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Biomedical subjects

S Honjo

Publications and source records attributed to S Honjo.

At least 127 records · Page 7Linked to original sources

The placental transfer of IgG in the cynomolgus monkey.

The placental transfer of IgG from the mother to her fetus was investigated with colony-bred cynomolgus monkeys. Very low levels of IgG were detected in sera of 84 days old fetus, indicating that transplacental transfer of IgG had started by this fetal age. Afterwards, gradual increase in the IgG level continued till 140 days of fetal age. A marked increase in the level was noted after 140 days of fetal age, during the last 4 weeks of full gestation term. Fetal anti-measles antibody increased in a pattern similar to that in the IgG level. The IgG level and anti-measles and anti-streptolysin O antibody titers of newborns never exceeded those of their mothers.

Animals↗

Immunoglobulins and measles antibody in sera of newborn cynomolgus monkeys and in milk of their mothers.

The changes in the serum immunoglobulin (Ig) level and in the measles antibody titer were examined with colony-born infant cynomolgus monkeys from 0 day to 26 weeks in age. In addition, their mother-monkey's milk was analyzed for Ig. The decrease in the IgG level after birth was more remarkable in the infants born with high IgG levels than those born with low IgG levels. The IgM level prominently increased for the first 3 weeks after birth in the infants born with low IgG levels, while the increase was not so prominent in those born with high IgG levels. Anti-measles antibody titers decreased linearly with a half-life of 3.4 +/- 0.4 weeks after birth regardless of the titer at birth. A significant amount of IgA, a very small amount of IgM and little IgG were detected in the milk collected just after parturition. Ig of any class was no longer found in the milk collected one to 6 weeks after parturition. These results suggest that the initial level of transplacentally transferred IgG must be one of the important factors influencing the subsequent development of infant monkey's own immunoglobulin synthesis.

Animals↗

Anti-A and anti-B blood group antibody levels in relation to age in cynomolgus monkeys.

Anti-A and anti-B blood group antibody levels were determined with serum samples of 583 cynomolgus monkeys of group-A and group-B, aged from 4 days to 15 years or more. Eight group-A infants free from anti-B antibody at ages of 4 to 25 days were consecutively followed up for the appearance of anti-B antibody. It appeared at ages between 68 and 160 days. Both anti-A and anti-B levels rose with increase in the age and reached a maximum at the age of 4 to 5 years. After that the levels gradually fell with aging.

ABO Blood-Group System↗

Isolation and pathogenicity of provisional serovar 1621-54 of "Shigella" from imported cynomolgus monkeys.

The provisional serovar 1621-54 of "Shigella" was isolated from 36 (13.2%) of 273 cynomolgus monkeys newly imported into Tsukuba Primate Center for Medical Science (TPC) from Indonesia during the period from 1980 through 1981. The biochemical properties of the isolates were in good agreement with those of previously described provisional "Shigella" serovar 1621-54. Clinically, 13 (36.1%) of 36 monkeys being positive for the organisms excreted diarrheal stools on arrival at TPC. In addition, the organisms were isolated also from three other monkeys contracting dysentery during the quarantine period at TPC. One of them died 2 days after the onset of dysentery. Histopathological findings of this case were essentially the same as those of Shigella-infected monkeys. Pathogenicity of the isolates was examined in three experimental infection models; (1) the infection model using cultured HeLa-S3 cells, (2) the keratoconjunctival infection model of the guinea pig, and (3) the intestinal infection model of the cynomolgus monkey. All the strains tested showed positive results in these experimental models, causing intracellular penetration and multiplication in HeLa-S3 cell cultures, keratoconjunctivitis in guinea pigs, and dysentery in cynomolgus monkeys. These results indicate that provisional "Shigella" serovar 1621-54 is a causative agent of dysentery in man as well as in monkeys.

Animals↗

[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.

Animals↗

Age-related immunoglobulin levels in cynomolgus monkeys.

Serum immunoglobulin levels were measured with 144 domestically-bred cynomolgus monkeys, aged 0 day to 18 years. IgG level of the newborn just after birth was somewhat lower than that of their mother monkeys, continuing to decrease for 3 postnatal months. Thereafter, the level began to increase gradually till 4 to 5 years when an adult level was attained. IgA was detected on the day of birth in half of the animals and started to increase soon after birth, reaching an adult level in 5 to 6 years. A relatively low level of IgM was detected in all animals at birth. The increase of IgM level continued till 5 years of age. These patterns of immunoglobulin levels related to age are very similar to those of rhesus monkeys and human.

Age Factors↗

Natural transmission of Entamoeba histolytica from mother cynomolgus monkeys (Macaca fascicularis) to their newborn infants under indoor rearing conditions.

Natural transmission of Entamoeba histolytica from infected mother cynomolgus monkeys (Macaca fascicularis) to their newborn infants was investigated by the stool examination under indoor individually-caged conditions. Every infant became positive for E. histolytica between 5 and 10 weeks after birth. Although some infants were demonstrated to harbor the trophozoites, no overt amebic diarrhea occurred in any of the infants throughout the period of this study.

Amebiasis↗

Detection of ABO group-specific substances on the red cells of the cynomolgus monkey.

Several attempts were made to demonstrate the presence of ABO blood group substances on the red blood cells (RBC) of the cynomolgus monkey. Neither the direct hemagglutination test nor the antibody absorption test was successful in detecting these substances from whole RBC, the stromata or the butanol extracts of RBC. By the heat elution of antibodies, however, the presence of ABH substances was demonstrated on RBC of every phenotype without fail. In all cases, there was a reciprocal relationship between the ABH substances of RBC and of saliva and the anti-A and anti-B antibodies in serum, being in good agreement with Landsteiner's rule. Accordingly, it can be concluded that a small amount of ABH substances must be present on RBC of the cynomolgus monkey.

ABO Blood-Group System↗

Absence of antibodies against SV5, measles and herpes simplex in indoor colony-bred cynomolgus monkeys.

One hundred and eighty-one cynomolgus monkeys born and raised at Tsukuba Primate Center for Medical Science (TPC) were serologically examined for the presence of antibodies against simian virus 5, measles virus and herpes simplex virus. All of them were virtually free from infections with these viruses, whereas wild-originated breeders kept at TPC were highly positive for these antibodies. These results can be regarded as demonstrating that an indoor breeding system such as TPC's is useful and valuable for producing nonhuman primates of good quality being completely free from those viral infections.

Animals↗

Serological survey for SV5, measles and herpes simplex infections in newly-imported cynomolgus monkeys.

On 592 cynomolgus monkeys of newly-imported 14 different groups, sero-epidemiological follow-up surveys of natural infections with SV5, measles (MV) and herpes simplex (HSV) were conducted both at the time of arrival and at the end of the 9-week quarantine period at Tsukuba Primate Center for Medical Science (TPC). At the time of arrival, the positive rate of antibodies against these viruses greatly varied with different countries of origin. As regards SV5, the positive rate ranged widely from 0 to 94.9% among different import-groups, being markedly low in the Philippine monkey groups. The positive rate of MV antibody was generally very high, varying from 11.1 to 78.2% in almost all import-groups except two groups from Indonesia in which no positive case was detected. Concerning HSV, every import-group had a very high positive rate though the average antibody titer was not so high. Generally, the positive rates of SV5 and MV markedly increased by the end of quarantine period. Especially, MV positive rate reached 100% in almost all of the import-groups. However, two Indonesian groups showed no increase of SV5 and MV positive rates during the quarantine period. No increase of SV5 positive rate was detected either with any of three Philippine groups. As for HSV, the positive rate remained unchanged or rather decreased during the quarantine period in almost all groups except two Indonesian groups having shown a significant increase.

Animals↗

[Two cases of natural infection of Angiostrongylus cantonensis in cynomolgus monkeys (Macaca fascicularis) (author's transl)].

Two of 80 cynomolgus monkeys, Macaca fascicularis, imported from Indonesia showed weakness, anorexia, paralysis of extremities and dysstasia. The blood test conducted at the time of autopsy proved that the white blood cell count markedly decreased in both cases and the blood urea nitrogen content increased in Case No. 1. In Case No. 2, a high blood sugar value, a low red blood cell count and a low hematocrit value were recognized. Histologic examinations revealed the presence of fragments of a nematode in the subarachnoid space of the cerebrum, granular layer of the cerebellum and gray matter of the cervical spinal cord. The findings of eosinophilic meningitis, necrosis, foreign body giant cells and cellular infiltration predominantly with eosinophils were also noted there. Morphological features of the nematode found in the tissue sections were identical, in all respects, with those described by predecessors who made morphological observations on the cross sections of Angiostrongylus cantonensis. Immunoelectrophoretic analyses of sera from these monkeys demonstrated the presence of band "a", which has been described to be highly specific to human A. cantonensis infection. Based on the above-mentioned evidences, the parasite fragments found in the histological sections from the monkeys were identified as A. cantonensis. The cases of natural infection reported herein represent the first, to our knowledge, in which migration of A. cantonensis larvae in the central nervous system of monkey was demonstrated. The present observation suggests applicability of simian angiostrongyliasis as a model for infections in man.

Angiostrongylus↗

Detection of macaque chorionic gonadotropin in the placenta of the cynomolgus monkey (Macaca Fascicularis).

The biologically detectable period of macaque chorionic gonadotropin (mCG) was estimated by the mouse uterine weight method with 22 placentas of the cynomolgus monkey at various pregnancy stages. The hormone was detectable in the placental extracts of the 4th and 5th week of gestation, but not in those of the 6th week or later. This fact may be compatible with our previous finding that mCG was not detectable in urine after the 6th week of gestation in the cynomolgus monkey.

Animals↗

Mixed cell agglutination reaction of ABO substances in the saliva and determination of human-type ABO blood groups in the cynomolgus monkey.

For detection of ABO substances in the saliva of the cynomolgus monkey, the mixed cell agglutination reaction (MCAR) gave specific and clear results with a very small amount of saliva. Anti-A and anti-B antibodies in the sera of the same species showed the clearest hemagglutination by the saline agglutination method. The combined use of both methods was demonstrated to be easily and accurately applicable to the determination of human-type ABO blood groups of the cynomolgus monkey.

ABO Blood-Group System↗

Bone growth aud development of secondary ossification centers of extremities in the cynomolgus monkey (Macaca fascicularis).

The development of so-called long bones in the extremity has been studied roentgenographically in forty-seven males and fifty-one females cynomolgus monkeys bred and reared at the National Institute of Health. The age of the females ranged from five months to eight years and nine months, and that of the males was from four months to seven years. In addition, the fetuses of six to twenty weeks of gestation age were examined for the time of appearance of ossification centers. As the biological parameters concerning body growth, the body weight and the bone length were measured and the secondary ossification centers were scrutinized and assessed the maturity process on the basis of the criteria that divided the state into eleven stages. Also the allometric analyses of body weight against bone length was conducted. Most of the secondary ossification centers except the proximal fibulal epiphysis appeared during the period from the prenatal stage (15-20 weeks of gestationage) to the postnatal one (several months of age). From four to five months of age, many ossification centers had developed to some extent. But, the appearance of proximal fibulal epiphysis was delayed and often lacking until 10 months of age in female and one year and three months of age in male. The earliest epiphyseal fusion was observed at the distal humeral epiphysis in both sexes. The latest epiphyseal fusion was observed at the distal ulnal epiphysis in both sexes and at the distal ulnal and radial epiphyses in female. From this study, the time of fusion was at five and three guarters years of age in females and at six and a half years of age in males. As a result, it is suggested that the estimation of animal's age might be put to practical use by introducing the assessing method that the score was given from the observation of the secondary ossification center.

Animals↗

Breeding of cynomolgus monkeys through successive generations by indoor cage system.

Vital statistics on the breeding through successive generations were presented for the cynomolgus monkey colony of NIH, Tokyo. The results of this retrospective survey clearly demonstrated the third (F2) and the fourth (F3) generations could be bred and reared successfully by the indoor caged-breeding system in which either individual timed-mating or group mating procedure was adopted. Several important and difficult problems involved in the production of successive generations of the cynomolgus monkey by our breeding system were discussed from the standpoint of laboratory animal science.

Age Factors↗

Weight and size of the placenta in cynomolgus monkeys (Macaca fascicularis).

A gross anatomical survey of the placental development was carried out in 24 cynomolgus monkeys (Macaca fascicularis) of 4, 5, 6, 7, 8, 9, 10, 15 and 20 weeks of gestational age. Eight of the 24 placentas examined were found to be single discoidal and the remaining 16 bidiscoidal. The weight and size of placentas of each animal were measured. The average weight of the 20th week placentas was about 94 times heavier than that of the 4th week ones; the average diameter of the former was about 5 times larger than that of the latter.

Animals↗