Genotyping Toxoplasma gondii from wildlife in Pennsylvania and identification of natural recombinants virulent to mice.

Recent studies indicated the predominance of Toxoplasma gondii haplogroup 12 in wildlife in the USA. However, still little is known of the genetic diversity of this parasite circulating in wildlife. In the present study, we tested coyotes (Canis latrans), red foxes (Vulpes vulpes), white-tailed deer (Odocoileus virginianus), and geese (Branta canadensis) from the state of Pennsylvania for T. gondii infection. Antibodies to T. gondii were found in 160 of 367 animals, including 92 (34.5%) of 266 coyotes, 49 (62.0%) of 79 white-tailed deer, 17 (85.0%) of 20 red fox, and two of two Canada geese tested by the modified agglutination test (cut off titer 1:25). Tissues from 105 seropositive animals were bioassayed in mice, and viable T. gondii was isolated from 29 animals, including 10 of 53 coyotes, 11 of 16 foxes, 7 of 49 deer, and one of one goose. DNA isolated from culture-derived tachyzoites of these isolates was characterized initially using multilocus PCR-RFLP markers. Nine genotypes were revealed, including ToxoDB PCR-RFLP #1 (4 isolates), #2 (2 isolates), #3 (4 isolates), #4 (6 isolates), #5 (4 isolates), #54 (1 isolate), #141 (1 isolate), #143 (1 isolate), and #216 (6 isolates), indicating high genetic diversity of T. gondii in wildlife in Pennsylvania. Pathogenicity of six T. gondii isolates (5 of #216 and #141) was determined in outbred Swiss Webster mice. Three of #216 and the #141 isolates were acute virulent to mice, and the other 2 #216 isolates were intermediate virulent. To determine the extent of genetic variation of these as well as a few recently reported virulent isolates from wildlife in North America, intron sequences were generated. Analysis of intron sequences and PCR-RFLP genotyping results indicated that the #216 isolates are likely derived from recombination of the clonal type I and III lineages. To determine if T. gondii virulence can be predicted by typing, we genotyped a collection of strains using PCR-RFLP markers for polymorphic genes ROP5, ROP16, ROP18 and GRA15, which are known to interact with host immune response. The results showed that there is an association of genotypes of ROP5 and ROP18 with mouse-virulence, however, additional gene(s) may also contribute to virulence in distinct T. gondii genotypes.

A fall prevention educational program for community dwelling seniors.

The purpose of this research was to assess participants' responses to a fall prevention educational program. Fourteen persons volunteered to participate in the study conducted at a large senior center. Descriptive statistics were used to characterize the sample and to assess subjects' awareness about falls, attitudes about fall risk, fall prevention behaviors, and incidence of falls before the fall prevention program and again at one month and three months after the program. Forty-six percent of the sample had fallen in the previous year. In general, subjects' perceptions that their risk of falling was lower than others of the same age and sex increased following the fall prevention program. Additionally, subjects were somewhat more concerned about falling after attendance at the fall prevention program. Most of the participants completed the home safety checklist; however, very few subjects made changes at home to reduce the risk of falling or did the recommended muscle strengthening exercises. Suggestions for community fall prevention programs are offered based upon the pilot results.

Developing guidelines for local use: algorithms for cost-efficient outpatient management of cardiovascular disorders in a VA Medical Center.

Local use of practice guidelines requires paying close attention to the concerns of the patient within the framework of society, to the professional and educational needs of the provider, and to the realities of cost. One Veterans Affairs facility took the challenge of balancing these factors and developed their own algorithms for three cardiovascular disorders.

Postsynaptic alpha- and beta-adrenergic supersensitivity of recovery properties in the canine ventricle.

We studied postsynaptic manifestations of adrenergic supersensitivity in the canine left ventricle (LV) regionally denervated by phenol in 14 dogs. Measurements were performed from 17 to 23 days later under alpha-chloralose anesthesia after sinoaortic denervation and vagotomy. After the sternum was split, multipolar pacing and recording electrodes were placed in both innervated and denervated LV. With isoproterenol infusion at 0.1, 1, and 10 micrograms/min, there was no change in activation times or pacing threshold. However, supersensitivity was manifested by a parallel left shift in the isoproterenol dose to effective refractory period (ERP) response curve (greater than or equal to 5.7 ms) in the denervated endocardium and epicardium compared with the respective innervated LV (P less than 0.05). In addition, local repolarization in the denervated area shortened more than the innervated area with isoproterenol infusion and correlated (r = 0.56) with the change in ERP. Postsynaptic supersensitivity of Purkinje to isoproterenol was also manifested by a parallel left shift (greater than or equal to 10 ms) in the dose to relative refractory period response curve in the denervated compared with the innervated area (P less than 0.05). In addition, a greater prolongation of Purkinje refractoriness was observed with phenylephrine only at 50 micrograms.kg-1.min-1. We conclude that postsynaptic supersensitivity occurred with the beta-agonist isoproterenol in both muscle and Purkinje. However, only Purkinje in the denervated area demonstrated an enhanced response to the alpha-agonist phenylephrine.