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Biomedical subjects

M Burns

Publications and source records attributed to M Burns.

At least 55 records · Page 3Linked to original sources
PubMed1988

The effects on performance of two antidepressants, alone and in combination with diazepam.

1. Ninety healthy adult men participated in a study of the effects on performance of 60 mg fluoxetine, 50 mg amitriptyline or placebo, alone and in combination with 5 mg diazepam or placebo. 2. In a 2X3 factorial design study, groups of 15 Ss received one of six possible treatment combinations. 3. Ss were tested with a battery of laboratory tests at two post-dosing times. 4. Amitriptyline impaired the performance of all tasks. When diazepam was added to the amitriptyline treatment, the impairment of three tasks increased. Diazepam alone produced impairment on two measures. 5. Fluoxetine alone impaired no task; some impairment occurred with the fluoxetine-diazepam combination.

Adult↗
PubMed1986

Acanthamoeba sclerokeratitis. Determining diagnostic criteria.

Acanthamoeba infection of the cornea is an entity now recognized with increasing frequency. We saw two cases of Acanthamoeba sclerokeratitis in contact lens wearers in whom scleritis (anterior and posterior) played a central role in the clinical course of the disease. Scleritis is probably a more common component of Acanthamoeba infection than has generally been acknowledged. Posterior scleritis has not, to our knowledge, been reported previously in this disorder. The clinical diagnosis of Acanthamoeba infection has often been missed due to lack of a definition of the historical and clinical criteria by which this disease is characterized. We reviewed the 26 previously reported cases and suggest a set of criteria that can be used to establish an early diagnosis. Historical criteria include minor corneal trauma, exposure to soil or standing water, or contact lens wear. Clinical characteristics include severe pain, infiltrative (often ring-shaped) stromal keratitis, variable anterior uveitis, epithelial erosion, scleritis, standard bacterial culture negativity, chronicity, and lack of response to antimicrobial agents.

Adolescent↗
PubMed1986

Technical consideration in management of renovascular hypertension in an infant with double renal arteries.

Renovascular hypertension is a curable disease that has recently been recognized with increasing frequency. A renal scan in a 1-month-old hypertensive white male showed diminished function of the right kidney, and his peripheral vein renin was elevated. Multiple antihypertensive medications failed to control his hypertension, and right kidney function deteriorated. An arteriogram showed two stenotic renal arteries supplying the right kidney. The smaller inferior artery supplied 35% of the kidney. Selective vein renin levels were greater than 15,000 ng/dL on the right side. Technical considerations in the repair of this lesion included midline transabdominal incision to expose the abdominal aorta and the inferior vena cava; dissection of inferior vena cava (IVC) with division of selected lumbar veins; full mobilization of right kidney and transsection of both renal arteries and the renal vein; perfusion of kidney via each renal artery with cold Sach's solution after resection of arterial stenoses; end-to-side microvascular anastomosis of the smaller (2 mm) renal artery to the main renal artery at the hilum with 10-0 nylon over in situ perfusion cannula; renal artery passed under the IVC to the aorta; and right kidney autotransplanted to a new site on the abdominal aorta with an end-to-side (5.0 mm) renal artery to the aorta and an end-to-side renal vein to IVC anastomosis. Following revascularization, perfusion was excellent and the blood pressure returned to normal. At 6 months follow-up, selective renal vein renins were normal and an arteriogram showed no stenosis. Meticulous dissection, cold perfusion, microvascular anastomosis, and autotransplantation salvaged this kidney and resolved the hypertension.

Humans↗
PubMed1986

Pursed lips breathing training using ear oximetry.

Pursed lips breathing (PLB) training is often used in the management of patients with chronic obstructive lung disease (COLD). Previous clinical studies have demonstrated that PLB improves arterial oxygen saturation (SaO2) and CO2 removal as well as relieving dyspnea. Twelve hypoxemic subjects with stable COLD were randomly assigned to either the pursed lips (P) or control group consisting of general relaxation (R). The SaO2 was monitored via ear oximetry, and respiratory rate and tidal volume were monitored using a strain gage transducer and the minute volume was calculated. The PLB was taught by an experienced instructor using the ear oximeter as a monitoring display with a goal toward increasing SaO2. The subject was taught general relaxation (Rlx) with the aid of pleasant music. We compared PLB and Rlx treatments using an A-B-A crossover study design. In both groups, PLB significantly improved SaO2 over baseline (p less than 0.001) whereas Rlx did not. We conclude that patients can learn to increase their SaO2 by PLB using ear oximetry adjunctively.

Aged↗
PubMed1986

A comparison of the effects of trazodone and amitriptyline on skills performance by geriatric subjects.

Fifteen healthy adults, aged 60 years and older, participated in a double-blind, crossover study of trazodone in comparison with amitriptyline and placebo. A battery of laboratory tests was used to measure drug effects on information processing, attention, and visual-motor skills. Amitriptyline 50 mg impaired vigilance and tracking performance and increased drowsiness. Trazodone 100 mg impaired only the most difficult tracking task. This study demonstrates that cognition and performance are less adversely affected in geriatric subjects by trazodone than by amitriptyline beginning 90 minutes after a single-dosage trial.

Administration, Oral↗
PubMed1985

Positive direct antiglobulin test associated with hyperglobulinemia in acquired immunodeficiency syndrome (AIDS).

This study determined the prevalence and clinical significance of a positive direct antiglobulin test (DAT) observed in pretransfusion tests on red cells from patients with acquired immunodeficiency syndrome (AIDS). Transfusion service records showed that prevalence of a positive DAT on red cells was 18% (10/55) in AIDS patients compared to 0.6% in general hospital patients during a 2-year period (1981-1983). A similar rate of 18% (8/45) was observed in other hyperglobulinemic patients. Of the 10 AIDS patients whose red cells were DAT positive, four had IgG and complement, four had IgG, and two had complement alone on their red cells. The eluates were not reactive with normal red cells nor with penicillin or cephalothin-coated red cells. Clinically, no hemolysis was observed. In this series a positive DAT in AIDS patients appeared not to be associated with autoimmune hemolytic anemia. The positive DAT in AIDS patients may be due to the hyperglobulinemic state.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Dual mechanism of inhibition of rat liver uroporphyrinogen decarboxylase activity by ferrous iron: its potential role in the genesis of porphyria cutanea tarda.

Hepatic iron overload amplifies the uroporphyrinogen decarboxylase enzyme defect in human porphyria cutanea tarda. To understand its mechanism, we studied the effects of iron on the enzyme activity from rat liver cytosol. Enzyme activity was inhibited about 50% by 0.10 mM Fe2+ or by 0.16 mM Zn2+ directly regardless of whether the cations were added immediately, or were first preincubated for 2 h at 37 degrees C in the absence or presence of oxygen. Cysteine (6.7 mM) protected the enzyme from inhibition by Fe2+ under strictly anaerobic preincubation conditions; cysteine also protected enzyme inhibition by Zn2+ even in the presence of oxygen. Under aerobic conditions, cysteine enhanced the inhibition by Fe2+ to about 70%. This additional 20% inhibition was reversed by vitamin E, an antioxidant. The results suggest dual inhibitory effects of iron (a) by direct interaction of Fe2+, as well as Zn2+, with the essential sulfhydryl group(s) of the enzyme and (b), indirectly, due to generation of free radicals in the presence of oxygen and an electron donor such as cysteine. These radicals might interact directly with the enzyme and/or oxidize the porphyrinogen substrates to nonmetabolizable porphyrins, which accumulate in porphyric patients.

Aerobiosis↗
PubMed1980

Effects of diphenhydramine and alcohol on skills performance.

Twelve men were subjects in a repeated measures experiment on the effects on performance of diphenhydramine, alcohol, and diphenhydramine and alcohol in combination. Behavioral measures included compensatory tracking, a divided attention task, information processing rate, and critical tracking. Performance impairment occurred under all treatments with an additive effect under the combined drug-alcohol treatment.

Adult↗