Cartilage alterations after SCI would not be explained by only a suppression of mechanical forces by unloading and immobilization, but there may be influences on the cartilage in addition to the change in mechanical forces.

This study investigated the spontaneous beat-to-beat variabilities in R-R intervals of six traumatic neurologically complete quadriplegic (QP) males and six age-matched healthy males (control) while they were at rest in the supine position in a climatic chamber (temperature 30 degrees C, relative humidity 60%) by means of autoregressive power spectral analysis. As shown by earlier studies, in the control group there were two major spectral components, a high-frequency (HF) component [center frequency 0.30 +/- 0.02 (SE) Hertz equivalent (Hz eq), power 767.5 +/- 384.6 ms2] and a low-frequency (LF) component (0.11 +/- 0.01 Hz eq, 707.5 +/- 198.8 ms2). On the contrary, in the QP group, only the HF component was observed (0.30 +/- 0.02 Hz eq, 421.8 +/- 134.7 ms2). The results suggest that 1) the disappearance of the LF component in the QP subject is presumably caused by the interruption of the spinal pathways linking supraspinal cardiovascular centers with the peripheral sympathetic outflow, and 2) the cervical spinal sympathetic pathways may be instrumental in the genesis of the LF component in humans.

This study was made to elucidate the changes in the periarticular connective tissue that can underlie the contracture after spasticity development. Sixteen Wistar rats underwent a spinal cord injury and 16 rats were either sham- or nonoperated. The periarticular connective tissue of the knee joint was assessed with histological, histomorphometric, immunohistochemical, and biochemical analyses. Histological results showed a smaller synovial intima, a dense subintimal and posterior joint capsule without fibrosis, and a disarranged posterior capsule in the spinal cord-injured knees with the flexion contracture. The synovial intima length was shortened only at the posterior capsule. Neither the distribution nor expression of type I and III collagen was affected. Contractures after spinal cord injuries are characterized by synovial intima adhesions. A dense and disarranged capsule may lead to joint stiffness. The alteration of periarticular connective tissues exhibits properties characteristic of the contracture after spasticity development.

Study design: Experimental, controlled trial. Objectives: To identify the relationship between the muscular and articular factors in the progression of contractures after spinal cord injury (SCI). Setting: Hiroshima University, Hiroshima, Japan. Methods: In total, 48 female Wistar rats were used. The 24 experimental rats that underwent a spinal cord transection and the other 24 control rats that underwent a sham-operation were assessed at 2, 4, 8, 12, 16, or 24 weeks postsurgery. Knee joint motion was measured for flexion and extension. Myotomy of the transarticular muscles was then performed and range of motion was measured again. The degree of contractures was assessed by goniometry measuring the femorotibial angle before and after the myotomies. Results: The spinal cord-injured rats demonstrated flaccid paralysis during the first few days postsurgery and thereafter spastic paralysis. Intra-and inter-rater reliabilities for all measurements were 40.814. Knee flexion contractures developed in the all experimental rats, and progressed for the first 12 weeks and plateaued thereafter. Both the muscular (4875%) and articular (5275%) factors contributed almost equally to the overall progression of the contracture. Conclusion: The present findings may shed light on the underlying pathophysiology of contractures and should help guide research towards finding the elucidation of contracture development after SCI.

A ring chromosome 6 was identified in an apparently healthy girl with short stature and microcephaly. Of 100 peripheral lymphocyte metaphases analyzed, chromosome 6 was replaced in 73% by a monocentric ring chromosome, in 10% by a dicentric, in 1% by a tricentric, and 3% by two rings. Thirteen other cells were 45,XX,-6, which may represent 46,XX,r(6)/45,XX,-6 mosaicism. The breakpoints were located on bands p24 or p25 and q26 or q27. Eight other patients with a ring chromosome 6 have been reported. The most characteristic findings in subjects with a ring chromosome 6 are mental retardation and eye and ear abnormalities, none of which were present in our patient.