Replication of Canine distemper and rinderpest viruses was morphologically studied in primary chick embryo cells and in a line of African green monkey kidney (Vero) cells. BOth viruses Closely resembled each other in all respects with regard to cytopathic effect seen in stained preparations, uitrastructure of virions and mode of viral particle formation as observed by electron microscopy. In cells infected with either canine distemper virus or rinderpest virus, eosinophilic, cytoplasmic inclusions and syncytia were observed as the first manifestation of infection, and about 24 hours later, eosinophilic, intranuclear inclusions began to appear. Under the electron microscope, both the cytoplasmic and intranuclear inclusions were observed to be composed of numerous tubular strands identical to the internal nucleoprotein component or nucleocapsid within virions. The incorporation of nucleoprotein strands formed in the cytoplasm into the viral envelope occurred by a process of budding at the cell surface in a similar manner to that described with other paramyxoviruses. Only a limited amount of nucleoprotein strands synthesized in the cytoplasm was utilized for assembling virions, and most of them accumulated in the cytoplasm as an aggregate, undoubtedly corresponding to the cytoplasmic inclusion seen by light microscopy. Filamentous budding particles frequently found in cells infected with WB virus, parainfluenza virus SV5, type 2 parainfluenza virus, and mumps virus were not seen in the present work. Virions of canine distemper and rinderpest were pleomorphic and various in size, but most of them were spherical in outline, with sizes ranging from 200 to 500mμ in canine distemper and from 250 to 500 mμ in rinderpest. No evidence suggested that the nucleocapsids accumulated in the nucleub play some role in the replication of both viruses. The results obtained with canine distemper and rinderpest viruses are quite consistent with those described for measles virus except that intranuclear nucleocapsids arranged in paracrystalline arrays have often been found in measles virus-infected cells whereas they were arranged only in a haphazard fashion in the present systems.

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As histopathological change common to the three cases examined in the present investigation, it was noticed that the osseous tissue in the cortex of the diaphysis had not reached maturity as yet. Namely, no external basic lamellae had been formed. These changes were very distinct in the postrior parts of the tubular bones, mainly and especially in the middle portion of the diaphysis. In such areas, moreover, the abnormal and irregular development of osseous tissue was sometimes recognized. The osseous tissue was often hyperplastic in the cortex of a part opposite the part showing the abnormal development. This phenomenon must have been caused by a delay in maturity of the osseous tissue. In some bones, the osseous tissue was markedly hyperplastic even in the anterior part of the cortex. One of the authors, YAMAGIWA, and his associates have previously studied the thickleg disease. In their investigation, an irregular formation of intra-medullary bone tissue was recognized in cases No. 3 (White Leghorn, 250 days of age), No. 8 (White Leghorn, 250 days of age), No. 13 (White Leghorn, 250 days of age), and No. 17 ("Goto" Cornish, 435 days of age). In these cases, the birds were much older than those in the present study. Furthermore, in the authors' previous report, part I, on bone dysplasia of chickens, an abnormal, irregular intra-medullary development of osteogenous tissue, or the osseous tissue remaining in an incompletely mature state was observed. The case of autopsy exhibiting such findings were as follows: No. 882 (36 days of age), No. 891 (56 days of age), No. 874 (68 days of age), No. 886 (81 days of age), No. 879 (95 days of age), No. 860 (120 days of age), No. 861 (120 days of age), No. 862 (120 days of age), and No. 863 (120 days of age). In these cases, the birds were also older than those in this study. It seems that the osseous tissue in chicks 32 days of age may have come to maturity at least once. In the authors' previous report, part I, it was confirmed that the osseous tissue had already reached maturity as early as 36 days of age. In the present cases, however, it is thought that a delay in maturity of the osseous tissue may have been brought about by some reason, and that the bone tissue may have developed abnormally and intensely, although such changes occurred limitedly to some areas. Areas exhibiting such changes as mentioned above were found frequent in the cortex of the middle portion of the diaphysis, or in the cortex corresponding to the ossification center near the epiphysis. Clinically, the three cases studied showed deformity of the leg bone, bowleg (genu varum). The origin of this sign may be made clear by such histological changes of the osseous tissue as mentioned above. Namely, it is thought that the unnatural posture, bowleg, has developed, because the bone tissue did not reach such degree of hardness as to be proportional to an increase in weight (broiler chicks begin to exhibit a remarkable increase in weight already at 14 days of age) and that abnormal development progressed in the bone tissue irregulary. In this study, the frequency of occurrence of affected chicks was 16% of the birds of the same group when judged from the outward appearance. Of 192 individuals manifesting the symptoms, only three birds 32 days of age were examined histopathologically. These affected birds showed the same symptoms as mentioned above. Consequently, it may be considered that these affected chicks have occurred collectively on a poultry farm. Judging from the histopathological findings of the osseous tissue, the present cases can be classified into the same category as those at least once studied in the authors'previous report, part I. It must be noticed, however, that no abnormal development has been found out in the epiphyseal osseous tissue in the present cases, different from the authors' previous cases. [the rest omitted]

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In the previous investigation, the authors established an agglutination procedure, which they called the "bouillon method", for the diagnosis of atrophic rhinitis (AR) in naturally infected swine. The present experiment was carried out to study the significance of the agglutination (AG) reaction and a possibility of applying it to 400 field specimens, in comparison with bacteriological and pathological findings. The results obtained are as follows. 1. Positive responses were observed in 218 samples (54.5%) out of 400 in the AG test at a titer of 1:20 or higher. It was suggested that Bordetella infections might have occurred in a piggery or a farm as a unit, spreading from the sow to her young or from one pig to another. 2. Bordetella bronchiseptica was isolated at a high rate during the first stage of infection (1 to 3 months after birth). The isolation rate decreased gradually after the second stage (4 to 5 months) with the advance in age. AG antibody became detectable at 12 or 20 weeks of age. It seemed that at the same time the isolation rate of the causative organism from the nasal cavity might begin to decrease. 3. Comparison of three diagnostic methods, i.e., serological (agglutination test), pathological (gross lesion examination), and bacteriological (B. bronchiseptica isolation) tests, revealed that the results were not always coincidental among the three tests, Lesions were found in 85 (91.4%) out of 93 serologically positive pigs. Of 110 pathologically positive cases, 85 (77.3%) showed a positive reaction in the AG test. From these results, it was concluded that the serological test was available for the diagnosis of B. bronchiseptica infection among pigs in the field.

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