TPC NEWS Vol.12, No.2, Summer, 1992 ( Whole Number 21)
(English Summary)
Page-3
Messaage from the director-general of NIH, Japan
Towards
the future together: Establishment of a new primate center for medical
research
Dr. Syudo
Yamazaki was appointed the director-general of NIH, Japan
this April, after he had served as the vice-director-general for two
years.
This is
a summary of his message to the TPC, only branch of NIH, Japan.
Now, the
NIH, Japan, which has just completed moving to the new
site of
Toyama in
Shinjuku-ku, is facing the time of renewal.
It has to make
fresh start,
aming
to become
a Research
Center
of Exellence
for Controling
Infectious Diseases.
The TPC
has experienced many problems in its history of
15 years.
In particular,
the demand for the reform in the plans for supply
and breeding
laboratory primates by the Board of Audit and the outbreak of
varicella-like disease
in the cynomolgus monkey colony are still fresh in our
memory.
He expect the TPC to step forward to become the primate center of
excellence for medical research.
Page-5
Message from the former director-general of NIH, Japan
Dr. Tokunaga, the former director-general of NIH, Japan, retired from the
position under the age limit at the end of this March.
This is the summary of his message:
There
were much problem and big tusk such as the removal of the
site of
NIH, Japan
from Minato-ku to Toyama, Shinjuku-ku, and the
establishment
of the Center for Biologics, Control and Research during his term.
However, the NIH's people have attained the purposes with patience and
cooperation.
Now, the
importance
of the
research
using
laboratory
primates
is increasing
more and more, and the TPC is strongly expected to contribute
to the filed of health science, although, in fact, the TPC has various
problems hard to be solved.
He quarts
the words from the Romans as his farewell message to the
TPC's people:
"..affliction makes for endurance, and endurance for tested
virtue, and tested virtue for hope."
Page-5
Message from the director of TPC:
Developer
Yasuhiro Yoshikawa
Since the end of last yesr, I have held a committee for making future
plan of the Tsukuba Primate Center (TPC). There are three reasons why I set up
the committee. 1. Although the TPC has bred and supplied laboratory primates
for last 14 years, no prospect both in finance
and research progress could be if we stay in the present situation.
2. Kinds of Disese have changed because of the longivity society we are
going to meet.
Accordingly, the TPC's
mission, a
research
center
which supports the national
research
institutions
for health
science,
was made clear by the govermental
assessment
on national
institutions.
3. Demand
for the laboratory primate has expanded
from high
quolity animals
to those with additional medical values, such
as, disease
models.
Through the discussions of the committee, we gradually
knew what
the TPC lacks.
The field
of the experimental animal has, so far, been devided
into two
categories, breeders
and users. For
example, the TPC is a breeder
and the
National Institute
of Health, Japan, where safety vaccine tests
is carried
out, is
a user. Since
the last year, the tasks such as
developing
disease animal
models,
information service, and gene preservation, etc.
have been
added to
the TPC's
work.
They, however, are
not involved
into either
categories.
They are
to be the work of "developers."
The field
of the
experimental
animal would
be more understandable by thinking
the tripolar
category than the bipolar.
The role
and function of developers have been vague so far.
The elements needed
for developers are (1) the information service between
breeders
and users
as an
information center, (2)interdiciprinality as
an open
reserch center, and originality and research, that is, a developing
center. We
have to
make future plans, clearly considering that the TPC is to be a
developer as well as a breeder .
Page-28
Measurement of bone mineral density (BMD) in primate species employing
a dual energy X-ray absorptiometry
Takashi Yoshida
We successfully employed a dual energy X-ray absorptiometry (DPX- ,
LUNAR, USA) to
measure BMD in male African green monkeys.
For analysis
of spinal
bone mass
and area of the bone, we scanned the lumbear vertebrae
4-6.
For assessment of spinal bone density the monkeys had to
be placed in the supine position.
We used a restraining bed made of forming polystyrol to support the
animals in the supine position.
We could demonstrate
the age-related
changes in BMD of the spinal bone in ourlaboratory-bred males.
BMD increased
with age from about 0.3g/cm2 to 0.7g/cm2, and plateaued
at the
age of
five.
The BMD values of the
male laboratory-bred
and wild-originated
animals
aged over
ten years
were lower
than those
of the
laboratory-bred
animals aged between five and ten years. This suggests
that the male African green monkeys have the peak of bone mass (PBM) like
humans. The
African green monkey is expected as an experimental animal model
having the peak bone mass.
Page-9
A survey on Pneumocystis Carinii infection in cynomolgus monkeys
and red-bellied tamarins
Rieko kobayashi
We surveyed
Pneumosystis carinii infection in our cynomolgus monkeys
and red bellied tamarins.
The results obtained are shown in the talbe.
The
positive
rate of
anti-PC antibody in
newly
imported
cynomolgus monkeys
was similar to that of the cynomolgus monkeys bred in the TPC.
This result indicates that we could not decrease the positive rate of PC
infection by
our breeding
method. PC
cyst was found in the lung tissue of
only one
monkey of 67 spontaneously dead cynomolgus monkeys.
The positive
rate of
PC cysts in the lung
tissue
of our
red-bellied tamarins was higher than that of the cynomolgus monkeys.
We do not know
the reason yet.
This is
the first report on the infection of Pneumocystis
carinii in the
red-bellied tamarin.
Page-10
Comment on my research:
Animal model for AIDS research
Ryozaburo Mukai
Recently,
we have
established an AIDS animal model of monkeys
by using
SIVmac strains and rhesus macaques.
Since
the discovery
of causative virus of AIDS in 1983,
this
growing
epidemic
has spread over the world.
To understand the pathogenesis of
AIDS and
to provide concepts and strategies for therapeutics, it is necessary
to use animal models for AIDS
which enable us to get much information with less limitations, compared
to human specimens.
Monkeys
as experimental
animals for an AIDS model
and the
retroviral studies at the Tsukuba Primate Center.
Although
bovine and feline lentiviruses ( BIV and FIV ) which
may cause
immunodeficiency
syndrome have been found, their target cell range is
wider than
that of human immunodeficiency virus (HIV) and simian
immunodeficiency virus (SIV). In fact, FIV can infect fibroblasts and
epithelial cells as well as lymphocytes.
Because of the genetic similarity of SIV to HIV-1 and HIV-2, and
of the
striking
similarities
of symptoms
and
immunopathogenesis developed in the SIV infected macaques, nonhuman
primate models for AIDS
are used to develope vaccines and the drugs against AIDS.
In our primate center, the serological study for retroviruses started
in 1984.
Drs. Sasakawa,
Hayami and Honjo used HTLV-I infected
cells
as the
antigen and
screened the serum from the monkeys of our
breeding
colony.
The seropositive
rates for this virus in the cynomolgus and
African
green monkeys (AGM) were 12% and 65%, respectively.
Virus isolation (STLV-I)
from the
peripheral
blood
mononuclear
cells
(PBMC)
was successful
in
the seropositive
monkeys (AGM:83%, cynomolgus monkeys:4%). Moreover, 87% of
the AGM
were seropositive
to SIV and the
double-seropositive
rates
to both
STLV-I
and SIV in the AGM were 57%.
After the death of one of the AGM due to leukaemia by STLV-I infection
and the
determination of entire sequence of SIVagm genome by Hayami's labolatory, we
started the research on retroviruses at
TPC, including
experimental
infection
of SIVagm
isolated
from
an apparently healthy AGM.
Simian
AIDS
1.
Experimental infection of SIVagm to cynomolgus and African green monkeys.
Intravenous
infection
of SIVagm
TYO1
(1x106TCID50/animal)
caused infection
to three
cynomolgus and three AGMs.
It was demonstrated
by the
appearance of antibody to SIV and the isolation of the virus (Fig.1A and 1B).
No monkey
exhibited overt clinical disorders
throughout
the experimental
period of 42 weeks except for slight swelling of the axillary and/or inguinal
lymph nodes
for the
early period of the experiment (2
to 8
weeks
after infection).
We concluded that SIVagm TYO1 is not pathogenic to its
original host or to macaques. In fact, there is no report that describes
the onset of
AIDS in naturally infected wild originated AGMs.
However, Dr. Murayama of our lab got new findings about the
immunological response
of the
AGM. They are summarized as follows. (1)There is
no CD4
single positive
lymphocyte in the peripheral blood, lymphnodes
and thymus,
but there
are CD4 positive lymphocytes with CD8 antigen, besides CD8
single positive
lymphocytes.
(2)In vitro activation of CD4, CD8
double
positive cells
results in the disappearance of CD4 antigen from the
double
positive cells leaving CD8 antigen intact, which still maintain
their original helper activity.
(3)SIVagm
can infect
and propagate in
these
CD4, CD8
double positive cells, while SIVagm cannot infect the activated CD8
single positive
lymphocytes which
derived
from the double
positive
cells
having
helper activity (Fig.2).
From these observations, we propose the idea that
African green
monkeys
become
chronically and asymptomatically
infected
with SIV
despite of the horizontal and vertical SIV infection.
2.
Experimental infection of SIVmac in rhesus macaques
Intravenous inoculation of SIVmac251 to rhesus macaques developed AIDS
in 80%
of the
animals
(4 out
of 5) within
two years.
The clinical
and immunological
features were as follows: (1)reduction in number of CD4
cells (Fig.6)
and
decrease
in blastogenic
activity
of
PBMC
(Fig.5), (2)opportunistic
infections
such as
abcess formation
(S. aureus),
the reactivation
of CMV
and pneumonia (P. carinii), (3)anorexia,
diarrhea
and emaciation
(Fig.3),
(4)increase in antibody response against
SIV (Fig.4),
(5)enhanced virus
growth and it's isolation (Table 1), (6)change
of plasma
IL6 levels
similar
to that observed in human AIDS
patients
(Fig.7).
The clinical findings and symptoms in the AIDS monkeys are summarized in
Table 2.
Now, we are trying to find prognostic markers to predict the onset of
AIDS in monkeys.
We are
also studying the
mechanism
which
causes
lymphoid depletion
at the late stage of SIV infection.
There are some
possibilities to
know the
mechanism such as the
direct cytopathic effect of SIV
on the
lymphocytes and
cells
which constitute the lymphnodes,
and the
indirect effect by the qualitatively and quantitatively changed cytokines
and humoral
factors.
Furthermore,
it is
important
to study the mode
of SIV
transmission
in naturally
and experimentally
infected
monkeys with
SIV.
This line
of research
would
be of importance to exclude SIV from the AGM colony
at our
Center as well as to prevent the transmission of human AIDS.
Page-17
Invitation to Primate Center Forum through PC-network
Tsukuba Primate Center for Medical Science (TPC) has begun Primate
Center Forum
through PC-network to improve relationship and exchanging
information on laboratory primates among the people who work with
laboratory primates.
Page-18
Case report: The testis of an aged cynomolgus monkey
Ippei Sakakibara
Taro was the oldest monkey in our colony.
He died at the age of 29
years and
eight month.
His mating history and histopathological findings
of his
testis are described.
The table
shows
his mating history.
He mated
with 147
females,
and resulted
41 pregnancies
between the age of 15 and 25.
No pregnancy
was obtained during his age of 25 to 29, though he had mating 25 times.
Senile changes of his testis are summarized as follows:
The testis
atrophied and browned.
There was no spermatogenesis.
In the
seminiferous tubules, only Sertoli cells were seen on the basement
membrane, which were thickened and hyalinized.
The seminiferous tubules shrunk and the interstitium became fibrotic.
Deposition of lipofuscin pigment were observed in the Leydig cells.
The Leydig cells decreased in both size and number. The Leydig
cells
and basement
membrane of the tubules
were stained
by the
immunohistochemical stain for testosteron.
Page-19
Clinography: Inguinal hernia
Fumiko Ochikubo
Inguinal hernia is one of the common diseases in male cynomolgus
monkeys. In our
center, among the monkeys aged over 1 year old,
herniation
of the
inguinal region was recognized in 20 out of 570 male (3.5 %) and in five
out of
1076 female
monkeys
(0.5%) by palpation.
Before
the age
of three,
protrusion of
abdominal contents through the inguinal canal
is reducible.
However, herniration of aged monkeys become harder to reduce.
Herniration of eight of nine male monkeys who aged over 10 years was
unreducible.
In pediatrics, inguinal hernia is one of the most common diseases (2 to
6 % of the patients of the pediatrical surgery).
Figure shows the process of development of the hernial sac in fetal
stage of
human. Usually,
the prosessus vaginalis peritonei salients regresses
and disappears.
But most of the children with external inguinal hernia have
the residual precessus vaginalis peritonei.
The first
case I treated as a primate clinician was inguinal hernia.
The case
was a
26 years old male cynomolgus monkey.
He showed
acute
clinical signs such as dispersion, dehydration,
and vomiting.
I could not
diagnosed this case as inguinal hernia with the incarcerated intestinum,
though he had
the anamnesis
of herniation.
After that, I had done surgical
operation
on two
cases for acute herniation. They
were 18 and 24 years old
animals
and were anethetized a few days before the appearance of the clinical
signs.
The herniation may be occurred because of increased abdominal pressure
at the
recovery
stage of anesthesia and of the weakened muscles
of the
aged onkeys.
For the development of the animal models useful for
the longevity
science, I think that we need to do surgical operation for hernia to
prevent incarceration
of the intestine into the hernial sac, and we have to
observe carefully the animals of the recovery stage of anesthesia.
Page-20
Visit to the University of Puerto Rico Medical Sciences Campus
and "The
10th Annual Symposium on Nonhuman Primate Models for AIDS"
The director,
Yasuhiro Yoshikawa, has been to Pueruto Rico to attend
the 10th Annual Symposium on Nonhuman Primate Models for AIDS from
November 16 to 21, 1992. He reports on the visit in a diary format.
Page-23
Symposium "The Aging Monkey: Behavior and Neurobiology"
Keiji
Terao
The symposium titled "The Aging monkey: Behavior and
Neurobiology" was
held at Baltimore, Maryland from November 16 to 17,
1992.
Main objectives
were to
define
the current
status
of
knowledge
about
behavioral,
neuropathological
and neurochemical
changes occurred
in aged
nonhuman primates and to determine the suitability
of nonhuman
primates as models of human aging.
Nonhuman primates are thought
to be
the most suitable
model in
this research
area
but
methodological
difficulty
is given
in determination
of relation
between
functional and
structural
changes
of brain.
This
symposium
was
planed
to discuss the results
obtained
from a
collaborative research project which was
supported by National Institute
of Aging.
In this
project,
in total
of 18 rhesus monkeys aged from 3 to
30 years were subjected
to define
both the
functional ( behavioral, cognitive and
memory)
and structural
(pathological
and neurochemical)
changes
in relation
to age,
simultaneously.
Collaboration
of
researchers
in different
scientific
area including
psychology,
behavior,
pathology
and neurochemistry
tried to make it possible to define
the
relationships between functional and structural changes of aged brain.
As shown in Table,
they presented
several results
concerning
pathological
and neurochemical
changes of aged monkey brain and referred them
to the
results of
behavior, learning, memory and cognition in aged
monkeys.
However, there was
scarce significant relationships between functional and
structural changes of
aged monkey
brain.
One of the
impressive reports was
the category
of "successful aging", which was proposed as to be the
most aged
( human: over 80 years, monkeys: over 30 years).
Human
aging
can be divided into
three
categories,
Impaired
aging, Normal
aging, and Successful aging.
In rhesus monkeys,
the selection of successful
aging from
unsuccessful
aging
might occur
between 20 to 25
years
old. We
have focused
on the
physiological changes
in the
monkeys
aged over
25 years.
If
the
selection
of successful
and unsuccessful
aging occurs around 20
years
old, it
seems important to study the factors of aging using middle aged ( around
20 years ) monkeys in the future.
Page-27
Report on a lecture by Dr. Jane Goodall:
Innocent killers
Mrs. K.
Odagiri
encountered
with Dr. J. Goodall
through
one of
Dr. Goodall's
books
"Innocent Killers."
As those who
work with
experimental animals, Odagiri comments her impression of Dr. Goodall's
lecture which
was held at the Tsukuba Center for Institute, in Tsukuba on December 4,
1992.
Page-28
Introduction of Facilities: P3-Laboratory in TPC
Nonhuman primate AIDS animal models are indispesable for AIDS research.
At present, in Japan there is no other place but the TPC, where the
experiments using
Simian
Immunodeficiency Virus (SIV) can be
carried
out.
Director, Yasuhiro Yoshikawa describes
the neccesity
for establishing a P3 laboratory in the TPC.
Page-30
From the Front of Animal Feeding: Excrements, feces, and....
Mr. Ohto, animal technician, sketches out various scenes he has seen in
the TPC's animal rooms, focusing on the excrements of the monkeys.
Page-31
Memory of Trainees: My SIV study at TPC and
As a trainee at TPC