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The concept of insight as it applies to patients suffering from psychotic illness is reviewed. An exploratory study using structured interviews with patients recovering from psychotic illness indicated that the characteristics of insight fell into five main dimensions: (1) views about symptoms, (2) views about the existence of an illness, (3) speculations about etiology, (4) views about vulnerability to recurrence, and (5) opinions about the value of treatment. Some preliminary findings regarding the association of patterns of insight with diagnosis and chronicity of illness, and the implications of these findings for clinical work and for future research, are presented.

We report solution structural studies on 9--16-kilobase (kb) fragments of the 30-nm chromatin fiber isolated from calf thymus nuclei. Samples were stabilized by dimethylsuberimidate cross-linking in 100 mM salt concentration to ensure retention of a compact conformation. Electron microscopy, sedimentation diffusion, light scattering, and gel electrophoresis were used to characterize materials which were fractionated by size by utilizing sucrose gradient sedimentation. Measurements reported include the translational frictional coefficient as determined by quasielastic light scattering and the rotational frictional coefficient as deduced from transient electric dichroism. These frictional properties were combined to yield 33 +/- 3 nm for the diameter of the fiber and a length of 1.5 +/- 0.1 nm per nucleosome. Assuming a superhelix pitch of 11 nm, we calculate 7.5 +/- 0.5 nucleosomes per superhelical turn. The 30-nm fiber was found to reach saturation of electric field orientation at about 10--13 kV/cm and to lack a detectable permanent dipole moment, implying no polarity of the fiber. The limiting reduced dichroism rho was found to be +0.06, intermediate between the values expected if the nucleosomal disk diameters were parallel (rho expected = -3/8) or perpendicular (rho expected +3/4) to the fiber axis. This result implies an average angle of 51 degrees between the fiber axis and the local DNA (nucleosomal) superhelix axis and rules out many of the simple models which have been proposed for the detailed structure of the 30-nm fiber.

At low salt and high DNA concentration, rodlike DNA molecules form specific aggregates containing about seven parallel DNA molecules packed in a bundle. Bundle formation can be reversed by addition ofsmall amounts of EDTA, and formation of the specific aggregates can be induced at higher salt concentration by addition of trivalent ions. In contrast to monomeric DNA, the aggregated species has the optical anisotropy expected for the B form as observed in fibers.Since the proposal of a double helical structure for DNA (1), xray diffraction from fibers has provided information concerning DNA conformation. As the analysis of this data has progressed in precision and reliability (2-4), producing highly detailed structural models, the relationship ofthe results to the structure of DNA in solution has come increasingly into question.Two recent experimental observations fail to agree precisely with expectation based on the B-form structure of DNA Eisenberg and Tomkins (14). The refractive index-concentration gradient dn/dc was determined by using a Brice-Phoenix differential refractometer, and the value obtained agrees with the result ofVreugdenhil et al. (15). The DNA concentration range was 0.21-0.61 mg/ml in 1.8 mM ionic strength buffer, 20TC.Equilibrium Sedimentation Molecular Weights. These molecular weights were determined by using a Spinco model E analytical ultracentrifuge with multiplexed UV scanning optics. Standard methods (16) The publication costs ofthis article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U. S. C. §1734 solely to indicate this fact.

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