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J Sweetland

Publications and source records attributed to J Sweetland.

7 recordsLinked to original sources
PubMed1987

The effect of magnetic resonance imaging on human cognition.

Potential effects of MRI exposure on aspects of human cognition were investigated out of concern that possible safety hazards associated with the procedure may exist. One hundred and fifty-seven volunteer subjects were randomly assigned to either an imaged, sham-imaged or nonimaged control condition. The following psychological tests were administered in a double blind procedure at pretreatment, post-treatment and follow-up time periods: the Wechsler Adult Intelligence Scale-Revised (Digit Span, Block Design and Digit Symbol), the Wechsler Memory Scale Paired Associate Learning test, the Benton Revised Visual Retention test, the Vandenberg Mental Rotation test, the Sternberg memory scanning paradigm and the State Anxiety Inventory. The overall analysis of results indicated that MRI at 0.15 T has no significant effect upon the cognitive functions assessed.

Adolescent↗
PubMed1979

Labeling of complex III, with [35S]diazobenzenesulfonate: orientation of this electron transfer segment in the mitochondrial inner membrane.

[34S]Diazobenzenesulfonate has been used to tag the surface-exposed polypeptides of isolated complex III. All nine different component polypeptides were labeled, indicating that each is at least partially exposed on the surface of the isolated, detergent-dispersed complex. Labeling studies were also conducted on the membrane-bound complex. Preparations of intact mitochondria and submitochondrial particles were separately labeled with [35S]diazobenzenesulfonate in order to determine the distribution of the polypeptides of complex III between the outer (cytoplasmic) and inner (matrix) surfaces of the mitochondrial inner membrane, respectively. Polypeptides II and III were the only components labeled in a significant amount in submitochondrial particles (i.e., from the matrix side). Polypeptides III, IV, and VI were heavily labeled in mitochondria (i.e., from the cytoplasmic side). Polypeptides I,II, V, and VII were also labeled in mitochondria but to a much lesser extent. Polypeptides VIII and IX were not significantly labeled from either side of the membrane. The labeling data and information obtained from previous crosslinking studies [Smith, R.J. & Capaldi, R.A. (1977) Biochemistry 16, 2629-2633] are used to derive a picture of the arrangement of complex III in the mitochondrial inner membrane.

Animals↗
PubMed1977

Polypeptides in the succinate-coenzyme Q reductase segment of the respiratory chain.

Complex II (succinate-coenzyme Q reductase) was resolved into ten different polypeptides by polyacrylamide gel electrophoresis. Four polypeptides, CII-1, CII-2, CII-3, and CII-4 with molecular weights of 70 000, 24 000, 13 500, and 7000, were present in large amounts in all preparations examined. CII-1 and CII-2 are the flavoprotein and iron-sulfur protein, respectively, of succinate dehydrogenase; CII-3 and CII-4 have not been functionally indentified. Six polypeptides were present in much smaller amoumts as judged by staining intensity, and each of these comigrated with components in complex III. The amino acid compositions of several of the minor components in complex II were identical with that of an equivalently migrating polypeptide in complex III. We conclude that succinate-coenzyme Q reductase contains four different polypeptides and is contaminated with variable amounts of complex III when isolated as complex II.

Amino Acids↗
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Consumer Behavior↗