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Biomedical subjects

D Walsh

Publications and source records attributed to D Walsh.

At least 235 records · Page 13Linked to original sources
PubMed1990

Effect of fructose 1,6-diphosphate infusion on the hormonal response to exercise.

Exogenous fructose 1,6-diphosphate (FDP), a glycolytic intermediate, has recently been demonstrated to accelerate ATP production, prevent glycogen breakdown, stimulate glycogen synthesis, and synthesize free fatty acids in animals and humans. To assess the effects of FDP on the hormonal and metabolic response to exercise, ten trained males (34 +/- 7 yr) underwent 1 h of continuous exercise at 70% VO2max followed by 20 W.min-1 increments to exhaustion. Two hundred fifty mg.kg-1 body weight FDP or placebo was infused in randomized, double-blind, crossover fashion. No differences were observed in heart rate, blood pressure, gas exchange data, perceived effort, or glucose, insulin, free fatty acid, lactate, beta-hydroxybutyrate, glycerol, and glucagon concentration at rest, during exercise, or upon exhaustion. In contrast to the previously reported bioenergetic effects of FDP under conditions in which glycolysis is impeded (acidosis, hypoxia, and ischemia), FDP did not affect the gas exchange, hormonal, or substrate response to moderately high intensity exercise in healthy normals.

Adult↗
PubMed1989

Optimal sampling interval to estimate heart rate at rest and during exercise in atrial fibrillation.

To investigate the ideal sampling interval for the estimation of heart rate (HR) at rest and during exercise in atrial fibrillation (AF), maximal exercise testing with continuous electrocardiographic acquisition was performed in 10 patients with chronic AF (mean age 66 +/- 4 years) and 10 subjects in normal sinus rhythm (mean age 31 +/- 6 years). Measurements of HR were obtained at 9 different sampling intervals (1, 2, 3, 6, 10, 15, 20, 30 and 60 seconds) at rest and 7 different sampling intervals (1, 2, 3, 6, 10, 15 and 20 seconds) during the last 30 seconds of each minute during exercise. The HR obtained from each interval was compared with true HR (determined by a 4-minute sample at rest and by the last 30 seconds of each minute during exercise). Among patients with AF, large differences were observed between the HR obtained and true HR, both at rest and during exercise, using small sampling intervals. The mean of these differences ranged between 16 +/- 11 beats/min (range 14 to 22) using 1-second sampling intervals and 2.2 +/- 2.0 beats/min (range 1.6 to 4.4) using 20-second sampling intervals during progressive exercise. Variability of the HR obtained from a given random sample was also high when short sampling intervals were used among patients with AF. These observations were contrasted by subjects in normal sinus rhythm, among whom neither variability nor measurement error were influenced remarkably by changing the sampling interval or increasing HR.

Adult↗
PubMed1989

Topical dimethylsulfoxide may prevent tissue damage from anthracycline extravasation.

The optimal management of anthracycline extravasation remains unclear. Traditional topical measures to reduce local tissue damage, including corticosteroids, sodium bicarbonate, and ice applications, have not consistently demonstrated beneficial effects. This report describes our experience with four adult patients who suffered anthracycline extravasation and were treated with a regimen of ice, local glucocorticoid injection, and dimethylsulfoxide (DMSO) 55%-99% applied topically every 2-4 h after extravasation for a minimum of 3 days. In all four cases, pain and erythema resolved within 2 days; in no case did tissue necrosis or skin ulceration occur. Topical DMSO is a safe, inexpensive agent that appears to reduce the risk of anthracycline-induced tissue damage. Further studies are needed to determine the optimal dose and schedule of DMSO application and to assess its efficacy in extravasation injuries from other vesicants.

Administration, Topical↗
PubMed1989

Reperfusion arrhythmia: myth or reality?

Early reports of "reperfusion arrhythmia" after experimental temporary coronary occlusion raised concern that these arrhythmias, particularly ventricular fibrillation and ventricular tachycardia, might occur in association with reperfusion of an occluded coronary vessel during thrombolysis. Such an occurrence could increase the risk of transfer of such patients. To provide a more definitive answer to this question, we reviewed hospital and transfer records for all patients with acute myocardial infarction transferred by our critical care transfer service between January 1, 1985, and November 30, 1987, noting the occurrence of five types of arrhythmia: ventricular fibrillation, ventricular tachycardia, premature ventricular contractions, bradycardia, and atrioventricular block, both before and during transfer. Five hundred patients with acute myocardial infarction less than 48 hours old were transferred during this period. Two hundred twenty-five patients received thrombolytic therapy; 270 did not (five unknown). The type of acute myocardial infarction was known for 471 patients: 192 were anterior, 203 were inferior, and 76 were lateral. There were no deaths during transfer. Overall survival through hospitalization was 91%. The incidence of arrhythmia was 36% before transport and 12% during transport. There was no difference in arrhythmias overall, or with respect to any of the five arrhythmias specified, between patients who received thrombolytic therapy before and during transport and those who did not. Reperfusion arrhythmia does not appear to be a clinically significant entity during the transport of patients who are receiving IV thrombolytic therapy.

Arrhythmias, Cardiac↗
PubMed1989

The Structured Interview for Schizotypy (SIS): a preliminary report.

This article presents a new interview-based research instrument for assessing schizotypal symptoms and signs. The Structured Interview for Schizotypy (SIS), which was developed from experience gained in a large, controlled family study of schizophrenia in the west of Ireland and has been field-tested in three other locations, differs from previously available interviews in that it includes: (1) built-in contextual assessments of the pathological nature of certain symptoms (e.g., suspiciousness or ideas of reference); (2) multiple independently scored items, most with closed response options, per symptom scale; (3) extensive assessment of schizotypal signs; (4) symptom probes designed to make responding positively appear nondeviant; and (5) coverage of potentially relevant symptoms and signs not required in current criteria for schizotypal personality disorder. Schizotypal symptoms can be assessed with high reliability by the SIS. When sufficient variability is present, schizotypal signs are also reliably assessed by the SIS, although the reliability is generally lower than that found for symptoms. In three independent pilot studies, schizotypal symptoms and signs assessed by the SIS appear to discriminate significantly the relatives of schizophrenic patients from relatives of controls.

Adolescent↗
PubMed1989

Can maximal cardiopulmonary capacity be recognized by a plateau in oxygen uptake?

The failure of oxygen uptake to increase with increasing work has been considered a marker of the limits of the cardiopulmonary system for many years. However, the concept has suffered from inconsistencies in definition, criteria, and data sampling, all of which affect the interpretation of the relation between changes in work and oxygen uptake. To evaluate the response and reproducibility of the slope in oxygen uptake at peak exercise, six subjects (mean age, 33 +/- 6 years) performed two individualized ramp treadmill tests on separate days. During exercise, oxygen uptake (for a given sample of 30 eight-breath running averages) was regressed with time and the slope was calculated. Maximal oxygen uptake, maximal heart rate and maximal perceived exertion were reproducible from day 1 to day 2 (mean difference, 0.4 ml/kg/min, 1.0 beats per minute, and 0.2 for maximal oxygen uptake, heart rate, and maximal perceived exertion, respectively [not significant]). Considerable variability in the slopes was observed during each test and from day to day. This occurred despite the use of large gas exchange samples, averaging techniques, and constant, consistent changes in external work. A plateau, defined as the slope of an oxygen uptake sample at peak exercise that did not differ significantly from a slope of zero, was not a consistent finding within subjects between days. We conclude that marked variability in the slope of the change in oxygen uptake occurs throughout progressive exercise, despite the use of large samples and a linear change in external work. These findings appear to preclude the determination of a plateau by common definitions.

Exercise Test↗
PubMed1987

Emergency aeromedical transport of patients with acute myocardial infarction.

Traditional medical treatment of acute myocardial infarction (AMI) calls for immediate admission and observation in a special care unit and prohibits early interhospital transfer of patients. If persons with AMI are to benefit from emergency thrombolytic therapy, angioplasty, and other interventions, they may require emergency transfer within hours to one of the 10% of hospitals that provide these services. We report our experience with the emergency aeromedical treatment and transfer for acute intervention of 104 consecutive patients with suspected AMI. Between May 1983 and December 1984, 104 patients with suspected acute myocardial infarction were transported by an aeromedical team, including a physician and nurse, for emergency cardiac evaluation. AMI was confirmed in 94 (90%), and emergency intervention was carried out in 75 of 104 (72%). Ninety patients (87%) survived to be discharged from the hospital. There were no deaths during transport. Complications requiring treatment occurred in 13 (12%) of the patients during transport; physician skill or judgment was exercised in 27 of 104 transports (26%) and did not correlate with the Killip classification of physical findings. We conclude that emergency transfer of patients with AMI, traditionally considered hazardous, can be carried out safely using an aeromedical team. Physicians appear to play an important role in safe transport.

Acute Disease↗
PubMed1987

Diabetes, dialysate losses, and serum lipids during continuous ambulatory peritoneal dialysis.

We evaluated changes in dialysate losses of protein and absorption of glucose, serum chemistries including protein electrophoresis, and serum lipids among patients who had undergone continuous ambulatory peritoneal dialysis (CAPD) for at least 1 year. The patients' race, sex, and the presence of diabetes mellitus did not influence the results. Over a 2-year period, daily protein losses and glucose absorption from dialysate were constant, serum protein electrophoresis did not show changes consistent with the nephrotic syndrome, serum cholesterol increased after 1 year of therapy but stabilized thereafter, and concentrations of high density lipoproteins did not decrease.

Absorption↗