Hemophagocytic syndrome in a pancytopenic simian retrovirus-infected male rhesus macaque (Macaca mulatta).

Hemophagocytic syndrome (HPS) is a macrophage hyperactivation disorder triggered by disrupted T-cell macrophage cytokine interaction. HPS has been reported in humans, dogs, cats, and cattle, and it is infrequent and poorly characterized in animals. A 16-year-old male rhesus macaque was euthanized because of severe pancytopenia, including nonregenerative anemia (hematocrit = 5.5%), neutropenia (0.29 K/µl), and thrombocytopenia (21 K/µl). Bone marrow was hypocellular with normal maturation, myeloid hypoplasia, and few megakaryocytes. There were numerous morphologically normal macrophages (12% of nucleated cells), with 6% of nucleated cells being hemophagocytic macrophages in the bone marrow. Serology was negative, but polymerase chain reaction and immunohistochemistry were positive for simian retrovirus type 2. Blood and bone marrow findings were consistent with HPS. Cytopenias are common in simian retrovirus-infected macaques, but HPS has not been reported. An association between simian retrovirus infection and HPS is undetermined, but retrovirus-associated HPS has been observed in humans.

Safety of Brucella abortus strain RB51 in bull elk.

Some of the elk (Cervus elaphus nelsoni) of the Greater Yellowstone Area (Wyoming, Idaho, Montana; USA) are infected with Brucella abortus, the bacterium that causes bovine brucellosis. Brucella abortus strain RB51 vaccine is being considered as a means to control B. abortus induced abortions in cow elk. However, the most probable vaccination strategies for use in free-ranging elk might also result in some bull elk being inoculated, thus, it is important to insure that the vaccine is safe in these animals. In the winter of 1995, 10 free-ranging bull elk calves were captured, tested for B. abortus antibodies, and intramuscularly inoculated with 1.0 x 10(9) colony forming units (CFU) of B. abortus strain RB51. Blood was collected for hemoculture and serology every 2 wk after inoculation for 14 wk. Beginning 4 mo postinoculation and continuing until 10 mo postinoculation elk were serially euthanized, necropsied, and tissues collected for culture and histopathology. These elk cleared the organism from the blood within 6 wk and from all tissues within 10 mo. No lesions attributable to B. abortus were found grossly and only minimal to mild lymphoplasmacytic epididymitis was found in a few elk on histologic examination. In a separate study, six adult bull elk from Wind Cave National Park (South Dakota, USA) were taken to a ranch near Carrington (North Dakota, USA). Three were orally inoculated with approximately 1.0 x 10(10) CFU of RB51 and three were inoculated with corn syrup and saline. Ninety days post-inoculation semen was examined and cultured from these bulls. Strain RB51 was not cultured from their semen at that time. There were no palpable abnormalities in the genital tract and all elk produced viable sperm. Although they contain small sample sizes, these studies suggest that B. abortus strain RB51 is safe in bull elk.

Comparison of upper-extremity balance tasks and force platform testing in persons with hemiparesis.

BACKGROUND AND PURPOSE: The purpose of this study was to investigate the relationship between clinically accessible functional balance tools and sophisticated force platform measures in a standing position. SUBJECTS: Twenty persons who had hemiparesis secondary to a stroke and were ambulatory (mean age = 57.9 years, SD = 13.6, range = 35-79) were evaluated during a single testing session. METHODS: Performances on self-generated upper-extremity balance tasks using the nonparetic side (Functional Reach Test [FRT], arm raise and arm reach tasks) were compared with responses to external perturbations on the Balance System (postural sway, symmetry of weight distribution). RESULTS: No relationship was found between the upper-extremity balance tests and the force platform measures of postural sway. After suppressing the effect of age by means of partial correlation coefficients, the FRT was correlated with measures of postural symmetry in parallel stance on the Balance System (r = .66-.78). The FRT was only moderately correlated with the arm raise and arm reach tasks (r = .43 and .44). CONCLUSION AND DISCUSSION: Postural sway in response to force platform perturbations may have little relation to the postural control necessary for self-generated upper-extremity balance tasks. In contrast, the FRT and the force platform measures of postural symmetry appear to be evaluating comparable standing-balance abilities in persons with hemiparesis. The modest relationship between the FRT and the arm raise and arm reach tasks limits the finding's clinical relevance.

Sitting balance: its relation to function in individuals with hemiparesis.

OBJECTIVES: To evaluate test-retest reliability of sitting balance measures in healthy subjects and individuals with hemiparesis secondary to stroke, to evaluate the ability of the balance measures and Functional Independence Measure (FIM) to document changes over time, and to compare changes in the balance measures and FIM to each other. METHOD: Six nonpatient subjects were evaluated for test-retest reliability. Fourteen subjects with hemiparesis were tested every 2 weeks during their hospitalization on their ability to lean to either side, lean forward, and maintain a symmetrical posture. Maximum displacement was recorded using the Balance System. FIM scores were obtained for each testing session. RESULTS: Test-retest reliability for nonpatient subjects was high and for patients was moderate to high. Leaning forward and to the paretic side showed the greatest number of correlations with the FIM scores. All of the FIM scales and the forward lean measure documented progress. CONCLUSIONS: The protocol developed to test sitting balance, using the Balance System, seems appropriate for use with patient populations. The ability to lean maximally to either side or forward or sit symmetrically is not strongly related to function.