Linking perceptions of the community to behavior: are protective social factors associated with physical activity?

Although the relationship of psychosocial factors to physical activity has been explored, there is increased interest in how perceptions of the community environment influence behavior. However, few methodological studies have incorporated perceptions of the social and community environment (protective social factors) or addressed key measurement issues. Computer-assisted telephone interviews were administered to a national sample of 1,818 U.S. adults. Unadjusted and multivariate-adjusted odds ratios were calculated to compare active and inactive participants by Protective Social Factors (PSF) scores and selected sociodemographics. Confirmatory factor analysis and reliability analysis suggested strong PSF scale psychometric properties (alpha = .92). After adjustment for potential confounders, a 10-point rise in the PSF score resulted in a 12% increased likelihood of meeting Centers for Disease Control and Prevention/American College of Sports Medicine recommendations. Additional analyses indicated that greater perceived PSFs were associated with meeting these recommendations among Whites but not among African Americans.     

Effects of hypnosis on the features of multiple personality disorder

The authors compared 57 patients with multiple personality disorder (MPD) who had been hypnotized both before and after diagnosis to 38 patients who had not been hypnotized during assessment or treatment. The two groups did not differ on the diagnostic criteria for MPD or in number of personalities. Hypnosis therefore does not have a gross distorting effect on the features of the disorder. Hypnosis may, however, affect the recall of sexual and physical abuse and the manifestation of certain types of alter personality. These include child personalities, personalities of different age, sex, or race, and protectors. The authors hypothesize that the hypnotized group may require hypnosis for access of more traumatic memories held by child personalities.     

25-Hydroxyvitamin D3 metabolism in a human leukemia cell line

Summary 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) is a potent inducer of monocytic differentiation of the human promyelocytic leukemia cell line, HL-60. We have noted that 25-hydroxyvitamin D₃ (25(OH)D₃) in high doses is also capable of promoting monocytic differentiation of this cell line. To test the possibility that the latter activity is due to conversion of 25OHD₃ to 1,25(OH)₂D₃ by HL-60, we exposed HL-60 cells to 25OHD₃ and analyzed the products by HPLC and radioreceptor assay. When chromatographed in the traditional solvent system (isopropanol-hexane), a new peak appears which migrates with authentic 1,25(OH)₂D₃. However, in a solvent system containing dichloromethane, 90% of the peak migrates with another metabolite, 19-Nor-10-Keto-25OHD₃ (19-Nor-25OHD₃). Production of this metabolite is enhanced by living cells and is synthesized by both virgin HL-60 and those which have undergone differentiation. We next determined if authentic 19-Nor-25OHD₃ also promotes differentiation of this cell. As assessed by appearance of the monocyte-specific surface antigen (63D3) and macrophage-specific esterase activity, we find that this metabolite does, in fact, induce monocytic differentiation of HL-60 with a potency of approximately 1/200 that of 1,25(OH)₂D₃ and similar to that of 25OHD₃. In agreement with the effect upon cell maturation, 19-Nor-25OHD₃ displaces³H-1,25(OH)₂D₃ from its HL-60 receptor with an efficiency comparable to 25OHD₃. Hence, HL-60 cells convert 25OHD₃ to 19-Nor-25OHD₃, and 19-Nor-25OHD₃ induces monocytic differentiation of HL-60 with comparable efficiency to its precursor, 25OHD₃.     

Dissociated loss of vibration, joint position and discriminatory tactile senses in disease of spinal cord and brain

The clinical functions of the posterior columns of the spinal cord and the signs of disease of these structures have been debated for years. Todd in 1847 and Schiff in 1858 knew the functions of the posterior columns and 10 years later Brown-Séquard knew as well. Reynolds, Romberg, and Duchenne, each described a posterior column syndrome based on a disease in which the primary lesion was not in the posterior columns. In the last 150 years almost every white matter structure of the cord has been credited with serving the sensations that we now know are a function of the posterior columns. Vibration, joint position and movement as well as discriminatory touch each seem to be served by separate fibres of the posterior columns and medial lemniscus. There is evidence of this in cat and man. These sensations may be lost individually, totally, or in certain stereotyped combinations. Vibration or joint sense is commonly lost alone. When a discriminatory touch sensation is lost with one other sense, it is almost inevitably joint position sense. Absent discriminatory touch and vibration sense with normal joint position sense appears to be unknown. This functional separation continues into the thalamus. At the highest level there is no evidence that vibration sense has any conscious somatosensory cortical affiliation, while joint position and discriminatory touch senses definitely do.