© 1999 Robert A. Freitas Jr. All Rights Reserved.

Robert A. Freitas Jr., Nanomedicine, Volume I: Basic Capabilities, Landes Bioscience, Georgetown, TX, 1999

1.2.3.3 Prognosis and Treatment

Prognosis is a judgement or forecast, based upon a correct diagnosis, of the future course of a disease or injury, and of the patient's prospects for partial or full recovery. Guttentag²²³⁴ identifies prognosis as "the predicted course of the reduced state of the patient's psychosomatic freedom of action," and treatment as "the physician's ability to intervene."

But prognosis is a function of treatment as well as disease. From the post-Hippocratic era through the 18th century, treatments were almost purely empirical and often did more harm than good. During the 19th and early 20th centuries, treatments were scientific but largely homeostatic -- the medical intervention was rational but served mainly to assist the body in healing itself. Throughout the remainder of the 20th century, truly curative treatments began to rescue some patients from conditions from which their unaided bodies would not have been able to recover. Although conventional biotechnology will enable some important tissue and cellular replacement treatments by the early 21st century, nanomedicine will enable major reconstructive and restorative procedures at the tissue, cellular and molecular levels and will employ active antibiotic devices. The prognosis will almost always be good, except in cases of severe neural damage and a few other specialized circumstances. Therapeutic treatments will be selected to reverse all pathological effects of disease or injury, with a minimum of pain, discomfort, side-effects, intrusiveness and time, and with a maximum of effectiveness, efficiency, and likelihood of success, though of course some tradeoffs will always exist. Nanomedicine also will excel in the correction of molecular defects of a kind which Nature has no predesigned tools -- such as the breakdown and removal of intracellular lipofuscin (for which there appear to be no natural enzymes) and the removal of indigestible waste products which interfere with neuronal axon transport.

As in Section 1.2.3.1, we may compare the therapeutic response to a simple infection at several different levels of technological competence. Consider a patient who has been diagnosed with eastern equine encephalitis, a mosquito- or tick-borne arbovirus. In the 20th century, there was no specific treatment for this disease. Care was generally supportive, with the doctor attempting to maintain the patient's heart and lung function while the infection ran its course. The prognosis was poor. There was a 50%-75% mortality rate with frequent sequelae including seizures and paralysis, especially in children.²¹⁸⁰

Biotechnologists proposed a molecular approach to therapeutics using recombinant DNA technology that was not yet possible in 1996 but was regarded as likely by the early 21st century:²²³³

"A patient enters the hospital with high fever and intense headaches. A spinal fluid tap is submitted to the molecular microbiology lab. After screening for several viruses, a species of equine encephalitis virus is identified that is endemic to a location recently visited by the patient. A call to the Centers for Disease Control results in the emergency delivery of a new antiviral agent. Antisense oligonucleotides are injected into the cerebral spinal fluid. These small DNA pieces bind directly to the virus and block its further proliferation. A temporary reservoir giving access to the cerebrospinal fluid is placed and infusion of this therapeutic molecular inhibitor of the virus continues for 5 days until signs of encephalitis have passed."

The nanomedical therapy? As before, a nanomedical cure for eastern equine encephalitis may be far simpler, less painful and a great deal quicker. A single therapeutic dose consisting of ~0.1 cm³ of isotonic saline fluid containing ~10 billion active micron-size virucidal nanodevices, a 10% volumetric nanodevice suspension, is injected into the cerebrospinal fluid. Each therapeutic nanorobot has chemical sensors that can unambiguously recognize fluidborne or in cyto arbovirus particles and, once recognition has occurred, destroy them and also reverse the cellular damage. A nanorobot population of this size should be able to destroy all viral particles and effect needed repairs in at most an hour (Chapter 19),³²³³ after which the devices are programmed and equipped either to eliminate themselves from the body (Chapter 16) or to be manually exfused (e.g., nanapheresis; Section 10.3.6).

Last updated on 5 February 2003