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Biomedical subjects

D J Cox

Publications and source records attributed to D J Cox.

At least 109 records · Page 6Linked to original sources
PubMed1985

Physical properties of chicken erythrocyte HMG-1, HMG-2 and HMG-E.

HMG-1, HMG-2 and HMG-E were purified from chicken erythrocyte chromatin without exposure to overt denaturing conditions and subjected to several types of physical measurement. The principal conclusions drawn from the measurements were: none of the proteins has a strong tendency to self-associate, although HMG-1 does weakly self-associate; the frictional properties of HMG-1 and HMG-E (and probably HMG-2) indicate that the proteins deviate significantly from compact, moderately hydrated spheres; and each of the proteins contains approximately 40% helix and little if any beta-pleated sheet.

Animals↗
PubMed1985

Measures of knowledge and attitude toward preventive cardiology.

In this paper, the authors describe the development and validation of an inventory of preventive cardiology at the University of Virginia. The inventory contains two instruments designed to measure medical students' preinstructional and postinstructional knowledge of and attitude toward preventive cardiology. The knowledge test subscales provide unique and significant information about knowledge in preventive cardiology and can discriminate among groups differing in level of instruction and expertise in preventive cardiology. The attitude survey provides information about two attitude factors: cardiovascular disease prevention and cardiovascular disease research priorities. In the study reported here, attitudes appeared not to differ among groups of students with different preventive cardiology instructional levels and expertise. Both instruments were demonstrated to be useful measures of medical students' knowledge and attitudes concerning preventive cardiology educational programs.

Adult↗
PubMed1984

The relationship between psychological stress and insulin-dependent diabetic blood glucose control: preliminary investigations.

Clinical literature has frequently alluded to the role of psychological stress in diabetic blood glucose fluctuations. Past research in the area has been minimal and inconsistent. Recent methodological and measurement advances have made it possible to more accurately assess the impact of psychological stress on long-term diabetic control. Study 1 of this report found a significant positive correlation between the Hassles Scale and Hemoglobin A1 levels in a group of 59 adult insulin-dependent diabetic patients. Social Supports, Type A behavior, and reported therapeutic compliance neither correlated with hemoglobin A1 nor influenced the Hassles-Hemoglobin A1 relationship. In a separate sample of 123 subjects, Study II revealed that diabetic patients generally perceive stress as a very potent factor in blood glucose control, but that different stressors may have differential effects for different diabetic patients. A factor analysis of these data reveals three different stress dimensions of the perceived stress-blood glucose relationship: fight/flight, passive/ruminative, and positive affect.

Adolescent↗
PubMed1984

Ultrasound in the localisation of bladder tumours for radiotherapy treatment planning.

Radiation treatment fields have been established in 40 patients with carcinoma of the urinary bladder using a technique based on B-scan measurements of tumour dimensions and position. Three-dimensional data were obtained using omnidirectional calipers and the in-built measuring system of the scanner gantry, and by measurement from the recorded images. All measurements of the tumour dimensions and co-ordinates of the tumour centre were related to a fixed patient reference point. The ultrasound measurements were superimposed on to the AP and lateral planning radiographs after multiplication by the appropriate magnification factor. Ultrasound tomograms provided accurate data for radiotherapy planning and offer a convenient method for monitoring the response to treatment on follow-up.

Humans↗
PubMed1983

Menstrual symptoms in college students: a controlled study.

Thirty-five male and thirty-five female subjects completed daily a checklist consisting of 15 symptoms commonly associated with menstrual distress. Premenstrual, menstrual, and midcycle days' ratings were compared within and across groups. Males and females did not differ in symptom ratings during the premenstrual and midcycle periods. Females reported experiencing more sharp cramps, dull cramps, stomach pain, and bloating during the menstrual period. Females reported these symptoms to be only modestly distressing.

Adult↗
PubMed1983

Reliability of symptom-blood glucose relationships among insulin-dependent adult diabetics.

Symptoms and blood glucose levels were recorded by 23 insulin-dependent diabetics during three separate intervals. Each interval spanned 7-10 days, involving 40 symptom-blood glucose recordings. Each symptom's ratings were correlated with their respective blood glucose recording to yield a separate symptom-blood glucose correlation for each interval. These separate symptom-blood glucose relationships were themselves correlated across the three intervals to assess the temporal stability of the symptom-blood glucose relationships. Reliability was found to be variable. Possible explanations for this variability are discussed.

Adolescent↗
PubMed1981

Purification and characterization of the entomocidal protoxin of Bacillus thuringiensis.

A procedure for purifying the insecticidal parasporal protoxin of Bacillus thuringiensis and a description of its biochemical and biophysical properties is provided. Mild alkali titration was necessary to generate a functional protoxin in a soluble form, and anion-exchange chromatography was used to remove contaminating cytoplasmic proteases that are nonspecifically bound to whole native parasporal crystals. Polyacrylamide gel electrophoresis, gel filtration chromatography, and meniscus depletion sedimentation equilibrium analysis revealed an apparent molecular weight for the protoxin of 1.34 x 10(5). The only NH2-terminal residue found was methionine. The soluble protoxin was 2.5 times more toxic to insect larvae than was the parasporal crystal. At alkaline pH the protoxin slowly converted to a low molecular weight toxin (apparent Mr = 6.8 x 10(4)). The molar specific toxicities of the protoxin and toxin were identical.

Amino Acid Sequence↗
PubMed1981

Physical symptoms related to blood glucose in insulin-dependent diabetics.

Thirty hospitalized diabetics completed symptom checklists immediately prior to monitoring their own blood glucose level seven times a day for 6--10 days. For each subject, simple correlations were computed between each of the physical symptoms and blood glucose level. Most subjects evidenced several symptoms that were highly correlated with glucose fluctuations. Further, the symptoms that were related to glucose differed from subject to subject. The symptom-glucose correlations were reliable and unrelated to sex, age, duration of diabetes, and other individual difference variables. The findings point to a technique wherein patients can learn to perceive physical sensations indicative of changes in blood glucose in natural settings.

Adolescent↗
PubMed1980

Chromatographic change in histone H3-H4 preparations during short term storage and its reversal by bisulfite.

Chicken erythrocyte histone H3-H4 preparations stored at 4 degrees in 50 mM sodium acetate (pH 5.0) exhibit altered gel chromatographic properties that are detectable within 2 days. After 5-7 days, material with chromatographic properties of the H3-H4 tetramer is absent, but the H3 and H4 polypeptides are intact, as judged by gel electrophoresis. The change in chromatographic properties results from an oxidation reaction: The change is accelerated by bubbling oxygen through H3-H4 preparations, and it is reversed by exposure to dithiothreitol. Because chicken erythrocyte H3 contains a single cysteine residue the oxidation reaction is intermolecular disulfide bond formation between H3 molecules. High molecular weight aggregates formed by the H3 dimers and some histone H4 probably are the same aggregates observed but unexplained by other workers. The H3-H4 tetramer can be regenerated by exposure of aged preparations to bisulfite, presumably as a result of cleavage of disulfide bonds and formation of S-sulfonated H3.

Animals↗
PubMed1978

Behavioral treatment parameters with primary dysmenorrhea.

Fourteen women with primary dysmenorrhea were administered four sessions of systematic desensitization (SD) by either a male or a female therapist. The following measures were taken during the flow periods before and after treatment and at a 6-month follow-up: menstrual symptom checklist, medication usage, invalid hours, and menstrual attitudes. At pretreatment, menstrually distressed women had significantly higher scores on all measures compared to a normative group and an explicitly nondistressed group. At posttreatment, treated women's scores on the dependent variables were significantly reduced. All indices were reduced to a "nondistressed level" at posttreatment and at 6-month follow-up. Type of dysmenorrhea (congestive vs. spasmodic), trait anxiety level, and therepist sex did not predict differential responsiveness to SD. SD did not affect frontailis EMG, peripheral blood flow, or pain threshold. A Retrospective Symptom Scale of menstrual distress was found to be highly reliable, valid, and sensitive.

Adolescent↗
PubMed1978

Isoelectric focusing of a dimerizing solute in rapid chemical equilibrium: comparison of simulation procedures.

The approach to isoelectric focusing equilibrium of a rapidly dimerizing solute was simulated by two different computing procedures: a stationary-grid model developed by Cann and Stimpson and a distorted-grid technique derived from the method of Cox. The results given by the two models were virtually identical at all times during the approach to equilibrium. Of the two procedures, the distorted-grid method has an advantage in computing time, while the stationary-grid model is applicable to a broader range of transport experiments. The effect on the focusing experiment of varying the electric field was examined by distorted-grid simulations. When the field was increased, the equilibrium distribution sharpened somewhat and the peak of the concentration profile shifted toward the isoelectric position of the dimer. The rate of approach to equilibrium was approximately proportional to the field strength.

Isoelectric Focusing↗