Cell biology of smooth muscle in culture: implications for atherogenesis

Smooth muscle cells are one of the most important, if not the most important component of atheromatous plaque. Smooth muscle cells from developing and regenerating arteries, as well as atheromatous plaques, show similar morphological and biochemical characteristics which differ from adult tissue. During primary culture, adult smooth muscle cells alter their morphology to resemble those of the developing, regenerating and atheromatous material. We propose that primary cell culture of smooth muscle cells provides a model for the study of smooth muscle cell changes during atheroma formation.     

The histopathology of freezing injury to the rat spinal cord. A light microscope study. I. Early degenerative changes

In an effort to develop a method of tissue injury which would provide a model for the study of axonal regrowth in adult mammalian central nervous system (CNS), we have analyzed the effects of freezing in the dorsal columns of more than 200 rat spinal cords. The effects of temperature and time of exposure upon the size, shape, distribution and histologic characteristics of the lesion have been assessed during the first seven days following the injury. The upper threshold for injury occurs at -3 degrees C for 15 minutes. Between -3 degrees C and -12 degrees C the tissue changes vary in extent and characteristics. Selective damage to axons and myelin occurs with sparing of the supportive cells followed by proliferation of a cellular matrix. At seven days, the lesions produced by -8 degrees C for 15 to 60 minutes have neither axons nor myelin sheaths and consist of a dense cellular matrix of macrophages and presumed glial cells. With these tissue characteristics, and the preservation of tissue continuity without obstructive barriers, this model would appear to be potentially suitable for the study of axonal regrowth potential in mammalian CNS.     

Anterior horn changes of motor neuron disease associated with demyelinating radiculopathy

Morphologic study of the spinal cord of a patient with generalized motor deficits revealed changes in the anterior horns characterized by the selective loss of large motor neurons, gliosis and the abnormal accumulation of 10 nm filaments which appeared as argyrophilic spheroids in the perikarya and axons of motor neurons. The ventral roots were predominantly affected and showed a variable loss of axons. The remaining axons displayed prominent onion-bulb formations, frequent axonal sprouting and occasionally evidence of active demyelination. The coexistence of a demyelinating motor radiculopathy and anterior horn changes simulating those of amyotrophic lateral sclerosis (ALS) may contribute to our understanding of the unresolved question of whether the neuronal perikaryon or its axon is the primary target in the pathogenesis of ALS. These observations also indicate that a rigid separation of pathogenetic mechanisms into neuronopathy, axonopathy and myelinopathy may not be always possible.     

Stress selectively influences center region activity of mice in an open field

Effects of immobilization and footshock stress on locomotor activity in different areas of an open field were examined in mice. Center region activity, peripheral region activity and total activity were used as measurement indices. These results indicate that both immobilization and footshock stress significantly increased total activity across 24 min of behavioral testing. Further analyses revealed that the difference in total activity between the experimental and control groups were mainly attributal to an increase in center region activity. Both stress manipulations markedly augmented peripheral region activity for only the first 6 min. More important, when the proportion of center to peripheral activity was used as an index, both experimental groups manifested an inverted U shape relationship with the maximum effect occurring between 13-18 min of behavioral testing. Similarities of these activity measures in response to different stressors suggests that common neurochemical and/or neurohormonal mechanisms may mediate these behavioral changes.     

Orthopedic disorders, morbidity, and sick absenteeism in men with different levels of serum gamma-glutamyltransferase

All orthopedic treatment administered between 1970 and 1982 was analyzed in random subsamples of men 28, 38, and 48 years old being screened for serum gamma-glutamyltransferase (GGT) levels. Of 1,151 screened participants, 631 men had been treated for fracture, distortion, contusion, low-back pain with or without sciatica, or radial epicondylitis. The extent of care and incidence of the different diagnoses over the 13 years, as well as the number of sick days incurred by these men during 1981, were investigated for different GGT brackets. Those men with the highest GGT values (greater than or equal to 1.34 mu kat/liter approximately 80 IU) had 4-6 times more fractures and consulted surgeons 6-13 times more often than those men with the lowest GGT values (less than 0.35 mu kat/liter approximately 20 IU). Epicondylitis and distortion showed the opposite frequency distribution, with the highest incidence occurring in the lowest GGT brackets. Increasing GGT values were also correlated with sick leave days. Men in the highest decile for sick leave had 25 times more fractures than those men with no sick absenteeism. We conclude that an accumulation of alcohol-related orthopedic disorders occurs among men with high GGT values.