This study was designed to evaluate the effect of cyclophospaide(CY) on dietynitrosamine(DEN)-induced hepatic tumors in rats. Thirty five male of femal Sprague Dawley rats were continiously given water containing O.01% DEN for 10 weeks and then were give with CY 25mg/rat/day in water for 3, 5, 7 or 9 days. The livers of rats were removed and fixed in 10% buffered neutral formalin. The appearances of positive cells by immunohistochemical methods using proliferating cell nuclear antigen (PCNA) antibody, p53 antibody and apoptotic kit were investigated. The livers of rats given with CY were grossly brilliant, red-brown color, flexible, and thin border, and stainability of the liver cells were restored microscopically, and the vaccuolated and degenerated regions were differentiated from restored regions. These restored findings also were advanced in control group becouse of no DEN treatment but tended to be less avanced. In immunohistochemistry, positive cells to PCNA antibody appeared more numerous in control groups than that of CY treated groups. Appearance of positive cells in CY-treated group for 7 days and for 9 days were more numerous than those of CY-treated groups for 3 days and for 5 days, respectively. So these findings suggested that CY suppressed cell proliferations and effects of these action were decreased with CY-treated days. The numbers of positive cells to PCNA antibody were more prominent in hepatocelular carcinoma regions and cholangiocarcinoma regions, and then were ranked as order of large liver cell regions and normal liver cell regions. Also the numbers of the positive cells by apoptotic kit tended to be higher in hepatocelular carcinoma regions and cholangiocarcinoma regions but not uniformly in order in all regions nd were much less numbers than those of OCNA positive cells. So immunohistochemical methods using PCNA antibody together than using apoptotic kit alone when anti-carcinogen experiments. Rats with positive cells by p53 antibody were 11 of 15 rats(73.4%) in control groups and 12 of 18 rats(66.7%) in CY treated group, respectively. These positive cells appeared focally in early vacuole-occurring regions and were low in numbers.

This study was conducted to detect the toxoplasma-specific DNA in peripheral blood collected from cats experimentally infected with Toxoplasma gondii (RH strain) and from domiciled cats by B1 gene-base polymerase chain reaction (PCR). The sensitivity of oligonucleotide primer, T-1 & T-2, designed from toxoplasma B1 gene amplification method was compared with parasite detection by mouse inoculation(MI). And also, latex agglutination test(LAT) and indirect fluorescent antibody test(IFAT) were conducted to detect the fluctuation of serum antibodies compared with the detection of toxoplasma by PCR and MI. Toxoplasma B1 gene PCR was shown consistently high sensitivity and the results obtained by PCR agreed completely with those from MI. All blood samples collected before infection with T gondii gave negative results by PCR and MI. Also, toxoplasma B1 gene PCR was not cross reaction with Neospora caninum DNA and normal cat leucocyte as cnotrols. The toxoplasma-specific DNA was detected by PCR in blood of 5 cats experimentally infected with T gondii 6 days after infection and the detection of this specific-DNA was long lastedin blood for 64 days after infeciton. The detection of toxoplasma-specific DNA by PCR could be identified as few as 10 tachyzoites and the isolation of T gondii by MI could be isolated as few as 1 tachyzoite from tenfold serial dilution of T gondii with normal cat blood, respectively. In healthy domiciled cats, the toxoplasma-specific DNA and the parasite were detected and isolated in blood from 3 of 56(5.3%) cats by both PCR and MI, respectively. In the results of antibody test from the total 56 heads of healthy domiciled cats, the positive rates are 15(26.7%) by LAT and 19(33.9%) by IFAT. These results suggest that PCR detection of toxoplasma can be applied as a sensitive and specific diagnostic and research tool.

To determine sex of bovine embryos using hamster histocompatibility Y(H-Y) antibodies, bovine compact morulae were incubated for 6 hours in TCM199 supplemented with 10% hamster H-Y antiserum and the embryos with developmental arrest were diagnosed as male embryos, while the embryos showing development during the incubation as femalle embryos. This presumptive embryo sexing was confirmed by polymerase chain reaction(PCR)method. 1. In the result of hamster sperm cytotoxicity test to measure H-Y antibody titer, the rate of dead sperm was considerably lower in H-Y antiserum absorbed with hamster male splenocytes than in H-Y antiserum absorbed with hamster female splenocytes or H-Y antiserum umabsorbed with splenocytes(p0.01). 2. The rate of oocytes fertilized in vitro and the rate of blastocysts of the fertilized oocytes were 58.5% and 32.4%, respectively. The rate of blastocysts on day 8 was 15.9%, denoting the highest rate during whole culture period posterior to in vitro fertilization(IVF). 3. The bovine 16 cell and compact morulae embryos incubated in the medium supplemented with hamster H-Y antibodies showed 37.1% and 48.9% of developmental arrest which were diagnosed as male, respectively, and rates of redeveloped embryos from the arrested were 24.1% in 16 cell and 44.3% in compact morulae embryos, respectively, denoting higher rater of sex determination and rate of redevelopment in compact morulae than 16 cell embryos. 4. Bovine compact morulae of Korean cattle and Holstein were treated with hamster H-Y antibodies for sex determination and the rates fo developmental arrest(deagnosed as male) were 48.4% for Korean cattle and 47.9% for Holstein, respectively. The rates of redeveloped embryos to blastocyst after treatment were 42.6% for Korean cattle and 41.8% for Holstein, respectively, ahowing no sighificant differences of sex determination and redevelopment between both breed. 5. The sex determination of bovine cmbryos(Korean cattle Holstein) using hamster H-Y antibodies was diagnosed by PCR for confirmation, denoting the rates of 86.1% for Korean cattle and 85.9% for Holstein male embryos, respectively, and the rates of 91.9% for Korean cattle and 90.1% for Holstein female embryos, respectively, with no significant differences of sex determination between both breed. These results indicated that hamster H-Y antibodies can be usable for sex determination of bovine embryos of Korean cattle and Holstein, the viability of bovine embryos was sustained while being cultured in the medium supplemented with hamster H-Y antibodies of appropriate titer and sex determination of bovine embryos by PCR can be feasible for confirmation.

Ischemic preconditioning (IPC), i.e., a preliminary brief episode of ischemia and reperfusion, has been shown to reduce the cell damage induced by long ischemia and reperfusion. Superoxide radical which is produced during reperfusion after ischemia was recongnized as a factor of the ischemic injury and it is dismutated into H2O2 and O2 by two types of intracellular superoxide dismutase (SOD), Cu,Zn-SOD in cytoplasm and Mn-SOD in mitochondria. Recently oxygen free radicals are suggested to induce the apoptosis, however mechanism of the reduced apoptosis by ischemic precondition was unknown, while many studies performed in mammalian heart indicated that ATP-sensitive K+(K atp) channel activation related with the protective effects. The aim of present study is toinvestigate 1)whether IP upregulate the Cu,Zn-SOD and Mn-SOD activities, and 2)whether ischemic preconditioning decreases apoptosis via K atp channel activation in timely reperfused skeletal muscle after long ishemia. The experimental animals, Sprague-Dawley rats weighing 250~300g, were divided into 8 group; 1)control group, 2)ischemic preconditioning only groups, 3)pinacidil, a K atp channel opener, treatment only groups, 4)glibenclamide, a K atp channel blocker, treatment only groups, 5)ischemia groups, 6)ischemia after IPC groups, 7)ischemia and pinacidil treatment groups, and 8)IP and ischemia after glibenclamide pretreatment groups. Animals of the control group were administered with the vehicle (DMSO) alone. Pinacidil (1mg/kg) was administred intravenously 5 minutes after initiation of ischemia, and glibenclamide(0.5mg/kg) was injected intravenously 20 minutes before IPC. In rats that were ischemic preconditioned, the left common iliac artery was occluded for 5 minutes followed by 5 minutes of reperfusion by three times usign vascular clamp. Ischemia was done by occlusion of the same artery for 4 hours. The specimens of left rectus femoris muscle were obtained immediately (0 hours), 12 hours, 24 horus after drug administrations, IP or ischemia and reperfusion. The immunoreactivities of SOD and its alterations were observed by use of sheep antihuman Cu,Zn-SOD and Mn-SOD antibodies onthe 10 micro meter cryosections. The incidencies of apoptosis were observed by TUNEL methods with in situ apoptosis detection kit on 6 micro meter paraffine section. The results obtained were as follows: 1. After IPC, immunoreactivities of Cu,Zn-SOD mainly in the small-sized fibers were increased by 24 hours, that of Mn-SOD at 0 hour and 24 hours. 2. No significant changes in immunoreactivities of SDO was observed in the pinacidil and in the glibenclamide treatment only groups, and in the ischemia only groups. 3. The immunoreactivities of the Cu,Zn-SOD were incresed in the ischemia after IPC groups and the ischemia and pinacidil treatment groups. 4. The immunoreactivities of the Cu,Zn-SOD in the IPC and ischemia after glibenclamide pretreantment groups were not increased except for the 12 hours reperfusion group. But, Mn-SOD immunoreactivities were incresed in to 0 hours, 12 hours and 24 hours after reperfusion. 5. In the control group, the IPC only groups, and the pinacidil treatment only groups, negative or trace apoptotic reactions were observed, but the positive apoptotic reaction occured in the glibenclamide treatment groups. 6. Moderate or many number of apoptosis were revealed in the ischemia groups, and also the IPC and ischemia after glibenclamide pretreatment group except for 12 hours and 24 hours after reperfusion. However, the incidence of apoptosis was decreased in the ischemia after IPC groups and in theischemia and pinacidil treatment groups. 7. There is a coincidence between the increase of Cu,Zn-SOD immunoreactivities and the decrease of apoptosis in thepresence of ischemia and reperfusion. These results suggest that the protective effects of ishemic preconditioing may related to the SOD activation, and the ischemic preconditioning decreases the apoptosis partially via K atp channel activation in timely reperfused rat skeletal muscle. It is also suggested that inhibition of apoptosis by IPC may related with the SOD activation.

Galectin-3 plays an important role in cell development, differentiation and cancer metastasis, including cell-cell/extracellular matrix (ECM) interactions and is supposed to have an effect of apoptosis on T-cells in thymic clonal selection. In this study, to know the effect of galectin-3 on thymocyte development, we used recombinant human galectin-3 (rHgal-3) from Escherichia coli, JM105, which was inserted with human gal-3 gene-transformed plasmid vector (prGal-3) to express human galectin-3. Expressed rHgal-3 was confirmed by western blot using the culture supernant of hybridoma (M3/38) producing monoclonal antibody to human galectin-3. Sepharose gel affinity chromatography was used to purify the expressed rHgal-3. Thymocytes and hepatocytes from 6-week-old male BALB/c mice were incubated with rHgal-3 and showed marked increase of apoptotic population on analysis using flow cytometry with 7-AAD in a dosedependent manner. However, rHgal-3 failed to induce apoptosis on hepatocytes. Interestingly, this apoptotic effect was not inhibited by lactose, a specific lectin domain inhibitor. From these results, we concluded that extrinsic galectin-3 induces apoptosis on mouse thymocytes, and galectin-3 may have an apoptotic effect on T-cells in thymic clonal selection.

The prevalence of antibody to Getah virus was serologically followed among those horses in Korea. Blood samples were taken from 575 horses in Feb and 462 horses in Sep. 1985. Overall percentage of horses with seropositive to Getah virus was 37% in Feb and 47% in Sep. The data suggest that the Getah virus infection was endemic in Korea and the increase in prevalence may be associated with the seasonal activity of arthropod vectors. This entails preventive precautions of the horses against this viral infection before the entry into Korea