Twenty-nine cases of feline infectious peritonitis were studied histopatho-logically. It was notable that, in most cases examined, there existed degenerative andproliferative changes in the blood vessels of different parts, especially in endothelial andmedial layers of fine and smaller veins or arteries with perivascular infiltration of neutro-phils and mononuclear cells. Every case had varied amounts of ascites and/or hydrothoraxwith fibrinous precipitates covering the entire surface of peritoneal and thoracic cavitiesas well as visceral organs. Metaplasia and hyperplasia with syncytium formation wereremarkable in mesothelial and mesenchymal cells of the peritoneum and pleura. In mostcases multiple necrotic foci with infiltration of neutrophils and mononuclear cells andhemorrhage were seen in the serosa, omentum and mesenteries, and the same lesionsappeared also in the parenchyma of the liver, spleen and mesenteric Nymph nodes of somecases.

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Renal juxtaglomerul;tr cell granulation in some mammals was demonstratedby Bowies staining method. Hartroft and llatrofts index was applied to different speciesin one trial. It was high in the mouse and rat, and low in the hamster. These resttlts werecorrelative with those reported by Capelli who measured the renal renin content in sonnemammalian species. In the horse, cow, sheep and guinea pig large grantnles, whiclt werestained by Bowies method, were observed near the glomerular arteriole. Then in themouse these granules were studied by electron microscope. It was observed that large cellswhich contained many heterogenous lysosomes were present in the outer layer of theepithelium of the glomerular capsttle. This observation suggested that the large granulesseen by light microscope might not be juxtaglomerular cell granules, bttt ordinarylysosomes.

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Biochemical properties of feline herpesvirus (FIIV) hemagglutinin obtainedfrom infected feline lung cell (FLC) cultures and receptors on feline erythrocytes were in-vestigated. Generally, a close parallelism was shown to exist between the infectivity andhemagglutination (H, X) activity of fresh and crude FIIV suspensions. When FHV suspen-sion was held at 37C, its HA activity was slightly enhanced and maintained, while itsinfectivity was reduced. The HA Liter of the virus fluid supplemented with polyoxyethylencsorbitan mono-oleate (Tween 80) ahead of ethyl ether treatment was 2 to 4 times higherthan that of the virus fluid without Tween 80. Hemagglutinin was proved to be associatedwith the viral envelope. Viral hemagglutinin obtained by Tween 80-ether treatmentpossessed the character of a glycoprotein. A large quantity of hemagglutinin which wasnot always considered to be derived from the mature virion was also detected in the in-fected FLC. The agglutinability of the feline erythrocyte was inactivated by the trypsintreatment. Discussion was made on the HA reaction of FIIV in comparison with that ofequine abortion and measles viruses.

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Twenty-eight cows with cystic ovarian disease (COD) were used. In them oneor more follicular cysts 2.0 cm or more in diameter persisted for at least l to 2 weeks. Theyexhibited such abnormalities either in estrous signs as masculinized appearance, intensiveestrus, continuous estrus, feeble estrus, and anestrus or in the estrous cycle as ata irregularcycle or a lack of cycle. Of the 28 cows, six were derived from herds which had often beentreated with a large dose of gonadotropin for COD (Group A) and the remaining 22 cowsfrom herds rarely treated with gonadotropin (Group B). The 6 cows of group A wereinjected intramuscularly (i.m.) with 2, 000 pg of gonadotropin-releasing hormone (GnRH).Of the 22 cows of group B, ten were injected i.m. with 1, 500 pg, three i.m. with 2, 000 pg, seven intravenously (i.v.) with 1, 000 pg, and two i.v. with 3, 000 pg of GnRH. Blood sampies were collected from 21 cows via the jugular vein before the treatment and from 5 cowsagain 6 to 9 days after the treatment.Sixteen (57%) of the 28 cows conceived after the GnRlI treatment. There was a signifi-cant difference (P i0.05) in recovery rate (the number of cows which conceived / the num-ber of cows treated) between the two treatment groups. No cows of group A respondedto GnRII, but 16 COXVS of group B showed response to GnRH. There seems to be littledifference in effects of GnRH among the cows given different doses either intramuscularlyor intravenously.There was a trend that the pretreatment serum level of progesterone was higher in thecows having responded to GnRH than in those not responding. In 4 cows with fo1[icu]arcysts luteinized, the serum level of progesterone increased remarkably 6 to 9 days after theinjection, but did not in 1 cow with follicular cysts remaining unchanged.

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The present studies were done to determine the presence of Yersinia entero-colitica in dogs. During 13 months from August 1974 to August 1975, the contents of theileum, cecum, colon and rectum, and the mesenteric Nymph nodes of 451 dogs in Sapporowere examined. Three hundred and ninety-five strains of Yersinia enterocolitica were iso-lated from 25 out of 451 dogs examined. Two hundred and eighty-two strains from 16dogs were determined as 0 group (0) 3, biovar 4; 60 strains from 5 dogs 05B, biovar 2:47 strains from 2 dogs 09, biovar 2; 4 strains from 1 dog 06, biovar 1; and 2 strains from2 dogs 05A, biovar 1. O group of strains isolated from 1 dog was the same in 24 of the25 dogs. From the other I dog, however, the strains of both 03 and 09 were isolated atthe same time. The isolation of 09 strains from dogs is the first in Japan. The strainsof 03 or 09, which are known to be pathogenic agents in man, were isolated in 17 dogs, and many of them, from the contents of ileum, cecum, colon and rectum in 9 dogs. Onthe basis of these results, the significance of the presence of Yer.sinia enterocoZitica in dogswas discussed.

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Pathological studies were carried otzt on cerebrocortical necrosis in fotzr offive heifers affected in a group of 12 rearing calves. These calves were kept in an isolatedbarn on a fattening farm of moderate scale, and fed moulded hay harvested two yearsbefore. Clinical observation revealed diarrhea followed by the typical nervous symp[ontsof the disease and leucocytosis. Macroscopically, the edematous turbid meninges yellowishbrown in color with hemorrhagic spots, and softening of the yellowish zonal area corresponding to the gray matter were demonstrated in the cerebral hemisphere. Ilistologicalobservation disclosed neuronal necrosis, edema[ous degeneration of astrocytes, proliferation of compound granular corpuscles, and vascularization with swollen endothelial cellsin the gray matter. Pyramidal cell necrosis, edematous enlargement of the cytoplasrn andprocesses of degenerative glia cells, degenerative disorder of the neuropil in the lesionwere observed by electron microscopy. Discussion was made on the pathogenesis of thedisease.

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Ilistopathological observation was performed mainly on the heart and cardiacnervous system in 8 horses affected with atrioventricular (AV) block. Main histopathologi-cat lesions emphasized on the 8 horses were as follows: (l) Focal myocardial fibrosis andedematous loosening and/or fibrous swelling of the walls of small and minute blood vessels, to be put forward microvascular alteration, in the posterolateral region of the rightatrium, as well as in the interatrial septum. (2) Microvascular alteration in the proximalportion of the AV junction, hydropic degeneration of the AV nodal fibers, and focalmyocardial fibrosis close to the AV node. (3) Lesions in the intrinsic cardiac nerves in theinteratrial septum, right atrium and AV junction. (4) Multifocal lesions in the extrinsiccardiac nervous system.Histopathogenetically, myocardial fibrosis should be regarded as a result of local circulatory insufficiency (ischemia) due to microvascular alteration. The following lesions mayalso have closely taken part in the occurrence of AV block through the hypofunction and/or circulatory insufficiency (hypoxemia or ischemia) in the tissue concerning impulse con-duction: myocardial fibrosis and microvascular alteration in the posterolateral region ofthe right atrium, as well as in the interatrial septum, and/or the microvascular alterationand hydropic degeneration of specialized fibers in the AV node, and organic disturbancesin the cardiac nervo.ts system.

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To clarify the restoration from inhibition of the gonad induced by hexestroldicaprylate (H.), adult male rats were injected subcutaneously with a single dose of 400 pg/0.2 mZ of H. in oil, and autopsied 3, 6, 12 and 24 weeks after the injection. In the reproduc-tive organs an atrophic tendency was observed clearly 3 weeks, a maximal decrease inweight 6 weeks, and a tendency to recover in weight 12 weeks after the injection. Thesperm concentration decreased obviously in all the rats 3 weeks after the injection. Nosperms were found in the majority of the rats 6 weeks after the injection. The spermato-genetic function was recovered to almost the same level as that of untreated control ratsby 24 weeks after the injection. The recovery of fertilizing ability of those rats was con-firmed 29 weeks after the injection, when all the rats successfully mated with normal adultfemales, which became pregnant. II. was a weak synthetic estrogen, as proved by thevaginal estrous test on spayed female rats. It was revealed, however, that injection witha single dose of H. could inhibit spermatogenesis in adult male rats for a long time with-out inducing any macroscopic side effect, and that spermatogenesis was restored 6 to 7months after the injection.

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