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Biomedical subjects

M A Elliott

Publications and source records attributed to M A Elliott.

At least 55 records · Page 3Linked to original sources
PubMed1998

Splenic irradiation for symptomatic splenomegaly associated with myelofibrosis with myeloid metaplasia.

Twenty-three patients who had myelofibrosis with myeloid metaplasia (MMM) were treated at our institution with 50 courses of splenic irradiation (SI) for symptomatic splenomegaly. The median dose of radiation per course was 277.5 cGy, administered in a median of 7.5 fractions. 8/23 patients received multiple courses of SI. Of 49 evaluable courses of SI, 46 (93.9%) resulted in an objective decrease in spleen size. The median duration of response was 6 months (range 1-41). Reduction in spleen size was associated with symptomatic relief in all patients. Overall median survival after SI was 22 months. Significant cytopenia occurred in 10 (43.5%) patients, or 16 (32%) of the 50 courses of SI. Prolonged, life-threatening pancytopenia after a single course of SI occurred in six patients (26%), resulting in fatal sepsis or haemorrhage in three (13%). Nine patients underwent subsequent splenectomy: the perioperative mortality rate was 11%. One third of patients experienced postoperative intra-abdominal haemorrhage necessitating surgical re-exploration. SI can provide symptomatic relief and a reduction in spleen size in most MMM patients. The increased risk of postoperative bleeding in patients requiring subsequent splenectomy dictates against considering SI as an alternative to splenectomy for patients who are otherwise good surgical candidates.

Adult↗
PubMed1997

Investigation into the concanavalin A reactivity, fucosylation and oligosaccharide microheterogeneity of alpha 1-acid glycoprotein expressed in the sera of patients with rheumatoid arthritis.

alpha 1-Acid glycoprotein (AGP) exists as an heterogeneous population of glycosylated variants (glycoforms) in plasma. The concentration of AGP increases some 2-5 fold in certain pathophysiological states exemplified by the chronic inflammatory disease, rheumatoid arthritis (RA). Moreover, the expressed glycosylation pattern alters in such conditions, indicating functional significance that is likely to be related to the oligosaccharide heterogeneity. We have investigated the heterogeneity of AGP glycosylation using the technique of high pH anion-exchange chromatography (HPAEC). AGP was isolated from the blood of RA sufferers, partially separated by Concanavalin A (Con A) affinity chromatography into bound and non-bound fractions and was enzymatically deglycosylated. Chromatography on the pellicular HPAE resin at pH 13 separated the released oligosaccharides and allowed a comparison of profiles in terms of branching and fucosylation. Results demonstrate an abnormal RA AGP glycosylation, with a tendency towards tri- and tetra-antennary oligosaccharides and enhanced fucosylation, in addition to the possible existence of penta-sialylated RA AGP glycoforms.

Arthritis, Rheumatoid↗
PubMed1997

Volumetric measurement of human calf muscle from magnetic resonance imaging.

Muscle mass is a determining factor in skeletal muscle function and is affected by inactivity, immobilization, disease, and aging. The aim of this study was to develop an objective and time-efficient method to quantify the volume and cross-sectional area of human calf muscles using three-dimensional magnetic resonance images. We have estimated the errors incurred in muscle volume measurements arising from artifacts known to occur in magnetic resonance imaging (MRI). The largest source of error was due to partial volume effects, which resulted in overestimation of phantom volumes ranging from 145 to 900 cc by 6% to 13%. The magnitude of this effect has been shown to increase with decreasing object size and decreasing spatial resolution. We have presented a straightforward correction for this effect, which has reduced the volume measurement error to less than 4% for all cases. Through the use of computer simulations, the correction algorithm has been shown to be independent of object shape and orientation. To reduce user subjectivity, a semiautomated computer program has been developed to segment MRI data for particular muscle groups. Images from seven human subjects were analyzed by the program, yielding muscle volumes of 154.2 +/- 23.2, 281.2 +/- 35.8, and 432.2 +/- 83.7 for the lateral gastrocnemius, medial gastrocnemius, and soleus, respectively.

Adult↗
PubMed1997

New drugs in essential thrombocythemia and polycythemia vera.

Among the chronic myeloproliferative disorders, polycythemia vera and essential thrombocythemia are unique because of their association with thrombohemorrhagic manifestations and their relatively indolent clinical course. Patients with essential thrombocythemia may not have a significant shortening of life-expectancy and most may not require specific therapy. However, patients with polycythemia vera have a significant risk of transformation of polycythemia vera into acute leukemia or postpolycythemic myelofibrosis (or both). 'High-risk-for-thrombosis' patients with either polycythemia vera or essential thrombocythemia require specific therapy with a platelet-lowering agent to prevent thrombotic complications. Currently, the standard agent used for this is hydroxyurea. However, its tetratogenic and leukemogenic potential has been of concern. As a result, new platelet-lowering agents are being evaluated in the treatment of polycythemia vera and essential thrombocythemia. Anagrelide and interferon alfa are two such agents and have been shown to be effective in reducing platelet counts in patients with chronic myeloproliferative disorders. The putative mechanism of action of these drugs, their specific activity in polycythemia vera and essential thrombocythemia, side-effect profile, and current indications are discussed herein.

Antineoplastic Agents↗
PubMed1997

Interferon-alpha therapy in polycythemia vera and essential thrombocythemia.

Essential thrombocythemia (ET) and polycythemia vera (PV) are chronic clonal myeloid disorders that originate from the multipotential hematopoietic stem cell. They are characterized, respectively, by excessive thrombocytosis and erythrocytosis, a high incidence of thrombohemorrhagic events, vasomotor symptoms, and an inherent tendency to undergo leukemic transformation. Current standard therapies to control the excess accumulation of myeloid cells and to provide symptomatic relief carry either a persistent risk of thrombosis, as in the case of phlebotomy, or, in the case of hydroxyurea, the potential for inducing leukemia. None alter the natural history of these diseases. Interferon-alpha has been shown to have potent antiproliferative effects on the hematopoietic stem cells and bone marrow fibroblasts and, as a result, has received much attention as a therapeutic agent for chronic myeloproliferative disorders. The ability of interferon-alpha to induce hematologic and cytogenetic remission in chronic phase chronic granulocytic leukemia has further increased interest in this agent. Interferon-alpha has shown therapeutic activity in PV and ET, as demonstrated in multiple small studies and single-arm trials reviewed in this article. Reported beneficial effects include the ability to control excessive erythrocytosis and thrombocytosis and such disease-related features as vasomotor symptoms, pruritus, and splenomegaly. Recent reports of cytogenetic remission and reversal of bone marrow fibrosis after interferon therapy are of interest. Advantages over current therapeutic standards include lack of known leukemogenic and teratogenic effects and the potential to alter the underlying course of disease. Nevertheless, none of the information available allows definite therapeutic recommendations for the use of interferon-alpha in PV or ET. The available data support the need for randomized controlled trials comparing interferon-alpha with standard therapy.

Cell Division↗
PubMed1996

Familial hemiplegic migraine, nystagmus, and cerebellar atrophy.

Familial hemiplegic migraine (FHM) is an autosomal dominant disorder characterized by transient hemiplegia during the aura phase of a migraine attack. Nystagmus has been reported in individuals affected with this disorder, but the origin of the ocular motility findings is unknown. A three-generation family with FHM is described and clinical histories are outlined. Ocular motility evaluations were performed on 7 family members, 5 with a history of hemiplegic migraine and 2 without history of migraine. All affected family members had abnormal eye movements consistent with vestibulocerebellar dysfunction. Magnetic resonance imaging scans in affected family members revealed cerebellar vermian atrophy. DNA linkage analysis revealed a common marker in all the affected family members on chromosome 19. We suggest that the hemiplegic migraine attacks and the cerebellar degeneration are linked genetically and that the eye movements are not the ischemic sequelae of recurrent migraine. Strikingly similar ocular motility findings and cerebellar degeneration are reported in both FHM and a genetically related disorder, hereditary paroxysmal cerebellar ataxia (HPCA). The significance of these similarities is discussed along with a proposed pathophysiology for FHM.

Adolescent↗
PubMed1996

Dilemmas for the empowering nurse.

The issue of patient empowerment has been commonly debated in nursing journals in the 1990s as its NHS popularity has grown. We discuss here how this issue impacts on the role of the nurse by examining a number of key features of this popular term, given that it underpins our strategic direction as a nursing development unit.

Decision Making, Organizational↗
PubMed1994

Heterogeneity of alpha 1-acid glycoprotein in rheumatoid arthritis.

alpha 1-Acid glycoprotein (AGP) or orosomucoid is a major serum glycoprotein, of unknown physiological function, which is classified as one of the positive acute phase reactants since its plasma concentration becomes elevated two- to five-fold in certain disease states. Additionally, the proportions and identities of the five asparaginyl-linked complex oligosaccharide chains are altered during several physiological and pathological conditions, which may be functionally significant. The key to studying the structural heterogeneity of AGP is to develop a procedure that will isolate AGP without structural degradation. We have developed a method for the purification of AGP, using procedures unlikely to damage the glycoprotein structure, which was utilised to isolate AGP from samples of normal and rheumatoid plasma. The effectiveness of the purification procedure was examined by enzymatically deglycosylating each sample of AGP and separating the released oligosaccharides by chromatography on a pellicular high-performance anion-exchange (HPAE) resin at pH 13. The analytical profile for normal AGP was consistent with that previously reported thus indicating that the purification procedure did not denature the oligosaccharide chains of AGP. Additionally, there was a noticeable difference between the profiles for AGP from normal and rheumatoid plasma.

Arthritis, Rheumatoid↗
PubMed1994

Managing a mid-career crisis.

Recognizing career and life stages can enable individuals to ensure a smooth mid-career transition. Working together, nurses and the organization identify individual needs and potential causes of mid-career crisis as a self-managed career concept is formed.

Career Mobility↗
PubMed1991

Professional responsibility in sports dentistry.

Our professional responsibility related to sports dentistry extends beyond the office. By our active involvement in continuing dental education, we can become more knowledgeable in this relatively new area of sports dentistry. Although it is still in its infancy, sports dentistry is an ever-expanding field. As dentists in practice, whether as general practitioners, specialists, academicians, or researchers, each one of us has a professional responsibility to become involved. Sports dentistry is certain to be a part of our future.

Adolescent↗
PubMed1990

Odontodysplasia in a pediatric patient: literature review and case report.

A case of a three-year-old Caucasian male with odontodysplasia is presented. Although the etiology of this condition is unknown, this anomaly involves both the mesodermal and ectodermal dental components and results in deficient and abnormal formation of dentin and enamel. The orofacial characteristics and dental findings of the condition are presented in this case report.

Child, Preschool↗