TPC
NEWS Summer 1989
Vol.8 No.1 (Whole Number 15)
(English
Summary)
Page-3
Essay: TPC and international exchange
Eleven years have passed since Tsukuba Primate Center (TPC) opened.
Today, TPC's name is fairly well known to overseas primatologists and
related research facilities. The
number of visitors to TPC from abroad for this
period has amounted to about three hundred, and they have come from thirty-five
different countries. Visitors
from China and America have been most numerous --- 62 and 57, respectively.
Although we have not yet had guests from the U.S.S.R., we are exchanging
information and literature
with the Primate Information Center in Sukhumi, U.S.S.R., which belongs to the
oldest institute for laboratory primates in the world.
The Institute of Experimental Pathology and Therapy.
Three hundred foreign
visitors is by no means a small number for TPC, which has only about ten senior
researchers. And chances to present
our research results to scientific journals in and out of Japan have increased
remarkably.
Needless to say, international exchange is indispensable for improving
research and developing science and technology.
TPC's openness to foreign visitors may be considered good.
At the beginning, however, we had a tendency to be tense when we received
guests from abroad, because our English was
weak. But now we are at ease
in explaining our work because we have achieved a measure of fluency in English.
I sincerely believe that the linguistic ability to communicate with
people of different countries is the first condition of successful international
exchange, and a steady character as a person/researcher is the second.
Many of TPC's personnel have achieved these two conditions, and are now
contributing to international exchange.
On the other hand, the
systems which officially support our efforts are really imperfect and not
functioning well. For
example, there are some agreements, such
as the Japan-U.S. Nonenergy Science Research and Development Cooperative Program
and the Collaborative Program on Science and Technology between Japan and China,
through which a task, development of laboratory primates, is given to us.
The national budget to realize these tasks, however, is very little, and
the systems supporting continuity of the exchange are inadequate. Even if a part of the cost needed for the exchange is
recognized in this year's budget, under the present conditions we can
not definitely promise the exchanging partners any concrete plans,
because there is no guarantee for the following year.
Moreover, expenditures for visitors should be involved in the budget, I
think.
Internationalization' and 'Informationalization' are key words to
understand the social and political trends of
today's Japan. Although the
Japanese government is using these words, it seems a propaganda effort, since
the actual circumstances on the front of science and technology, where the most
active international exchange is needed, are very poor.
(March 26, 1989)
Page-4
Breeding Topics: Breeding of squirrel monkeys ---
Mating-potency test
About ten years have passed
since TPC started breeding of squirrel
monkeys imported from Bolivia. Recently, the alternation of generations
from breeders of wild origin to colony-bred breeders has begun.
But, colony-bred animals can not always be well in performing mating
behaviors. In the case of wild
cynomolgus and African green monkeys, the majority of pairs begin copulation
within several minutes after they are housed together in the same cage.
However, mating behaviors of the squirrel monkey are scarcely observed in
the daytime. At
TPC, we have adopted mating potency test for colony-bred squirrel monkeys
so that we can select successful male breeders.
Healthy candidate breeders are selected from sexually matured male
monkeys. They are housed together
with parous females. The male candidates who prove fertile are registered as
breeders in "Rotation Line Breeding System".
Up to now, fourteen males have undergone this mating-potency test.
Nine of them were fertile. The
youngest among the nine animals was three and a half years old.
In the near future, we will confirm the age of sexual maturation in the
squirrel monkey, for example, by measuring testosterone levels in blood.
We have 12 successive breeding lines in our squirrel monkey colony.
Each line consists of one male and four to five females.
The first seven sons of seven breeding lines, who are nuclei of each
line, already passed this potency test. Therefore,
we have discontinued mating between the animals of wild origin and colony-bred
animals in six breeding lines. It means that the alternation of generations of breeders have
been done successfully. However,
two or three years will be required for the remaining six lines, as the age of
the colony-bred breeders is too young.
The colony-bred female
breeders who became pregnant in these breeding
lines have delivered normally. But
most of them rejected to nurse their own babies. In the case of wild animals, rejection of nursing seldom
occurs. Now, we
are faced with another problem brought by females not males.
Page-5
Bacteriological survey on lung lesions in cynomolgus monkeys
Isolation of bacteria from the materials taken from natural death cases
is one of the routine work at TPC. Mrs.
Kohno reports the results obtained from the survey on the lung lesions of
cynomolgus monkeys, which died during the period
from April, 1986 to March, 1989. The
results are shown in the Table.
Almost all of the bacterial species isolated from the colony-bred monkeys
were harmless bacteria
at normal times. However,
Mycobacterium tuberculosis
was found
in a monkey imported from Indonesia.
The monkey suddenly died after the
quarantine period of nine weeks,
and tuberculous lesions were found by autopsy
(See, page 7), although this monkey was negative for Tuberculine test.
This was the first isolation
of Mycobacterium tuberculosis for TPC which has imported
about 2,500 cynomolgus monkeys since its opening. It was a matter of regret that
we could
not notice this tuberculosis
infection before the monkey's death. Paying
the utmost attention is needed when we work
with newly-imported wild
monkeys.
Page-6
Introduction of Facilities: Isolation
building
The isolation building is
close to the quarantine building. It
consists of the area for isolated animals and the laboratory area( Fig. I).
Its total area is 324 m2.
Thirty two isolators of negative pressure are set in three animal rooms
(Photo. 2). Air of the area for
isolated animals and of the sterilized room
is controlled through the HEPA filter so that bacilli are filtered off.
A steam sterilizer is installed in each animal room.
Solid filth, such as
excrement, leftover and carcasses, is carried out
after it is sterilized by a double-faced autoclave (Photo. 1) and
incinerated. Cages are
disinfected and washed with a cage washer(Photo. 1).
Sewage water from this building is
treated with disinfectants: It is stored for a moment in a
cistern placed in the sewage water sterilization quarter adjoining the
isolation building, and pumped up
into a reactor to be sterilized with sodium
hypochlorite. After being
neutralized, the sewage water flows out to a sewage treatment facility.
Articles and fixtures are carried into
the area
for isolated animals through a pass box, and carried out after being
autoclaved. Fortunately, up
to now, there has been no seriously infected animal which has to be isolated
into this building.
Page-7
Case Report: Tuberculosis in a cynomolgus monkey
Tuberculosis is one of the important infectious diseases for both man and
nonhuman primate. Therefore, we carry out tuberculin test
( 1/ 100 old tuberculin
solution) on every monkey kept at TPC. Although
we imported 2,485 monkeys from Southeast Asia
during the past ten years,
we have found no tuberculin
positive case. This tuberculosis case is the first one we experienced
at TPC.
[Case]
A wild male cynomolgus monkey imported from Indonesia.
His estimated age was over five years old.
[Result
of Tuberculin test] He was
negative for tuberculin test on arrival at
TPC, pseudopositive 9 weeks after
arrival negative 10 weeks later. He
died 14 weeks after arrival.
[Histopathological
findings] A little amount of
exudated fluid was seen in both right and left pulmonary lobes.
The left lobe adhered to the chest wall, and a pale yellow tuberculous
lesion (3/1 cm) upheaving from the lung surface was seen in the adherent part.
Tubercles of hemp-seed size were scattered in the right pulmonary lobe,
and those of red-bean size were clustered or diffused on
the surface and parenchyma of the spleen.
In the lesions, caseous
necroses and epitheloid cells and Langhans giant cells were recognized.
Calcareous deposition was seen near Langhans giant cells in the spleen. Bacilli stained by Ziehl-Neelsen method were seen in
the necrotized parts.
[Microscopic
findings] Mycobacterium
tuberculosis were isolated
from the lesions.
This case
seems that it had been
infected with
tuberculosis before
his arrival at
TPC. Because almost no
tuberculosis case has been found in the monkeys
living in their natural habitat, this monkey might contract tuberculosis from
man after he was caught in Indonesia.
This case was negative or
pseudo-positive for
tuberculin test
while alive. The decline
in the
monkey's reactivity or the
suitability of the concentration of tuberculin solution
used may be considered as a reason for the false negativity.
Page-8
A Special Article: Peripheral Nerve Graft
Nerve graft involves critical problems in basic and clinical medicine.
When nerve bundles are
severed, the axons of the distal part, except for Shawnn cells, degenerate and
are phagocytosed. The Shwann cells
elongate gradually and make cell
columns. On the other hand, regenerated axons grow out from the
proximal end to the distal end through the Schwann cell columns.
This is the pattern of nerve regeneration seen after the ordinary
surgical operation, the end-to-end suture.
However,
when part of nerve is lost
through serious injuries, for example,
nerve graft
is necessary. Regenerating
axons grow through the Schwann cell column of grafted nerve segments, and can
reach their targets. In nerve
graft, the problem is from what the grafts are obtained.
For example, in nerve
autograft, the nerve segment is obtained from another nerve of the recipient.
Although the
nerve autograft using the calf nerve is
carried out
clinically today, it has various defects. For example, thick nerves are not available
and the skin
controlled by the calf nerve loses its
sensibility. If
allograft, which uses
the nerve
segments of individuals of the
same species
but of disparate genotype
were available for humans, it would have wide application.
In allograft, however, immunoreaction is a big problem. Although many
studies have been done about
controlling immunoreaction, no allograft has been
applied clinically yet.
We had done nerve graft
experiments using mice and rats in our university
. And this
time, at TPC, we tried the experiments using
monkeys, pursuing
the possibility of clinical application of allograft.
The nerve fiber is composed
of an axon and Schwann cells which enclose
the axon. The surface of the
Schwann cells is enclosed with basal laminae of a non-cellular
element. It can be said that
axons and Schwann cells are in the tube
of basal lamina.
As I mentioned before,
Schwann cells/Schwann cell columns are indispensable
in nerve regeneration.
Recently it has been demonstrated that regenerating
nerves do not need the living
Schwann cell columns, but require only the
basal lamina scaffold of
Schwann cells as their pathways. The
nerve segment of mice treated
by repetitive freezing and thawing was again grafted into the
original sciatic nerve.
While the dead Schwann cells were phagocytosed by
macrophages, the basal laminae
of the
Schwann cells
remained tubular
scaffolds, and regenerating
axons grew through such scaffolds from the proximal stump. These
findings suggest that the basal laminae of Schwann cells play an important role in nerve regeneration, indicating the possibility of
allograft.
We performed allograft between two different strains of mice.
The process of nerve regeneration
in the allograft was the same as that seen in
the previous autograft.
The basal laminae survived without being immunologically
rejected. But sciatic
nerve segments of mice are no more than one centimeter in
length. We tried the
experiment using rats, because is was possible to excise the
nerve segments of about three centimeters from the rats. The results were the same.
These experiments
clarified that the basal laminae of
Schwann cells
were effective in allograft
in mice and rats. However, the
nerves of those species are so
simple that they can not compare with human or monkey nerves.
Allograft in mice and rats was significant from a view point of basic
medicine, but there is
a wide gap between these experiments and their clinical application.
It is impossible to apply
allograft of basal laminae to clinical
medicine without experiments
on monkeys. Moreover, it would be
ideal that the monkeys, which are used for
such experiments as nerve
graft, are known exactly their
origin, rearing history and
mating relation. But, our
university has
neither good facilities nor
the personnel for keeping monkeys as laboratory animals. When I was
lost in thought, one of my friends introduced TPC to me.
And our hope
to conduct experiments
using monkeys was realized
through the courtesy
of Dr. Honjo, Director of
TPC and Dr. Cho.
Materials
and Methods
Nineteen cynomolgus
monkeys aged
6-7 were used.
The ulnar
nerve was transected at the point of 2 cm from the internal condyle of humerus and pre-denervated. Nerve
segments of 2-7 cm long were excised from the distal portion of the
transected ulnar nerves. The monkeys were divided
into three groups, (A),(B)
and (C). The nerve segments without
any treatment were grafted into the monkeys
of group (A), and those treated by repetitive freezing and thawing to kill
the Schwann cells were grafted into the monkeys of group (B).
Both groups consisted of
eight monkeys each. The grafted
nerve segments were sutured
on both the
proximal and distal ends of the host ulnar nerve with
3-6 stitches.
The remaining three monkeys,
group (C), underwent nerve autograft.
Two, five and eight weeks
after grafting, the grafted nerve segments
of each two animals of
(A) and
(B) were excised together
with the
host nerves
adjoining the segments. They were prepared by routine histological methods and
observed under the electron
microscope. The remaining
each two animals of(A) and
(B) were under
observation of the recovery
process of sensibility for more
than five months.
Each one animal of the group (C), was examined at each period of 2, 5 and 8 weeks.
Results
Two weeks, and five weeks
after grafting, there were no regenerating
nerves in the grafted
segments of (A). Although after
eight weeks a little number of regenerating nerves
were in the distal part of grafted segment, they were not
myelinated yet.
The recovery of the sensibility
was not recognized in
this group after six months.
Two weeks after grafting there were no regenerating nerves in the group
(B). After five weeks, many
regenerating nerves were seen and a
part of them reached the recipient's nerve, but not myelinated.
All regenerating axons grew into and through the basal lamina scaffolds.
But there were many basal lamina scaffolds
remaining as an empty tube, too. Eight weeks after grafting
the regenerating nerve
fibers reached the distal
part of the host, crossing over the grafted
segment of
2.5 cm and having myeline sheaths.
Recovery of
the sense
was recognized in the palm of the animals five months after grafting.
The group (C) is under observation at present.
Discussion
This study
demonstrated that in peripheral nerve allograft in
monkeys the nerve fibers
grow out through the basal lamina scaffolds of Scwhann cells of the grafted
segments which have been pre-treated by freezing and thawing. The fact that
basal lamina scaffolds were found in nerve segments 5 weeks after
grafting means that basal
lamina scaffolds
can work at least
for about
5 weeks.
Regenerating nerves
grow 1 mm per day, therefore the effective length
of the graft might be 3-4
mm. In the group (A), the
immunological rejection was not so remarkable
as we
had expected, but nerve regeneration was
far behind.
The causes are now under consideration.
These results indicate the possibility that allograft with the nerve
segments treated by freezing and thawing can be clinically applied.
Page-10
The Second Japan-China Workshop on "Laboratory Animals"
The Second Workshop on Research and Development of Laboratory Primates
under The Sino-Japanese
Cooperation Agreement on Science and Technology was held on November 11-12,
1988, in Kunming, China. Thirty-five
researchers from seventeen Chinese institutes and six researchers from Japan
participated in the workshop. For
the two days, thirty-seven lectures in total, including five
by our Japanese side, were presented.
The lectures presented by Chinese researchers were full of various
subjects. According to the contents
of the lectures, it seems that China is strongly endeavoring to establish many
laboratories and colonies of nonhuman primates inhabiting China, rhesus monkeys
and tupaia, in particular, according to the contents of the lectures.
The reports on the monkeys of Callithricidae. were seven in number.
This matter reflects that he
demand for these monkeys, which are useful in the study of
hepatitis A and the development of vaccine, is increasing in China.
Every lecture presented by Chinese researchers was excellent, and we
could know that the present stage of research and development of laboratory
animals in China. Further exchange between Japan and China in this field is
expected.
Page-11
Visit to Yunnan National Laboratory Primate Center of China
The author, Dr.Sakakibara, visited China to attend The Second Japan-China
Workshop on Laboratory Primate with Dr. Takasaka, the author of the previous
page. Dr. Sakakibara reports
on the present state of the Yunnan National Laboratory Primate Center, as well as on his
impression of the visit.
Yunnan National Laboratory Primate Center is located in Xishuangbanna,
Yunnan Province bordering Vietnam,
Laos and Burma. It takes about one
hour by air plain from Kunming where the second
Japan-China workshop was held. In
Xishuangbanna, the climate is subtropical and the yearly mean temperature is 22
C. The Primate Center is one of the most important primate
facilities in China, and there a large-scale primate breeding is comprehensively
conducted.
The most characteristic feature of the Primate Center is to be natural.
It originated in the fact that the Center was established in the natural
habitat of the primates. The Center is on the mountainside facing a river, and
its outdoor open system colony is located in the shadow of the mountain.
The open cages with roof(7
/ 7 / 4 m) have a concrete
floor which can be flushed, and the
breeze from the river is so pleasant that no air conditioning is needed.
The infant monkeys born in the colony are weaned and undergo artificial
nursing. The cages for the infants
are set, adjoining their mother's cage, so that the infants and mothers can hear
mutual voices, and see each other. This
is an attempt to ease the stress of weaning.
The outline of breeding rhesus monkeys, which were presented at the
workshop, are as follows: Three breeding systems have experimentally been
adopted, (1) harem, (2) fixed-pair and (3) unfixed-pair breeding systems.
The harem breeding system was the best
from the economical point of view and
also from the reproductive efficiency.
There was little difference in breeding
performance between the male
to female ratio 1 to 4 and 1 to 16. The
pregnancy rate from 1984 to 1988 was 85%, and the rate of normal delivery was
75%. It was reported to
be important to separate infants from their mothers before
breeding season for raising reproductive efficiency.
As for the management of the Center, the expenditure for
the establishment was
supplied by the Chinese central government and the provincial office.
But now, the enter is taking
an independent profit system, and it has a future plan to become
a worldwide primate center, which will hold over 3,000 monkeys and supply them
to the world.
Page-13
A Comment on My Research: Somatometorical
analysis of growth in cynomolgus monkeys
At TPC,
each animal technician has his own research theme, taking
care of monkeys.
About six years ago, Dr. J. Suzuki, the present assistant of the Primate
Research Institute of Kyoto University, came to TPC as a trainee of graduate
student from the University of Tokyo to make morphometrical study on cynomolgus
monkeys. I was looking for my own
research theme in those days. As
I helped him with his work I learned somatometrical method.
However, after one year, he had to leave TPC, because he got the position
in the Primate Research Institute of Kyoto University.
By the time, I had already learned enough the technique of somatometry
and fully been aware of its importance. I
decided to do morphometrical study on physical growth in cynomolgus monkeys as
my research theme.
First of all, I planned to analyze physical growth in infant animals.
Because TPC produces about 200 infant monkeys every year.
The number of research
subjects was enough. The next
problem was how to analyze the data obtained.
Fortunately, at that time, Professor Gotoh of Kobe University had been
working for National Institute of Animal Health in Tsukuba.
He suggested me to apply multivariate analysis.
The method is an effectual method to analyze such data with over ten
measuring items per animal. Very few multivariate analyses have been before concerning
the growth of monkeys. Thanks to
his great help, I could analyze the morphological characteristics of
physical growth in infant
cynomolgus monkeys from the view point of relative growth
(Seichou/Growth, 24,111-113,1985 and Jikken Dobutsu/Experimental Animals,
37, 145-151, 1988.).
In this study, I applied the principle component analysis, one of
the multivariate analyses, to the data of infant cynomolgus monkeys aged
from birth to 12 weeks (Fig. 1 and 2). The
value of the first principal component (PC 1) is acceptable as a size factor,
because it increases with age, but changes
in body proportion with age are not detected by this analytical method.
Then, the multivariate allometric analysis was applied to know the
relative growth against the growth rate of head breadth.
It revealed that the growth rates concerning trunks were higher than
those of limbs and arms (Fig. 3).
This means that the growth of limbs and arms in cynomolgus monkey
newborns is almost completed before birth, on the other hand, the trunk grows
remarkably after birth. This
fact may facilitate corresponds to the behavior of newborn monkeys: baby monkeys
generally have to cling tightly to their mother's chest immediately after birth.
Their limbs and arms should have grown enough before birth.
Judging from the growth rate of head and face, the face of an infant
cynomolgus monkey grows protrusively, becoming a dog like face.
Next, I surveyed cynomolgus monkeys aged until nine years; because the
growth of this species seems to be almost accomplished by the age of nine. The
animals of different age groups ( 92 females and 84 males ) were examined.
Fig. 4 shows their body weight growth.
The result of the multivariate analysis using principal components
revealed the first principal component(PC 1)
became a constant value at the age of about five with males and at the
age of about three with females. These
ages correspond to the age at which the value of body size becomes constant. The
value of PC 1 is also acceptable as a size factor.
The values of the second principal component (PC 2) were around 0 in each
the value of age group, having no difference among them until the age of three.
But, in the groups aged more than five years, PC 2 showed big plus
numbers with males, whereas
negative numbers with females. This
means that the difference in body proportion between females and males appeared
from the ages: Males are characterized by stout
trunks and long limbs and arms, andemales by
plump trunks and comparatively shorter limbs and arms.
The value of PC 2 in the male group aged nine was bigger than that of the
group aged seven, but female groups of those ages had no difference in the value
of PC 2. Body proportion change
still went on after the age of seven in male cynomolgus monkeys.
The time when the difference of body proportion between males and females
began to appear corresponded to the time when sexual maturation was
completed. The cumulative
contribution ratio of these two principal components accounted for 99.0%.
In order to now the relative growth rate among the 14 measuring
items, multivariate allometric analysis
was also applied to the data. Two
figures demonstrating typical patterns are shown (Fig. 5 and 6 ).
The figures have some critical points
corresponding to the time of separation
from their
mothers and/or the time of sexual maturation of the animals.
These figures, however, have left
the individual differences of animals out of consideration.
Therefore, I started a
longitudinal study with 20 females and males each, four years ago, taking
individual differences among animals of the same age into consideration.
Four or more years are needed to complete this study.
Analysis of the growth of monkeys requires very long
time, but it is necessary and important for making TPC a treasure house
of scientific data.
Page-17
Report from the
Front of Animal Feeding: Beautiful
African Green
Monkeys
Hello, our dear readers! How
have you been?
The African green monkey has recently become one of the objects of
broad attention in biomedical science. The
other day, I entered, for the first time, the colony of African green monkeys at
TPC as a member of the team composed for periodical health checkups.
Now I am going to report what I saw and experienced there.
TPC established a colony of African green monkeys in 1979 with eight male
and 30 female breeders of feral
origin. The colony is in the quarantine building, and 165 monkeys are
now being kept in three animal rooms. Up
to now, 122 F1 and F2 offsprings were born. Almost
all cages for green monkeys have a
squeezing panel, so that we can anesthetize the monkeys without using a catching
net.
Well, let me introduce a young animal-technician, Mr. H. to you.
He has taken care of the green monkeys since the colony was opened. He
knows almost everything about the animals he loves ( See, p. 23 ).
The African green monkeys undergo periodical health checkup as the
cynomolgus monkeys do.(See, TPC NEWS Vol. 7, No. 2, p 15). In the case of green monkeys, fifty animals are examined at a
time.
By the way, I did not see
only a small number of obese green monkeys,
comparing with the cynomolgus monkeys.
The body weight of the
male green monkeys
remarkably increases from the age of three and a half years, and reaches around
four kilograms by the age of four. And
the body weight of the female monkeys becomes about three kilograms by the age
of five. As for the colony-bred monkeys, testes size measurement, vaginal swab
examination and observation of the color of the scrotum are added to the items
of routine health checkups to determine their sexual maturation.
According to the data obtained, the age of sexual maturation of these
animals seems to be five with the males and four with the females.
"Oh, beautiful", the words just jumped out of my mouth, when I
saw the abdomen of adult male monkeys. The
color of the scrotum was just cobalt blue.
The skin color of the scrotum changes from whitish flesh color to bright
blue when the animals reach the age of sexual maturation.
Do you think it is interesting if
the skin color of man changes with age?
A case of ATL-like disease caused by simian T-cell lymphotropic virus (STLV)
was found at this colony in early 1980s. Since
then, the African green monkey has been
much expected as a laboratory animal for the study of ATL.
Moreover, recently this species has been very useful in the study of
Acquired Immuno Deficiency Syndrome
(AIDS). The blood taken in the periodical health checkups undergoes
virological and biochemical examinations once a year.
By the way, the procedure
for blood taking in this colony is different from that I saw in the cynomolgus
monkey's. A disposable cylindrical
blood-taker is used instead of a vacuum blood-taker.
Both iodine and alcohol cotton are were for disinfecting the skin before
blood taking. Do you think it is
strange? It has reason of its own.
The first accident happened one morning in 1983.
A male green monkey was found dead with a furious look(See, TPCNEWS
Vol.7, No. 1, p 7, 14). He had been
very well until the day before. His
abdomen was extremely distended. "I deeply regret that I had been able to
do nothing for him.", Mr. H. said with a look of distress. Since that time eleven monkeys died like this.
They had something in common: almost all of them were offsprings of the
same lineage and they died the day after their blood taking.
On that day I entered the colony, as an infant of the lineage was
involved in the list of animals for health checkups, the animal-technician
taking blood, Mr. N., was warring about the next morning.
Unfortunately, the infant died next morning, too.
Now, these cases are under bacteriological, pathological and genetic
examinations.
It was revealed by biochemical serum examinations that a part of the
blood taken from the green monkeys showed the value of hypoproteinemia and
hypocalcemia. So, the fruit and
vegetables mixed with vitamin D 3 are given
to the monkeys every day except Sunday.
Although the mating system for the green monkeys is essentially the same
as that for the cynomolgus monkeys, a special system was designed to increase
their pregnancy
rate. It is called
"Every other day mating system".
A male and two female breeders are kept in a connected-type cage of three
individual cages. The male is kept
in the center cage. One of the
females is allowed free access to the male, for a day and next day another
female. This every other day mating system is carried out
for 14 weeks. The pregnancy rate
has become good, of course.
At present, there are nine breeding lines to produce F3.
A breeding line consists of one
male and four to five females of wild origin.
We are expecting to establish a breeding line which is composed of only F1
breeders and produces F2.
In this colony, where the beautiful African green monkeys are living,
many attempts are being performed
with a wonderful will, besides what I mentioned above.
Page-21
Who'll fight for the future? -- Growing strength of the advocates of
animal rights in the political area ---
The Use of Laboratory Animals in Biomedical and Behavioral Research, the
report of the National Academy of Science-National Research
Council (NAS-NRC) was released last year. On
the pages of "Perspective", of Science,
November, 1988, Professor John Kaplan, who had been on the committee that
authored the report, contributed his view that in the report there was something
missing: the most important, the practical aspect of the issue of "animal
rights" ---the political dimension.
He describes the damage and loss which animal rights activism has caused
in biomedical research, of which goals are cure of disease, alleviation of the
most painful conditions. He is much
concerned about the growing strength of he advocates of animal rights in the
political area. Because their
political power against the research community has up to now been very strong
and skillful.
He appeals to the research community to rise and fight for the sick, for
those who are in pain and for the future. Since
the beneficiaries of future medical technologies do not yet know of their need,
and have not given any thought to the matter, therefore
the political battle must be fought
by others. The problem is
that if scientists and patient groups do not undertake this struggle, no one
will do. And we shall all suffer
for it.
Page-22
Travel Report on the XIIth Congress of the International
Primatological Society in Brazil
TPC's young researcher, Dr. Fujimoto attended the XIIth Congress of the
International Primatological Society held in Brasilia, Brazil from July 24
to 29, 1988. He reports on the
Congress, recalling those days.
It was very significant that the Congress of the International
Primatological Society was
held in Brazil, where more than 50 species
of nonhuman
primates (about one third of
the primate species in the world) are inhabiting.
July in Brazil, it was
winter. Arriving at Brasilia from Japan with high temperature and high humidity,
I suffered not a little from jet lag and climate difference.
Brasilia is a big man-made
city constructed about thirty years
ago. I felt something
common between Brasilia and Tsukuba Science City which was also
artificially developed, although the scale of Tsukuba was much smaller.
The Congress was held mainly in the Convention Center situated in the
center of the city. According to the announcement of the congress office,
the subjects to be presented amounted to 463 in number, consisting of several
fields; social organization and behavior (18.0 %), ecology (9.5%), reproductive
biology (7.7%), genetics(6,7%) and conservation (6.3%), etc..
As for the congress participants, in addition to a large attendance from
Europe and North America, many young researchers of Brazil and Latin America
participated in. And it has
become the happiest memory for me that I got acquainted with them.
Symposiums and paper sessions were held simultaneously in seven places.
I presented "Type II
collagen-induced arthritis in cynomolgus monkeys as an experimental model for
rheumatoid arthritis in humans." in a paper session. There were many
sessions I would like to attend, but the number I could participate was limited.
In a poster session hall, there was a corner for Japan where the next
congress of IPS will be held.
I do hope that I will be able to see my friends again
in Japan.
Page-23
Sketches from Animal Rooms:
(1)
A decade of a colony of African green monkeys
Mr. H, who has been in
charge of the African green monkey colony since its opening, thinks back to the
past ten years, with his affection on the monkeys of wild origin.
The colony was opened with eight male and thirty female breeders of
wild origin. Although
there were many trials and errors at the beginning, now 160 monkeys are being
kept in the colony. The wild
monkeys are still employed as breeders, but they have become fairly old.
Mr. H. expresses his hearty thanks
to the monkeys for their contribution to the medical science, and he strongly
hopes that an adequate supply system of those aged monkeys for
gerontology-related studies will be realized.
(2)
Dietary test and growth
Recently, some metabolic diseases such as obesity and diabetes are seen
in the colony-bred cynomolgus monkeys of our center. Dietary regimen is considered to be one of the causes.
Since June of 1986, we have been carrying out a long term dietary test.
Forty colony-bred infant cynomolgus monkeys were divided into four
groups, A, B, C and D. Excess
amount of diet was given to the group A, but the amount of the diet for group B,
C and D was limited. Although the
amount of fresh fruit given in the morning was the same, that of solid-type
monkey diet differed one another:
group A - 50 g, B - 30 g and C&D - 20 g.
About two years after the beginning, the growth rate of the animals of C
and D decreased. The amount of
monkey diets was reconsidered, and increased to 100 g for A, 50 g for B and 40 g
for C and D. This
test is still under way. We
shall be able to get its results in several years.
Page-25
A Memory of a Trainee: Polymerase
chain reaction (PCR) method
----An attractive technique for DNA replication----
A trainee, Mr. T. has been studying the technique for DNA replication at
TPC from the last summer. The
technique is called Polymerase Chain Reaction (PCR) method, and it is very
useful and attractive method for biomedical science and also for molecular
biology. He expresses his thanks to
the research staff of TPC who gave him the chance to study such a valuable
method.