As aged polyuria is often observed in the IVCS strain of mouse, biochemical and histological studies were undertaken in order to clarify its etiology. Polyuria was observed at 7-8 months of age, and significant increases in water intake and urine volume were noted at 10-11 months of age. IVCS strain mice over one year old showed water intakes and urine volumes about five to six times greater than those in DDI strain mice. The osmolarity of urine excreted from polyuric mice was low compared with DDI strain mice, and elevations of sodium and potassium excretion were observed at an early stage of polyuria. At a more advanced stage of the disease, proteins of low molecular weight were excreted in most animals. Furthermore, depression of kidney response to ADH was recognized soon after onset of polyuria compared with normal IVCS strain mice. Thus, polyuria observed in IVCS strain mice may result from a functional defect of the renal tubules. In addition, significant deposition of amorphous substances, especially in the liver, kidney and spleen, occurred almost in parallel with polyuria. From these findings, it is obvious that mice of the IVCS strain exhibit characteristic polyuria and storage disease as they age.

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The ocular fundi of 1, 151 apparently healthy colony-born cynomolgus monkeys (Macaca fascicularis) ranging in age from newborn to 19 years were examined using an ophthalmoscope. Two hundred and thirty-eight abnormal findings were recorded in 219 of the 1, 151 monkeys. Of these, 23 were related to the optic disc and 115 to the retinal vessels. Of the remaining 100 abnormal findings, 91 were retinal degenerations and 9 were retinal hemorrhages. The 23 optic disc abnormalities consisted of 3 cases of micropapilla, 4 of ectasia and 16 of myelination of the retinal nerve fibers. Of the 115 retinal vascular abnormalities, 87 were arterial tortuosity, one was venous tortuosity, 2 were tortuosity of both artery and vein, 2 were artery-vein crossing, 20 were copper-wire artery, one was inosculation of the artery, one was vascularization of the vein and one was persistent hyaloid artery. Of the 91 retinal degenerations, one was degeneration of the periphery of the macular and the optic disc, 8 were macular degeneration and 82 were peripheral degeneration. Nine cases of retinal hemorrhages appeared under 6 years of age.

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Horizontal transmission of mouse mammary tumor virus (MTV) was investigated in cage mates of the same and opposite sex of low (BALB/c) and high mammary cancer strains (DD/Tbr, SHN and GR) . By MTVp27 and MTVgp52 radioimmunoassay, MTV antigen expression was found in the salivary glands, mammary glands and secondary male genital organs of the MTV-free BALB/c strain. Infectivity and oncogenicity were also found in DDf or BALB/c mice by inoculating extracts of salivary gland and/or seminal vesicle in high mammary cancer strains. It is suggested that the primary source of the infectious agent in cases of caged animals of the same sex is saliva, while the primary source in cases of caged animals of the opposite sex is the seminal fluid, although additional infection through saliva cannot be ruled out in the latter case.

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An epizootic of dermatitis with erosion, ulcer and crust broke out in an experimental colony of JCL®-ICR mouse over a period from December 1975 to June 1976. The disease was detected in 592 of a total of 1831 mice of 3-24 months old, especially in males of 7-24 months old (517/821) . At the beginning of December 1975, only a few males of 12 months old were found to have the lesion on the back skin, and thereafter the dermatitis prevailed gradually among the mice. Histopathologic examinations showed the loss of the epidermis, necrosis and/or collapse of the corium, accumulation of serous exudate with neutrophilic cell infiltration and a few cocci scattered on the surface. In chronic cases, fibrious granulation tissues with neutrophilic cell infiltration were formed in the corium. Staphylococcus aureus was isolated in pure culture from the skin lesions in all of the mice examined. Skin disease similar to that of the field case was reproduced in mice inoculated subcutaneously with 10⁷ viable organisms of the fresh isolate. By giving chlortetracycline in drinking water for 7 days, treatment of the affected mice was efficacious in mild cases, but not in servere cases.

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The characteristics of 167 isolates of S. aureus from 106 mice suffering dermatitis were examined. All 167 isolates coagulated both rabbit and human plasmas and 161 of them also coagulated bovine plasma. All the isolates produced heat-stable and heat-labile DNase, phosphatase and yellow pigment, reduced nitrate, hydrolysed egg yolk, Tween 80, and hippurate, and grew on crystal violet agar in colonies of the negative type C and on medium with 10% NaCl. The majority of them produced fibrinolysin, protease and acetoin. Fifty-three percent were gelatinase positive. In hemolysis tests, 25, 57 and 45 isolates showed α-, β-, αβ-hemolysis, respectively. Forty isolates did not produce hemolysins in the rabbit and sheep blood agar. All of 75 isolates tested produced acid from fructose, galactose, glucose, glycerol and mannose, but did not from arabinose, dextrin, inulin, raffinose, salicin, sorbitol and xylose. Most of these isolates produced acid from lactose, mannitol, sucrose and trehalose. All of the 75 isolates were highly sensitive to penicillin, methylphenylisoxazolyl penicillin, erythromycin, spiramycin, lincomycin, chloramphenicol, tetracycline, kanamycin, gentamicin and cepaloridine, but were resistant to sulfisoxazole. With phages of the human set, all 167 isolates were typable at 100×RTD. All but one of the typable isolates belonged to mixed lytic groups. These were I+III (35 isolates), I+M (1), I+III+M (124) and I+II+III+M (6), with long phage patterns. When the 167 isolates were biotyped as described by Hájek and Maršálek [7, 8], 5 belonged to biotype A, 1 to biotype B and 60 to biotype C. The remaining 101 isolates could not be assigned to any of the known biotypes. They produced fibrinolysin and grew in negative type (violet) colonies on crystal violet agar, criteria considered to be reliable for characterization of human isolates, but, at the same time, they coagulated bovine plasma, a character posessed by isolates of bovine origin. Thus these 101 isolates showed properties intermediate between biotypes A and C.

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The effect of an anesthetic, ketamine, on the serum prolactin level was examined in wild-originating female cynomolgus monkeys (Macaca fascicularis) imported from South East Asia. Serum prolactin levels were measured by the homologous radioimmunoassay system which was developed for human prolactin. The validity was confirmed by using an extract of pituitary gland from a female cynomolgus monkey as well as serum and amniotic fluid from a pregnant monkey. Additionally, serum luteinizing hormone (LH) levels were determined by the radioreceptorassay system developed in our laboratory using Leydig cells collected from rat's testes as a receptor fraction. The experiment was repeated three times at one-month interval, using twenty animals that were divided into three groups consisting of 5, 7 and 8 monkeys each. In the first experiment, the first group was injected with physiological saline and the second and third groups were intramuscularily given ketamine at a dose level of 5 mg/kg B. W, and 15 mg/kg B. W., respectively. In the second experiment, the first and second groups were given ketamine at a dose of 5 mg/kg B. W. and of 15 mg/kg B. W., respectively, and the third group was served as control injected with saline. In the third experiment, the first and third groups were administered with 15 mg/ kg and 5 mg/kg of ketamine and the second group was injected with saline. In short, all of the twenty monkeys received the three different treatments for two months. The serum prolactin level showed a marked increase after the administration of ketamine. However, this increase was observed only in half of the twenty monkeys and no change was observed in the remaining half. In contrast with the prolactin level, no effect was produced on the LH level by the administration of ketamine in all of the animals used. The effect of ketamine on prolactin secretion from pituitary gland in cynomolgus monkeys varied with every individuals. That is, the secretion of prolactin was significantly stimulated in some animals and was not in some other. The reason why this difference was existing among individuals is not clear as yet. However, the present study suggests that such an individual difference my explain a cause of discrepancy among the results of previous reports.

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A two-way selective experiment for total hemolytic complement activity (CH50) was carried out in a colony of New Zealand White rabbits for the purpose of developing hereditary deficiency of complement cemponent and estimating the realized heritability ( h²) of CH50. The results obtained were as follows. 1) The mean value of CH50 with a standard error (SE) in 203 adults rabbits was 9.0±0.2 U/ml, and the range of CH50 was 2 to 18 U/ml. 2) Individual differences of CH50 in rabbits were comparatively stable regardless of time and season. 3) The realized heritability (h²) of CH50 was estimated to approximately 0.3. 4) Two rabbits with a hereditary C8α-γ deficiency were obtained from a cross between low CH50 individuals (male : 5.9 U/ml × female : 5.6 U/ml) . From other crosses (male : 3.2 U/ml×female : 5.6, 5.7 U/ml), five rabbits with a hereditary C6 deficiency were obtained. 5) The frequencies of C8α-γ and C6 deficient genes in the colony were estimated to at least 0.005, 0.003, respectively. 6) It was suggested that a downward selection for CH50 was a useful method for developing hereditary deficiency of complement component in the rabbit.

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In a colony of Kyo : Wistar strain of rats, we found animals with curled whiskers and hair. These rats exhibited tremor when they moved. There were no sex differences in phenotype and behavior, and the affected animals of both sexes were sterile. Among pairs that produced at least one tremorous offspring, 21.8% of the females and 21.7% of the males were affected ; these proportions suggest that the anomaly is caused by an autosomal recessive gene. When the presumed heterozygous males were crossed with WAG/Rij females, about half of their female F₁ hybrids were heterozygous, and they produced 26.1% (43/165) of the affected offspring when backcrossed to the sires. Again these results suggested that the disorder is caused by an autosomal recessive gene. We tentatively designated the gene as tremor (tm) . The main pathological changes were seen in the gonad and central nervous system. The gonads of both sexes were aplastic even in adult animals. Vacuole formation was seen widely in the central nervous system and sometimes exhibited a spongy appearance. After administration of α-methyl-p-tyrosine, the norepinephrine content of the cerebellum was high, indicating that some anomalies of catecholamine release were present. The mutation is being maintained by random mating of the littermates of affected animals. Detailed pathological, endocrinological, neuropharmacological, and genetical studies are proceeding.

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In the TW inbred rat, about 50% of the males show bilateral or unilateral testicular hypoplasia with aplasia of the ipsilateral epididymis, ductus deferens and gland of the ductus deferens. To investigate the pathogenesis of the testicular abnormality in the TW rats, the weight and morphology of the testes on the aplastic and normal side were studied between one week and one year of age. The weight of the testes on the affected side was greater than those on the normal side at four and five weeks. However, it rose to a plateau at six weeks and then remained at about one half to one third the weight of a normal testis. As for the testicular histology, there were no obvious changes from one day to three weeks of age. The diameter of the seminiferous tubules became larger and the number of germ cells decreased at four and five weeks. At six weeks, degeneration and loss of germ cells were observed and many multinucleated giant cells appeared. Thereafter, the loss of germ cells became more severe, and they eventually disappeared with increasing age, but Sertoli's cells continued to exist. In the interstitial area, edematous changes and proliferation of Leydig's cells were observed. The efferent duct of another strain, with normal testes, was ligated at three weeks of age, and changes of the testis after the operation were examined to investigate whether or not these anomalies of the TW strain were due to the absence of the accessories, which may block the excretion of the testicular fluid. The weight of the ligated testis increased at one and three weeks and decreased at six and 12 weeks after the operation. The number of germ cells had decreased after one week. Degeneration and loss of germ cells were observed, and giant cells appeared after three and six weeks. Most of the seminiferous tubules decreased in size, and the germ cell layers disappeared after 12 weeks. Edema and proliferation of Leydig's cells were also observed in the interstitial area. These results indicate that testicular anomalies of the TW strain can be attributed to the blockage of testicular fluid excretion by the absence of the accessories.

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A quarantine was performed on conventional Hartley guinea pigs free from Streptococcus zooepidemicus, Bordetella bronchi septica and Salmonella spp., but infected with Eimeria caviae, which were purchased from twenty-five commercial breeders by the National Institute of Health. Physical examinations revealed an incidence of 0.88 per cent or 1, 461 sick animals in 166, 050 guinea pigs quarantined during the period 1964 to 1982. The result obtained showed the following significant differences between the periods 1964 to 1971 and 1972 to 1982: Annual incident of sick animals in the period 1972 to 1982 increased twice as many as 0.56 to 0.81 per cent during the 1964 to 1971, and monthly incidence showed bimodal occurrence at April and October in the former period but continual occurrence from November to April in the latter period. Major clinical signs in the former period were death and diarrhea, which occurred usually within a week after arrival of the guinea pigs at our institute and caused significant decrease of body weight, but those in the latter period were retarded growth and weakness which became detectable during 1-3 weeks after arrival of the animals. Discussions were made on possible reasons concerning the differences in incidence of sick animals during the two periods.

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Artificial inseminations were performed on two female chimpanzees from July 1981 to April 1983 and three conceptions were obtained. Semen samples collected by rectal probe method of electroejaculation were incubated at 37°C for about 20 minutes for liquefaction. Liquefied portion of the semen was sucked up into polyethylene tube about 30cm in length attached to a syringe and was inseminated into cervix of each female of which pelvic region was raised in prone position under anesthesia. Ovulation time was speculated by swelling of sex skin in earlier two cases and by urinary LH level in last case. Three offsprings were obtained 234, 235 and 235 days after last insemination, respectively. All of three show normal developments.

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An 6-week-old male Sprague-Dawley rat which had undergone no experimental treatment died from enlargement of the abdomen. At necropsy, a spherical mass measuring about 3×4cm in diameter was connected to the retroperitoneal region cross to the middorsal line of the body. The tumor was composed of skin, ganglion, striated and smooth muscle, cartilage, bone, pancreas, glands, lymph node, and fibrous and adipose tissue, and diagnosed as teratoma.

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Male Sprague-Dawley rats of six weeks of age were fed on ten percent crude protein diets for a ten day experimental period. The net protein utilization (NPU) by carcass analysis of six kinds of revised stock diets for rats and mice was compared with that of purified whole-egg protein and milk casein. NPU values for all revised stock diets and milk casein were lower than those for purified whole-egg protein. Compared to milk casein, two kinds of revised stock diets showed lower NPU, but the remaining four diets had similar NPU.

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