Biomedical subjects
D Hughes
Publications and source records attributed to D Hughes.
Prognostic value of a persistently positive technetium-99m stannous pyrophosphate myocardial scintigram after myocardial infarction.
Technetium-99m stannous pyrophosphate myocardial scintigrams were obtained in 138 clinically stable patients 32.7 +/- 47.3 weeks (range 6 to 260) after acute myocardial infarction. Of the 138 patients, 74 (54 percent) had a persistently positive scintigram. Patients with such a scintigram were more likely to have severe angina pectoris, compensated congestive heart failure, anterior location of acute myocardial infarction, Q waves and S-T segment elevation in the electrocardiograms, cardiomegaly, left ventricular dyssynergy (dyskinesia or global dyssynergy), and an ejection fraction of less than 50 percent. During a follow-up period of 11.6 +/- 6.9 months after scintigraphy, 42 percent of the patients with a persistently positive scintigram had either a cardiac death, a nonfatal myocardial infarction, unstable angina pectoris or decompensated congestive heart failure compared with 13 percent of the patients with a negative scintigram (P less than 0.001). Of the 14 patients with cardiac death, 13 (93 percent) had a persistently positive scintigram. A persistently positive scintigram not only was the best single predictor of cardiac death and combined end points, but also added significantly to the predictive ability of the other clinical variables, including age, location of acute myocardial infarct, clinical status, electrocardiographic findings, and chest X-ray findings. It is concluded that technetium-99m stannous pyrophosphate myocardial scintigraphy has prognostic value in patients after acute myocardial infarction.
Multiple sclerosis-associated agent. Failure of MS brain and serum to depress the polymorph count in normal mice and mice inoculated with cells containing C/type particles.
The groups that originally reported and confirmed the demonstration of a multiple sclerosis associated agent (MSAA) are now, along with others, unable to reproduce this effect. In view of this confusion and the potential importance of this work for multiple sclerosis (MS) we have done a strict double-blind trial using larger groups of mice (10) and counting more cells (900) than in previous reports to offset the high variability of mouse polymorphonuclear neutrophil (PMN) counts. Sera from 5 active MS patients and 4 normal subjects were tested in mice, half of which had previously been injected with PAM line cells (containing C-type particles and subject to reduced cell yield when cultured with MS brain extract). No significant PMN depression was found in either MS or normals on any basis of comparison. However, a significant depression was seen following PAM cell injection irrespective of serum origin. Higher counting accuracy did not reduce PMN variability. A single MS brain specimen was also without effect. consequently we have been unable to confirm the existence of an MSAA as defined by PMN depression in mice.
Isolation of Yersinia enterocolitica from milk and a dairy farm in Australia.
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Effect of prazosin vs placebo on chronic left ventricular heart failure.
The effect of the vasodilator prazosin vs placebo on exercise duration until marked dyspnea, and on left ventricular function measured by echocardiography, was evaluated in a double-blind, randomized study in 24 patients with chronic left ventricular failure despite digitalis and diuretic therapy. Compared with the double-blind placebo, prazosin reduced resting systolic and diastolic blood pressure and systolic blood pressure times heart rate, improved clinical symptoms, decreased cardiothoracic ratio measured by chest roentgenography, decreased left ventricular and left atrial dimensions, improved ejection fraction and Vcf measured by echocardiography, and improved treadmill exercise duration. All 12 patients taking prazosin had greater than or equal to 20% improved treadmill exercise duration; none of 12 receiving placebo improved. In six of 12 patients taking prazosin, roentgenographic evidence of pulmonary venous congestion disappeared compared with none of the patients on placebo. These data suggest that prazosin may be effective in treating chronic left ventricular failure.
Effect of tamoxifen pre-treatment on the retention of tritiated oestradiol and 5alpha-dihydrotestosterone and on glucose metabolism in human breast carcinomas.
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Comparison of trimazosin and methyldopa in hypertension.
Eighteen patients with hypertension participated in a double-blind, randomized study to evaluate the effect of trimazosin, methyldopa, and placebo on supine and standing blood pressure and heart rate. Of 6 patients on methyldopa, one developed drug fever (and was dropped from the study) and one developed impotence. None of 6 patients on trimazosin and none of 6 patients on placebo developed any adverse effects. The mean supine blood pressure on 900 mg trimazosin daily was 17.0/12.8 mm Hg lower than that on the first placebo trial (p less than 0.01) and 17.0/12.1 mm Hg lower than that on the second placebo trial (p less than 0.01). The mean supine blood pressure on 2,250 mg methyldopa daily was 17.8/12.4 mm Hg lower than that on the first placebo trial (p less than 0.01) and 16.8/13.0 mm Hg lower than that on the second placebo trial (p less than 0.01). The mean supine blood pressure was not significantly affected by placebo. Trimazosin, 900 mg daily, and methyldopa, 2,250 mg daily, were equally effective in lowering supine and standing systolic and diastolic blood pressure and did not affect supine or standing heart rate.
Experimental allergic encephalomyelitis in the guinea pig. Failure to suppress with crude human chorionic gonadotrophin.
A single intraperitoneal dose of 3000 IU of crude human chorionic gonadotrophin (HCG), of proven in vitro immunosuppressive activity, gave only marginal effect on the clinical and histopathological course of experimental allergic encephalomyelitis (EAE) in guinea pigs, which did not reach statistical significance. Treatment 7 and 11 days after immunization significantly reduced the Mantoux reaction concomitant with decreased perivascular inflammation, but with unaltered or (when treated at onset) slightly enhanced clinical disease, with in vitro lymphocyte reactivity increased in accord. Much earlier treatment gave the opposite effect of a marginal improvement. HCG in vitro immunosuppressive potency was dependent on its concentration, intensity of immune response and sequence of addition. While the action of HCG on EAE does not point to an effective therapy for multiple sclerosis, as suggested by the influence of pregnancy on this disease, non-HCG fractions of urine during pregnancy may yet contain highly efficacious immunosuppressants.
Chemoprophylaxis in chronic bronchitis.
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Comfortable effort level: an experimental variable.
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Letter: Containment of unsealed sources of radionuclides in hospitals.
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The effect of clomipramine on prolactin levels--pilot studies.
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Letter: Immunosuppression by linoleic acid.
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Specific inhibitory action of polyunsaturated fatty acids on lymphocyte transformation induced by PHA and PPD.
Both saturated (SFA) and unsaturated fatty acids (UFS) inhibited PHA- and PPD-induced lymphocyte transformation. The degree of inhibition varied with the nature of the fatty acid (FA) and further comparison with their effect on unstimulated lymphocyte cultures suggests a specific action of polyunsaturated fatty acid (PUFA) on the lymphocyte PHA- and -PPD interaction. These findings are briefly discussed in the light of similar observations with PUFA-derived prostaglandins.
Stimulation of the vestibular receptor by means of step temperature changes during continuous aural irrigation.
A technique for rapid, balanced hot/cold stimulation of the vestibular receptor is presented. During continuous aural irrigation the temperature of the irrigation fluid is switched between hot and cold values at times computed according to a mathematical model of heat conduction in the labyrinth area. As a result, the induced temperature difference across the lateral semicircular canal describes an approximately sinusoidal time course, reaching peak values of equal magnitude but opposite sign. Application of the test to 32 clinical subjects demonstrated that the heat conduction model and the analysis used in timing the sequence of thermal pulses was accurate. We expect that, with further refinements, the new technique will prove superior to conventional caloric test methods in the detection and measurement of subtle as well as gross abnormalities of the vestibular system.