The relation between blood pressure and delivery in pregnant rats was investigated when the blood pressure of pregnant rats was controlled by a pressor or hypotensor drug in the middle or final stage of pregnancy. All of the pregnant rats studied delivered in a 23°C environment in spite of blood pressure control by a pressor or hypotensor drug. At 33°C, the pregnant rats were divided into two groups whose blood pressure was increased severely (160-175 mm Hg) or moderately (145-155 mm Hg) at 10 days of pregnancy. Those in the former group delivered, but those in the latter died in the final stage of pregnancy. When the pregnant rats in the group with high blood pressure on day 10 were treated with a hypotensor drug in the middle stage of pregnancy or with a pressor drug in the final stage, the mortality rate was 100 per cent in both cases. The delivery rate was 57 per cent when the pregnant rats were treated with a hypotensor drug from the middle to the final stage of pregnancy. In the grop with low blood pressure on day 10, all of the pregnant rats delivered when they were treated with a pressor drug in the middle stage of pregnancy. However, the delivery rate was 89 per cent when the pregnant rats were treated with a hypotensor drug in the final stage of pregnancy.

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The mode of larval migration (visceral larva migrans) in Toxocara canis infection was compred for BALB/c, C57BL/6, C3H/He, DBA/2, NC and BALB/c nude mice following oral infection with 400 eggs. The mean recovery of larvae from the liver on day 2 post infection (PI) was not different in terms of the strain, age or sex of the mice. The number of larvae recoverd from the liver decreased in all strains on days 6, 12 and 21 PI, but the mean for BALB/c and (NC X BALB/ c) F1 mice was significantly higher than that for C567BL/6, NC and BALB/c nude mice, unless the total number of larvae in the carcasses on day 21 PI was the same among those strains including athymic nude mice. The mean recovery of larvae from the liver on day 6 PI increased with age in both NC and BALB/c mice, although no sex difference was observed. From these results, it is emphasized that the age and strain of animals should be properly selected for animal experimentation with T. canis infection.

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We examined the age-related behavior under open-field conditions using 925 Wistar-Imamichi rats of both sex ranging 21 to 695 days old. The mean score of ambulation and rearing increased between 28-56 days old, and both decreased after those ages. The coefficients of variation were stable and kept minimum values between 28-98 days old. Other parameters, except for ambulation and rearing, did not show the age-related change. Each parameter was divided into 3 one-minute-values in order to detect the change in minutes after exposure in open-field conditions. The chronological change in each behavioral parameter has its own specific pattern regardless of age and sex. Namely, it has been proved that a rat has an invariable natural behavioral pattern with regard to a time course in open-field conditions. It is important to detect a change of chronological pattern in each parameter, because an abnormal subject would be identified by an appearence of change in the chronological pattern. Sexual difference also was identified in all ages. It is necessary to evaluate separately parameters depending on sexual difference.

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A mutant strain, Nagase analbuminemia rats (NAR), was established from Sprague-Dawley rats. Hematological evaluations were made on NAR of 4 to 52 weeks of age. NAR had an abnormally low number of red blood cells (RBC), a low hematocrit, a reduced hemoglobin concentration and an increased number of reticulocytes. Their plasma electrolyte level was normal. Osmotic fragility of RBC was slightly increased in the rats. Thus NAR shows a slight anemia. The in vitro experiments on RBC were performed. The incubation of blood showed a hemolytic tendency and elevated potassium efflux in the blood of NAR. In addition, an increased efflux of potassium was found in the RBC of NAR, when the RBC was washed with phosphate buffered saline and then was incubated with the saline containing CaCl₂. This potassium efflux was prevented in the presence of rat albumin. These findings suggest that the deficiency of serum albumin may increase the permeability of potassium in erythrocyte membrane in NAR.

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Forty seven skulls of the crab-eating monkey (Macaca fascicularis) were investigated for their morphological characteristics. Five of them were disintegrated into component bones by the use of the papain. Each cranial and facial bone of this species resembled that of the rhesus monkey (M. mulatta) in its general morphology. Some obvious differences, however, were noticed in the detailed structure of the skulls between these two species. The uncinate process of the ethmoid bone was found in the rhesus monkey but was not found in the crab-eating monkey. The intrajugular process of the temporal and occipital bones was present in the crab-eating monkey but absent in the rhesus monkey. The nasal procoss of the incisor bone was sutured with frontal bone in the rhesus monkey but was not sutured with that bone in the crab-eating monkey.

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Differential bone marrow cell and peripheral blood cell counts in new-born mice from zero to twenty-one days of age were investigated. 1. In the bone marrow, erythroblasts rapidly increased whereas granulocytic cells decreased with time. The G/E ratio was 6.7 on day zero and 0.5 on day four, and as the G/ E ratio of adult mice is normally from 0.8 to 2.4, these values would be the highest and lowest respectively for the whole life span of a mouse. 2. In the peripheral blood, MCV decreased each day, closely matching the changes in the Price-Jones curves. The results of erythrocyte area measurements indicate that the larger the erythrocyte area, the earlier in days of age it disappeared and the shorter its life span.

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The translocation of indigenous bacteria from the gastrointestinal tract to the mesenteric lymphnodes was compared in ten strains of mice. Indigenous Escherichia coli were cultured from the mesenteric lymphnodes of only two of the six mouse strains examined. Thus, spontaneous translocation of indigenous enteric bacteria across the intestinal barrier did not occur to any significant extent in any of the mouse strains examined. Since bacterial overgrowth in the gastrointestinal tract promotes bacterial translocation, bacterial traslocation was tested in ten mouse strains including B10 series after antibiotic-decontaminated and subsequent colonization with streptomycin-resistant E. coli C25. E, coli C25 populated the ceca of the mice at levels of 10⁸ to 10⁹ per gram and translocated to 90-100% of the mesenteric lymphnodes with mean of 10^1.13 to 10^1.86 per mesenteric lymphnode. However, there were no significant differences between mouse strains as to the translocation incidence or the numbers of viable E, coli C25 per mesenteric lymphnode. Thus, genetic differences between mouse strains did not influence bacterial translocation from the gastrointestinal tract to the mesenteric lymphnodes.

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A total of 1, 278 strains of Streptococus faecalis, 688 of Str. faecium and 796 of Staphylococcus epidermidis were collected from laboratory animals of 20 colonies in 1980, and tested for their resistance to 20 drugs. Thirteen percent of Str. faecalis, 12% of Str, faecium and 25% of Staph. epidermidis were drug resistant. Multiple drug resistant organisms were frequently detected in laboratory animal colonies where antibiotic treatment had been undertaken. TC-resistant streptococci and EM-resistant Staph. epidermidis were distributed in about half of the colonies regardless of the history of antibiotic usage.

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Routine monitoring on levels of serum uric acid in the rats has been widely employed as an important factor in the nucleic acid metabolism, despite of the presence of the uricase in them. In this paper, it is confirmed that the levels of allantoin in serum and urine of the normal rats were higher than those of uric acid. Therefore, the concentration of allantoin in serum and urine of the rats with abnormal nucleic acid metabolism caused by adenine administration were measured. The results indicated that the value of serum allantoin was more sensitive to abnormal nucleic acid metabolism.

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During the quarantine of 15 guinea pigs acquired from a breeder in February 1983, several became weak and moribund, and one died. A tremendous number of Giardia sp. bodies were detected from stamp smear preparations of the duodenal contents of some necropsied animals in this group. Histopathological examinations of the intestine revealed slight inflammatory changes and cystic enlargement of the crypts in the duodenal and jejunal mucous membranes. From these findings and the fact that other major pathogenic organisms were not detected, this disease was diagnosed as giardiasis in guinea pigs.

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Vaginal atresia was observed with 5.8% morbidity (58/998 females) in adult BALB/cA-nu/+ and -nu/nu mice. Twenty-seven of the diseased mice were pathologically examined. In the affected mice, the vaginal orifice failed to open even 2 months of age and the perineal region was swollen, being scrotumlike. In addition, an increase of the follicle and a decrease of the corpus luteum were noticed in the ovary. This disorder was regarded as a malformation concerned with a heredity.

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