The frequency of appearance of HI antibody against Japanese encephalitis virus was investigated over the three-year period 1982 through 1984. The sample population consisted of 1306 cattle in Saitama prefecture (located in central Japan), and 536 cattle in Kagoshima prefecture (located in southern Japan). During the study period, there was no significant difference in the average antibody-positive rate between cattle in Kagoshima (68.8 %) and those in Saitama (65.5 %). Variations in the monthly antibody-positive rate and mean monthly antibody titer in the Saitama cattle followed a mountain-like pattern with the peak observed during summer. In the Kagoshima cattle, both parameters also increased in summer and these increases persisted even in winter. The distribution of antibody-positive rate as a function of age ranged from 64.0 % to 82.8 % in Saitama, though no correlation was observed between these two factors. In the Kagoshima cattle, however, the antibody-positive rate increased with age as follows; the values averaged 29.4 % in the one-year-old cattle group, 50.0 % in the two-year-old group, 47.4 % in the three-year-old group and 74.5 % in the four-year-old group. There was no significant correlation between the mean antibody titer and age in either Saitama cattle (15.3-22.5) or Kagoshima cattle (20.0-32.3)

In order to enumerate the T-lymphocytes in bovine peripheral blood lymphocytes (PBL) by E rosette assay, KGRBC were treated with various concentrations of 2aminoethyl-isothiouronium bromide (AET) and dextran (Dex), singly or in combination. To further standardize the assay, optimum concentration of AET-and/or Dex-treatment and incubation time for rosette forming cell (RFC) counts were determined. The levels of B-lymphocytes in the PBL were evaluated by erythrocyte-antibody (EAfc)- and erythrocyte-antibody-complement (EAC)- rosetting techniques. The PBL from 20 clinically normal Korean cattle were formed as low percentage of spontaneous E-rosette (6.7 +- 2.4 %) in control group, whereas in KGRBC treated with 0.1M AET for 20 minutes and 8 % Dex were formed as 37.3 +- 2.7 % and 45.1 +- 2.1 %, respectively. And the synergistic effects were noted no less than 66.5 +- 5.6 % when the KGRBC treated with 0.1M AET and 8 % Dex subsequently and rate of RFR did not change significantly between 3-24 hours incubation time at 4deg C, EA-and EAC-RFR were 23.3 +- 9.1 % and 23.1 +- 7.9 %, respectively. These results suggest that the KGRBC would be a useful agent for the enumeration of T-lymphocytes by E rosette assay and B-lymphocytes by EA-or EAC-rosette assay in cattle-PBL

A survey on the prevalence of internal parasites in the laboratory rats in the Chonnam and Kyonggi areas was carried out. A total of 208 rats was selected for necropsy and the parasites were collected from the organs and the fecal samples. The infection rate of the internal parasites was high as 63.9 % and eight species of parasites were identified. Among the species identified A tetraptera (21.6 %) and H diminuta (20.7 %) appeared with relatively higher infection rates than any other species identified. A significant difference in numbers of parasites was recognized between the regions as 8 species in Chonnam and 4 species in Kyonggi. The laboratory rats reared in stainless steel cage showed the higher infection rate than those in polycarbonate cage, with some exception in H spumosa and H nana. In this survey T crassicauda was firstly in the laboratory rats in Korea

This study was carried out to evaluate the possibility of sex preselection by gradients methods using bovine serum albumin in rabbits. Artifical insemination was performed with sperm from the top and bottom layer of rabbit semen separated by bovine serum albumin gradients. Various characteristics of separated sperm, and the conception rate secondary sex ratio at artificial insemination with separated sperm were compared. The sperm from the bottom layer showed significantly high value in motility, percent of normal sperm and progressive motility as compared with control sperm and the sperm from the top layer. The conception rate of sperm from the bottom layer was higher than that of the top layer. But secondary sex ratio was not altered by this methods

This experiment was carried out to determine the progesterone concentration of bovine plasma by liquid phase double antibody enzyme immunoassay. The optimum conditions of assay-system, enzyme conjugate and gelatin were investigated. The sensitivity, recovery rate and reproducibility by this assay were also analyzed. The suitable supplementation level of gelatin was 0.2 %. As the gelatin level increased to 1 %, coefficient variation of interassay was shown to be irregular. The optimum dilution rate of enzyme conjugate was 30 times. Enzyme activity was greatly fluctuated depending on the minor condition of enzyme conjugate technique. Therefore, it was considered to be checked when determined. The sensitivity of the assay was 12 pg/tube. Recovery rate was decreased when the amount of sample was too little or too much, but the recovery rate was high as 97.8 % when the amount of sample was between 50 and 200 micro l. Mean intra-assay and inter-assay coefficient of variation was 4.5 % and 5.9 %, respectively. By using liquid phase double antibody enzyme immunoassay, progesterone in plasma can be detected, and also this assay system is applicable to study the physiological function of progesterone and diagnosis of reproductive disorders

The study was undertaken to obtain indirect values of volume of packed red cell (VPRC) without centrifugation, using the erythrocyte sedimentation rate (ESR) of diluted blood in dogs. ESRs of diluted blood using the diluent of autologous plasma in which formed numerous RBC-rouleau clumps, autologous serum in which formed a few RBC-rouleau clumps, and 5 % dextrose or 6 % sucrose solutions in which formed numerous RBC-aggregation clumps, were accelerated. But ESR of diluted blood using the 0.9 % saline, D-S, ACD-B, CDP or D-PBS solutions were sluggish, because erythrocytes were dispersed in these diluents. Reliable values of VPRC on the basis of the correlating regressive equation to the ESR could be derived from values of 60deg C-angled-micro-ESR/40 min in the mixture, four parts of 5 % dextrose solution and one part of whole blood. In the ESR values of diluted blood with low ratio, 1 : 1-3 : 1, 60deg C-micro-ESR was higher than 60deg C-Wintrobe-ESR. But, in the diluted blood with high ratio, 4 : 1-5 : 1, there was no different ESR values. For an aid of practical use, authors suggested a list of the 60deg C-micro-ESR/40 min in the diluted blood with equivalent VPRC of whole blood

This study was undertaken to investigate the changes of enzyme activities resulted from low concentrated carbon monoxide poisoning on the caudate nucleus in rat. The activities of cytochrome oxidase, succinate dehydrogenase and lactate dehydrogenase were observed histochemically, after the experimental animals were poisoned to 100 ppm carbon monoxide for 8 hours every day from one day to 16 days. The materials were sliced from coronal section at the level of the optic chiasm and immediately frozen sections of 10 micro m thickness were cut on the cryostat at -15deg C and incubated in the medium containing substrate for histochemical detection of cytochrome oxidase, succinate dehydrogenase and lactate dehydrogenase. The sections were mounted in glycerol gelatin and observed under light microscope. It was obtained that cytochrome oxidase activity decreased moderately and succinate dehydrogenase activity showed marked or moderate activity during entire poisoning period and lactate dehydrogenase activity showed marked or moderate activity from one to 8 days but recovered to normal condition at 16th day

These studies were carried out to investigate the changes of blood pictures, histological findings and testosterone concentrations after orchidectomy in ageing rat. The total W.B.C. counts were 9.27 +- 12 x 10** (3)/mm** (3) in the control group, 9.54 +- 34 x 10** (3)/mm** (3) in the sham-operation group and 12.08 +- 28 x 10** (3)/mm** (3) in the orchidectomy group when it was checked 50days after the operation. The number of lymphocytes after orchidectomy began to increase gradually as time passes, thereafter markedly increased 10.12 +- 03 x 10** (3)/mm** (3) at 50 days after orchidectomy. The concentration of testosterone in serum began to decrease gradually after orchidectomy showed lowest level 1.68 +- 0.61 pg/ml at 50 days after orchidectomy while it was 5.82 +- 0.39 pg/ml in control group. The histological findings of thymus after orchidectomy marked increase of thymic lymphocyte, disapearance of fat cells and appearance of mitotic figures

In order to manifest the presence of Na-K pump and its property on the unfertilized egg membranes of mouse, membrane potential was recorded under the physiological condition (at 37deg C and 4mM Ca** 2+). After an induction of superovulation, the fresh eggs with zona pellucida were collected from mouse oviduct. Transient hyperpolarization as pump action was recorded after the switch into the high potassium perfusate (15mM K+) from K-free perfusate, and the difference between membrane potential observed just before the perfusion of high potassium solution and the maximal membrane potential during the perfusion of high potassium solution was regard as pump activities. Resting membrane potential was depolarized under the treatment of 10** (-5) ouabain. Pump activities of the unfertilized mouse eggs were -3.38 +- 0.61mV (Mean +- SD, n=6), recorded as transient hyperpolarization due to the electrogenic property. Pump activities were blocked by both treatment of 10** (-5)M ouabain and perfusion of Na-free solution, while increased by high Na + (300mM) perfusion (-7.45 +- 0.75mV, n=2). Hyperpolarization due to pump activity was not altered by Mn 2+. Above results confirm the presence of ouabain-sensitive Na-K pump, which affected the membrane potential directly, on the unfertilized egg membranes of mouse

A total of 108 strains of C jejuni isolated from pigs and chickens were examined for the susceptibility to 10 antimicrobial agents and normal sera of cattle, sheep, guinea pigs and chickens. Minimal inhibitory concentration (MIC) ranges of antimicrobial agents to C jejuni isolates were = 100 micro g/ml for erythromycin, rifamycin, streptomycin and tetracycline, 50 to 100 micro g for cephalothin, = 50 micro g for ampicillin,