Four studies were conducted to delineate potential neural processes involved in retention of a peripherally induced postural asymmetry. In the first experiment, dorsal and ventral spinal root section following varying intervals of stimulation successfully abolished peripherally induced hindlimb asymmetry. Experiment 2 revealed that 50 min of ventral root stimulation, in the absence of central connection, was not effective in producing asymmetry persistence. In an attempt to more closely delineate the time parameters involved in peripherally induced asymmetry retention, Experiment 3 was conducted. Asymmetry was found to consistently outlast a spinal transection if 40 min of stimulation was given. Finally, possible modulatory higher brain center influences on the retention processes were demonstrated in Experiment 4. Asymmetry persistence was consistently observed in animals that received 10, 20, 30, 40, or 50 min of hindlimb stimulation if 50 min were allowed to elapse between the onset of stimulation and spinal section. These results, when coupled with the findings of earlier studies, suggest an active involvement of spinal reflex centers in the fixation process. In addition, these studies indicate that the manner in which reflex activity is altered is not crucial as long as underlying time parameters are adhered to. Finally, the present studies demonstrate that higher center influences can modulate retention of a postural asymmetry in a complex manner.

Animals↗

PubMed1981

DNA-anti-DNA circulating complexes in the nephritis of systemic lupus erythematosus.

In order to determine whether circulating antigen-antibody complexes in systemic lupus erythematosus (SLE) consist of DNA and anti-DNA, cryoglobulins were isolated from the sera of 38 patients with SLE nephritis and analysed for DNA and anti-DNA. Cryoglobulins were detected in 36 of the 38 sera, and DNA was found in 30 of 33 examined by either fluorescence of ethidium bromide or a radioimmunoassay. Anti-DNA activity was not detectable in any of the whole cryoglobulins but anti-IgG activity was found in 17. Twenty cryoglobulins were therefore treated by acid dissociation and ultracentrifugation to obtain isolated immunoglobulins; IgG was isolated from all, and IgM from eight. Using a modified Farr assay to detect anti-dsDNA and an enzyme-linked immunoadsorption assay to detect anti-ssDNA, anti-dsDNA activity alone was found in five IgG fractions, anti-ssDNA activity alone in five, and both anti-ds- and anti-ssDNA activity in four. Anti-dsDNA activity was found in three of the IgM fractions. In all, anti-dsDNA activity was found in nine of these 20 cryoglobulins, and anti-DNA in 14. Analysis of these 14 cryoglobulins with anti-DNA Ig fractions showed that there was enrichment of the IgG anti-DNA activity in the cryoglobulin compared to the patient's serum in all but two cases. In six of the 20 cryoglobulins studied there was no detectable anti-DNA activity in isolated IgG or IgM fractions. We therefore concluded that DNA-anti-DNA complexes were present in most of our patients with SLE nephritis, but there was clearly a substantial minority in whom they were undetectable. In some of the latter who also had active disease the cryoglobulins had anti-IgG activity. Thus it would seem that SLE can occur in the absence of DNA-anti-DNA complexes, but with other complexes present. DNA was also found in cryoglobulins isolated from patients with idiopathic glomerulonephritis, but, in contrast to recent reports, anti-DNA activity was not detectable in immunoglobulins isolated from their cryoglobulins.

Adult↗

PubMed1979