me clarify something

You post a page that is clearly biassed in favour of the point of view that ultrasound causes problems- but it ignores the lack of supporting evidence. It includes a deliberately scary picture of a damaged metal pump. It's entirely one-sided and doesn't give anything like a balanced report.

 

I put forward a contrary point of view and you call it biassed.

You don't see that your complaint about my message but not the original, is evidence of your own bias. Instead you compare yourself with Einstein.

 

 

re ".a plain honest concern, based on reasoned facts..."

Nope, the facts are that we don't have an epidemic of birth defects so a reasoned concern would realise that this can't be much of an issue. It is not reasonable to extrapolate from the (known) effect of cavitation in pumps (where cavitation is known to happen) to the case of ultrasound scans (where it isn't).

 

"On the contrary, you have presented absolutely nothing in evidence"

Just as well that I never said that I had then, isn't it?

 

"Your imagination is manifestly lacking something which comes without strain or effort to my imagination: the possibility that the author(s) are motivated by a good-faith and soundly-reasoned concern for the welfare of the general public. "

Nope, wrong again.

I considered this but rejected it.

The welfare of the general public is not served by people issuing scaremongering reports.

You would be right if the work were "soundly reasoned" but the lack of an epidemic starting about 1950 shows that it is not sound or reasoned.

So, there must be another reason.

I suggested that it might be attention seeking.

 

And, as I said that my only interest was that of maintaining the quality of the site, you can accept that I don't have any other interest in the matter- I'm not a medical professor or whatever and I'm not in the business of selling ultrasound equipment.

If I were then I would have said so.

I said I only had one interest in the matter.

I don't appreciate your implication that I might have lied about that.

 

I didn't "skirt the question: I answered it directly.

Your own bias seems to have stopped you understanding it.

What, exactly, did you think the word "only" meant?

[proximity1]

" The effects of ultrasound technology, particularly as concerns effects on soft tissues in fetuses in utero, are quite reasonably liable to be at the cellular level, and not, as you’ve confined the “search-area” to be—in obvious defects in internal or external organs of the new-born."

 

I remind you that the original text you quoted is the one which introduces the idea of teratogenicity

So the search area I chose was the one that you chose for me.

 

While birth defects are often apparent at birth, they sometimes only show up later- for example the "hole in the heart" problem.

If scanning produced these then they too would have become more common and people would have noticed that..

The time-scale for diagnosis doesn't affect my reasoning. If scanning was harmful we would have noticed the harm.

We have't so it isn't (unless there's evidence that the incidence of birth defects has risen in line with ultrasound.)

 

Let me clarify something

You post a page that is clearly biassed in favour of the point of view that ultrasound causes problems- but it ignores the lack of supporting evidence. It includes a deliberately scary picture of a damaged metal pump. It's entirely one-sided and doesn't give anything like a balanced report.

 

I put forward a contrary point of view and you call it biassed.

You don't see that your complaint about my message but not the original, is evidence of your own bias. Instead you compare yourself with Einstein.

 

 

re ".a plain honest concern, based on reasoned facts..."

Nope, the facts are that we don't have an epidemic of birth defects so a reasoned concern would realise that this can't be much of an issue. It is not reasonable to extrapolate from the (known) effect of cavitation in pumps (where cavitation is known to happen) to the case of ultrasound scans (where it isn't).

 

"On the contrary, you have presented absolutely nothing in evidence"

Just as well that I never said that I had then, isn't it?

 

"Your imagination is manifestly lacking something which comes without strain or effort to my imagination: the possibility that the author(s) are motivated by a good-faith and soundly-reasoned concern for the welfare of the general public. "

Nope, wrong again.

I considered this but rejected it.

The welfare of the general public is not served by people issuing scaremongering reports.

You would be right if the work were "soundly reasoned" but the lack of an epidemic starting about 1950 shows that it is not sound or reasoned.

So, there must be another reason.

I suggested that it might be attention seeking.

 

And, as I said that my only interest was that of maintaining the quality of the site, you can accept that I don't have any other interest in the matter- I'm not a medical professor or whatever and I'm not in the business of selling ultrasound equipment.

If I were then I would have said so.

I said I only had one interest in the matter.

I don't appreciate your implication that I might have lied about that.

 

I didn't "skirt the question: I answered it directly.

Your own bias seems to have stopped you understanding it.

What, exactly, did you think the word "only" meant?

 

 

I didn't "skirt the question: I answered it directly.

Your own bias seems to have stopped you understanding it.

What, exactly, did you think the word "only" meant?

 

 

I'd understood it to mean, in the absence of any qualifying information to the contrary, as follows:

 

"My only interest as a participant in this discussion ..." & etc.

 

This seems to me an entirely reasonable reading of your assertion, given that you made nothing else clear about how one should read the term "interest" or "interested", or how you intended "interest" to be understood, and as that might have otherwise included a potential gainful interest on your part in the issue of ultrasound technology. In that situation, I contend that my reading was fairly construed and I had no clear indication at that point from you to the contrary.

 

 

 

 

I'm not a medical professor or whatever and I'm not in the business of selling ultrasound equipment.

 

 

I specifically asked you, "Are you a medical professional or otherwise professionally interested...?" and not merely whether you are or were a medical professor.

 

Again, in reply I get ambiguity from you; and the reason I ask your credentials in this matter is that you are emphatically presenting your views as presented here to be superior in value and probity to those of E.L. Williams and, I add, those of Michael F. Casanova, M.D.

 

Would you please explain why the reader ought to give your views greater weight than those of Williams and Casanova? Are you, as well, a medical doctor? I don't know how to be more precise, and you take every opportnity to make the most pains-taking precision necessary in order to get a simple, straight, answer.

 

Is it "John Cuthber, M.D." or not ? If not, what qualifies you to mock and deride the informed opinions of Dr. Casanova and his associate researcher, E.L. Williams, please?

 

 

RE:

 

 

"I remind you that the original text you quoted is the one which introduces the idea of teratogenicity

So the search area I chose was the one that you chose for me."

 

 

 

 

Please note, and show how the following is false, if so in your opinion:

Teratology

From Wikipedia, the free encyclopedia

Jump to: navigation, search

Teratology is the study of abnormalities of physiological development. It is often thought of as the study of human birth defects, but it is much broader than that, taking in other non-birth developmental stages, including puberty; and other non-human life forms, including plants. A newer term developmental toxicity includes all manifestations of abnormal development, not only frank terata. These may include growth retardation or delayed mental development without any structural malformations.

 

 

I note that the author, E.L. Williams, specifically referenced this page at Wikipedia in the body of her article. It seems clear, then, that as she intended the very word linked, "teratology," it is, I quote, "much broader than" "the study of human birth defects".

Edited January 13, 2013 by proximity1

[Arete]

Is it "John Cuthber, M.D." or not ? If not, what qualifies you to mock and deride the informed opinions of Dr. Casanova and his associate researcher, E.L. Williams, please?

 

It would probably aid discussion if you don't use logically fallacious devices like argument from authority.

Edited January 13, 2013 by Arete

[proximity1]

 

It would probably aid discussion if you don't use logically falacious devices like argument from authority.

 

In court, if a witness testifies to the inadequacy of facts or opinions (revised in editing) when these have been offered under auspices of one or the other party's scientific or other expert's credentials, with a view to impeaching the worth of that other witness's testimony, then the opposing counsel has every right and duty to insist on a presentation of the supposedly better grounds for the (claimed or implied) superior authority of the counter-witness.

 

Here, J. Cuthber is asserting that, in effect, his views are correct, are better-founded, superior, in effect, to those of the author, E.L. Williams. Well, why are they better? On what basis, on what evidence? Cuthber says his views are free of the taint of base motives (pandering for attention) that he imputes by innuendo are behind the publication of author Williams' text, all without the slightest evidence offered, except, of course that he "considered" a more respectable motive on her part and "rejected" that.

 

ETA: The crux of Williams' view is the suggestion that there is to date not enough solid knowledge of the potential for harm posed by pre-natal ultrasound scans and that, from her knowledge and experience in microbiology lab research, important dangers are being taken too lightly. Cuthber asserts that, because, by his claim, no evidence of harm is available, Williams' concerns are not only unreasonable but amount to scare-mongering and pandering for attention.

 

But, logically, it may be that the actual dangers of pre-natal ultrasound scans have been missed--because they are at the cell level and perhaps, as it seems to me may be the case, have not been and are not being sought there. In such circumstances, a supposed lack of "evidence" of harm is due to a failure to know where to look and what to look for, and not an absence of actual harm. This line of reasoning rebutts Cuthber's argument that, if there has been no significant harm found, then, it must be because there has been none.

 

Are you persuaded, as a scientist, by such reasoning?

 

Are law courts wrong about such a principle of expertese in testimony? Why? If they (the law courts) are justified in following a principle which requires one posing as an authority on a topic to show proof of the basis of the authority, why ought we take a different view here?

 

"the argument from authority" goes like this: (paraphrased here, in effect) "Only authorities (i.e. by formal qualifications, credentials) may have a valuable opinion, point of view, on a topic under debate, discussion."

 

That is the gist of the agument from authority. I am not making that argument. Instead, I am asking for reasoned grounds from J. C. for why his obvious contention that his opinions here trump those of Williams & Casanova, is valid.

Edited January 13, 2013 by proximity1

[John Cuthber]

I'm not a medical professor or whatever and I'm not in the business of selling ultrasound equipment.

 

Look at that again and see if it's now any clearer?

Does that make it obvious that I'm not a medic in any way?

All I did was underline what I already wrote

 

Once again, you don't actually seem to have read what I wrote.

 

" Is it "John Cuthber, M.D." or not ?"

No, not least because (like you) I don't use my real name here and I have never made any secret of that.

Doing so means that I don't have to worry about posting an opinion which disagrees with my employer's.

The point is that I can act as a disinterested party here.

 

I'm not a medic but, among other things, I'm a trained expert witness and I can assure you that you are wrong in saying

" In court, if a witness testifies to the inadequacy of one or the other party's scientific or other expert credentials as a means of impeaching the worth of that other witness's testimony, then the opposing counsel has every right and duty to insist on a presentation of the supposedly better grounds for the (claimed or implied) superior authority of the counter-witness. "

The court has the right to expect evidence that one argument or the other is more convincing. It doesn't matter if the better argument is put forward by a 5 year old. It's not a superior witness that makes the difference, it's a superior logical rationalisation of the evidence.

Thinking that a medic is better placed to comment on this is, (as was already pointed out) an appeal to authority.

 

I'm saying that my argument wins because if ultrasound harms babies then there would be lots of babies who were harmed.

Where are they?

 

I'm not saying my argument is better because I'm anything special.

I'm saying it's better because it doesn't predict an epidemic of babies with problems.

The particular definition of teratogenesis you choose doesn't actually alter my point (I already pointed that out) for two reasons. firstly we know that many forms of foetal damage do produce birth defects.

Secondly, it just broadens the issue a bit.

Instead of looking for an epidemic of birth defects we would look for an epidemic of other health problems which tracked the rise in the use of ultrasound scans.

Unless there is such an epidemic, the point still stands.

 

By the way, since I work in toxicology (among other things) I may well count as an expert on things like teratology or I may not. It doesn't matter since the question here is actually one of epidemiology (Yep, you may have guessed it, that's another field I work in).

 

So, if an argument from authority is valid then, since I'm an expert in epidemiology, my view wins.

If arguments from authority are not valid then their status as doctors is irrelevant and the fact that my view doesn't predict an epidemic which is not actually observed means that my view wins because the evidence is on my side.

 

Find the epidemic which E L W predicts or take your pick of reasons why I'm right.

[Arete]

"the argument from authority" goes like this: (paraphrased here, in effect) "Only authorities (i.e. by formal qualifications, credentials) may have a valuable opinion, point of view, on a topic under debate, discussion."

That is the gist of the agument from authority. I am not making that argument.

 

 

Actually, this is incorrect. The logical fallacy of appeal to authority is as such:

• Person A is (claimed to be) an authority on subject S.
• Person A makes claim C about subject S.
• Therefore, C is true.

http://www.nizkor.org/features/fallacies/appeal-to-authority.html

 

The above article explicity goes into detail in relation to how citing a degree as evidence of the validity of an argument is an appeal to authority fallacy.

 

The statement you made below:

Would you please explain why the reader ought to give your views greater weight than those of Williams and Casanova? Are you, as well, a medical doctor?

 

is a textbook example. You're claiming that the fact that Williams and Cassanova are assumedly MD's, and that John Cuthber is assumedly, not - means we should give less weight to John criticisms. The supposed degrees of the argument's sources have no bearing on the validity of the arguments posed within - which logically need to be addressed on their merits and not on the supposed authority of their sources. It's an unequivocal appeal to authority fallacy.

 

John's argument was as follows (to paraphrase): " A testable prediction of the hypothesis presented is that there would have been a significant increase in birth defects/prenatal mortality at the time ultrasound became widely implemented. Is that predicition supported?"

 

Levelling an appeal to authority at that argument does not do anything to address the valid question posed within and therefore doesn't add to or facilitate further discussion. To logically address the criticism, you'd need to provide the data to test the prediction.

 

Additionally, John's proposal that the article is motivated to scare readers is substantiated in the article itself:

Admittedly, this image is meant to scare you

 

Finally, I would personally criticise the use of that image in the first place. A damaged water pump does nothing to substantiate ultrasound causing significant cavitation which in turn damages cellular structures. It proves that hydraulic cavitation shock at macro scales wears out propellors over time.

http://en.wikipedia.org/wiki/Cavitation

 

If that's the best evidence available, you have a fairly wild speculation at best. Significant experimental validation, and the correlative data John requested is needed to substantiate it.

 

I would add an addtional motivation - generating hype for an upcoming publication, and potentially as an avenue to express some of the controversial interpretations of their data which didn't make it through peer review in the article:

 

It’s been borrowed from one of our in-press publications

Edited January 14, 2013 by Arete

[jp255]

In my point of view, nothing in the article supports the initial statement. The article is written in a way that (IMO) attempts to misguide people to the conclusion that ultrasound could seriously be harmful.

 

No where in the article does she discuss the referenced experimental data and compare it to the way in which ultrasound is used to monitor pregnancies etc. For example, she mentions absolutely nothing about the intensities or frequencies. What if the settings were vastly different in the experiments? Also the paragraph where she mentions the VEGF stimulation and whatever else, the experiment itself was intending to investigate the cause of the therapeutic effects of ultrasound, yet she tries to portray these effects in a bad light and leaves the conclusion to "promotes growth" and then she states that "the effect is real". Yes, the therapeutic effect is real!

 

The rest of the article is just as bad. She only supplies information which can contribute to the negative light she is trying to place on ultrasound and she makes no attempt to explain or discuss the "evidence". It is far from balanced, with the ending paragraph expressing a grave concern about ultrasound despite the lack of evidence.

 

I'd be embarrassed to have my name on an article like that.

[John Cuthber]

Arete, Thanks for spotting that they say "It’s been borrowed from one of our in-press publications".

That observation rather supports my suggestion that it's attention seeking of some sort.

 

I did have a quick look on Amazon to see if there was a book she was promoting (which was my first suspicion) but didn't find one.

[hypervalent_iodine]

!

Moderator Note

proximity1,

 

John C and Arete pretty covered the crux of this warning, this is just an official note to let you know that your use of appeal to authority is not an acceptable form of debate here.

[Mud]

Good day. I thought that this post was quite compelling, and the debate was worth signing up to add my two cents.

 

I would like to reply to the argument that ultrasound does not have detectable "birth defects" with a quote from INTERNATIONAL PROGRAMME ON CHEMICAL SAFETY: ULTRASOUND - a text that dates back to 1982, published by the World Health Organization:

6.5.4.  Summary    There are many gaps in the data from human studies that prevent a meaningful risk assessment of ultrasonic exposure.  It is therefore necessary to use the results of animal studies to test the hypothesis that similar effects may also occur in human subjects. Animal studies suggest that neurological, behavioural, developmental, immunological, haematological changes and reduced fetal weight can result from exposure to ultrasound.

There has been some research since that publication; however, I have not been convinced that there have been sufficient studies to say with certainty that prenatal sonograms are safe enough to justify the increase in number of sonograms prescribed for low-risk pregnancies. I agree that these concerns are reasonable, and these practices need review: Rise in ultrasounds prescribed for low-risk pregnancies needs review

 

I would also like to draw attention to the idea that subtle side effects could have insidious impacts on a child's development. For example, consider this animal study: Low-intensity ultrasound applied to the testes of aged rats

 

Previous studies from our laboratory have shown that low-intensity ultrasound applied to the scrotum of prepubertal rats causes a 62% increase in plasma testosterone, suggesting a possible stimulation of LH receptors and/or the enzymes controlling the steroidogenic process. The purpose of the present study was to investigate whether low-intensity ultrasound has a stimulatory effect on the androgenic activity of the aged testes. In addition to plasma testosterone, LH, and FSH, the testicular spermatogenic status was also
analyzed. Ultrasound applied to the scrotum of aged rats did not stimulate sperm production, which was significantly reduced compared to sexually mature animals, and failed to re-establish the steroidogenic testicular function, which was decreased by 74%, suggesting an inherent loss of gonadal steroidogenic competence.

The intensity of ultrasound used in that study was very low (20 mW/cm^2 is well beneath the 720 mW/cm^2 max I_SPTA allowed in modern fetal scanning), and the duration did not match a typical sonogram schedule. However, the effect has been documented.

 

Is it possible that ultrasould's induction/suppression of gonadotropins/enzymes could potentially alter hormone levels significantly enough to promote a change in sex-related growth and development? It seems to have some effect akin to this in plants: Effects of ultrasound on cell growth and secondary metabolite production in plant cell cultures

 

This definitely deserves more research. I agree wholeheartedly with EL Williams' concerns, as do others in the field, apparently: David A Toms - Safety Issues in Fetal Ultrasound

 

I hope these links help stir the bee hive a little. To not be skeptic of lucrative, barely regulated medical procedures puts the onus of your child's health in the knowledge of the practitioner. Considering insufficient research has been done to prove that ultrasound is safe for fetal development, that knowledge is speculative. It does also seem that tangible profit vs unknown risks is not a solid grounds for proper risk vs benefit assessment.

[proximity1]

This is to correct a mistake in the opening post concerning Dr. Casanova's correct first-name--

 

it is Manuel F. Casanova, not, Michael, as I mistakenly wrote it in the opening post. I apologize to Dr. Casanova and Emily Williams and other readers for my error.

Edited March 16, 2013 by proximity1

[John Cuthber]

Still waiting for evidence of the epidemic.