Cats are important in the epidemiology of Toxoplasma gondii because they are the only hosts that can excrete environmentally resistant oocysts. The prevalence of T. gondii was determined in 58 domestic cats from 51 homes from Santa Isabel do Ivai, Parana State, Brazil where a water-associated outbreak of acute toxoplasmosis had occurred in humans. Antibodies to T. gondii were found with the modified agglutination test in 49 of 58 (84.4%) cats at a serum dilution of 1:20. Tissues (brain, heart, and skeletal muscle) of 54 of these cats were bioassayed in T. gondii-free, laboratory-reared cats; T. gondii oocysts were excreted by 33 cats that were fed feline tissues. Brains from these 54 cats were bioassayed in mice; T. gondii was isolated from 7. Skeletal muscles and hearts of 15 cats were also bioassayed in mice; T. gondii was isolated from skeletal muscles of 9 and hearts of 13. The results indicate that T. gondii localizes in muscle tissue more than the brains of cats. In total there were 37 T. gondii isolates from 54 cats. Most isolates of T. gondii were virulent for mice. Genotyping of the 37 isolates of T. gondii, using the SAG2 locus, revealed that 15 isolates were type I and 22 were type III. The absence of type II genotype in cats in this study is consistent with the previous studies on T. gondii isolates from Brazil and is noteworthy because most T. gondii isolates from the United States are type II. These findings support the view that Brazilian and North American T. gondii isolates are genetically distinct. This is the first report of genotyping of T. gondii isolates from the domestic cat.

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Our findings suggest that HMGB1 play a role in the induction of apoptosis via inflammatory reaction.

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We studied the origin and mechanism of spinal cord pulsation in ten dogs in order to elucidate its clinical significance. Under general anesthesia, a 6 cm length of the animals' cervical spinal cord was exposed and the cerebrospinal fluid removed. The amplitude of spinal pulsation was then measured by means of ultrasonography in Mode M. The measurements were made after the spinal cord was cut: (I) on the cranial side; (2) on the cranial as well as caudal side, with the nerve roots and radicular arteries intact; (3) on both sides as in (2), which was then supplemented with the severance of the nerve roots and radicular arteries. It was demonstrated that, while the pulsation amplitude stood at an average of 88.0,um before the surgical treatment, it rose to 455.0,um in (I) and 274.8,um in (2), but dropped to nearly zero in (3). The 5.2-fold increase in pulsation following the cordotomy on the cranial side was attributed to two factors: (1) the increased spinal mobility due to the cordotomy; (2) the elevation of blood pressure. The results of the three different degrees of spinal detachment suggested that spinal pulsation derived mainly from the radicular arteries and that its presence indicated low tonicity in the spinal cord and favorable circulation in the radicular arteries.