Effects of levamisole dilutions on HA of Newcastle Disease virus were studied in vitro and the findings are: 1. Treatment period 4 hours (at room temperature) - 1.1 When levamisole were mixed up to make final dilutions of 0.02 and 0.05% with NDV, no effect on HA was apparent; 1.2 When the final dilutions were 0.1, 0.25, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0%, the HA dropped significantly; 1.3 When the final dilution were 4.5 and 5.0% all HA activities of the NDV were destroyed. 2. At final dilution 0.02% levamisole did not affect the HA when the NDV were treated for 24 hours at room temperature. 3. HA activities of NDV was usually affected when NDV were treated longer than 4 hours when the final dilutions of levamisole were higher than 2.0%. Levamisole dilution should not exceed 0.1% when it is used as ND Vaccine diluent.

A radioimmunoassay for measuring serum progesterone (P), 17-hydroxyprogesterone (17-OHP) and 17-B-oestradio (E2) in buffaloes was described. One cm3 of pooled serum with three steroids added for recovery was extracted with ether and chromatographed on a celite microcolumn. The recovery of the standard P, 17-OHP and E2 was 72.9-89.6%, 77.0-97.0% and 85.5-101.3% respectively. The precision of within assay variance of these three steroids expressed as percentage of coefficient of variations was 8.2% (P and 17-OHP) and 8.3% (E2). The between assay variance was 13.2%(PT), 11.2% (17-OHP) and 12.9%(E2). The sensitivity of the assay varied between 3.5-25.0 pg. P, 4.0-25.0 pg 17-OHP and 2.5-10.0 g E2. Levels of serum progesterone, 17-hydroxyprogesterone and 17-B oestradiol were measured in the same serum samples at daily stages of the oestrous cycle in four female buffaloes; altogether there were 11 cycles. The swamp buffaloes have the normal oestrous cycles of 19-27 days. Progesterone levels in pre-oestrous-oestrous were 9.7 +-8.5 ng/100 cm3, the level beginning to rise by day 7 or 10, and reaching a peak of 38.8 +-12.2 ng/100 cm3 in 15.6 +-3.7 days of the cycle, then declining rapidly to the basal level about 4-7 days before the next oestrous cycle. The serum levels of 17-hydroxyprogesterone rose significantly in three peaks: preostrous-oestrous (21.3 +-8.3 ng/100 cm3), metoestrous (14.6+-6.6 ng/100 cm3) and dioestrous (20.2 +-8.1 ng/100 cm3). The average values in these three phases were 15.1+-7.1 ng/100 cm3, 9.7+-5.2 ng/100 cm3 and 10.6+-4.0 ng/100 cm3 respectively. The basal levels were below 5.0 ng/100 cm3. The oestradiol levels reached a peak on the day before oestrous. The average value of the peaks was 13.0+-4.0 ng/100 cm3. The duration of the peak was about four days, then it sharply declined to basal levels of 3.9+-1.0 ng/100 cm3.

Aeromonas hydrophila is a fish-pathogen microorganism. The organism could also produce diseases in reptiles, e.g. snakes and turtles, and in amphibian, e.g. frogs. The epidemic of the ulcer disease in catfishes have been studied for the last 6 months in this laboratory. The disease was observed in the fish-cultures in Rangsit, Sampran and Supanburi. The markable lesion was the center necrosis surrounded with haemorrhage. In the severe cases the flesh was sloughed and the vertebrates were exposed. The disease in the adult fishes occasionally had the primary infection in the kidney. The nodule (or nodules) was observed at the area over the anterior kidney with the characteristic of haemorrhage and then broken out to form the ulcer. In some cases the papules were developed. The mortality rate was 5-20%. Most of the organisms produced the typical lesion in fishes after I/M inoculation 24 hrs with the dosage of 8 x 10/ml. The infection of this organism was also observed in white gibbon and swine. The gibbon had the following clinical signs; lethargic, anorexia, polydipsia, diarrhea and dyspnea. The animal died 4 days after showing the signs of sickness. In the swine case, the incoordination and circular movement was observed. The post-mortem revealed meningitis. The pathology and serological studies are in progress.

The suitable diluters for the buffalo semen are milk yolk and coconut milk yolk. Diluted semen is kept at 4-5 degrees Centigrade with the result of sperm survice 6-2 days, in some cases the viable sperm up to 60 percent for 8 days in recorded.

The gram negative bacteriam Aeromonas hydrophila is a common cause of different diseases of fish in Thailand. The most serious disease caused by this organism is ulcer disease in catfish (Clarias batrachus). One hundred and eight strains of A. hydrophila were isolated in May 1976 to March 1978. All tested strains were sensitive to Kanamycin, 1 percent resistance to nitrofurantein and polymyxin B, 5% to neomycin, 8% to chloramphenicol, 9% to tetracyclin, 13% to trimethoprim, 15% toerythromycin, 40% to sulfamethoxine and sulfathiazole, 45% to streptomycin, 46% to sulfamerazine, 52% to sulfadiazine, 97% to penicillin. The results indicated that the local isolated strains are more resistant to antimicrobial agents than the Danish strains.