The mental status of patients with Friedreich's ataxia.

In the clinical literature, the majority of patients with Friedreich's ataxia are described as having signs of intellectual decline and serious psychiatric symptomatology. Recent studies contradict this clinical picture, but indicate some discrete mental status changes, such as slowing of information processing speed not related to motor abnormality, in a more strictly defined Friedreich's population. This study describes the mental status changes in a sample of 38 patients seen at the University of California at Los Angeles Neuropsychiatric Hospital, Ataxia Clinic. The sample was defined using strict clinical and biochemical criteria. Only one of the 38 patients showed evidence of intellectual deterioration. Ninety-two percent of the patients experienced some affective difficulty, however, ranging from major depression to normal grief. Three patients have reached their mid-forties (one is 64 years of age) without any serious mental status changes. These findings point out the importance of nurses' expecting these patients to function normally in the cognitive domain. Implications related to specific nursing interventions are discussed.

Cells transformed by temperature-sensitive mutants of avian sarcoma virus cause tumors in vivo at permissive and nonpermissive temperatures.

Chick embryo (CE) fibroblasts and normal rat kidney (NRK) cells transformed by temperature-sensitive (ts) mutants of avian sarcoma virus (NY68, LA23, LA24, LA25, LA29, LA31, GI201, GI202, GI251, GI253 induce tumors on the chorioallantoic membrane (CAM) of chick eggs at temperatures that correspond to the permissive and nonpermissive temperatures used to induce conditional expression of the "transformed" phenotype in these cells when cultured in vitro. Chick embryo cells infected with transformation-defective mutants of ASV (td101, td108) or RAV-50 were nontumorigenic under the same conditions, as were nontransformed CE and NRK cells. This indicates that the CAM is not an unusually susceptible substrate for cell growth and that the ability of tsASV-transformed cells to form tumors at nonpermissive temperatures reflects their true tumorigenicity. In contrast, a ts mutant chemically transformed rat liver cell line, ts-223, only formed tumors on the CAM under permissive conditions. The wild-type parent cells (W-8) of this mutant produced tumors at both permissive and nonpermissive temperatures. Direct implantation of microprobe thermometers into tumors caused by ts-ASV-transformed cells at nonpermissive temperatures confirmed that tumor formation occurred in a stable temperature environment and was not due to temperature fluctuations which might have created semi-permissive conditions for tumor growth. Cells isolated from tumors formed at nonpermissive temperatures and recultured in vitro displayed temperature-dependent hexose transport and colony formation in agar similar to the orginal parent cell inoculum. Similarly, virus recovered from tumors at nonpermissive temperatures retained the ts mutation.