These patients are about to get RADIATION THERAPY. This CT scan will be delivered immediately before they are to receive a lethal radiation dose at the same location to kill their tumor. Reduction of dose in diagnostic CT (not cone-beam) is a much more valuable accomplishment.
LOL...if it is a _lethal_ dose, why treat the patient?
They are going to get a _theraputic_ dose of directed radiation to target a specific tumor bed. The reduction in the imaging scan portion will lower _total_body_ dosing.
Not all body tissues deal with radiation the same way. Thyroid and small bowel mucosa are the most radio-sensitive tissues, while areas like bone and muscle are much more tolerant...If you can avoid thyroid cancer or radiation enteritis, you'll have or be a much happier patient.
Neat. Does this also reduce the running costs of the machines, or would that be a negligible benefit compared to not irradiating your patients?
From the point of view of the hospital? It's the other way around; increasing the lifetime of the expensive X-ray tube (which this will indeed do) is the important benefit, and not irradiating your patients as much is just a side effect.
Certainly not from the perspective of a physician. I continually bear in mind the cancer risk for CT scans that I order....the problem is that what I'm scanning for is an immediate threat to life, so I have to take a long term potential risk to offset a more immediate, more probable, and higher risk.
As for saving time...it is negligible...most new scanner (64 slice and up) process the images as quickly as the machine can scan. And even if there is a delay (e.g. 16 slice machines) most scans are put into a queue while the machine continues to process the signals and are read after the 3-5 scans done earlier are read. The exception is when I show up, the radiologists are required to prioritize my scans...(I'm a trauma surgeon)...but I usually don't have to wait very long even with the older scanners (most are done within 15 min)...if my patient is too unstable to wait 15-20 min for a scan, I take them directly to the OR.
As for saving electricity, there are several factors...1) the machines are always kept "on", 2)there is the power consumed to generate the x-rays and 3) there is a mechanical gantry (that I estimate weighs 0.5 to 1 ton) that spins around the pt when the scan is being performed that probable outweighs the power used by the other two put together.
This development will significantly lower that risk.
Eventually it might.
The exact technique they are using is for planning a radiation _treatment_ (cone beam CT), not a _diagnostic_ (helical scan) CT. They are quoted at the bottom that it _might_ be applicable. There are probably 100 to 1000 diagnostic scans for every treatment protocol.
"CT dose has become a major concern of medical community. For each year's use of today's scanning technology, the resulting cancers could cause about 14,500 deaths.
"Our work, when extended from cancer radiotherapy to general diagnostic imaging, may provide a unique solution to solve this problem by reducing the CT dose per scan by a factor of 10 or more," says Jiang.
There currently protocols that are used to lower the radiation dose for pediatric patients...the problem is that not all hospital use them. Except in a life threatening emergency, the parents should ask before a routine/elective scan is performed on their children.
Source: someone who has ordered enough scans to have statistically killed someone.
FLASH: Man sues Nature over patent infringement...
Mr I. M. Atwit, lead council for Dewy, Suck'em, and Dry Corp headquartered in Topeka KS, was quoted as saying "Nature has finally overstepped her bounds by infringing on our copyright! We intend to prosecute this to the fullest extent of the law [of man]."
Nature, unfortunately, could not be reached for comment.
In unrelated news, NASA and several prominent astronomers today warned of an impending meteorite strike that was predicted to hit somewhere in the Mid-West of the US. The most like impact site was around Topeka, KS.
I am a C programmer with 25 years experience in real time systems. If a client needs a database to track their pencils then I am the best person to come to because I understand all the implications: race conditions, middle ware, infrastructure; you name it, I know it.
But the fact is that they client will pay some guy half what I earn to knock their database up in MS Access. It will fall over from time to time but do a reasonable job.
So can I get cheap but acceptable surgery with a robot?
Well...no. First the robot costs more to use...the instruments are of limited use - they only function X times before the lock out - that way the company can keep making money after the robot is sold. Those intruments also cost a lot more than standard lap instruments (and don;t last as long).
Second, as was noted in another post, this isn't really an automaton. It is still _very dependent_ upon the skill and judgement of a trained, experienced surgeon. A teenager may be able to operate it, but won't have a clue what to do. Surgery residency is at least 5 years of 80 hrs/week (used to be 100-120+ hrs/wk) (fellowship adds 1-3 years of additional training). So from that alone, I have well over to 30,000 hrs of expereince and training in the OR and managing my patients pre- and post-operatively and I'm still a young surgeon.
In addition, as I noted, the robot adds a layer of complexity (requiring more training to master) than a normal laparoscopic surgery, even though the procedures are often very similar, the un-natural-ness of controlling the robot and the slim margin of error (you can't swing an instrument wildly while it is inside a body) have all consipred to limit the use of the "robots".
Third, a lot of the cost of surgery is in the pre and post operative period. The OR itself in often just a portion of the total bill. I've had cases where a weeks worth of antibiotics cost 2-3 times the reimburstment of the surgery itself....
To conclude, let me take your anaolgy one step further...the first time the database blows up.: someone dies. How would that look on the bottom line?
Surgery (and medical care in general) is not somewhere you want to find the lowest bidder.
-- QG
Actaully, being a surgeon who has used the robot, you stand a greater chance of injury.
To set the record staight, the robot is a tool looking for a problem. The robot is no better than a skilled laparoscopic surgeon, and in fact suffers from a "fatal flaw". I'll explain: the most common procedure for the robot is for prostatectomy which involved going deep into the pelvis to remove a walnut sized gland at the base of the penis and below the bladder. To do this using standard laparoscopic instruments is hard beause you would have to stand where the pt's head is to have the proper angle. The robot can operate "upside down" and removes this restriction.
The draw back to the robot is that it does not provide "haptic feedback" or force-feedback....a skilled surgeon relies on his sense of touch as much as his sense of sight. I've removed a pt's colon doing 80% of the surgery not needing to see what I was doing and just going by touch which was more revealing than my sight for those parts of the procedure(hand assisted laparoscopic colectomy). If I can't feel the tumor in the bowel because the robot doesn't provide a sense of touch, guess what - the robot will not provide any advantage.
The true falacy is that the human surgeon is a butcher and that the precision of the robot will be superior. In truth, the surgeon relies on the body's ability to heal to accomplish the miracle of the cure. I cut, but I rely on the body's ability to mend. There are precious few procedures out there that requrie such precise touch...and trust me I've sewn a 1mm vein to a 2mm artery during a bypass operation using my own hand, and with a suture that would break if you sneezed on it (another reason to use a surgical mask!). This case would not be possible with the current generation of robots.
Now, don't get me wrong, there may be some advances in the furture where the robot-assisted surgeon can out perform me, but for at least the next 5-10 years, the robot will be relegate the corner of one of our ORs and used 2-3 times a week for the RALP (robot assisted lapr prostatectomies).
As an aside, the tele-surgery concept may be a valid use in the future, but A) you need 100% up-time on your link B) you still need a semi-qualified individual at the pt's beside to 1) set up the robot, 2) put the ports in so the robot can slip the intruments in to the pt. And in reality, you need someone on stand-by to take over if the case can not be completed and you are stuck at a critical juncition.
I, as I have stated, am a surgeon and not a nephrologist...so I have less direct knowledge of the exacting details....but as I understand it:
[hemo] dialysis is using a counter current "dialysate" to effect a net removal of solvent and solute from the blood...aka accomplishing a filtration the way a kidney works by using a semi-permeable membrane. Can also be done via a process of peritoneal dialysis using a catheter inserted into the abdominal cavity.
plasmaphoresis is the process of removing the plasma from the body and replacing it with albumin or other colloid solution (fresh frozen plasma). This is used to reduce the immune components of the blood e.g. antibodies. Most commonly used for auto-immune disorders.
lukopheresis is selectively removing the white cells from blood. This is mostly commonly used in packed red cells used in transfusions.
The latter two procedures would be contraindicated in the face of a bacterial infection as they would severely inhibit the immune function of the body.
Theoretically yes. It would just take rerouting the incoming kidney blood supply into a loop to bypass it into dialysis. However, you would likely have to filter the drugs out, pass it back to the kidney, reroute it out again and restore the drug. Wouldn't help if your kidneys died from lack of blood supply. Last case scenario stuff probably though.
While the idea sounds like a good idea on paper, I have to tell you, as a practicing surgeon, it really sucks.
First let me clear up, the antibiotics themselves are either directly nephrotoxic (damage the kidneys) or their breakdown products are. Its not a matter of taking the kidneys “off-line”. And in addition not all drugs are removed with dialysis.
To access both renal arteries and veins (assuming normal anatomy many people have duplicated renal vascular systems) is not an benign undertaking. The vessels are in the retroperitoneum (behind all the structures in the "classic" abdominal cavity. So it is not a "trivial" procedure. Next to totally bypass the kidneys is not a great idea...extended bypass systems tend to cause a lot of damage to the blood, they can speed up the drestructiong of red cells (oxygen carrying) and platelets (clotting cells). The circuit also tends to active the clotting system and you get a paradoxical, hyper/hypo-coagulable state. This is similar to DIC (Disseminated intravascular coagulation) [http://en.wikipedia.org/wiki/Disseminated_intravascular_coagulation]
Also the bypass circuit itself is made of synthetic material with acts to harbor bacteria. Given large scale infections, we as surgeon, routinely remove all sorts of prosthetics (AV graft material used for dialysis, artificially heart valves, pacemakers, rods and screws from orthopedic procedures)
The information in the article itself is not new. When I did a rotation in a burn unit in 2004, we had a standing problem with the unit harboring several species of Acinetobacter, and these organisms were resistant to all the antibiotics that the lab routinely tested. We routinely had to use Imipenem(tm) [http://en.wikipedia.org/wiki/Imipenem]. And it was not unusual to have bugs start to build resistance to that drug. We usually had to resort to poly-pharmacy as opposed to mono-therapy as we usually prefer.
Again as I posted a few weeks ago: As physicians we need to be vigilant in our use of antibiotics, but patients need to be respectful of them as well and to stop asking for an antibiotic (that is useless for viral infections) for every little sniffle when you have the common cold or flu (both caused by viruses).
Forgive me for quoting wikipedia, but I felt some footnotes were warrented. I usually yell at my students and residents when they quote it to me, but for the level of discussion here, it is adequate.
How long do you think it will be before they are able to do a full system like this. Or at least the brain, eyes, lungs, and heart. That would be amazing!
Quite a while. Part of the success they had with lungs is that they don't require blood...or more precisely hemoglobin which carries oxygen...so they can get away with just "feeding" the lung nutrients as they oxygenate themselves.
There are currently systems used that keep solutions circulating through transplant kidneys, that help keep them viable longer.
Brains pose unique problems. We don't have the technology to reconnect them so they function properly...and no prospect of fixing this anytime soon.
Not really. An iron lung works by negative pressure outside the body causing a negative intrathoracic pressure which draws a breath into the lungs. This is mimicking the physiologic function of the chest wall where the intercostal muscles contract causing the ribs to rise (bucket handle) and the diaphram to contract and drop. This increases intrathoracic volume and decreases the pressure.
Looking at the video, they are using a positive pressure system, where much like the modern ventilators, forces air into the lung. This is less physiologic, but more efficient and provides more precise control.
Corneal transplants are done by ophthalmologic surgeons and as a general surgeon, I have no exposure to this area. What I do remember from medical school is that the eye is an "immunologically privileged" area of the body and as such may be "immune" from rejection (pun intended). This sticks in my memory as the eye is one of the areas cited as a reservoir for the HIV virus which would help HIV to survive from a lot of "blood purification" techniques that were floated a few years back. The other reason is that the corneal, if I remember correctly, is relatively a-cellular and would not provoke an immunologic response and the few cells it does have do not directly receive blood (would cloud your vision) and are sustained from diffused oxygen and nutrients.
Is caused by the immune system not recognizing a foreign invader, the organ being transplanted.
No?
No. Rejection is the appropriate response by the body. With immunsuppresion, we modulate that response.
Then this guy wants to turn off that ability in the body?
Yes?
No, not quite. Their proposal is to stimulate the immune system, but to add this "complex" that says "It's ok...don't attack"
Historically speaking, whenever doctors have taken that approach it results in massive infection, and usually heart and lung problems.
Well, if that were the case, most of the transplant pt's would be dead. Obviously you have taken this a little to far (reduce ad absurdum). First, keep in mind there are two major (humoral aka antibody mediated and c-mediated) and several minor arms to the immunesystem. The humoral system is relative untouched by immunosuppression while the cell-mediated system is what is modulated, but not turned off. And yes there is a risk of infection with immunosuppresion, but not as much as you might expect. The trick to turn off just enough of the immune system to allow the graft to survive, but not enough to endange the patient.
You would think after so many complications from transplants, they would stop pursuing that direction.
Well there are risks, but quality and quantity of life are better with transplant. Kindey failure itself increases the risk of infection, causes chronic refractory anemia (often requiring frequent transfusions) and increases the risk of heart disease. Hemodialysis (filtering the blood to replace kidney function) requires most people to be hooked to a machine for 3-4 hours three times a week (during business hours!). These patients often undergo numerous surgeries to create or correct the vascular access required to get HD. The HD process itself is very draining.
Liver failure really sucks. You can become encephalopathic (an altered mental state typically confusion and altered sleep cycles), you become coagulopathic (bleed easily), you can develop varices (dilated venin in the esophagus, abdominal wall, rectum, etc) which can bleed and are a bitch to stop when you are coagulopathic. Liver failure is deadly with or without treatment. Kidney failure is also deadly, but with HD you can susrvive.
Adult stem cell research seems to be the best approach to me. Same tissue so no rejection, and they do not have all of the problems fetal cells have. (i.e. Fetal stem cells have a nasty habit of becoming tumors.)
Somehow, Adult stem cells "know" what to do and when to stop growing appropriately much better than fetal stem cells when considering tissue regeneration in heart attack patients for example.
I agree that stem cells and gene therapy are our ideal goals but with the state of the art being the equivalent of trying to park your car by dropping it into the city at 50,000 ft (15240 m) we still have a long way to go. In the mean time, transplants remain a sound medical treatment
Not that doctors understand any of this process, but why they continue to invest so much money in transplant research is baffling. The quality of life for people financially and medically sucks for current transplant recipients.
For the majority, you are quite ill-informed. Most patients are quite happy with their transplants and their quality of life improved markedly. Also, kidney transplants that last 5 years are more economical than being on dialysis for that time period. This is why insurance companies actually pay for transplants.
While I am not a transplant surgeon I have worked on a surgical transplant service as part of my training. From my experience that first article has so many flaws in its description that it is not worth reading. I hope it does not reflect the original article.
For starters "killer T-cells" are usually referred to as NK-cells and they are NOT thought to be part of the normal rejection process (they do not require activation and thus would no be stopped by immunosuppresion). There are three types of rejection hyperacute (pre-formed antibodies attack the organ in minutes - the organ literally dies as soon as it is transplanted - this is avoided by the "matching" process), acute (where T-cells [not NK-cells] attack the organ since it is not "self" and therefore "bad" - this is where immunosuppresion helps) and chronic (the body slowly rejects by allowing fibrosis of the vessels leading to the organ).
Actual survival statics for all kidney allografts exceeds 95% today. 80% is quite a drop!
Grafts are not assumed to "take" after 100 days allowing us to stop immunosuppresion! Immunosuppression is currently LIFELONG. There are a few instances where people have tolerated a non-identical twin transplant without medications, but this is _very_ rare. There is active research into finding the key to allow "tolerance" whereby we can drop the medications, but this is still early.
IL-2 suppression is the _mainstay_ of current immunosuppressants both blocking its production via calcineurin ihibitors (cyclosporin and tacrolimus), inhibiting the response (sirolimus/rapamune), or by blocking the receptor with antibodies (basiliximab/daclizumab). (Please understand this is only about half of the therapies that are in use for immunosuppresion, I'm just focusing on the Il-2 aspect).
Just followed the second link and it is _much better_. Still, I strongly disagree with their assertions of 100 days, just doesn't happen in humans. Apparently this study is using IL-2 STIMULATION with a complex that attempts to increase the regulatory T-cells...To me this means that this treatment will not co-exist with the current immunopupression dogma... this means that they will have to have a "complete" replacement for immunosuppresion they won't be able to add this to the current regiment and that means this treatment protocol will be quite sometime in the pipeline. And (fortunately) the authors acknowledge that they are optimistic, but aren't rushing off to collect their Nobel yet:
I am also aware that effective approaches in mice do not necessarily give good results in humans because of subtle differences in the immune systems of mouse and man.
Seriously why would anyone choose to quit? I periodically quit just to feel the pain of it but that is just self flagellation.
I had to.
A hand tremor as a surgeon is _not_ what your patients want to see. As an aside, to break the ice with some patients I do a variation of the Gene Wilder's deputy on "Blazing Saddles"....
Pt: So how steady are your hands?
[I hold up a steady left hand]
Pt: Good, steady as a rock!
[While bringing up a flapping right hand and with a southern draw]
Me: Yeah, but this here is ma' operatin' hand.
Usually get a good chuckle from my patients, but every once in a while I get a wild-eyed-jaw-dropping-looking-for-the-nearest-fire-exit look that totally makes the joke worth it.
Sorry, but I think you missed some of my points. Negative side-effects such as the exposed Fe+2 reducing nictric oxide in a patient are NOT acceptable. We are talking about people who are on the "knifes edge" and the "cure" can't make these people worse!
Also, please read their website. It is NOT artificial blood. It is not recombinant but rather purified bovine hemoglobin.
Directly from their website:
Manufacturing Process Manufacture of Hemopure and Oxyglobin occurs in four major steps: First, bovine blood is processed to remove plasma and then to remove the hemoglobin protein from red blood cells.
And as such may still carry viral vectors and prions and are potentially susceptable to bacterial contamination.
And before people start knocking the FDA, please be aware that they spare the American public and to a lesser extent the world from over-eager pharaceutal companies.
While this release is a nice breakthrough, there is still *a lot* of work to replace blood. Many substances have been tried to date and they have failed.
First transfusions cause immune reactions [that are technically not rejection] but while these may be major events, they are NOT very frequent. Nurses stop transfusions at the slightest reaction. In the past six years I have seen one transfusion reaction and I work at a major urban trauma center.
Secondly, blood that is transfused is usually near the end of its shelf life and as such you are lucky if 50% of the cells are viable. Within 48 hrs, most (75-80%) of the blood is useless.
Thirdly, blood itself causes immunesuppresion. Couple this with the SIRS/sepsis response in the body and you are going to have a hard time managing this pt in the long term (this is why patients die weeks to months after surviving the initial trauma (tri-modal mortality - on-scene, early in the ED, and late).
Fourth, is the ethical issues - not everyone accepts blood - Jehovah's Witnesses classically. (We also happen to be the city's "bloodless surgery" center - but that's a whole other rant).
The problem with blood replacement is that they also fail in one of these areas. Some substances will cause immune reactions or toxic effects to the body. Hemoglobin and myoglobin (the analogue in the muslces) and their breakdown products are *toxic* to the body...fortunately we have mechanisms to eliminate them safely (most of the time). But what of this protein? Are the breakdown products safe? Does it need to be wrapped in a cell wall to protect the body from it? The article mentions the immune system attacking the molecule, but will the molecule function in physiologic conditions that allow it accept oxygen and release it appropriately? Will it cause other portions of the body to fail? Is the compound stable? How will the body eliminate it?
As for not needing a substance that transports oxygen efficiently, try again. The human body can only tolerate so much volume. If this substance is only 5% as efficient I need 20x the volume. Not very helpful - I'll stick with blood thank you. And, yes you can survive being bled out to 33 to 50% of your blood volume if you are healthy....but if you are also a trauma patient with injuries, you can tolerate much less blood loss - see above for late trauma mortality. As for the soldiers bleeding out pink koolaid...your medics need to be retrained. The current accepted protocols are not to "flood" the traumas with non-oxygen carrying fluids (crystalloids) but to try to maintain perfusion until surgical control of bleeding can be established.
And finally, one of the largest hurdles to artificial blood is the ethical concerns. Healthy volunteers may tolerate the substance, but actual "sick" people may not....In 1999 UPenn killed a young relatively healthy volunteer Jesse Gelsinger with their attempt at correcting his ornithine carbamoyltransferase deficiency with their "gene therapy". It wasn't necessarily that the treatment was bad, but due to his illness, he reacted badly to the adenovirus used as a vector. And in the early 1990's Shock Trauma in Baltimore took a huge publicity hit for proposing to use blood substitutes in acutal trauma patients...the problem was that in a trauma patient you cant' get accurate informed consent to an experimental treatment. This ended up becoming a racial issue as the young male African-American population was the largest demographic group "visiting" their facility. Major uproar.
Now, I for one would love to see a stable, safe, useful blood substitue, they are still a long way off from offering a product I can use on my patients.
What do you _want_to_do_?
Do you want to work as a programmer? I'd say stay away from a PhD.
Do you want to do research? Then is it theoretic (language constructs...) or practical (AI, computer vision...)? If so a strict PhD in CS is probably better.
Do you want to work in management? Then experience (ok, questionable here) and an MBA are probably the way to go.
Do you want to create a startup? Quit now and move back in with your parents until you create the next Facebook or Google.
Think you get the drift here...you have not rigorously defined your objective.
They can study it all they want, memorizing countless tomes of wisdom on parenting, and it still won't adequately prepare them for parenting. Nothing but the actual experience of raising a child yourself will prepare you for it, regardless of how intelligence you might be. This introduces a bit of a problem, as you probably interpret this idea to mean that no parent on this planet knows what they're doing until they learn from mistakes made along the way.
Sounds a lot like preparing soldiers for combat....and probably just as dangerous to one's health and sanity.
I remember my trip to the NSA museum. We went in the early 1990's (c 1991). Now, please remember, this was 1) pre-Google 2) at the time when the cold war was not quite over and 3) the NSA was doing a much better job of staying out of the limelight and was rarely required to submit accounts of their actions even to Congress.
Just finding the place required a few _weeks_ of detective work. We called the NSA a few times to get directions (and did we get some interesting questions from our department chair as to why we had to call the NSA in the first place), and the stock response we received was, "We don't have a museum". Very classic for "No Such Agency."
Finally packing the group up and traveling down to Ft Mead, we must have traveled up and down the road for an hour looking for the turn off. I still remember that it was a small unmarked road (not a dirt road) that ran beside a (Shell?) gas station.
Once we got there I seem to remember having to pass though a metal detector, which was very odd for a museum at that time! We then ran into two or three guys wearing dark blue blazers and khakis who inquired as to the purpose of our visit. Too young to be "veteran volunteers" and too old to be minimum wage flunkies, these guys eerily followed us around the entire museum, always hovering within earshot, but always trading off like they were practicing "trailing". The best was having to "sign" the guest log before entering. Now mind you, after the trouble to get there, the less than hospitable welcome, a minor grilling as to the purpose of our visit, we sure as in hell we're signing our real names!
I suppose that the museum branch of the NSA has mellowed in the intervening years. At least I hope so, I fear that under President Bush, a trip there today could involve some waterboarding so that they could elicit the "true" reason for your visit....
Slashdot Mirror
...can we start calling cigarettes, "All natural inhaled plant extracts"?
These patients are about to get RADIATION THERAPY. This CT scan will be delivered immediately before they are to receive a lethal radiation dose at the same location to kill their tumor. Reduction of dose in diagnostic CT (not cone-beam) is a much more valuable accomplishment.
LOL...if it is a _lethal_ dose, why treat the patient?
They are going to get a _theraputic_ dose of directed radiation to target a specific tumor bed. The reduction in the imaging scan portion will lower _total_body_ dosing.
Not all body tissues deal with radiation the same way. Thyroid and small bowel mucosa are the most radio-sensitive tissues, while areas like bone and muscle are much more tolerant...If you can avoid thyroid cancer or radiation enteritis, you'll have or be a much happier patient.
From the point of view of the hospital? It's the other way around; increasing the lifetime of the expensive X-ray tube (which this will indeed do) is the important benefit, and not irradiating your patients as much is just a side effect.
Certainly not from the perspective of a physician. I continually bear in mind the cancer risk for CT scans that I order....the problem is that what I'm scanning for is an immediate threat to life, so I have to take a long term potential risk to offset a more immediate, more probable, and higher risk.
As for saving time...it is negligible...most new scanner (64 slice and up) process the images as quickly as the machine can scan. And even if there is a delay (e.g. 16 slice machines) most scans are put into a queue while the machine continues to process the signals and are read after the 3-5 scans done earlier are read. The exception is when I show up, the radiologists are required to prioritize my scans...(I'm a trauma surgeon)...but I usually don't have to wait very long even with the older scanners (most are done within 15 min)...if my patient is too unstable to wait 15-20 min for a scan, I take them directly to the OR.
As for saving electricity, there are several factors...1) the machines are always kept "on", 2)there is the power consumed to generate the x-rays and 3) there is a mechanical gantry (that I estimate weighs 0.5 to 1 ton) that spins around the pt when the scan is being performed that probable outweighs the power used by the other two put together.
This development will significantly lower that risk.
Eventually it might. The exact technique they are using is for planning a radiation _treatment_ (cone beam CT), not a _diagnostic_ (helical scan) CT. They are quoted at the bottom that it _might_ be applicable. There are probably 100 to 1000 diagnostic scans for every treatment protocol.
"CT dose has become a major concern of medical community. For each year's use of today's scanning technology, the resulting cancers could cause about 14,500 deaths. "Our work, when extended from cancer radiotherapy to general diagnostic imaging, may provide a unique solution to solve this problem by reducing the CT dose per scan by a factor of 10 or more," says Jiang.
There currently protocols that are used to lower the radiation dose for pediatric patients...the problem is that not all hospital use them. Except in a life threatening emergency, the parents should ask before a routine/elective scan is performed on their children.
Source: someone who has ordered enough scans to have statistically killed someone.
Mr I. M. Atwit, lead council for Dewy, Suck'em, and Dry Corp headquartered in Topeka KS, was quoted as saying "Nature has finally overstepped her bounds by infringing on our copyright! We intend to prosecute this to the fullest extent of the law [of man]."
Nature, unfortunately, could not be reached for comment.
In unrelated news, NASA and several prominent astronomers today warned of an impending meteorite strike that was predicted to hit somewhere in the Mid-West of the US. The most like impact site was around Topeka, KS.
Software analogy:
I am a C programmer with 25 years experience in real time systems. If a client needs a database to track their pencils then I am the best person to come to because I understand all the implications: race conditions, middle ware, infrastructure; you name it, I know it.
But the fact is that they client will pay some guy half what I earn to knock their database up in MS Access. It will fall over from time to time but do a reasonable job.
So can I get cheap but acceptable surgery with a robot?
Well...no. First the robot costs more to use...the instruments are of limited use - they only function X times before the lock out - that way the company can keep making money after the robot is sold. Those intruments also cost a lot more than standard lap instruments (and don;t last as long).
Second, as was noted in another post, this isn't really an automaton. It is still _very dependent_ upon the skill and judgement of a trained, experienced surgeon. A teenager may be able to operate it, but won't have a clue what to do. Surgery residency is at least 5 years of 80 hrs/week (used to be 100-120+ hrs/wk) (fellowship adds 1-3 years of additional training). So from that alone, I have well over to 30,000 hrs of expereince and training in the OR and managing my patients pre- and post-operatively and I'm still a young surgeon.
In addition, as I noted, the robot adds a layer of complexity (requiring more training to master) than a normal laparoscopic surgery, even though the procedures are often very similar, the un-natural-ness of controlling the robot and the slim margin of error (you can't swing an instrument wildly while it is inside a body) have all consipred to limit the use of the "robots".
Third, a lot of the cost of surgery is in the pre and post operative period. The OR itself in often just a portion of the total bill. I've had cases where a weeks worth of antibiotics cost 2-3 times the reimburstment of the surgery itself....
To conclude, let me take your anaolgy one step further...the first time the database blows up.: someone dies. How would that look on the bottom line? Surgery (and medical care in general) is not somewhere you want to find the lowest bidder. -- QG
To set the record staight, the robot is a tool looking for a problem. The robot is no better than a skilled laparoscopic surgeon, and in fact suffers from a "fatal flaw". I'll explain: the most common procedure for the robot is for prostatectomy which involved going deep into the pelvis to remove a walnut sized gland at the base of the penis and below the bladder. To do this using standard laparoscopic instruments is hard beause you would have to stand where the pt's head is to have the proper angle. The robot can operate "upside down" and removes this restriction.
The draw back to the robot is that it does not provide "haptic feedback" or force-feedback....a skilled surgeon relies on his sense of touch as much as his sense of sight. I've removed a pt's colon doing 80% of the surgery not needing to see what I was doing and just going by touch which was more revealing than my sight for those parts of the procedure(hand assisted laparoscopic colectomy). If I can't feel the tumor in the bowel because the robot doesn't provide a sense of touch, guess what - the robot will not provide any advantage.
The true falacy is that the human surgeon is a butcher and that the precision of the robot will be superior. In truth, the surgeon relies on the body's ability to heal to accomplish the miracle of the cure. I cut, but I rely on the body's ability to mend. There are precious few procedures out there that requrie such precise touch...and trust me I've sewn a 1mm vein to a 2mm artery during a bypass operation using my own hand, and with a suture that would break if you sneezed on it (another reason to use a surgical mask!). This case would not be possible with the current generation of robots.
Now, don't get me wrong, there may be some advances in the furture where the robot-assisted surgeon can out perform me, but for at least the next 5-10 years, the robot will be relegate the corner of one of our ORs and used 2-3 times a week for the RALP (robot assisted lapr prostatectomies).
As an aside, the tele-surgery concept may be a valid use in the future, but A) you need 100% up-time on your link B) you still need a semi-qualified individual at the pt's beside to 1) set up the robot, 2) put the ports in so the robot can slip the intruments in to the pt. And in reality, you need someone on stand-by to take over if the case can not be completed and you are stuck at a critical juncition.
[hemo] dialysis is using a counter current "dialysate" to effect a net removal of solvent and solute from the blood...aka accomplishing a filtration the way a kidney works by using a semi-permeable membrane. Can also be done via a process of peritoneal dialysis using a catheter inserted into the abdominal cavity.
plasmaphoresis is the process of removing the plasma from the body and replacing it with albumin or other colloid solution (fresh frozen plasma). This is used to reduce the immune components of the blood e.g. antibodies. Most commonly used for auto-immune disorders.
lukopheresis is selectively removing the white cells from blood. This is mostly commonly used in packed red cells used in transfusions.
The latter two procedures would be contraindicated in the face of a bacterial infection as they would severely inhibit the immune function of the body.
Theoretically yes. It would just take rerouting the incoming kidney blood supply into a loop to bypass it into dialysis. However, you would likely have to filter the drugs out, pass it back to the kidney, reroute it out again and restore the drug. Wouldn't help if your kidneys died from lack of blood supply. Last case scenario stuff probably though.
While the idea sounds like a good idea on paper, I have to tell you, as a practicing surgeon, it really sucks.
First let me clear up, the antibiotics themselves are either directly nephrotoxic (damage the kidneys) or their breakdown products are. Its not a matter of taking the kidneys “off-line”. And in addition not all drugs are removed with dialysis.
To access both renal arteries and veins (assuming normal anatomy many people have duplicated renal vascular systems) is not an benign undertaking. The vessels are in the retroperitoneum (behind all the structures in the "classic" abdominal cavity. So it is not a "trivial" procedure. Next to totally bypass the kidneys is not a great idea...extended bypass systems tend to cause a lot of damage to the blood, they can speed up the drestructiong of red cells (oxygen carrying) and platelets (clotting cells). The circuit also tends to active the clotting system and you get a paradoxical, hyper/hypo-coagulable state. This is similar to DIC (Disseminated intravascular coagulation) [http://en.wikipedia.org/wiki/Disseminated_intravascular_coagulation]
Also the bypass circuit itself is made of synthetic material with acts to harbor bacteria. Given large scale infections, we as surgeon, routinely remove all sorts of prosthetics (AV graft material used for dialysis, artificially heart valves, pacemakers, rods and screws from orthopedic procedures)
The information in the article itself is not new. When I did a rotation in a burn unit in 2004, we had a standing problem with the unit harboring several species of Acinetobacter, and these organisms were resistant to all the antibiotics that the lab routinely tested. We routinely had to use Imipenem(tm) [http://en.wikipedia.org/wiki/Imipenem]. And it was not unusual to have bugs start to build resistance to that drug. We usually had to resort to poly-pharmacy as opposed to mono-therapy as we usually prefer.
Again as I posted a few weeks ago: As physicians we need to be vigilant in our use of antibiotics, but patients need to be respectful of them as well and to stop asking for an antibiotic (that is useless for viral infections) for every little sniffle when you have the common cold or flu (both caused by viruses).
Forgive me for quoting wikipedia, but I felt some footnotes were warrented. I usually yell at my students and residents when they quote it to me, but for the level of discussion here, it is adequate.
How long do you think it will be before they are able to do a full system like this. Or at least the brain, eyes, lungs, and heart. That would be amazing!
Quite a while. Part of the success they had with lungs is that they don't require blood...or more precisely hemoglobin which carries oxygen...so they can get away with just "feeding" the lung nutrients as they oxygenate themselves.
There are currently systems used that keep solutions circulating through transplant kidneys, that help keep them viable longer.
Brains pose unique problems. We don't have the technology to reconnect them so they function properly...and no prospect of fixing this anytime soon.
So they've basically re-designed the iron lung?
Not really. An iron lung works by negative pressure outside the body causing a negative intrathoracic pressure which draws a breath into the lungs. This is mimicking the physiologic function of the chest wall where the intercostal muscles contract causing the ribs to rise (bucket handle) and the diaphram to contract and drop. This increases intrathoracic volume and decreases the pressure.
Looking at the video, they are using a positive pressure system, where much like the modern ventilators, forces air into the lung. This is less physiologic, but more efficient and provides more precise control.
Corneal transplants are done by ophthalmologic surgeons and as a general surgeon, I have no exposure to this area. What I do remember from medical school is that the eye is an "immunologically privileged" area of the body and as such may be "immune" from rejection (pun intended). This sticks in my memory as the eye is one of the areas cited as a reservoir for the HIV virus which would help HIV to survive from a lot of "blood purification" techniques that were floated a few years back. The other reason is that the corneal, if I remember correctly, is relatively a-cellular and would not provoke an immunologic response and the few cells it does have do not directly receive blood (would cloud your vision) and are sustained from diffused oxygen and nutrients.
Is caused by the immune system not recognizing a foreign invader, the organ being transplanted.
No?
No. Rejection is the appropriate response by the body. With immunsuppresion, we modulate that response.
Then this guy wants to turn off that ability in the body?
Yes?
No, not quite. Their proposal is to stimulate the immune system, but to add this "complex" that says "It's ok...don't attack"
Historically speaking, whenever doctors have taken that approach it results in massive infection, and usually heart and lung problems.
Well, if that were the case, most of the transplant pt's would be dead. Obviously you have taken this a little to far (reduce ad absurdum). First, keep in mind there are two major (humoral aka antibody mediated and c-mediated) and several minor arms to the immunesystem. The humoral system is relative untouched by immunosuppression while the cell-mediated system is what is modulated, but not turned off. And yes there is a risk of infection with immunosuppresion, but not as much as you might expect. The trick to turn off just enough of the immune system to allow the graft to survive, but not enough to endange the patient.
You would think after so many complications from transplants, they would stop pursuing that direction.
Well there are risks, but quality and quantity of life are better with transplant. Kindey failure itself increases the risk of infection, causes chronic refractory anemia (often requiring frequent transfusions) and increases the risk of heart disease. Hemodialysis (filtering the blood to replace kidney function) requires most people to be hooked to a machine for 3-4 hours three times a week (during business hours!). These patients often undergo numerous surgeries to create or correct the vascular access required to get HD. The HD process itself is very draining.
Liver failure really sucks. You can become encephalopathic (an altered mental state typically confusion and altered sleep cycles), you become coagulopathic (bleed easily), you can develop varices (dilated venin in the esophagus, abdominal wall, rectum, etc) which can bleed and are a bitch to stop when you are coagulopathic. Liver failure is deadly with or without treatment. Kidney failure is also deadly, but with HD you can susrvive.
Adult stem cell research seems to be the best approach to me. Same tissue so no rejection, and they do not have all of the problems fetal cells have. (i.e. Fetal stem cells have a nasty habit of becoming tumors.)
Somehow, Adult stem cells "know" what to do and when to stop growing appropriately much better than fetal stem cells when considering tissue regeneration in heart attack patients for example.
I agree that stem cells and gene therapy are our ideal goals but with the state of the art being the equivalent of trying to park your car by dropping it into the city at 50,000 ft (15240 m) we still have a long way to go. In the mean time, transplants remain a sound medical treatment
Not that doctors understand any of this process, but why they continue to invest so much money in transplant research is baffling. The quality of life for people financially and medically sucks for current transplant recipients.
For the majority, you are quite ill-informed. Most patients are quite happy with their transplants and their quality of life improved markedly. Also, kidney transplants that last 5 years are more economical than being on dialysis for that time period. This is why insurance companies actually pay for transplants.
For starters "killer T-cells" are usually referred to as NK-cells and they are NOT thought to be part of the normal rejection process (they do not require activation and thus would no be stopped by immunosuppresion). There are three types of rejection hyperacute (pre-formed antibodies attack the organ in minutes - the organ literally dies as soon as it is transplanted - this is avoided by the "matching" process), acute (where T-cells [not NK-cells] attack the organ since it is not "self" and therefore "bad" - this is where immunosuppresion helps) and chronic (the body slowly rejects by allowing fibrosis of the vessels leading to the organ).
Actual survival statics for all kidney allografts exceeds 95% today. 80% is quite a drop!
Grafts are not assumed to "take" after 100 days allowing us to stop immunosuppresion! Immunosuppression is currently LIFELONG. There are a few instances where people have tolerated a non-identical twin transplant without medications, but this is _very_ rare. There is active research into finding the key to allow "tolerance" whereby we can drop the medications, but this is still early.
IL-2 suppression is the _mainstay_ of current immunosuppressants both blocking its production via calcineurin ihibitors (cyclosporin and tacrolimus), inhibiting the response (sirolimus/rapamune), or by blocking the receptor with antibodies (basiliximab/daclizumab). (Please understand this is only about half of the therapies that are in use for immunosuppresion, I'm just focusing on the Il-2 aspect).
Just followed the second link and it is _much better_. Still, I strongly disagree with their assertions of 100 days, just doesn't happen in humans. Apparently this study is using IL-2 STIMULATION with a complex that attempts to increase the regulatory T-cells...To me this means that this treatment will not co-exist with the current immunopupression dogma... this means that they will have to have a "complete" replacement for immunosuppresion they won't be able to add this to the current regiment and that means this treatment protocol will be quite sometime in the pipeline. And (fortunately) the authors acknowledge that they are optimistic, but aren't rushing off to collect their Nobel yet:
I am also aware that effective approaches in mice do not necessarily give good results in humans because of subtle differences in the immune systems of mouse and man.
Already exists. It's used in pediatrics for bradycardia (slow heart rate). http://www.drugs.com/ppa/caffeine.html
Seriously why would anyone choose to quit? I periodically quit just to feel the pain of it but that is just self flagellation.
I had to.
A hand tremor as a surgeon is _not_ what your patients want to see. As an aside, to break the ice with some patients I do a variation of the Gene Wilder's deputy on "Blazing Saddles"....
Pt: So how steady are your hands?
[I hold up a steady left hand]
Pt: Good, steady as a rock!
[While bringing up a flapping right hand and with a southern draw]
Me: Yeah, but this here is ma' operatin' hand.
Usually get a good chuckle from my patients, but every once in a while I get a wild-eyed-jaw-dropping-looking-for-the-nearest-fire-exit look that totally makes the joke worth it.
Sorry, but I think you missed some of my points. Negative side-effects such as the exposed Fe+2 reducing nictric oxide in a patient are NOT acceptable. We are talking about people who are on the "knifes edge" and the "cure" can't make these people worse!
Also, please read their website. It is NOT artificial blood. It is not recombinant but rather purified bovine hemoglobin.
Directly from their website:
Manufacturing Process
Manufacture of Hemopure and Oxyglobin occurs in four major steps: First, bovine blood is processed to remove plasma and then to remove the hemoglobin protein from red blood cells.
And as such may still carry viral vectors and prions and are potentially susceptable to bacterial contamination.
And before people start knocking the FDA, please be aware that they spare the American public and to a lesser extent the world from over-eager pharaceutal companies.
First transfusions cause immune reactions [that are technically not rejection] but while these may be major events, they are NOT very frequent. Nurses stop transfusions at the slightest reaction. In the past six years I have seen one transfusion reaction and I work at a major urban trauma center.
Secondly, blood that is transfused is usually near the end of its shelf life and as such you are lucky if 50% of the cells are viable. Within 48 hrs, most (75-80%) of the blood is useless.
Thirdly, blood itself causes immunesuppresion. Couple this with the SIRS/sepsis response in the body and you are going to have a hard time managing this pt in the long term (this is why patients die weeks to months after surviving the initial trauma (tri-modal mortality - on-scene, early in the ED, and late).
Fourth, is the ethical issues - not everyone accepts blood - Jehovah's Witnesses classically. (We also happen to be the city's "bloodless surgery" center - but that's a whole other rant).
The problem with blood replacement is that they also fail in one of these areas. Some substances will cause immune reactions or toxic effects to the body. Hemoglobin and myoglobin (the analogue in the muslces) and their breakdown products are *toxic* to the body...fortunately we have mechanisms to eliminate them safely (most of the time). But what of this protein? Are the breakdown products safe? Does it need to be wrapped in a cell wall to protect the body from it? The article mentions the immune system attacking the molecule, but will the molecule function in physiologic conditions that allow it accept oxygen and release it appropriately? Will it cause other portions of the body to fail? Is the compound stable? How will the body eliminate it?
As for not needing a substance that transports oxygen efficiently, try again. The human body can only tolerate so much volume. If this substance is only 5% as efficient I need 20x the volume. Not very helpful - I'll stick with blood thank you. And, yes you can survive being bled out to 33 to 50% of your blood volume if you are healthy....but if you are also a trauma patient with injuries, you can tolerate much less blood loss - see above for late trauma mortality. As for the soldiers bleeding out pink koolaid...your medics need to be retrained. The current accepted protocols are not to "flood" the traumas with non-oxygen carrying fluids (crystalloids) but to try to maintain perfusion until surgical control of bleeding can be established.
And finally, one of the largest hurdles to artificial blood is the ethical concerns. Healthy volunteers may tolerate the substance, but actual "sick" people may not....In 1999 UPenn killed a young relatively healthy volunteer Jesse Gelsinger with their attempt at correcting his ornithine carbamoyltransferase deficiency with their "gene therapy". It wasn't necessarily that the treatment was bad, but due to his illness, he reacted badly to the adenovirus used as a vector. And in the early 1990's Shock Trauma in Baltimore took a huge publicity hit for proposing to use blood substitutes in acutal trauma patients...the problem was that in a trauma patient you cant' get accurate informed consent to an experimental treatment. This ended up becoming a racial issue as the young male African-American population was the largest demographic group "visiting" their facility. Major uproar.
Now, I for one would love to see a stable, safe, useful blood substitue, they are still a long way off from offering a product I can use on my patients.
What do you _want_to_do_? Do you want to work as a programmer? I'd say stay away from a PhD. Do you want to do research? Then is it theoretic (language constructs...) or practical (AI, computer vision...)? If so a strict PhD in CS is probably better. Do you want to work in management? Then experience (ok, questionable here) and an MBA are probably the way to go. Do you want to create a startup? Quit now and move back in with your parents until you create the next Facebook or Google. Think you get the drift here...you have not rigorously defined your objective.
They can study it all they want, memorizing countless tomes of wisdom on parenting, and it still won't adequately prepare them for parenting. Nothing but the actual experience of raising a child yourself will prepare you for it, regardless of how intelligence you might be. This introduces a bit of a problem, as you probably interpret this idea to mean that no parent on this planet knows what they're doing until they learn from mistakes made along the way.
Sounds a lot like preparing soldiers for combat....and probably just as dangerous to one's health and sanity.
Looks like a clear case of prior art:
http://www.xkcd.com/413/
I remember my trip to the NSA museum. We went in the early 1990's (c 1991). Now, please remember, this was 1) pre-Google 2) at the time when the cold war was not quite over and 3) the NSA was doing a much better job of staying out of the limelight and was rarely required to submit accounts of their actions even to Congress.
Just finding the place required a few _weeks_ of detective work. We called the NSA a few times to get directions (and did we get some interesting questions from our department chair as to why we had to call the NSA in the first place), and the stock response we received was, "We don't have a museum". Very classic for "No Such Agency."
Finally packing the group up and traveling down to Ft Mead, we must have traveled up and down the road for an hour looking for the turn off. I still remember that it was a small unmarked road (not a dirt road) that ran beside a (Shell?) gas station.
Once we got there I seem to remember having to pass though a metal detector, which was very odd for a museum at that time! We then ran into two or three guys wearing dark blue blazers and khakis who inquired as to the purpose of our visit. Too young to be "veteran volunteers" and too old to be minimum wage flunkies, these guys eerily followed us around the entire museum, always hovering within earshot, but always trading off like they were practicing "trailing". The best was having to "sign" the guest log before entering. Now mind you, after the trouble to get there, the less than hospitable welcome, a minor grilling as to the purpose of our visit, we sure as in hell we're signing our real names!
I suppose that the museum branch of the NSA has mellowed in the intervening years. At least I hope so, I fear that under President Bush, a trip there today could involve some waterboarding so that they could elicit the "true" reason for your visit....