No abstract

No abstract

1. The viscosity of sputum in patients with chronic bronchitis has been measured with the Weissenberg rheogoniometer, a cone and plate system, using oscillatory movement at low shear rates.2. A characteristic pattern is described not previously reported for sputum or any other biological fluid.3. Sputum viscosity decreased steadily with increasing shear rate; over a narrow range of shear rates a 'notched plateau' was shown. The destruction of this plateau by higher frequencies of oscillation was attributed to breakdown or rearrangement of the gel structure.4. The effects of time on viscosity measurement, presumably caused by drying, are also described.

Breeding experiments confirmed that a hereditary form of kyphoscoliosis in the BDL strain mouse was due to an autosomal recessive gene (ky). Sagittal sections of whole vertebral columns from adult homozygous recessive mice (ky/ky) were examined histologically. All mice showed varying degrees of degenerative change in one or more intervertebral discs between the fifth cervical and the second thoracic vertebrae. The changes comprised loss of cells, loss of distinction between nucleus pulposus and annulus fibrosus, loss of characteristic ring-like structure in the annulus, and development of wedge-shaped discs. In most animals, degenerative disc substance protruded from the disc space, usually posteriorly, sometimes anteriorly, and occasionally through the vertebral end plate cartilage. Posterior protrusions impinged on the spinal cord.