These new developments show the value of MR in studying a phase of metabolism hitherto unavailable, namely that of “preventive” study prior to significant lactate formation and surely prior to the cell damage edema and cell death so characteristic of stroke and heart disease. We believe that these approaches can be developed appropriately for clinical application and will thereby open a new type of diagnosis and therapy.

In 1971, Victor Papanek published Design for the Real World (1), a book which attacked the lack of problem-oriented and population-based reasoning in industrial design. The lack of congruence between need and production, from Papanek's perspective, had resulted in exotic, costly, and idiosyncratic responses to a gadget-oriented market (2).

The association between a slow pulse and fainting episodes dates back to Mor-gagni's original description in 1761, when he discussed two elderly men whose pulses were very slow and who suffered from epileptic seizures. Subsequent reports by Adams in 1827 and Stokes in 1846 substantiated that the slow heart rate was caused by degenerative changes in the heart and not by a disorder of the brain.

It has long been assumed that the service sector—that part of the economy devoted to producing intangible commodities—will continue to grow and become the major employer and generator of wealth in developed societies. Such writers as the American sociologist Daniel Bell assume that countries of the first world will advance naturally to become “postindustrial” (i.e., postmanufacturing) societies.

“Service workers” already constitute over half the work force in most developed countries, and take comfort from a view which seems to guarantee their future livelihoods. But, their comfort may be unfounded. I shall outline a contrary, less cozy, alternative view, and suggest its implications for the medical sector.

Magnetic resonance spectroscopy (MRS), especially of 31phosphorus, seeks to collect biochemical and metabolic information related to energy metabolism, intracellular pH, and oxygen delivery to the kidney (1,2). Earlier applications in clinical medicine have been established in diagnosis of metabolic myopathy (3,4), infantile cerebral anoxia (5), stroke (6,7), and in vascular insufficiency of the lower limb (8).

When first introduced in the early 1950s, the pacemaker was driven by a battery-powered impulse generator that was large and cumbersome (Figure 1). The introduction of transistors later in the 1950s made it possible to build a generator small enough for implantation beneath the skin (Figure 2), allowing patients to walk about freely.

Nuclear magnetic resonance (NMR) imaging has recently become an accepted technique in the medical practitioner's armory (38). NMR spectroscopy (44) is a subtly different application of the same physical principles underlying NMR imaging, but the clinical potential for this modality is currently still under evaluation. The most important application of clinical NMR spectroscopy is for the nonin-vasive monitoring of changes in metabolite levels and intracellular pH of intact tissues during physiological stress or in response to pharmacological agents or disease. The 31phosphorus (31P) nucleus has been the most commonly investigated in muscle disease (39) but the applications of proton (1H), (4,5,8) and 13carbon (13C), (2,7) are currently being explored.

Curtiss, F. R. (1984). Reimbursement dilemma regarding home health-care products and services. Am. J. Hosp. Pharm., August, 41(8), 1548–57.

Reimbursement mechanisms for home health-care products and services are discussed in detail. The two major categories of the home health care industry—(1) skilled nursing, homemaker, and other services, and (2) equipment, supplies, and other products (including drugs)—are reimbursed by third-party payers differently. While prospective pricing of inpatient care encourages the growth of home-care services, government administrators are concerned about potential spending growth at time of ballooning deficits, and private health insurers are uncertain about coverage criteria. Nuances of Medicare coverage criteria and private insurance reimbursement for home health care services are described. Medicaid coverage of drugs and biologicals for home patients is also described. The Health Care Financing Administration (HCFA) is expected to clarify and restrict Medicare coverage and payment of home-care products, equipment, and supplies. Medical justification will probably become more specific with greater attention to patient diagnoses and prognosis of patient therapies. Per-case payment methods will be refined to encompass home care. The government and private insurance programs will move toward capitation payment methods under which institutions will have even greater incentives to develop sophisticated home-care programs to substitute for institutional care. L.A.M.

During the last decade, microsurgical improvements have developed extremely rapidly in eye surgery. The use of operating microscopes has opened this field to a wide range of technical innovations such as finger suture materials, more sophisticated instruments, and new implants. The result has been better rehabilitation of patients, whose vision was impaired by opacities in the refracting media of the eye. The most frequent cause of poor vision in the elderly is cataract, which is an opacification of the lens in the eye. Most people older than 70 years will have some cataract, with about 30% having opacities that markedly reduce visual acuity and often produce glare phenomena in at least one eye (see Figure 1). There is at present no medical treatment for cataract.

Drs. Weinstein and Wulff (in issue 1:3) have raised legitimate and important concerns about the ethical acceptability and feasibility of randomized control trials (RCTs) of diagnostic technologies. Their criticisms are all the more compelling in light of their strong advocacy of rigorous evaluation, and their insights into the advantages of RCTs and potential problems with alternative approaches as outlined with great clarity in Dr. Weinstein's paper. We shall not attempt a point by point rebuttal (partly because we are in full or partial agreement with most of their comments) but instead will highlight several issues which we believe merit further discussion.

In a standard whole-body NMR-scanning machine, the static magnetic field is generated by an electric current driven through large solenoid coils. Dynamic magnetic gradient fields are generated by electric current pulses in coils located at various orientations, thus producing magnetic gradients in x, y, and z directions. The Rf (radiofrequency) radiation is transmitted through a specially shaped coil which also serves as an antenna receiving the NMR signals.

During the last few years evidence has accumulated that fetal neurons, implanted into the depth of the brain in adult rats, can reestablish damaged connections in the host brain and substitute functionally for elements lost or damaged as a result of a preceding lesion. This research work has led to the realization that, contrary to traditional views, the adult mammalian CNS has a potential to incorporate new neuronal elements into already established neuronal circuitry and that such implanted neurons can modify the function and behavior of the recipient. For a long time it was thought that the remarkable regenerative and functional potential of CNS tissue grafts that had been demonstrated in cold-blooded vertebrates reflected a fundamental difference in the regenerative properties of central nervous tissue between cold-blooded vertebrates and mammals. During the last few years it has become evident however, that at least certain types of intracerebral neural grafts can perfoum just as well in developing and mammals as in developing or adult submammalian vertebrates.

Of all the diseases afflicting the elderly, the degenerative brain disorder, known as Alzheimer's disease, may be the crudest because it kills its victims twice. The mind dies first. The patients display decreased knowledge of recent events, both about their own personal lives and the world around them. Decreased performance is manifested in demanding situations at work, traveling, and managing personal finances. These symptoms are commonly accompanied by anxiety, denial, social withdrawal, and loss of initiative. The patients' performances on psychometric tests are well below average, yet they may be able to function safely in a limited familiar environment with familiar routines.

This paper recounts the origins of consensus development as a means of technology assessment and traces the evolution of the process from its rather amorphous and variable beginnings to the codified and consistent model of today. Where appropriate, evaluative findings and anecdotal observations will be recounted.