An attempt was made by the authors to survey the distribution of C. renale in apparently healthy Korean male cattle and dairy cattle, and to determine the types of C. renale isolated in Korea. A total of 153 urine samples and 240 vaginal smears were collected from 253 cows for examination, and 124 urine samples of Korean cattle were investigated. Of them, one case showed cystitis symptoms. The results obtained are summarized as follows: 1. The organism was detected from 8(6.5%) of 124 specimens of Korean cattle. The isolates studied in this survey belonged to type I (4.1%), type III (1.6%) and untypable(0.8%) of C. renale. 2. The rate of isolation of C. renale was 7.5% (19 of 253 individuals) in apparently healthy cow. The 26 strains isolated from the 19 dairy cattle belonged to type I (38.5%), type II (26.9%), type III (24.6%) and untypable(11.5%) in the serological classification. From the cow with clinical cystitis, type III strain was isolated. 3. It appears that the isolation rate depends on the history of pasture rather than the number of cattle; higher percentages were detected from the pasture which had fed for longer period. 4. From the findings mentioned above, it is clear that three types of C. renale were distributed in the apparently healthy Korean and dairy cattle in Korea. And this is the first report on the isolation and distribution of C. renale in Korea.

An agglutinability between naturally infected positive chicken serum of pullorum disease and hyperimmumized rabbit antiserum was compared. And the following results were obtained and summarized. 1. On the agglutinability, Salmonella pullorum antigen which irradiated gamma-ray was more excellent than another both formalized and heated antigen. 2. Time of judgemented as positive titer in the tube agglutination test to the naturally infected positive chicken serum was it most suitable for 12 hours at $37^{\circ}C$. 3. Agglutination titer of positive immune chicken serum against gamma-ray irradiate Salmonella pullorum were as 320~640x.

Studies on pathogenicities and developmental stages of Nosema apis (Zander, 1909) were carried out through artificial infection to Nosema free honey bees with various levels of spores isolated from local honey bee colony. The results obtained were summarized as follows: 1. The clinical symptoms were observed as dysentery, enteritis of mid-gut (enlargement and decoloration), crawling posture and shortening of the longevity of worker bees in the rearing honey bee colony inoculated with the spores. 2. Number of spores harvested from laboratory rearing honey bees were progresively increased to 4 weeks after inoculation. The regression equations and coefficients of correlations to various spore levels were as follows in each treatment colony. Colony 1. ($$1,000{\times}10^4spores/ml$$) $$y_{c1}=471{\times}10^{4}x+454{\times}10^4(r=0.65^*$$) Colony 2. ($$500{\times}10^4spores/ml$$) $$y_{c2}=340{\times}10^{4}x+207.8{\times}10^4(r=0.99^{**}$$) Colony 3. ($$100{\times}10^4spores/ml$$) $$y_{c3}=150{\times}10^{4}x+84.2{\times}10^4(r=0.99^{**}$$) Colony 4. ($$10{\times}10^4spores/ml$$) $$y_{c4}=13.8{\times}10^{4}x+13{\times}10^4(r=0.98^{**}$$) 3. Average longevity of worker bees artificially infected with Nosema apis was shortened as 21.7~43.8% compare to the control. (p<.05, p<.01) 4. The spores which were isolated from honey bee colony infected with Nosema disease were ovoid or spherical form, and measured, as a rule, from $4.7{\mu}m$ to $6.1{\mu}m$ (mean $5.3{\mu}m$) in length and from $2.4{\mu}m$ to $3.2{\mu}m$ (mean $2.9{\mu}m$) in width. 5. In the mid-gut of honey bees, the spore was progresively germinated and became trophozoite stage. The trophozoites were grown to meronts and their binary fission were begun. The divided two sporoblasts were developed to the spores which had elastic membrane. The new spores were shed in excreta of honey bees 10~15 day after inoculation at $25{\pm}2$ centigrade. 6. The ultrastructure of spore membrane consisted of three layers, such as, outer, middle and inner layer. The sporoplasm consisting lamellar structure occupied only anterior part of the spore and was often extended to posterior direction where definite vacuoles and a polar filament was able to detect.

악상남도(惡尙南道) 김해군(金海郡) S 양돈장(養豚場)에서 1975년 4월 하순부터 5월 하순 사이에 사육돈(飼育豚) 1,200두중 약 350두에서 출혈성하리(出血性下痢)를 주증(主症)으로 하는 전염성(傳染性)이 강한 소화기질환(消化器疾患)이 발생하였다. 환돈(患豚)은 7주령(週齡)에서부터 14주령(週齡)까지에서 가장 많이 발생하고 급성(急性) 또는 아급성(亞急性)으로 경과하였으며 다량의 황백색(黃白色), 수양하리(水樣下痢)를 발하다가 황갈색(黃褐色), 포말성하리(泡沫性下痢) 또는 암적갈색(暗赤褐色) 점액성하리(粘液性下痢)를 나타내었다. 육안적(肉眼的) 병변(病變)은 대장(大腸)에 한하였으며 카타아르성(性), 출혈성(出血性) 내지 괴사성장염(壞死性腸炎)을 시현(示顯)하였으며 괴사(壞死)는 광범(廣凡)하나 표재성(表在性)이고 어떤 예에서는 결장점막(結腸粘膜) 속에 대소(大小)의 미세결절(微細結節)이 밀발(密發)한 것이 특징이었다. 조직학적검사(組織學的檢査)에서는 대장점막(大腸粘膜)에 현저한 배세포증식(杯細胞增殖), 울혈(鬱血) 및 원형세포침윤(圓形細胞浸潤)과 더불어 표재성괴사(表在性壞死)가 관찰되었고 상기(上記) 결절(結節)은 장선(腸腺) 속에 점액(粘液), 섬유소(纖維素) 및 붕괴세포(崩壞細胞)가 축적되어 선와(腺窩)가 확장되고 피복상피(被覆上皮)의 이형성(異形成)(dysplasia)을 일으키고 있음이 판명되었다. 병변부(病變部)의 세균염색(細菌染色)에 의하여 대형(大型) Spirocheta와 Vibrio 고균(孤菌)이 무수(無數)히 발견되었고 Spirocheta가 병변형성(病變形成)에 더 밀접하게 관련되어 있음이 밝혀졌다.

The livers of 300 cases of Korean native cattle which were collected at slaughted house in Pusan were examined by gross and histopathological means to study patterns of pathological changes of the organ. 1. The most dominated lesion of the liver was those of fascioliasis showing incidence rate as 907 per cent of inspected cattle. 2. On age distribution of the fascioliasis lesion in the liver, higher incidence was seen in animals that were from 6 to 9 years of age. 3. Significant changes of the hepaticparenchyma caused by immature flukes included thrombosis, migrational tracks such as hemorrhagic foci with massive eosinophilia and hepatic necrosis. The changes of chronically infected livers of cattle were recognized as proliferation of periductal eosinophilic granuloma of various degrees in each portal triad. And this easential cholangiohepatitis might develop into multiple focal cirrhosis or diffuse perilobular cirrhosis. 4. Most cases with gross lesion of swelled bile ducts on visceral surface of the liver showed histological evidences of fascioliasis lesion throughout hepatic lobes.

Hematological studies were conducted in reference to the immune enhancing mechanism of formalin applied to, as an inactivating agent, a formalin inactivaed anthrax vaccines in rabbits. Rabbits were inoculated two types of formalinized anthrax immunogens namely capsular and spore vaccines in addition of formalin saline as a control. From immune rabbits, peripheral blood was collected and subjected to count a total erythrocytes, leukocytes, and pyroninophilic lymphocytes. The experimental results were summarized as followings. At a level of 0.5M 0.5ml formalin with or without the addition to vaccine, a total leukocytes count was increased. Due to the increased lymphocytes, the ratio of neutrophil and lymphocyte was lowered within 4 to 12 hours of the postinoculation. Formalin saline, anthrax spore vaccine and capsular vaccine, without group difference, caused an increased level of pyroninophilic lymphocytes in peripheral blood. Throughout the studies, a possible role of immune enhancement by formlin was disscused and suggested.

The growth of Sal. choleraesuis and its kunzendorf variety in tetrathionate broth containing various amounts of iodine solution was studied and compared with that of Sal. typhi, Sal. typhimurium and E. coli. The results obtained were as followings. 1. When 2.0 ml of iodine solution, normal amount, was added to 100 ml of tetrathionate broth base, the number of Sal. choleraesuis decreased rapidly until 24 hours after inoculation and slightly increased 48 hours after inoculation. The numbers of Sal. choleraesuis var. kunzendorf and E. coli decreased rapidly and none of the organisms recovered 24 and 48 hours after inoculation, respectively. The growth of Sal. typhi and Sal. typhimurium, however, was not inhibited at all. 2. When 4.0 ml of iodine solution was added, to 100 ml of tetrathionate broth base, the growth of all the organisms was inhibited, among which Sal. choleraesuis, Sal. choleraesuis var. kunzendorf, and E. coli were not recovered 24 and 48 hours after inoculation. 3. When reduced amounts of iodine solution, 1.0 ml and 0.5 ml, were added to 100 ml of tetrathionate broth base, the growth of all the organisms was not inhibited.

In the sequence of carbon tetrachloride hepatotoxicity, increased serum levels of a number of enzymes have been demonstrated in experimental animals. These observations, therefore, have served to help in detecting hepatic injury. The serological influence of chlorpromazine (CPZ) and iproniazid on the acute $CCl_4$ poisoning was executed in this investigation taking use of 6 albino rabbits (around 2 kg b.w.) in each group. By measuring of blood sugar level (Nelson-Somogyi method), S-GOT and S-GPT activities (Reitman-Frankel method), the pharmacological effects of the drugs was evaluated setting pretreated groups against the control. The results obtained were summarized as follows: 1. The intramuscular injection of $CCl_4$ led to increase the blood sugar level in first 3 hours and, after that, to decrease reasonably. But CPZ-pretreated group showed a tendency of increasing in compare with the control, and iproniazid-pretreated group inhibited evidently. 2. In S-GOT activity, the increased level was induced by $CCl_4$ in control. And CPZ-pretreated group showed a increased level until first day and decreased rapidly. But this property inhibited inhibited significantly by pretreating with iproniazid. 3. Although a single dose of $CCl_4$ increased the S-GPT activity, the more increasing trend was observed in CPZ-pretreated group. But these tendencies depressed remarkably in the iproniazid-pretreated group. It seemed to be attributed not to defend the $CCl_4$ toxicity but to be suppressed the enzyme systems in the liver by iproniazid that the blood sugar level and serum transaminase activities was decreased significantly in pretreating with iproniazid.

A total of 736 Holstein cows were examined for incidence of infertility and 57 infertile cows of them were examined for blood values. The results obtained were as follows: 1. Fifty eight heads (7.9%) of 736 Holstein cows examined were proved to be infertile and the causative disease of 58 infertile cows were diagnosed as silent heat (31.0%), repeat breeder (20.8%), dysfunction of ovary (15.5%), lutein cyst (13.8%), endometritis (8.6%), follicular cyst (5.2%), cervicitis (1.7%), pyometra (1.7%), and free-martin (1.7%). 2. Among the data of blood values of 57 infertile cows, values of total serum protein and serum calcium were remarkably lower (p 0.01) than those of normal cows. Meanwhile the unbalanced Ca/P ratio (1.1) was observed.

Observation was performed for incidence of chronic necrotic pododermatitis to 1,387 heads of Hostein cows in 25 dairy herds during one year period from March 1975 to Feb. 1976. The results obtained were as follows: 1. Sixty four heads of cow affected chronic necrotic pododermatitis during the observation period and the incidence rate shown 4.61%. 2. Incidence of chronic necrotic pododermatitis was more prevalent of all foot disease and it was occupied 60.9% of all foot disease. 3. The highest incidence was observed on August and September in the season high in temperature and humidity. 4. The disease was more frequently seen affecting in hind than front limbs, and lateral than medial claws. 5. The disease was more frequently seen affecting in older cows, and higher production cows.

In order to investigate the effects and acting mechanism on ovaries, thyroid glands and hypophyses of rabbits in short term administration of sulfadimethoxine (SDM) as medical dose, a total of 90 virgin albino rabbits (mean body weight, 1,362g) were selected at random and alloted to two groups. Rabbits in one group served as controls and the others were administered SDM of 50 mg/kg/day for 5 weeks, and then reared without medication for 4 weeks. Pathological changes of the three organs were observed each week for 9 weeks and the results obtained were summarized as follows: 1. Mean body weights of both groups manifested slow increasing tendency but mean hypophysis weights fluctuated throughout the experimental term. Mean ovary weights of experiments were decreased significantly from the 3rd to 6th week but mean thyroid weights of experiments were increased significantly from the 1st to 6th week compared with those of controls. 2. Many ovarian follicles of each developing stage showed follicular atresia accompanying atrophy or necrosis of oocytes and of disintegrated follicular cells. Theca interna cells and sudanophilic interstitial cells showed atrophy and diminished sudanophilic granules and also liquor folliculi were diminished. These changes icreased from the 1st week, remaining so for 5 weeks and returned to normal status in the 8th or 9th week. 3. The thyroid gland showed a typical hyperplastic goiter. Hypertrophic and hyperplastic epithelia follicular manifested cuboidal or columnar form showing tiny or small vacuoles in cytoplasm. The follicles showed atrophy and decreasing colloidal materials. Necrotic and regenerative changes were also present. The interfollicular vessels showed congestion and hemorrhage. These changes increased from the 1st week, remaining so for 5 weeks and returned to normal status in the 9th week. 4. The rates of differential cell counts of hypophyses revealed increase of basophils (gonadotrophs and thyrotrophs) and decrease of chromophobes. Basophils which had diminished granules stainable with HE, PAS and AF revealed hypertrophy, hyperplasia, and increasing of tiny or small vacuoles in cytoplasm. These changes increased from the 1st week, remaining so for 5 weeks and returned to normal status in the 8th or 9th week. As summarized above histologically, administration of SDM led thyrotrophs and gonadotrophs of pituitary glands to hyperactivity but revealed retrogressive and compensatory changes with functional disturbance in ovaries and thyroid glands. These changes were transitional and attributed to direct actions of the drugs on the ovaries and thyroid glands.

In order to clarify the histopathological changes resulting from nitrate poisoning, rabbits were experimentally poisoned by the oral administration of $KNO_3$ or $NaNO_2$ and examined clinically and histopathologically. In addition, the quantitative changes of glycogen level in hepatic cells were histochemically observed. The results obtained were summarized as follows: 1. Clinical symptoms observed from the acute cases which died within 2 hours after the administration were severe cyanosis of visible mucosa, frequent urination, and dyspnea. However, in chronic cases administrated daily with $KNO_3$ for 43, 50 and 74 days respectively, no marked symptoms were observed. 2. Macroscopic changes observed in acute cases were severe methemoglobinemia, cloudy swelling of hepatic cells, hemorrhage and hyperemia of gastric mucosa, and hyperemia of other organs. In chronic cases there were marked hyperemia, dark-red coloring and increasing of consistency in liver and kidney, and swelling of spleen. 3. Microscopic changes observed in acute cases were hemorrhage and hyperemia of various organs, cloudy swelling and centrilobular necrosis of hepatic cells and necrosis of convoluted tubular epithelium in kidney. In chronic cases there were round cell infiltration of the interlobular connective tissue and epithelial proliferation of interlobular bile ducts in the liver, and necrosis of the convoluted tubular epithelium and proliferation of interstitial connective tissue in kidney, thickening of alveolar septa of lungs, activated hemopoiesis of bone marrow, and myeloid metaplasia of sqlenic pulp. 4. Glycogen storage in liver cells was decreased in acute cases, on the contrary, increased in chronic cases.