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Biomedical subjects

L Elliott

Publications and source records attributed to L Elliott.

At least 73 records · Page 4Linked to original sources
PubMed1992

The use of head-upright tilt table testing in the evaluation and management of syncope in children and adolescents.

Recurrent syncope in an otherwise healthy child or adolescent is a common anxiety provoking disorder. Vasovagally mediated hypotension and bradycardia are believed common, yet difficult to diagnose, causes of syncope in this age group. Upright tilt table testing has been suggested as a potential method to test for vasovagal episodes. This study evaluated the utility of this technique in the evaluation and management of recurrent syncope in children and adolescents. Thirty patients with recurrent unexplained syncope were evaluated by use of an upright tilt table test for 30 minutes, with or without an infusion of isoproterenol (1 to 3 micrograms/min given intravenously), in an attempt to produce hypotension, bradycardia, or both. There were 15 males and 15 females, mean age 14 +/- 6 years. Each of the tilt positive patients received therapy with either fluorohydrocortisone, beta blockers, or transdermal scopolamine. Syncope occurred in six patients (20%) during the base line tilt and in 15 patients (50%) during isoproterenol infusion (total positives 70%). All initially positive patients were rendered tilt negative by therapy. Over a mean follow-up period of 20 months, no further episodes have occurred. We conclude that tilt table testing is a useful and effective test in the evaluation of unexplained syncope in childhood.

Adolescent↗
PubMed1992

Head-upright tilt-table testing: a useful tool in the evaluation and management of recurrent vertigo of unknown origin associated with near-syncope or syncope.

Recurrent idiopathic vertigo associated with near-syncope and syncope is a common perplexing problem, some cases of which are considered autonomically mediated (vasovagal). Upright-tilt-table testing has emerged as a potential method to test for vasovagal episodes. This study evaluated the use of this technique in the evaluation and management of patients with recurrent idiopathic vertigo associated with near-syncope or syncope. Twenty-one patients with recurrent unexplained vertigo and syncope/near-syncope and 11 control subjects were evaluated by use of an upright-tilt-table test for 30 minutes, with or without a graded isoproterenol infusion (1 to 4 micrograms/min given intravenously), in an attempt to provoke hypotension, bradycardia, or both, which reproduced the patient's symptoms. The patients included 10 men and 11 women (mean age, 51 +/- 16 years). Eleven controls with no history of vertigo were also studied. Transcranial Doppler sonography was used to assess cerebral arteriolar blood flow during tilt. All tilt-positive patients were placed on therapy with either beta-blockers, disopyramide, or transdermal scopolamine, the effectiveness of which was determined with another tilt-table study. Symptoms occurred in seven patients (33%) during the baseline tilt and in eight patients (38%) during isoproterenol infusion (total positives, 71%). Transcranial Doppler sonography demonstrated a 225% +/- 192% increase in pulsatility index and a 70% +/- 29% increase in resistance index (indicative of cerebral arteriolar vasoconstriction) at the time of vertigo. No control subject experienced syncope during this test. Each tilt-positive patient eventually became tilt-negative with therapy, and over a mean follow-up period of 26 months, no further episodes have occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

A training project helps the poor. A rural healthcare facility offers job training, gains employees.

As poor Americans look for work, healthcare facilities face a shortage of workers. One facility, Saint Francis Medical Center in Grand Island, NE, found a way to help some of the area's financially disadvantaged persons receive technical training and employment as it eased its own personnel shortage. Saint Francis leaders assembled a team of representatives from the hospital's staff, the Greater Nebraska Job Training Program, Lincoln, and Central Community College, Grand Island, to establish the Rural Allied Medical Business Occupations program. The team reviewed several job descriptions to help it decide which jobs to include in the program and surveyed area hospitals to ensure the positions selected were experiencing shortages. The program received a grant as a demonstration project from the U.S. Department of Education. After identifying participants who had the aptitudes and interests for the jobs, the Rural Medical Allied Medical Business Occupations program arranged for participants' training and assistance with items such as tuition, child care, and transportation. Participants received training at Central Community College and at Saint Francis Hospital. Saint Francis Medical Center deemed the program a success. The hospital has hired seven healthcare workers who would not have been available if they had not been trained through this program. Moreover, the program provides yet another way for the hospital to help fulfill a major portion of its mission: to help the poor.

Allied Health Occupations↗
PubMed1991

Differentiation of convulsive syncope and epilepsy with head-up tilt testing.

OBJECTIVE: To evaluate the usefulness of head-upright tilt table testing in the differential diagnosis of convulsive syncope from epileptic seizures in patients with recurrent idiopathic seizure-like episodes. DESIGN: Prospective, nonrandomized study. SETTING: Electrophysiology laboratory of a university hospital. PATIENTS: Fifteen patients (8 men and 7 women patients; mean age, 29 +/- 20 years) with recurrent unexplained seizure-like episodes, unresponsive to antiseizure medication. MEASUREMENTS: Head-upright tilt table testing with or without isoproterenol infusion. Five patients who were initially tilt positive had a second tilt test with continuous electroencephalographic (EEG) recording. MAIN RESULTS: Syncope associated with tonic-clonic seizure-like activity occurred in six patients (40%) during the baseline tilt and in four patients (27%) during isoproterenol infusion (total positive tests, 67%). The EEG showed diffuse brain wave slowing (not typical of epileptic seizures) in five of five patients during the convulsive episode. All patients who had positive test results eventually become tilt table negative after therapy, and over a mean follow-up period of 21 +/- 2 months, no further seizure-like episodes have occurred. CONCLUSION: Upright tilt table testing combined with isoproterenol infusion may be useful to distinguish convulsive syncope from epileptic seizures.

Adolescent↗
PubMed1991

Implementation and evaluation of a strategic parasite control program for captive exotic ungulates.

A parasite control program was designed for greater than 1,200 exotic ungulates maintained in mixed-species enclosures at the San Diego Wild Animal Park. Three strategically-timed anthelmintic treatments were given during 1988-1989, and their success was evaluated by monitoring pretreatment and posttreatment fecal egg counts. Adequate parasite control was achieved for animals in 52 ungulate species, as evidenced by low pretreatment egg counts and the absence of egg-shedding after treatment. However, animals belonging to 11 species in the subfamilies Antilopinae, Hippotraginae, and Caprinae were identified as important targets for more intensive control efforts because they shed either greater than 100 eggs/g of feces before treatment, or greater than 0 eggs/g after treatment, at 2 or more sampling periods. These results and observations were used to generate management recommendations and illustrate how a model parasite control program can be developed for collections of exotic ungulates.

Animals↗
PubMed1991

Utility of upright tilt-table testing in the evaluation and management of syncope of unknown origin.

PURPOSE: Vasovagally mediated hypotension and bradycardia are believed to be common, but difficult to diagnose, causes of syncope. Upright tilt-table testing has been proposed as a possible way to test for vasovagal episodes. This study investigated the clinical utility of this technique in the evaluation and management of patients with syncope of unknown origin. PATIENTS AND METHODS: Twenty-five patients with recurrent unexplained syncope and six control subjects were evaluated by use of an upright tilt-table test for 30 minutes, with or without an infusion of isoproterenol (1 to 3 micrograms/minute given intravenously), in an attempt to provoke bradycardia, hypotension, or both. Of the 25 patients, there were 14 males and 11 females, with a mean age of 50 +/- 16 years. Six control patients with no history of syncope were also studied. All tilt-positive patients received therapy with either beta-blockers, disopyramide, transdermal scopolamine, or hydroflurocortisone, the efficacy of which was evaluated by another tilt-table test. RESULTS: Syncope occurred in six patients (24%) during the baseline tilt and in nine patients (36%) during isoproterenol infusion (total positives, 60%). None of the controls had syncope during the test. All patients who had positive test results eventually became tilt-table-negative by therapy, and over a mean follow-up period of 16 +/- 2 months no further episodes have occurred. CONCLUSION: From this study we conclude that upright tilt-table testing combined with isoproterenol infusion is clinically useful in the diagnosis of vasovagal syncope and the evaluation of pharmacologic therapy.

Adolescent↗
PubMed1991

Modulation of T-cell function by gliomas.

Patients with primary intracranial tumors (gliomas) exhibit a profound decrease in immunity, the mechanism of which has, until recently, remained obscure. Here Thomas Roszman, Lucinda Elliott and William Brooks reveal that T cells obtained from these patients exhibit defects in interleukin 2 secretion and in expression of the high-affinity IL-2 receptor and they discuss the role played by immunosuppressive factors produced by gliomas in inducing these defects.

Brain Neoplasms↗
PubMed1991

Resolution of high initial epicardial patch defibrillation thresholds following chronic implantation.

To determine what effect chronic implantation of automatic implantable cardioverter defibrillator epicardial patch electrodes had on initial high defibrillation thresholds at implant, six patients were studied. There were five men, one woman, mean age 61 years. Three had coronary artery disease and three had dilated cardiomyopathies. Mean ejection fraction was 20%. Two patients underwent concomitant coronary artery revascularization and one underwent mitral valve replacement. No patient was on antiarrhythmic drugs. At the time of initial implant, adequate defibrillating thresholds could not be obtained in any patch configuration despite the use of up to 40 joules. Further testing was precluded in each patient due to the development of profound hypotension (less than or equal to 70 mmHg systolic) that was poorly responsive to pressors. The patch electrodes were then implanted in an arbitrary anterior-posterior position and the leads were tunneled to an abdominal pocket. After 10-15 days (mean 11), the lead ends were exposed and defibrillation testing was performed again. In all six patients, adequate defibrillation thresholds were obtained (mean 18 joules). We conclude that if adequate defibrillation thresholds cannot be obtained at implant and if further testing cannot be performed without jeopardizing the life of the patient, the patch electrodes should be implanted and retesting performed at 10-15 days.

Aged↗
PubMed1991

Cerebral vasoconstriction during head-upright tilt-induced vasovagal syncope. A paradoxic and unexpected response.

BACKGROUND: To determine the effect of vasovagally mediated syncope on the cerebral circulation, transcranial Doppler sonography was used to assess changes in cerebral blood flow velocity during head-upright tilt-induced syncope. METHODS AND RESULTS: Thirty patients (17 men and 13 women; mean age, 43 +/- 22 years) with recurrent unexplained syncope were evaluated by use of an upright tilt-table test for 30 minutes, with or without an infusion of intravenous isoproterenol (1-4 micrograms/min), in an attempt to provoke bradycardia, hypotension, or both. Transcranial Doppler sonography was used to assess middle cerebral artery systolic velocity (Vs), diastolic velocity (Vd), ratio of systolic to diastolic velocities, pulsatility index (PI = Vs-Vd/Vmean), and resistance index (RI = Vs-Vd/Vs) before, during, and after tilt. Syncope occurred in six patients (20%) during the baseline tilt and 14 (46%) during isoproterenol infusion (total positives, 66%). In the tilt-positive patients, concomitant with the development of hypotension and bradycardia, transcranial Doppler sonography showed a 75 +/- 17% decrease in diastolic velocity, unchanged systolic velocity, a 46 +/- 17% decrease in mean velocity, a 295 +/- 227% increase in pulsatility index, and a 73 +/- 34% increase in resistance index. CONCLUSIONS: These findings reflect increased cerebrovascular resistance secondary to arteriolar vasoconstriction distal to the insonation point of the middle cerebral artery. This is paradoxic because the expected response of the cerebral circulation to hypotension is vasodilation. We conclude that abnormal baroreceptor responses triggered during vasovagal syncope result in a derangement of cerebral autoregulation with paradoxic vasoconstriction in the face of increasing hypotension.

Adult↗
PubMed1990

Subcellular localization of newly incorporated myosin in rabbit fast skeletal muscle undergoing stimulation-induced type transformation.

Immunogold labelling was used to study the distribution of newly synthesized slow muscle myosin (SM) at the ultrastructural level as it replaced fast muscle myosin (FM) in rabbit muscles undergoing stimulation-induced type transformation. Control fast muscle was labelled strongly with antibody to FM and control slow muscle with antibody to SM; label was confined to the A-band. Well-defined differences in the distribution of label within the A-band suggested that the monoclonal antibodies used corresponded to epitopes on different parts of the myosin molecule; this was confirmed by Western blots of subfragments prepared from FM and SM. After 4 weeks of continuous stimulation at 10 Hz, fibres of the tibialis anterior muscle reacted with antibodies to both isoforms; after 6 weeks, labelling was obtained only with antibody to SM. After a 7-week period of stimulation and 3 further weeks of recovery, fibres again reacted with both antibodies. In all positively-labelled sections, the distribution of gold particles was characteristic of the antibody and independent of the origin or history of the fibres. This observation supports the conclusion that newly synthesized myosin is capable of being incorporated throughout the length and cross-section of the A-band.

Animals↗
PubMed1990

External pacing for the termination of sustained supraventricular tachycardia in children.

Cardiac pacing from either endocardial or transesophageal sites has proven useful in termination of sustained supraventricular tachycardia in children. In two patients we demonstrated the efficacy of external pacing in the termination of sustained supraventricular tachycardia. The ease and apparent safety of the technique make it an attractive addition to our current therapies for supraventricular tachycardia in children. The usefulness of external pacing in treating pediatric arrhythmias needs further evaluation.

Adolescent↗
PubMed1990

Training trainers: a new approach for community medicine.

During 1985, two separate one-day seminars for trainees and trainers in South East Thames Regional Health Authority highlighted the need for a 'training the trainers' course to be run for trainers throughout the Region. This was held during 1987 and this paper gives a descriptive account of the course, highlights the lessons learnt, and summarises the evaluation obtained from participants. Thirteen trainers started the course, one changed jobs and left the Region, leaving twelve completing the course. Spread over nine months, the course included an initial weekend but was mainly run on a day release basis. The facilitators for the course, a psychologist and sociologist, had teaching experience in running similar courses for GP trainers. The course emphasised an adult learning model in which the trainer enabled the trainee to identify and meet their learning needs through appropriate support and facilitation. Although the career change from clinical work to public health medicine is likely to be more traumatic than other transitions within clinical medicine, the approach is applicable on a much wider basis.

Adult↗
PubMed1990

The clinical use of external noninvasive pacing in the termination of sustained ventricular tachycardia.

In order to evaluate the potential use of external cardiac pacing (EXP) in the clinical termination of sustained ventricular tachycardia (VT), we attempted VT terminations in seven patients. All had recurrent sustained monomorphic ventricular tachycardia (mean rate 145 beats/min), which had previously required cardioversion. During subsequent VT episodes, all seven underwent overdrive pacing with EXP at a pulse amplitude of 120 mA, and rates of 200 pulses/min. A total of 18 of 18 episodes of VT were successfully terminated by EXP alone. In one patient, the first attempt at EXP termination of one episode of VT resulted in an acceleration of the tachycardia, which was then terminated by EXP. All patients tolerated EXP well with minimal sedation. We conclude that EXP may be an effective clinical modality for the termination of sustained monomorphic ventricular tachycardia.

Adult↗
PubMed1990

Models of renal blood flow and their use in the detection of renal artery stenosis.

First-pass studies of renal blood flow using 99Tcm-DTPA have been analysed in normotensive patients and those with renal artery stenosis. One and two component models of renal blood flow were examined for their ability to discriminate between these two groups. Using a two component model, 5/7 kidneys with proven renal artery stenosis were identified, with 38/40 kidneys in normotensive patients lying within the defined normal range. The two kidneys not detected by this technique both had extremely poor function. This model was also applied to other hypertensive patients referred for routine screening and appears promising in increasing the specificity of the 99Tcm-DTPA study for detecting renal artery stenosis.

Adolescent↗
PubMed1990

Morphometric analysis of Psoroptes spp. mites from bighorn sheep, mule deer, cattle, and rabbits.

A morphometric study of Psoroptes spp. mites was conducted to address difficulties encountered in species identification and to provide insights into the phylogenetic relationships between mites found on different hosts. A discriminant analysis employing 9 morphologic characters revealed that the lengths of the outer opisthosomal setae and the lateral margins of the opisthosomal knobs were the 2 most important characters for grouping mites according to host species. This analysis clearly separated mites collected from allopatric populations of bighorn sheep, rabbits, and cattle into discrete groups. However, differences were not detected between mites collected from sympatric populations of infested mule deer and bighorn sheep, suggesting that these mites were not host specific and represented a single interbreeding population. Differences also were not detected among mites collected from the ears and body of bighorn sheep and rabbits, demonstrating that the location of mites on a given host should not be used as a primary criterion in species identification.

Animals↗
PubMed1988

A retrospective cohort mortality study of workers exposed to formaldehyde in the garment industry.

In order to assess the possible human carcinogenicity of formaldehyde we conducted a retrospective cohort mortality study of workers exposed for at least three months to formaldehyde in three garment facilities which produced permanent press garments. A total of 11,030 workers contributing 188,025 person-years were included in the study. Vital status was successfully ascertained through 1982 for over 96% of the cohort. The average (TWA) formaldehyde exposure at the three plants monitored in 1981 and 1984 by NIOSH was 0.15 ppm but past exposures may have been substantially higher. In general, mortality from nonmalignant causes was less than expected. A statistically significant excess in mortality from cancers of the buccal cavity (SMR = 343) and connective tissue (SMR = 364) was observed. Statistically nonsignificant excesses in mortality were observed for cancers of the trachea, bronchus and lung (SMR = 114), pharynx (SMR = 112), bladder (SMR = 145), leukemia and aleukemia (SMR = 113), and other lymphopoietic neoplasms (SMR = 170). Mortality from cancers of the trachea, bronchus and lung was inversely related to duration of exposure and latency. In contrast, mortality from cancers of the buccal cavity, leukemias, and other lymphopoietic neoplasms increased with duration of formaldehyde exposure and/or latency. These neoplasms also were found to be highest among workers first exposed during a time period of high potential formaldehyde exposures in this industry (1955-1962). However, it should be recognized that these findings are based on relatively small numbers and that confounding by other factors may still exist. The results from this investigation, although far from conclusive, do provide evidence of a possible relationship between formaldehyde exposure and the development of upper respiratory cancers (buccal), leukemias, and other lymphopoietic neoplasms in humans.

Female↗