Ch. 12— Public and Private Funding Toward the Development of Alternatives • 261 
betes, and Digestive and Kidney Diseases with 
funds ($25,000 in fiscal year 1985) provided 
through the General Clinical Research Centers 
Program (28). 
An analysis of research systems within various 
projects and subprojects funded by NIH provides 
some idea of the patterns of subjects and models 
used overall for NIH; it may also indicate national 
patterns because NIH supports more than one- 
third of the health -related R&D in the United States 
(24). Use of both human subjects and mammals 
(expressed as the percentage of research projects 
using each) was essentially stable from 1977 
through 1982 (see fig. 12-1). At the same time there 
was a slight increase (approximately 5 percent) in 
the percentage of research dollars being spent on 
mammalian systems and a corresponding decrease 
in the percentage of research dollars spent on re- 
search involving human subjects (see fig. 12-2). The 
data in these figures do not indicate, of course, 
the number of individual animals used; they only 
illustrate the relative percentages of projects 
funded and dollars spent among several types of 
research subjects. 
NIH-supported research uses many models. 
Three widely used ones are in vitro cells and tis- 
sues, invertebrates, and mathematical and com- 
puter simulations, all commonly referred to in dis- 
Figure 1 2-1 . — Trends in NIH Research Subjects, 
1977-82, as Percentage of Research Projects 
SOURCE: J.D. Willett, "Biological Systems Used as Research Models in NIH Pro- 
grams," Animal Resources Program, Division of Research Resources, 
National Institutes of Health, Bethesda, MD, Sept. 24, 1984. 
Figure 12-2.— Trends in NIH Research Subjects, 
1977-82, as Percentage of Research Dollars 
Fiscal year 
SOURCE: J.D. Willett, “Biological Systems Used as Research Models in NIH Pro- 
grams,” Animal Resources Program, Division of Research Resources, 
National Institutes of Health, Bethesda, MD, Sept. 24, 1984. 
cussions about alternatives. In fiscal year 1981, 
12 bureaus, institutes, or divisions (BIDs) of NIH 
supported 378 research projects that used human 
cells or tissues, for a total commitment of over $32 
million (27). The projects included studies of cel- 
lular aging, in vitro studies of immune response 
and regulation of antibodies, the cellular basis of 
disease, and the mechanisms of DNA repair. A fur- 
ther 381 projects and subprojects used cells and 
tissues from sources other than humans in the 
course of their investigations. These accounted for 
nearly $34 million, directed toward research into 
models for diseases such as herpes, leprosy, and 
parasitic diseases; hormonal effects on the con- 
trol and function of differentiated cells; differences 
between tumors and normal tissues; and other cel- 
lular and biochemical mechanisms. Invertebrates 
used in fiscal year 1981 included annelids, aplvsia, 
cephalopods, crustaceans, Drosophila, echino- 
derms, gastropods, helminths, horseshoe crabs, 
mollusks, nematodes, platy helminths, and proto- 
zoans, accounting for 608 subprojects and over 
$46 million. 
Mathematical models were used by 8 BIDs, in 
23 projects and subprojects for nearly $1.2 mil- 
lion, to analyze renal flow and neural networks, 
to model biological waves and kinetics, to model 
clinical trials, to predict fetal outcomes , and to sup- 
port mathematical biology . Computer simulations 
