Tissue specimens from muscle, liver, kidney, and injection sites were collected, and serum was obtained from 3 calves euthanatized on each of posttreatment days 5 and 22. Calves were treated with 6.7, 13.4, or 20 mg of oxytetracycline (OTC)/kg of body weight, IM, once daily for 3 days; these dosages are 1, 2, and 3 times the label dose, respectively. One control calf was euthanatized on each of posttreatment days 5 and 22. In treated male calves killed 2 days after the last injection, OTC residues were detected in all tissues and serum, using high-performance liquid chromatography. Tissues from all injection sites also were considered positive for antimicrobial residues, using swab test on premises (STOP), microbial inhibition test (MIT), and thin-layer chromatography-biautography (TLCB) test. Kidney tissues from a calf given 13.4 mg of OTC/kg and kidney and liver tissues from a calf given 20 mg of OTC/kg also were considered positive, using the MIT and TLCB. Results of the STOP only were considered positive for the liver and kidney of a calf given 20 mg of OTC/kg, but substitution of Saskatoon antibiotic medium-3 for the original medium (antibiotic medium-5) allowed the STOP to detect residues in these tissues from all treated calves. In female calves killed 19 days after the last injection, the STOP, MIT, and TLCB procedures revealed positive results for tissues from some injection sites, but revealed negative results for other tissues. High-performance liquid chromatographic analyses detected OTC in tissues from injection sites from all treated calves, in muscle and liver from a calf given 20 mg of OTC/kg, and in kidneys from calves given 13.4 or 20 mg of OTC/kg. The STOP, MIT, and TLCB procedures lacked the sensitivity of high-performance liquid chromatography for detection of OTC residues.

Lectin binding of small intestinal goblet cells was examined in newborn, suckling, and weaned pigs. Sections of duodenum, proximal portion of the jejunum, distal portion of the jejunum, and ileum were embedded in a hydrophilic acrylic resin and treated with each of the following lectins: Canavalia ensiformis, Ricinus communis I, Glycine max, Ulex europaeus I, and Triticum vulgaris. Percentages of goblet cells binding each lectin were calculated within intestinal regions. Differences in lectin-binding affinity were detected among pigs of various ages and among various intestinal regions within pig age groups.

Uveitis was induced in dogs by intracameral injection of canine lens protein. The lipoxygenase inhibitors phenidone and norhydroguaiaretic acid, and dimethyl sulfoxide decreased fibrin production at 0.5 and 1 hour after induction uveitis. Phenidone and norhydroguaiaretic acid also inhibited the initial increase intraocular pressure early in the course of inflammation. Leukotriene B4 in the aqueous was measured by use of radioimmunoassay at 1 hour after inflammation. In control dogs, 230 to 1,700 pg of leukotriene B4/ml was measured; in dogs treated with phenidone, leukotriene, B4 was not measured.

Resistance of gram-negative bacteria to gentamicin has become an increasingly common problem among clinical isolates from human beings. Susceptibility of isolates from horses to gentamicin and amikacin was evaluated for the period from July, 1983 to June, 1985. All isolates of Escherichia coli, and species of Enterobacter, Klebsiella, Proteus, and Pseudomonas examined were susceptible to amikacin, except 2 of the 46 Pseudomonas isolates. In contrast, 13 to 50% of isolates were resistant to gentamicin. Escherichia coli, and Klebsiella, Proteus, and Enterobacter species isolates were highly significantly more susceptible to amikacin (P less than 0.01) than to gentamicin. Pseudomonas spp (P = 0.13) were not significantly different in susceptibility to the 2 drugs. There was significant variation among genera in their susceptibility to gentamicin (P = 0.002), primarily because of the frequency of resistance in isolates of Klebsiella spp and Proteus spp, compared with the other 3 organisms (E coli, Enterobacter spp, and Pseudomonas spp). There was no significant difference of susceptibility to amikacin among the genera studied (P = 0.06).

Neoplastic cells were isolated from 2 sibling Great Dane/Labrador Retriever mixed-breed dogs in which telangiectatic type osteosarcomas arose concurrently. Cells from various sites in the same osteosarcoma appeared similar in culture, but there were differences between the 2 osteosarcomas in growth characteristics and appearance of cells. Cells from 1 osteosarcoma had a small, but significant (P less than 0.05), cyclic adenosine monophosphate response to parathyroid hormone stimulation, indicating a low order of osteoblastic differentiation. Cells from the other osteosarcoma had no response to parathyroid hormone stimulation. Cells from both osteosarcomas and a concentrated cell-free filtrate from the osteosarcoma with osteoblastic differentiation were injected into nude mice, but osteosarcomas were not induced. Results of ultrastructural examination of osteosarcoma samples for viral particles were negative and supernatant fluids from cultured cells were considered negative for viral reverse transcriptase activity.

This study was undertaken to obtain basic data of the sternal development in Korean native cattle from the earliest sternal formation to the ossification using histological and histochemical methods. Thirty three sterna were collected from a series of embryos and fetuses ranging from 11 to 225mm (estimated age 37-120 days) in crown rump length. The bilateral sternal bars were observed in the 2nd group (CRL 21-30mm) of Korean cattle embryos. Those bars initiated to be fused in the 3rd group (CRL 31-40mm) and completed in the 7th group (CRL 71-80mm). The ossification centers were detected in the 8th group (CRL 81-90mm) also bilateral ossification centers were found in the same group. The typical epiphyseal plates, endochondral bone and calcium deposit were found in the 9th group (CRL 91-100mm). Osteocytes, osteoblasts, osteoclasts and myeloid cells appeared in ossification centers in the 10th group (more than CRL 101mm). The alcianophility responded markedly in the 9th group that was decreased and showed slightly positive reaction in territorial matrix of the 10th group. Marked positive reaction to PAS was observed in bony trabeculae in the 10th group. The positive reaction to calcium deposit by trichrome stain was observed initially in the hypertrophied zone of epiphyseal plate in the 9th group and was conspicuous in the calcified zone of epiphyseal plate in the 10th group. The 1st positive reaction to the von Kossa stain was observed in the 9th group.

Fecal samples were taken from 402 cows in Posung, Chonnam which was designated as a place for Korean native cattle breeding. Prevalence of internal parasitisms were determined by the fecal examinations using the floatation and sedimentation procedures. 62.9 % of the cows were found as positive cases with excretion of the eggs of Fasciola hepatica in the fecal specimens. Of those infected with F. hepatica 97 cows free of other pathogenic intestinal parasites were chosen for albendazole treatment. Albendazole tablets (10mg/Kg) were administered to the cows twice at the interval of 4 weeks. Blood samples were collected via jugular vein prior to the first treatment, four weeks after the first treatment and four weeks after the second treatment, respectively. At the same time fecal samples were collected for parasitological examinations by sedimentation methods. The mean pretreatment count was 44 fluke eggs per gram of feces, which compared with 27 epg and 17 epg four weeks after the first and second treatment, respectively. Most of the hematological and biochemical values fluctuated within the normal ranges during the experiment. Eosinophil counts were high initially, decreased after the first treatment and thereafter remained steady. The opposite was the case with aspartate and alanine aminotransferases.

Data from 34 yearling Hereford or Angus bulls were used to investigate relationships of testicular size, quantitative rates of sperm production, Sertoli cell numbers, numbers of germ cells supported per Sertoli cell, and the efficiency of spermatogenesis to daily sperm output and seminal quality. Two ejaculates were collected by electroejaculation from each bull on each of 2 days/week throughout the study. The percentage of progressively motile sperm and the percentage of morphologically normal sperm were determined from aliquots of fresh semen. Additional aliquots of semen were frozen in glass ampules or plastic straws and subsequently evaluated for postthaw motility and percentage of sperm with intact acrosomes. Sertoli cell numbers, the numbers of germcells per Sertoli cell, and the efficiency of spermatogenesis were unrelated to the quality of fresh or frozen semen (P greater than 0.05). In first ejaculates, the numbers of sperm and motile sperm were related (P less than 0.05) to testicular parenchymal weight (r = 0.38, and 0.50), daily sperm production (r = 0.45 and 0.53), and spermatids per gram of testicular parenchyma (r = 0.35 and 0.34). Testicular parenchymal weight and daily sperm production also were related to daily sperm output and to the average daily motile sperm output of these bulls (P less than 0.05), but could account for less than 25% of the variability in these end points among bulls.

The number and distribution of the retinal ganglion cells in the 2 years old Korean native cattle was determined from whole flat mounted preparation stained with methylene blue and thionin. The total number of retinal ganglion cells was estimated to be 3,085,200 in the bovine retina ranging from 2.214mm** (2) in total area. Visual streak was recognized at the area 2.5mm superior to the optic disc and ganglion cell density drops off rapidly to the direction superior to and inferior to the visual streak. Area centralis (6,800 cells/mm** (2)) was located at the area 10mm temporally from the point of 3mm superior to the optic disc. The number of alpha-type ganglion cells (above 15 micro) was 57,000 in the bovine retina and alpha-type ganglion cells constituted 18.5 % of the total cells. The relative frequency of alpha-type ganglion cells was higher in the peripheral regions than in the visual streak, especially higher in the superior-temporal quadrant than in other region of the bovine retina.