Tamotsu Tomimura

Characterization and localization of Paragonimus westermani antigen stimulating antibody formation in both the infected cat and rat.

Applicability of the adult Paragonimus westermani antigen for detection of anti-immature P. westermani antibodies in experimentally infected rats, a paratenic host of this lung fluke, was examined. The serum antibodies of the cats and rats infected with P. westermani metacercariae were detected by enzyme-linked immunosorbent assay (ELISA) with the adult-fluke antigen. The ELISA titers of serum samples of the rats infected with only immature flukes were as high as those of the cats infected with adult flukes. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and the immunoblotting technique showed that a major protein band of 27,000 daltons was recognized in the sera of the infected cats and rats. Immunoperoxidase staining applied on the sectioned flukes provided evidence showing that the antigenic substance was located on the surface of the gut epithelium and in the luminal contents in both adult and immature flukes. The adult-fluke antigen containing the 27,000-dalton substance is applicable as a standard antigen for diagnosis of paragonimiasis westermani in not only definitive hosts but also in paratenic hosts.

Cerebral Infarction Caused by Dirofilaria immitis in Three Dogs

Two cases of parasitic embolism of the cerebral arteries in the dog causedby Dirofilaria immitis were recorded by Olson (1970) and Patton and Garner (1970) inthe United States. No such cases had been reported in Japan where canine heart wormdisease is enzootic most prominently in the world. Recently, the authors had an oppor-tunity of examining three dogs with the cerebral arteries affected with D. immitis em-bolism, showing such sudden nervous signs as unstable gait, circling, tumble, roaring, visual disorders, disturbed swallowing, cloudiness of consciousness and coma. The resultsof pathological examination of these dogs are summarized as follows.l. In each dog, severe obstruction was established in the cerebral arteries by a singleworm of D. immitis. The parasite was so large and long in size that it filled the vesselalmost completely, extending from the left middle cerebral artery to the left posteriorcommunicating artery and the left posterior cerebral artery in dog No. 1, from the leftanterior cerebral artery to the left middle cerebral artery in dog No. 2, and from the leftposterior cerebral artery to the cerebral arterial circle and the basilar artery in dog No. 3(Fig. l).2. In each case, the size and severity of cerebral infarct corresponded generally to thedistribution of arteries occluded by v. immitis, as shown in rigs. 2 to 4; that is, theaffected areas of the cerebrum were the left temporal and occipital lobes in dog No. 1, the left frontal, parietal and temporal Robes in dog No. 2, and almost all the lobes ofthe right hemisphere and the left-side portions of the thalamus and hippocampus in dogNo. 3. It was confirmed microscopically that these affected cerebral areas were stillrecognized in the early stage of encepholomalacia.3. Worms recovered from the cerebral arteries of the three dogs were morphologicallyidentified as adult forms of D. immitis.