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Biomedical subjects

M Mason

Publications and source records attributed to M Mason.

At least 145 records · Page 8Linked to original sources

Alpha-Aminoadipate aminotransferase and kynurenine aminotransferase. Purification, characterization, and further evidence for identity.

Alpha-Aminoadipate aminotransferase and kynurenine aminotransferase activities were co-purified from the rat kidney supernatant fraction. The resulting preparation was determined to be nearly homogenous by analytical disc gel electrophoresis at pH 8.9 and 7.5 isoelectric focusing on polyacrylamide gels, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A molecular weight of approximately 85,000 was determined on Sephadex G-200 chromatography and sucrose density gradient analysis. The enzyme was determined to be comprised of two subunits of approximately the same molecular weight (45,500 +/- 850) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. An isoelectric pH of 6.56 +/- 0.06 was determined by focusing on polyacrylamide gels. Further evidence is provided to support the idea that the alpha-aminoadipate aminotransferase and kynureine aminotransferase activities are properties of a single protein: (a) co-purification of the two activities from the rat kidney supernatant fraction with the ratio of their specific activities remaining constant, (b) similar chromatographic behavior, (c) a similarity in their dependence on added pyridoxal-P for activity, and (d) a similar pattern of heat inactivation.

2-Aminoadipic Acid↗

The utility of contrast echocardiographic techniques in the care of critically ill infants with cardiac and pulmonary disease.

In order to assess the utility of contrast M-mode echocardiography in an intensive care nursery population of critically ill newborns with cardiac and pulmonary disease and to validate contrast echo methods, we performed 200 serial contrast echoes on 40 infants via umbilical arterial or venous catheters which had been placed into these infants for clinical indications. The resulting contrast echoes recorded from the precordium or the suprasternal notch allowed the delineation of intra- and extracardiac right-to-left and left-to-right shunting patterns. Patterns identified and validated by cardiac catheterization (in cardiac patients) were: right-to-left atrial shunts, right-to-left ventricular shunts, and left-to-right patent ductus arteriosus shunts. The studies were without complication. Serial application of these echocardiographic techniques was extremely important in assessing changing physiology in these neonates. Contrast echocardiography adds physiologic flow information to the anatomical information available from M-mode echoes and is quite important in the diagnosis and sometimes in the management of critically ill newborns.

Arteries↗

Coexistence of rheumatoid arthritis and ankylosing spondylitis--report of 10 cases.

The distinction between rheumatoid arthritis (RA) and ankylosing spondylitis (AS) has hitherto relied on supporting evidence of characteristic radiological changes in the sacroiliac joints, together with the Rose-Waaler and Latex tests for rheumatoid factor (RF). This distinction has remained incomplete since some 30 per cent of patients with RA may have sacroiliitis, a similar proportion having negative routine tests for RF. The identification of the HLA B27 antigen, present in 90 per cent of cases of AS and six per cent of the normal population, has enabled a number of cases to be recognized in which both diseases appear to co-exist. Ten cases are described in which either RA appears to have developed in patients with AS, or AS in patients with RA. They all fulfil the ARA diagnostic criteria for classical RA, and the criteria for classical AS. The likelihood of these two diseases occurring by chance in an individual might be of the order of 1:50,000 to 1:200,000.

Aged↗

Rheumatoid arthritis and ankylosing spondylitis occurring together.

Rheumatoid arthritis and ankylosing spondylitis are often difficult to differentiate, though it is important to do so as the natural history and treatment of the two conditions differ. Nine patients have recently been seen, each of whom fulfilled the criteria for both rheumatoid arthritis and ankylosing spondylitis. In eight of the nine patients the histocompatibility antigen HLA-27 was present. A possible explanation of these cases is that one of the diseases occurred by chance in patients already suffering from the other, but this is extremely unlikely. If a chance association is not the correct explanation the basic concepts defining rheumatoid arthritis and ankylosing spondylitis must be reconsidered.

Adult↗

Visual processing of nonlinguistic strings: redundancy effects and reading ability.

Visual redundancy effects were investigated in two experiments using nonalphabetic material. Experiment 1 had adult subjects search for the presence or absence of a predetermined target symbol through single six-symbol linear arrays. Reaction times were significantly faster in both a distributional redundancy and a spatial redundancy condition than in a no-redundancy condition. Experiment 2 had good and poor sixth-grade readers serve in the no-redundancy and spatial redundancy conditions of Experment 1. Poor readers were equivalent to good readers in the no-redundancy condition but were significantly slower in the spatial redundancy condition. Thus, spatial redundancy was shown to be operative in single symbol search time in a paradigm that avoided confounding by higher order linguistic variables. The present experiments, in conjunction with prior findings that good and poor readers differ in letter search time by their ability to use spatial redundancy, suggest that processes involved in the component skill of letter identification cannot be considered trivial to the reading process.

Adult↗

Development of a rating scale to measure learning in clinical dietetics. II. Pilot test.

When the instrument was pilot tested under actual conditions of a clinical course, it was found practical to use, provided the raters were sufficiently trained and were aware of the logistical problems that might occur. A consensus of both students and raters reaffirmed that the formative properties of the instrument were of value in student counseling, and the rating of students during each clinical session should continue. The objectivity of the instrument also appeared to be sufficient to allow summative grading of students without large differences of opinion within pairs of raters. Measurement of intra-rater reliability was not attempted. The investigators feel that any future study with the instrument should include this analysis. The process of construction and testing reported here appears to be useful in developing a rating scale to measure learning in clinical dietetics.

Dietetics↗

Ketoprofen in rheumatoid arthritis: its tolerance and therapeutic effect.

Four studies on ketoprofen [2-(3 Benzoylphenyl) propionic acid, 19583 R.P., Orudis, Profenid N.D.] have been carried out to establish whether it is well tolerated and effective in the treatment of patients with rheumatoid arthritis. Firstly a comprehensive open clinical and biological monitoring study was undertakin in 11 patients who received ketoprofen for an average period of 20 months without any serious or persistent adverse clinical reaction or adverse change in standard laboratory investigations. The second study involved the same patients who were also included in an ophthalmic screening study for drug toxicity. This established that no eye abnormalities attributable to ketoprofen occurred during this period of treatment. These tolerance studies were then followed by two comparative double-blind cross-over trials of ketoprofen in 117 patients with "definite" rheumatoid arthritis. One of them confirmed the significantly superior analgesic effect compared with placebo and showed that the incidence of adverse reactions was similar. The other trial showed that comparing ketoprofen 150 mg daily and indomethacin 100 mg daily the clinical effects of the two drugs were the same in 8 out of 10 indices. Only in severity of pain and rescue drug count was there a significant difference favouring indomethacin. Adverse reactions were more frequent with indomethacin despite prior exclusion from the study of patients known to be intolerant of indomethacin. It was concluded that on this evidence ketoprofen is a clinically active and well tolerated drug which should be valuable in the management of rheumatoid arthritis.

Adult↗

Effect of ergonovine on prolactin secretion and milk let-down.

The effect of ergonovine maleate on prolactin secretion and lactation was determined in 10 puerperal women. Serum prolactin concentration measured by radioimmunoassay resulted in 537.2 +/- 45.9 ng/ml (M +/- SE) before the oral administration of 0.6 mg ergonovine maleate, and 89.7 +/- 25.6 ng/ml after 7 days of therapy. The serum prolactin concentration seen in the control group of nonlactating women (562.0 +/- 36.1 and 218.0 +/- 27.3 ng/ml) was significantly greater than (P less than 0.01) that seen in the treated group. In 2 additional patients it was also demonstrated that the simultaneous administration of ergonovine by oral and intravenous routes potentiates the suppressive effect on prolactin secretion. Three of the 10 treated women showed progressive inhibition of lactation. This study shows that ergonovine maleate interferes with prolactin secretion, and may decrease milk production.

Administration, Oral↗

[Secretion of prolactin in normal anencephalic newborn infants].

Serum prolactin (PRL) was measured by radioimmunoassay in pregnant women at term and in newborns. In 38 newborns of gestational age 39--40 weeks, concentration of PRL in umbilical venous blood was 280.8 +/- 11.2 ng/ml; in maternal venous blood, concentration of PRL was 347.0 +/- 20.1 ng/ml. In the newborn it was found a significant difference in PRL values between both sexes (p less than 0.05), being higher in males than in females (290.0 +/- 14.6 vs. 260.0 +/- 17.1 ng/ml). In three anencephalic infants, PRL ranged from 92.6 to 369.0 ng/ml; 400 mug of thyrotropin-releasing hormone (TRH) administered as bolus injection evoked a rise in PRL in two out of the three, while synthetic luteinizing hormone releasing hormone (LH-RH) elicited no response of FSH secretion. These observations in the fetus and anencephalic infants confirm that the fetus produces high levels of PRL and that this function is independent of any hypothalamic control. The high levels of gestational estrogens seem to be the direct stimulus on the lactotropes to induce synthesis and secretion of PRL. The role of PRL during gestation has not been elucidated.

Anencephaly↗

Autoantibodies in childhood connective tissue diseases and in normal children.

The prevalence of nine serum autoantibodies has been studied in 117 children with various connective tissue disorders and in 134 normal controls. In juvenile rheumatoid arthritis rheumatoid factor was present in 5%, and antinuclear factor in 4%, compared with an incidence of 4% and 0% respectively in controls. In Henoch-Schönlein purpura there was little evidence of associated autoimmune disorder. Gastric parietal cell and thyroid microsomal antibodies were found in 9% and 10% of our control population, but the significance of this is not clear. It is concluded that in children the presence or absence of autoantibodies as diagnostic criteria should be interpreted with the greatest caution.

Adolescent↗

Clinical trails.

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Clinical Trials as Topic↗

Sodium in four canned vegetables. Effect of rinsing and heating in water.

Low-sodium canned vegetables are required for severely restricted sodium diets, but on the milder sodium-restricted diets, adjustments could be made on an individual patient basis to include specially treated regular canned vegetables. This investigation was planned to compare the sodium content of regular canned vegetables as processed with same canned vegetables when rinsed and heated in tap water. The study was also designed to compare the consistency of sodium content in canned vegetables between and within brands. Knowledge of the actual sodium content of regular canned vegetables will permit greater use of these foods on modified-sodium diets.

Cooking↗