We compared palpation and electrocardiograms (ECG) as methods of evaluation of acute rejections, and also studied the mode of expression of rejection from histological findings by means of a cervical heart transplantation model in LEW strain rats with (LEW × BN) F1 rats as donors. Evaluation by palpation mainly involved changes in the intensity of the beat of the transplanted heart. With this method, it was also possible to observe changes in the size of the graft, and to investigate these changes over time. Unlike with abdominal heart transplants, the time of cardiac arrest can be clearly determined without any influence from the heart rate of the recipient. But with the ECG evaluation method, it was possible to distinguish clearly between the waveforms of the graft and the recipient waveforms unlike with the conventional lead method. In histological findings, the time of transfer of infiltrating cells into the graft and the time of appearance of CD8 positive cells matched the times when changes occur in the intensity of the beat and in the heart rate seen with palpation. Unlike the palpation and ECG methods, however, these findings are not suitable for evaluation of the time of cardiac arrest of the graft. The graft survival time was 6.1 ± 0.6 days (n=73) by palpation and 8.5 ± 1.8 days (n=73) by ECG. Since the graft survival time was significantly longer in the ECG evaluation than in the evaluation by palpation (P<0.001), it appeared better to use these methods independently rather than concurrently in consideration of their features. Histological examination appeared to be useful in experimental systems for clarification of the mode of expression of the acute rejection after its has occurred.

View full abstract

Hair growth and skin structure were examined in kinky coat (kc) musk shrews, Suncus murinus. The first hair growth cycle and the development of hair bulbs were normal. Histological characteristics of hair follicles and bulbs were similar in kc/kc and normal +/kc shrews. The mean thickness of epidermis and dermis did not differ significantly between the kc/kc and +/kc shrews. And no histological abnormalities were observed in the epidermis, dermis and hypodermis of the kc/kc shrews. Consequently, it is clear that the kc mutation had no effects on the hair growth and skin structure, but caused hair shaft modifications as previously observed. These characteristics of the kc mutation were quite distinct from those of the previously reported rodent mutations causing complicated abnormalities in the hair and skin.

View full abstract

In an effort to study the pathophysiological events in the development of insulitis in NOD mice, we have developed ILI- and NOD-nu/nu mice. ILI mice are a nondiabetic inbred strain but are derived from the same Jcl:ICR mouse as NOD mice and share the same H-2 allotype with NOD mice. Splenocytes and CD4⁺ cells from diabetic NOD mice appeared to transfer insulitis to ILI-nu/nu mice, suggesting that ILI mice already express autoantigen(s) responsible for insulitis. But reciprocal thymic grafts from NOD mice into ILI-nu/nu mice and those from ILI mice into NOD-nu/nu mice failed to allow the development of insulitis, implying that ILI mice possess neither precursor T cells nor the thymic environment responsible for the development of insulitis. In addition, splenocytes from ILI mice appeared to contain regulatory cells which suppress the development of diabetes but not that of insulitis in NOD mice. The use of these nude mice should provide more information on the products of insulitis-susceptibility genes of NOD mice.

View full abstract

The influence of maternal rat virus (RV) infection on rat embryogenesis and fetus was examined by viral reisolation, immunostaining and PCR analysis. Vertical transmission caused by the UT-1 strain of RV depended on the stage of gestation when maternal infection occurred. When females were infected at the pre-mating point, the number of fetuses was smaller than that normally obtained, possibly due to infection at the stage of the hatched blastocyst, but almost all of the fetuses obtained were free from infection and developed normally. The incidence of transplacental infection was the highest when pregnant females were infected in the middle of the gestation stage, and some of the fetuses died. In pregnant females which were infected late in the gestation stage, all fetuses developed normally. Some of them were infected transplacentally and harbored the infectious virus. Much attention should be paid to performing reliable rederivation of RV-infected rat colonies by hysterectomy and embryo transfer.

View full abstract

Genetic factors controlling the deoxyribonuclease I (DNase I) activity level were examined in mice. A survey of inbred strains of mice revealed genetic variation in urinary and kidney DNase I activity levels, though a sex difference, males having significantly higher DNase I activity levels than females, was observed in all mouse strains tested. The sex difference in the urinary DNase I activity level was eliminated by testosterone administration to females or gonadectomy to males. The urinary DNase I level was closely correlated to that of the kidneys but no relationship between serum and urinary DNase I activity suggests that the production ratio of DNase I in the kidneys is responsible for strain variation in urinary DNase I levels. Inheritance of quantitative variation of urinary DNase I activity levels was studied by a test cross. The segregation ratio of backcross progenies fitted the model showing that urinary DNase I activity level was controlled by an autosomal single locus, Dna1 (χ²=0.1053, P>0.90). The allele Dna1r^a determines high DNase I inducibility in the kidneys and occurs in BALB/c, C3H/He and A/J strains. The allele Dna1r^b determines low DNase I inducibility in the kidneys and occurs in DBA/2 and C57BL/6 strains.

View full abstract

The hair follicles exhibit an intrinsic hair cycle that is divided into three phases; growth (anagen), transition (catagen) and quiescence (telogen). To make sure of the effects on hair growth by chemical substances, we should evaluate the induction of the anagen phase and/or elongation of the anagen period and delay in catagen separately, but the regulatory mechanism of the hair cycle is unclear. We have investigated the levels of biochemical markers in the third hair cycle period of C3H mouse (8 weeks, male) after depilation and compared them with those in a non-treated group. The dorsal areas (2 cm × 4 cm) were clipped and depilated with hair remover. The dorsal skin samples were collected 1, 8, 11, 15 and 18 days after depilation and the levels of biochemical markers, i.e. skin transglutaminase, skin sulfhydryl oxidase, cathepsin D, γ-glutamyl transpeptidase, alkaline phosphatase, acid phosphatase, tyrosinase activities and histamine content in each skin sample were examined. The levels of γ-glutamyl transpeptidase, tyrosinase and alkaline phosphatase were relevant to hair re-growth in the control group, but not skin transglutaminase, skin sulfhydryl oxidase, cathepsin D activities. The histamine content increased just after depilation treatment and returned to the normal level within two weeks, compared with the non-treated group. All these results suggest that the markers examined in this C3H mice model are useful for studying the distinctive process of hair re-growth caused by active substances.

View full abstract

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.

View full abstract

Many experimental techniques for bile collection have been investigated. Most have been used under conditions of anaesthesia, or early after biliary cannulation. These conditions affect both the volume and the components of the bile, and the liver metabolism. In order to solve these problems, we devised an experimental method in which a T-cannula was introduced into the common bile duct of beagles that had been trained to remain at rest on the experimental table. Using this method, all of the bile could be collected under conscious conditions without the influence of surgical invasion.

View full abstract

We attempted to apply FISH to chromosomal mapping of the human angiotensinogen (hAG) and human renin (hRN) transgenes which are carried by the parental strains of the Tsukuba hypertensive mouse. We report here that the hAG gene is mapped in the C2 region of Chr 19 and the hRN gene in the A1 region of Chr 6.

View full abstract

Lens luxation was found in a male CD-1 (ICR) mouse. Ophthalmologic examinations revealed conical cornea anterior synechia and corneal neovascularization in the right eye. The lens was dislocated heterocentrically within the posterior chamber. Histologically, anterior lens luxation and adhesion between the iris and cornea were observed.

View full abstract

Golden hamsters as alternative definitive hosts of Echinococcus multilocularis were used for coproantigen detection by means of sandwich ELISA. The test was performed in hamsters infected with approximately 20,000, 4,000, 500, 0 (control) and 100,000 (i.e., group I, II, III, IV and V respectively) protoscoleces. Comparison of mean OD values of each group showed significant differences depending on the number of protoscoleces administered and days postinfection. There was also a relatively high statistical correlation between the number of recovered worms and ELISA OD values (correlation coefficient=0.699, P<0.05), although accurate comparison of worm burdens among individual animals was difficult when numbers of infecting worms fell within the same range.

View full abstract

It is reported that high-dose methamphetamine (8 mg/kg) induces stereotyped behavior in ddY mice in an open field, but itis still not certain that low-dose methamphetamine (less than 2 mg/kg) can induce the stereotyped behavior in ddY mice in a narrow space. In order to investigate the problem, we evaluated the quantity of stereotyped behavior of ddY mice by using a mouse wheel-running apparatus. In this method, we have come to recognize an increase in the stereotyped behavior depending on the dose of methamphetamine and the reverse-tolerance phenomenon as a decrease in the wheel-revolution counts. The present findings indicate that low-dose methamphetamine can promote stereotyped behavior in ddY mice under conditions in which the ambulation is restricted to a narrow wheel space.

View full abstract

The paucity of information and the unagreed consensus about the estrous cycle of the Mongolian gerbil (Meriones unguiculatus) have rendered such studies rather difficult. The estrous cycle of the Mongolian gerbils in this report were divided into 5 stages: Stage I, proestrus; Stage II, estrus (scattering); Stage III, estrus (gathering); Stage IV, metestrus and Stage V, diestrus. The normal estrous cycle in the Mongolian gerbils was 4-6 days long. In our experimental conditions, 67.9% of virgin females had a 4-6 day cycle, whereas 26.4% had an unsettled cycle and 5.7% assumed pseudopregnancy. The changing pattern of the estrous cycle and copulatory behavior of the Mongolian gerbils after hormone (PMSG: pregnant mare serum gonadotropin, 10 IU; hCG: human chorionic gonadotropin, 10 IU) injection were examined. The change in the estrous stage after hormone injection could be roughly classified into two types. The vaginal smear of virgin females injected with PMSG at Stage I, II or III changed to Stage V the next day and to Stage I or Stage II after 48 hr, but in the case of Stage IV or V, the smear changed to Stage I after 48 hr. The females injected with PMSG at Stage I, II or III copulated at from 13:00 to 23:00, whereas others injected at Stage IV or V scarcely copulated at all between 13:00 and 23:00. Mating of these females with the male midnight was not observed.

View full abstract

Time course changes in anti-tumor activity induced in peripheral blood lymphocytes (PBL) with recombinant human interleukin-2 (rhIL-2) and phytohemagglutinin-P (PHA) were studied in dogs implanted with canine transmissible venereal sarcoma (CTVS) as a tumor-bearing model. The rhIL-2-dependent and PHA-dependent cultures allowed selective proliferation of lymphocytes expressing Thy-1 antigens. The lymphocytes acquired a prolonged anti-tumor activity against the CTVS cells, starting from 2 weeks after the culture, indicating generation of lymphokine-activated killer (LAK) cells. The LAK cells showed serial growth in rhIL-2-containing culture medium for at least a further 2 weeks without loss of the anti-tumor activity.

View full abstract

The protective effects of recombinant IFN-α/ β on MHV-2cc-induced chronic and persistent hepatitis in athymic nude mice were examined. The mice intraperitoneally (ip) inoculated with MHV-2cc at day 0 of experiment were divided into 4 groups. Three of them were administered ip with recombinant IFN-α/β at a daily dose of 1 × 10³ IU from -1 (-1D-group), 0 (0D-group), and +1 day of experiment (+1D-group), respectively, for 3 consecutive weeks. The remaining one (control group) was given 0.1 ml/mouse of PBS from +1 day of the experiment in the same way. Three mice in each group were killed at 1, 2 and 3 weeks post inoculation (WPI) with MHV, respectively. The liver virus titer in the control group increased gradually and maintained high levels throughout the experimental period. In the IFN-groups, particularly in the -1D- and 0D-groups, the virus titers were significantly lower than that in control group. Histopathologically, focal hepatic lesions were observed at 1WPI and large irregular inflammatory lesions developed at 3WPI in the control group. Similar but somewhat less severe lesions were observed in the +1D-group. In the -1D- and 0D-groups, lesions were not observed at 1WPI and only small organized lesions with mononuclear cell infiltration were seen at 3WPI. In conclusion, it was clarified in the present study that the progression of MHV-2cc-induced chronic hepatitis in athymic nude mice was effectively prevented by extrinsic IFN-α/β when administered from -1 day and 0 day of the virus infection.

View full abstract