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A survey of hydrothermal activity along the superfast-spreading (approximately 150 millimeters per year) East Pacific Rise shows that hydrothermal plumes overlay approximately 60 percent of the ridge crest between 13°50' and 18°40'S, a plume abundance nearly twice that known from any other ridge portion of comparable length. Plumes were most abundant where the axial cross section is inflated and an axial magma chamber is present. Plumes with high ratios of volatile (³He, [CH.sub.4], and [H.sub.2]S) to nonvolatile (Mn and Fe) species marked where hydrothermal circulation has been perturbed by recent magmatic activity. The high proportion of volatile-rich plumes observed implies that such episodes are more frequent here than on slower spreading ridges., The circulation of seawater through the geothermally heated rocks of oceanic spreading ridges is the principal agent for the transfer of energy and mass between the oceanic crust and its [...]

Background: The curvature and range of motion of the cervical spine decrease after laminaplasty. However, to our knowledge these changes have not been studied prospectively. Also, the effect of laminaplasty on the mobility of the occipito-atlanto-axial joints has not been studied in detail. The purpose of our study was to prospectively evaluate the range of motion and curvature of the cervical spine, including the occipito-atlanto-axial joints, following laminaplasty.Methods: We conducted a prospective study of twenty-six patients who underwent cervical laminaplasty. They were followed for a mean of 6.7 years (range, five to nine years). Radiographs were made before the operation and at one, three, and five years after the operation. The curvature index, the angle of each vertebra in the neutral position from the occiput to the seventh cervical vertebra, and the range of motion in the sagittal plane were measured.Results: The curvature index, the angle of the axis and the sixth cervical vertebra, and the angle of the axis and the seventh cervical vertebra in the neutral position were reduced after the operation. The rate of reduction declined between the third and fifth postoperative years. On the other hand, the mean distance between the occiput and the atlas as well as the mean angle of the axis and the atlas did not change significantly. The range of motion of the axis and the seventh cervical vertebra was decreased after the operation, and it continued to decrease slowly over the study period. The range of motion of the occipito-atlanto-axial complex increased slightly, which may represent a compensation for the decreased mobility of the middle and caudad parts of the cervical spine.Conclusions: Laminaplasty diminishes lordosis and straightens the cervical spine. The range of motion and lordosis continued to decrease, though at a diminishing rate, between the third and fifth postoperative years. [ABSTRACT FROM AUTHOR]

Overproduction of proinflammatory cytokines is characteristic of hemophagocytic syndrome (HPS), a highly lethal inflammatory disease. Peripheral blood monocytes include two distinct subpopulations according to surface antigen expression: a major type, CD14+/CD16− (classical monocytes), and a minor type, CD14+/CD16bright (proinflammatory monocytes). Among peripheral blood monocytes from HPS patients, CD14+/CD16bright cells were increased, together with lipopolysaccharide-induced production of tumor necrosis factor (TNF)-α and interleukin (IL)-6. By three-color immunofluorescence, CD14+/CD16bright monocytes exhibited more intense human leukocytic antigen DR than CD14+/CD16− monocytes, consistent with greater maturity. Serum IL-6, TNF-α, and IL-8 were increased in HPS patients. A sensitive inflammatory marker, neutrophil CD64 expression, also was significantly elevated in HPS patients. In conclusion, expansion of proinflammatory monocytes and increased expression of neutrophil CD64 appeared to be important in the pathophysiology of HPS. Expansion of CD14+/CD16bright monocytes and neutrophil CD64 expression could serve as indicators of the inflammatory state in HPS. [ABSTRACT FROM AUTHOR]