Degenerative osteoarthritis, similar to that seen in mammals, including man, was observed in the fifth to seventh thoracic vertebral bodies of 58 two-year-old laying hens. Main gross lesions were roughening of the articular surface, narrowing or focal thickening of the articular cartilage, chondrophytes at the margins of the joints, and a decrease in length from the dorsal to ventral edge of the epiphyseal vertebral body. Histopathological changes consisted of degeneration of the matrix with an appearance of collagen fibers, erosion or ulceration, proliferation of chondrocytes, and cleft-like fractures in the articular cartilage, and necrosis and eburnation in the subchondral bone. The degenerative changes with an appearance of collagen fibers in the cartilage matrix were regarded as the initial lesions. The pathogenesis of this disorder was not clarified, however, as in mammals the anatomical characteristics of the thoracic vertebrae, the rearing environments, an anomaly of the chemical constituents of the cartilage with increased age and mechanical stress such as weightiness should be taken into consideration as the important factors.

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The karyotype of Paragonimus westermani Filipinos was analysed by the air-drying method. The chromosome number of the fluke was n=11, 2n=22. The chromosomes were composed of one pair of large-sized metacentrics, four pairs of medium-sized subtelocentrics, three pairs of small-sized metacentrics or submetacentrics, and three pairs of small-sized submetacentrics or subtelocentrics. The karyotype of P. westermani filipinus mostly resembles those of the closely allied species such as P. westermani westermani and P. pulmonalis. General resemblance was also seen between these three species and the other congeneric species: P. ohirai, P. iloktsuennensis, P. miyazakii, P. sadoensis, and P. mexicanus (syn. P. peruvianus).

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Ibaraki virus grown in HmLu-1 cells, a stable cell line from hamster lung, agglutinated erythrocytes from cattle, sheep, goats, horses and rabbits, when concentrated by ultrafiltration from infectious culture fluid. The hemagglutination (HA) was dependent on not only the pH but also the NaCl concentration of the diluent; the HA titer significantly improved by increasing the NaCl molarity to 0.6 M and standardizing pH to 7.5. The incubation temperature did not affect the HA titer. In Sepharose 4B gel filtration the peak of the HA activity coincided in position with the infectivity peak. The HA reaction was inhibited by specific antiserum. Some factors involved in the HA and HA-inhibition (HI) were investigated and standard HA and HI tests were established. HI antibody titers of individual bovine sera showed a significant positive correlation with their neutralizing antibody titers.

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Chromosome examination by blood culture was conducted on 35 Japanese sika, Cervus (Sika) nippon, revealing that the number of chromosomes varied according to individuals, such as 65, 66, 67 and 68. This numerical variation depended on the presence or absence of large metacentric chromosomes and submetacentric chromosomes in the autosomes. It was possible to observe six karyotypes according to the presence or absence of these two kinds of chromosomes. Polymorphism of these chromosomes is presumed to be formed when either large metacentric chromosomes or submetacentric chromosomes are formed following fusion of four acrocentric chromosomes in the autosomes at the centromere. The fundamental number was constant, 70 in all cases. This is considered to be due to the so-called Robertsonian translocation. The common phenomenon observed in all the individuals examined was the presence of one pair of middle-sized metacentric chromosomes in the autosomes. The X-chromosome was the largest among the acrocentric chromosomes and the Y-chromosome could be easily identified as a small submetacentric chromosome.

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The indirect immunoperoxidase absorbance (IIPA) test was used to detect chicken serum antibody against avian leukosis viruses (ALVs). Total 155 serum samples collected from chickens experimentally infected and not infected with ALV were tested by the method and the result was compared with that of the virus neutralization (VN) test. As a result, there was a high correlation (R=0.648) between the two. Besides, the sera of chickens infected with Rous associated virus (RAV) showed type-specificity when examined by the method. Therefore, those infected with RAV-1 were clearly distinguished from those infected with RAV-2. Then eight chickens were inoculated with RAV-1 to study the rise and fall in antibodies. In them, IIPA antibody presented almost the same rise and fall as VN antibody.

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The genetic properties of 62 R plasmids derived from Escherichia coli isolated from mynahs imported into Japan from Thailand were investigated. Of these, 8 R plasmids showed thermosensitive transfer and 55 showed Fi- (no fertility inhibition) characteristics. About half of the R plasmids inhibited the development of phage λ, T2, T4 or T7. In incompatibility grouping, 8 R plasmids showing thermosensitive transfer were classified into Inc Hl, 14 were classified into W, and 11 were classified into Iα. Only a few were classified into M and FII. These results indicated that genetic properties of the R plasmids in the present study were different from those of Salmonella or E. coli R plasmids from domestic animals in Japan. On the other hand, because the mynahs which carry E. coli having such plasmids are raised at home, it is assumed that they may be potential reservoirs of R plasmids for home-families who raise and have intimate contact with them.

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To determine the essentiality of the ovary for the maintenance of Pregnancy in the bitch, 18 pregnant bitches were ovariectomized at different times in the second half of gestation period and the occurrence of abortion was examined. The effects of progesterone administration on the maintenance of pregnancy in these ovariectomized animals were also examined. In all of 7 bitches ovariectomized on days 40 to 55 of pregnancy, abortion occurred between 11 and 63 hr after ovariectomy. The interval between ovariectomy and abortion seemed to be shortend with the advance in gestation. Another 6 bitches were ovariectomized during days 39 to 50 and followed by daily administration with 20 to 50 mg of progesterone until day 55 or 61. Pregnancy was maintained without abortion and parturition took place normally in all of these animals. The remaining 5 bitches ovariectomized on day 50 were administered daily with progesterone up to day 62 or later. Four of these 5 animals were delivered of young on days 64 to 66, although atillbirths were seen in 2 animals. These results indicated that the ovary should play an essential role through the secretion of progesterone in the maintenance of pregnancy up to around day 55 in the bitch.

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The differences of the property in rat myocardium between newborn and adult were investigated. It was the most obvious alterations of rat ECG with age that Q-T interval became short and S-T segment disappeared. In accordance with these alterations, the alterations of ventricular action potential (AP) configuration were recognized, too: the duration of AP became short and the plateau phase disappeared with age. These alterations with age were independent of the stimulation frequency. The effect of Ca antagonist on the AP configuration was different between newborn and adult: the plateau phase of newborn's AP was reduced by it, but little effect was seen in adult AP. But the plateau phase was appeared and the duration of AP was prolonged even in adult under the condition of low temperature Tyrode solution, and this plateau phase, was reduced by Ca antagonist. Moreover, in each preparation the slow response induced by the activity of slow channel, which was obtained by elevated potassium concentration, was recognized. From these results, it was suggested that more rapid appearance of repolarization in adult than in newborn deprived of the opportunity of the activation of slow channel, so that no plateau phase was observed in adult AP.

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To evaluate the effectiveness of serotherapy for canine parvovirus (CPV) infection, immune serum was injected intravenously into dogs which had been infected experimentally with CPV or which showed clinical signs of CPV infection under field conditions. In experimentally CPV-inoculated group, serum-injected dogs showed mild clinical signs of the disease after serum treatment and all the dogs recovered, whereas non-serum-injected dogs showed severe clinical signs and half of the dogs died. In the field cases, many dogs recovered rapidly from the disease after the serum treatment. These results indicated the usefulness and effectiveness of the serotherapy for CPV infection in dogs.

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Structure of the vomeronasal organ was investigated from the viewpoint of comparative morphology in rats, mice and rabbits by light and electron microscopy. The organ in rats and mice was round in its transverse section and encircled by the bony capsule, whereas that in rabbits was elliptical and encircled by the cartilaginous capsule. Ultrastructurally, in all these species, the surfaces of the sensory and supporting cells of the vomeronasal sensory epithelium were provided with microvilli, which seemed to accept odoriferous molecules, and lacked cilia or other surface structures. The vomeronasal respiratory epithelium lacked receptor cells and assumed a form similar to that of the nasal respiratory epithelium. Hence, the function of the former seemed to be similar to that of the latter. The venous sinus was well developed. Several layers of smooth muscles encircled the wall of the venous sinus. Elastic fibers were observed in the connective tissue lying between the venous sinus and the respiratory epithelium. Junctional specializations were developed between cells standing side by side in the respiratory epithelium. All these structures were thought to suggest the propriety of the so-called pumping mechanism. Jacobson's glands consisted mainly of mucous acini and seemed to have functions similar to those of the nasal glands which were distributed on the wall of the nasal cavity.

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The effect of CuSO₄ and copper·o-phenanthroline complex (CuP) on cattle erythrocytes was investigated in vitro. When treated with CuSO₄, depletion of intracellular GSH, increase of methemoglobin formation and marked echinocytic changes of the erythrocytes were observed. These effects of CuSO₄ were prevented by the addition of bovine serum albumin (BSA) in the incubation medium. On the other hand, the addition of o-phenanthroline accelerated the toxic effects of CuSO₄ on the erythrocytes resulting in the GSH depletion, methemoglobin formation, echinocytic transformation and cross-linking of membrane proteins. These CuP-induced changes were not inhibited by BSA. Echinocytic transformation and the cross-linking of membrane proteins in CuP-treated cells were almost completely inhibited by the prior treatment of N-ethylmaleimide.

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Two pregnancy-associated proteins in the serum of pregnant rabbits were detected and analyzed by immunochemical methods. The newly discovered proteins are named pregnancy-associated leporine serum proteins (PALP), which consist of two subfractions. The minor fractions, PALP-1, appears specifically in association with pregnancy, and the major fraction, PALP-2, increases its concentration with progress of pregnancy. The concentration of maternal serum PALP-2 started to increase gradually at the middle stage (Day 15) of gestation and continued to increase at a significantly high rate during the period of Days 20-25, reaching the maximum level at the end of gestation. A considerably high PALP-2 level was maintained for about 15 days post partum.

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Physiologically important elements (Fe, Ca, Mg, Cl, K, S and P) were surveyed with a wave length dispersive X-ray microanalyser (WDX) attached to SEM on cross section of freeze-dried bulk specimens of canine abdominal aorta after denudation of the endothelial cells with a balloon catheter. Fe was unexpectedly the major element at every spot examined while P, Ca and K were only moderate in amounts. Traces of Mg, Cl and S were found in the smooth muscle, erythrocytes, platelets and endothelial cells. There was little difference in the levels of the above mentioned elements between intact and regenerated endothelial cells.

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Anti-bovine thymocyte serum (ATS) was prepared by immunizing rabbits with calf thymocyte, adsorbed by normal bovine red blood cells, liver powder and bone marrow cells, and applied to identify bovine T lymphocytes by indirect immunofluorescent antibody technique (FA). The frequency of T and B lymphocytes in the PBL, spleen and lymph nodes of 21 clinically normal cattle were investigated by indirect FA using ATS and by direct FA using FITC rabbit anti-bovine serum, respectively. Distributions of T and B lymphocytes were 66.4±6.4% and 25.4±3.9% in the PBL, 43.4±4.8% and 48.7±4.7% in the spleen and 59.4±6.8% and 28.2±5.6% respectively in the lymph nodes.

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A total of 1, 840 strains of fecal Escherichia coli isolated from laboratory animals in the colonies of 21 research laboratories and commercial breeders in Japan in 1980, were tested for resistance to 13 drugs and for conjugative R plasmids. Of the 1, 840 strains examined, 78(4.2%) from only 6 animal colonies were drug resistant. The drug resistance was detectable in strains from mice, rats and rabbits at incidence of 1.1, 10.3 and 1.9%, respectively, whereas all organisms from guineapigs and captured rodents were sensitive to all drugs tested. High incidence of drug resistant organisms was demonstrated in the animal colonies where treatment with tetracycline had been undertaken. In colonies in which treatment with tetracycline had been discontinued one to three years before the sampling, no resistant organisms were detectable. Conjugation anlysis revealed that all the resistant strains from mice and rabbits and 83.3% of those from rats carried their resistance determinants on R plasmids. It seemed that the majority of laboratory animals were free of drug resistant E. coli while antibiotic treatments increased the incidence of drug resistant organisms and conjugative R plsmids in laboratory animal colonies.

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