Simian T cell leukemia virus type I-induced malignant adult T cell leukemia-like disease in a naturally infected African green monkey: implication of CD8+ T cell leukemia.

Spontaneous T cell leukemia was found in an African green monkey (Cercopithecus aethiops, AGM) naturally infected with simian T cell leukemia virus type I (STLV-I). The hematological features and the evidence for monoclonal integration of provirus DNA in the leukemic cells revealed that the leukemia was an ATL-like disease. The expression of surface markers on the leukemic cells indicated that they were defined as an activated CD8+ T cell subset. Together with the finding that seven in vitro spontaneously STLV-I-transformed cell lines were CD4-CD8+, it is likely that CD8+ T cells are transformed by STLV-I in AGMs, in contrast with human ATL. Finally, we assessed characteristics of the CD8 chains on these transformed cells. The result indicated that the leukemic cells expressed only the alpha chains but not the beta chains. However, in the case of in vitro-transformed cell lines the expression pattern of the CD8 chains varied in individual monkeys. Thus, STLV-I may preferentially transform CD8+ (both alphaalpha+ and alphabeta+) T cells in AGMs.

Changes in bone mineral density of lumbar vertebrae after parturition in African green monkeys (Cercopithecus aethiops).

We examined the effect of lactation on the maternal bone components in laboratory-bred African green monkeys. Bone mineral density (BMD) with bone mineral content (BMC), bone area and mean width of lumbar vertebrae (L3-L5) were measured by dual-energy X-ray absorptiometry (DXA). Measurements were conducted at two-week intervals from parturition up to 40 weeks after parturition. The BMC and BMD values gradually decreased during the lactation period and then gradually increased after weaning, but the BMC and BMD of the maternal lumbar vertebrae did not recover completely to the values at parturition even at 40 weeks after parturition.

[Changes in bone mineral density of lumbar vertebrae during a six-month interval in African green monkeys (Cercopithecus aethiops)].

Changes in measurements of lumbar vertebrae (L3-L5) during a six-month interval in African green monkeys were demonstrated using dual-energy X-ray absorptiometry (DEXA, DPX-alpha, Lunar, USA). Area, mean width and bone mineral content (BMC) of L3-L5 were measured, and bone mineral density (BMD) was calculated using 62 laboratory-bred and 23 wild animals. Laboratory-bred animals were divided into 4 groups according to their gender and age, and in addition, two groups of wild animals were constructed according to gender. Although no remarkable change in BMD of laboratory-bred animals aged less than two years was observed at a six-month interval, significant decreases in BMD were detected in laboratory-bred animals aged over 6 years as well as in wild animals. Thus, DEXA seems to be useful for investigating the kinetics of BMD in aged animals during a relatively short period such as six-months.

[Relationship between serum biochemical measurements and spinal bone mineral density in African green monkeys (Cercopithecus aethiops)].

Spinal bone mineral density (BMD) of African green monkeys were measured by a dual-energy X-ray absorptiometry (DEXA). The value determined in male was rather higher (0.674 +/- 0.068g/cm2, Mean +/- S. D.) than that in female (0.611 +/- 0.105g/cm2), while the coefficient of variance was larger in female (17%) than in male (10%). Females were divided into two groups according to their diversity of BMD values. Serum biochemical values were compared among three groups, one male group (n = 37) and two groups of female (A: n = 31, B: n = 22), using a canonical discriminant analysis. As the result of the canonical discriminant analysis, closed relationship between serum biochemical properties and BMD was demonstrated. Lower BMD, lower serum protein concentration and higher serum inorganic phosphorus may be the reflection of malnutrition in this primate species. In conclusion, animals showing osteopenia were included in our breeding colony of the African green monkey judging by the value of bone measurements and serum biochemical measurements.

[Age-related changes in bone mineral density, mean width and area of the lumbar vertebrae in male African green monkeys (Cercopithecus aethiops)].

We were able to measure bone mineral density (BMD), mean bone width and the area of the lumbar vertebrae in male African green monkeys with a dual-energy X-ray absorptiometry (DPX-alpha, Lunar, USA). For analysis of spinal bone mass, mean width and area of the bone, we scanned lumbar vertebrae L3-L5 using a pediatric analysis program. We used restraining bed made of formed polystyrol to support the animal in a supine position. The precision of the measuring technique was calculated by averaging the coefficients of variance of the 5 scans obtained in 5 animals aged from 5 to 7 years. The precision values for BMD, bone width and area were 1.9%, 0.9% and 2.6%, respectively. Furthermore, age-related changes in bone measurements were demonstrated using laboratory-bred males (n = 45) and, additionally, wild-originated males (n = 7, estimated ages over 15 years old). The values of B M D, bone width and area at 6 months old were about 0.3 g/cm2, 1.2cm and 4.5 cm2 respectively. These values increased with aging to about 0.7 g/cm2, 1.5 cm and 11cm2 at 5 years old, respectively, and were judged to reach plateau. However, animals over 10 years old and wild-originated animals which had been kept over 10 years in our breeding colony showed rather smaller BMD and area values than the animals aged 5 to 10 years. The animals aged between 5 and 10 years seemed to have retained a peak bone mass in this primate species.

[Growth curves of body weight and their relationship to sexual maturity in laboratory-bred male African green monkeys (Cercopithecus aethiops)].

Nonlinear growth models having a three- or four-parameter family were applied to individual body weight data of 5 male African green monkeys for estimating their growth patterns. Body weight was measured from birth to six years of age and 58 to 114 data items per monkey were collected. The average body weight at birth was 360g with the standard deviation of +/- 25g, 4.54 +/- 0.29 kg at five years of age, and 4.50 +/- 0.12 kg at six years of age at which point body weight was judged to have reached a plateau. Five growth models (Gompertz, Logistic, Richards, Bertalanffy and Brody) were applied to the growth data in this study. As a result, two (Gompertz and Logistic) of the five models were found applicable to all data from the five monkeys. However, the coefficient of determination (R2) obtained by application of the two models were not so large (0.919 +/- 0.05 in Gompertz, 0.889 +/- 0.01 in Logistic). Therefore the data were divided into two groups according to monkey age: the first group being from monkeys between birth and 2 years 10 months of age and the second group was from monkeys older than 2 years 10 months of age. The Gompertz model fitted best the data of the first group in four of the five animals (R2 = 0.982 +/- 0.011). The age at the inflexion point in the Gompertz model nearly corresponded to the age of weaning. The Logistic model was most suitable for the date of the second group in all five animals (R2 = 0.955 +/- 0.038).(ABSTRACT TRUNCATED AT 250 WORDS)

[A method for collecting semen by fingers in the African green monkey (Cercopithecus aethiops) and properties of the semen collected].

We tried to make a successful collection of semen by human fingers, using ten African green monkeys (Cercopithecus aethiops) aged from 5-7 years, which were bred and reared at Tsukuba Primate Center for Medical Science. Under anesthesia, the animals were laid side way and their penis were gently stimulated by fingers. Semen was successfully obtained from five animals aged 6-7 years, but it was impossible to collect semen from the remaining five animals aged 5 years. It took only 5-15 seconds from the beginning of stimulation to the end of semen collection. The volume of semen collected, the number of spermatozoa and spermatozoal motility rate averaged 1.5 ml, 3.1 x 10(8)/ml, and 46%, respectively.

Experimental infection of African green monkeys and cynomolgus monkeys with a SIVAGM strain isolated from a healthy African green monkey.

An infection occurred in all African green monkeys and cynomolgus monkeys experimentally inoculated with SIVAGM [TYO-1], as demonstrated by the appearance of an antibody to SIVAGM [TYO-1] and the isolation of the virus. No monkey exhibited overt clinical disorders throughout the experimental period of 42 weeks. Thus, SIVAGM was not pathogenic to its original host or to macaques. This system is proposed as a model for HIV infection manifesting no overt disease.

[Growth curves of body weight changes in laboratory-bred female African green monkeys (Cercopithecus aethiops)].

Nonlinear growth models having three or four parameter family were applied to individual weight data of female African green monkeys for estimating their growth pattern. The body weight was measured continuously from birth to six years of age with five female laboratory-bred monkeys. A total of 95 weight data were collected from each monkey. The average body weight was 330 g with the standard deviation of +/- 15 g at birth, and 2.71 +/- 0.33 kg at four years of age. The body weight of female African green monkeys was judged to reach a plateau after about four years of age. Five growth models (Gompertz, Logistic, Richards, Bertalanffy, Brody) were applied to these weight to age data. The most suitable coefficient of determination between growth data and growth model was obtained by the application of Gompertz equation. Three parameters of Gompertz equation, mature size (A), rate of maturing (K) and inflexion point (e-1 A) were analyzed in relation to age of menarche. Strong correlations between age of menarche and maturing rate, as well as between age of menarche and inflexion point were observed.

The simian-type M and the human-type ABO blood groups in the African green monkey (Cercopithecus aethiops): their inheritance, distribution and significance for the management of a breeding colony.

We have established a new simian-type blood group system (M blood groups) in the African green monkey (Cercopithecus aethiops), using a haemagglutinating antibody which was developed by alloimmunization. The M blood groups consisted of two phenotypes, type-M and type-m. We have also determined the mode of inheritance as well as the distribution of both simian-type M and human-type ABO blood groups, employing 113 families including 160 animals. The family analysis revealed that (1) the simian-type M blood groups were governed by the two alleles, dominant M and recessive m, and (2) the human-type ABO blood groups were governed by 3 alleles, codominant A and B and silent O, although no monkey of phenotype-O was found in our breeding colony. Differences in the phenotypic distribution and gene frequency of respective M and ABO blood groups were observed among 3 populations imported at different times. The genetic management of the African green monkey breeding colony was discussed in relation to the difference in distribution of phenotypes of M and ABO blood groups between the parental (wild-originated) and the first filial (colony-born) populations.

Age-related changes of immunoglobulin levels in African green monkeys (Cercopithecus aethiops).

Serum IgG, IgA, and IgM levels were measured in domestically bred African green monkeys (Cercopithecus aethiops) ranging in age from 0 day to 49 months as well as in adult (5 years or older) animals of wild origin. Transplacental transfer of IgG was observed. IgG, IgA, and IgM levels increased with increasing age except for a temporal decrease of IgG level in the first month of life.

[Menstrual cycle lengths and the estimated time of ovulation in the cynomolgus monkey (Macaca fascicularis)].

Establishing of an efficient system for the judgement of an optimal mating time is an important prerequisite for the successful development of a large scale breeding of macaques as laboratory animals. In general, an optimal mating time has been judged on the basis of individual records of menstruation. The length of the previous menstrual cycle has usually been used for the prediction of the next cycle length. In the present study, the lengths of 240 menstrual cycles of 60 cynomolgus monkeys of our breeding colony were statistically analysed. The mean and the standard deviation of those cycle-lengths were 29.4 and 4.3 days, respectively. Correlationship between the length of a menstrual cycle and the length of its previous cycle was statistically significant (p less than 0.05). However, practically the correlation was not meaningful because the correlation coefficient (r) was very small even if the length of the second one of two successive cycles (r = 0.26) or the average length of three successive cycles (r = 0.36) is selected as a reference length. In other words, a cycle length can not be predicted on the basis of the length of the previous menstrual cycle. However, a marked increase of serum follicle stimulating hormone (FSH) concentration was observed from 8 to 15 days after menstruation. In 60 per cent of the animals observed, FSH increased 10 to 11 days after menstruation. Ovulation was observed one or two days later than the day of FSH increase. Therefore, the optimal mating time is judged to be between 11 and 14 days after menstruation regardless of the menstrual cycle length.