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Biomedical subjects

E Thompson

Publications and source records attributed to E Thompson.

At least 73 records · Page 4Linked to original sources
PubMed1999

A child with hemimegalencephaly, hemihypertrophy, macrocephaly, cutaneous vascular malformation, psychomotor retardation and intestinal lymphangiectasia--a diagnostic dilemma.

Although the clinical delineation of the majority of overgrowth syndromes is straightforward, we believe there is a subset of patients with overlapping features from a number of overgrowth syndromes. We report a patient with hemimegalencephaly, hemihypertrophy, macrocephaly, vascular lesions, psychomotor retardation and intestinal lymphangiectasia. The clinical history and findings posed a diagnostic dilemma as the features overlapped between several conditions, namely macrocephaly-cutis marmorata telangiectatica congenita (M-CMTC), Klippel-Trenaunay-Weber syndrome (KTWS), Proteus syndrome and a provisional unique syndrome described by Reardon et al. (1996, Am J Med Genet 66:144-149). We anticipate that only when the molecular basis is delineated will it become clear whether these disorders are separate entities or merely differing ends of the same spectrum.

Abnormalities, Multiple↗
PubMed1998

A multidisciplinary study investigating radiotherapy in Ewing's sarcoma: end results of POG #8346. Pediatric Oncology Group.

PURPOSE: To determine if involved field radiation (IF) is equivalent to standard whole bone radiation (SF) in local tumor control; to establish patterns of failure following treatment; and to determine response, event-free survival (EFS), and overall survival rates from multidisciplinary therapy in Ewing's sarcoma. METHODS AND MATERIALS: Between 1983 and 1988, 184 children with Ewing's sarcoma were enrolled onto Pediatric Oncology Group 8346 (POG 8346). A total of 178 (97%) met eligibility criteria; 6 had pathology other than Ewing's sarcoma. Induction chemotherapy of cyclophosphamide/doxorubicin (adriamycin )(C/A) x 12 weeks was followed by local treatment either surgery or radiation therapy and C/A, dactinomycin, and vincristine for 50 weeks. Resection was advised for patients with small primary tumors if accomplished without functional loss. Forty patients were randomized to receive SF, whole bone radiation to 39.6 Gy plus a 16.2 Gy boost (total 55.8 Gy) or IF to 55.8 Gy, and the remainder were assigned to IF radiation. RESULTS: Of 178 eligible patients, 141 (79%) had localized disease and 37 (21%) had metastases at presentation. Their 5-year EFS was 51% (SE 5%) and 23% (SE 7%) respectively. The response rate to induction chemotherapy was 88% (28% complete, 60% partial), but after radiotherapy the response rate increased to 98%. Thirty-seven of the localized patients underwent resection, of whom 16 (43%) required postoperative radiotherapy; the 5-year EFS of these surgical patients was 80% (SE 7%). The remaining 104 localized patients were eligible for randomization or assignment to receive radiotherapy; the 5-year EFS of these patients was 41% (SE 5%), with no significant difference in EFS between those randomized to SF vs. IF. Site of primary tumor correlated with 5-year EFS: distal extremity 65% (SE 8%), central 63% (SE 10%), proximal extremity 46% (SE 8%), and pelvic-sacral 24% (SE 10%) (p=0.004). Initial tumor size did not correlate significantly with EFS. Patterns of failure among the 141 localized patients revealed 23% of patients experienced a local failure, while 40% had a systemic failure. The 5-year local control rate for the surgical patients +/- postoperative radiotherapy was 88% (SE 6%), while for the patients undergoing radiotherapy alone it was 65% (SE 7%). There was no difference in local control between those randomized to SF vs. IF. The 5-year local control rate for the patients with pelvic-sacral tumors was 44% (SE 15%), significantly worse than the local control rates for those with central tumors 82% (SE 8%), distal extremity 80% (SE 8%), or proximal extremity 69% (SE 9%) (p=0.023). However, quality of radiotherapy correlated with outcome. Patients who had appropriate radiotherapy had a 5-year local control of 80% (SE 7%), while those with minor deviations had 5-year local control of 48% (SE 14%), and those with major deviations had a local control of only 16% (SE 15%) (p=0.005). The local failure was within an irradiated volume in 62% of patients, outside the irradiated volume in 24% of cases, while the precise location could not be determined in the remaining 14%. CONCLUSIONS: As most failures in Ewing's sarcoma are systemic, improved EFS requires more effective systemic chemotherapy. Adequate IF radiotherapy requires treatment to appropriate volumes as defined by MRI imaging and full radiation doses. Pretreatment review of radiologic images with a musculoskeletal radiologist to determine appropriate tumor volumes, as well as use of conformal radiotherapy techniques are important for improved outcome.

Adolescent↗
PubMed1998

Are rural general practitioner--obstetricians performing too many prenatal ultrasound examinations? Evidence from western Labrador.

OBJECTIVE: To determine the frequency of prenatal ultrasonography (PNU) in western Labrador in 1994, assess the appropriateness of the ultrasound examinations according to current guidelines and determine whether there was any relation between number of PNU examinations and patient management and obstetric outcomes. DESIGN: Review of all obstetric charts and PNU requisition forms for all deliveries in one hospital in 1994. SETTING: Labrador City and Wabush, Newfoundland. RESULTS: During the study period, there were 103 singleton deliveries, and these mothers underwent a total of 225 PNU studies (mean 2.16 studies per delivery). More than half (53.3%) of the examinations were classified as inappropriate. There were no significant differences in the number of studies between low- and high-risk pregnancies or between uncomplicated deliveries and those in which induction or instrumental or operative delivery occurred, nor was there any relation between number of PNU examinations and maternal or neonatal outcome. CONCLUSION: Compared with PNU use as recommended by the Canadian Task Force on the Periodic Health Examination, this type of examination was overused in Labrador City and Wabush, although the rate of use was comparable to that reported in other Canadian studies. This overuse was not associated with any identifiable effect on maternal or neonatal outcome or on the management of pregnancy and labour. More judicious use of PNU, in accordance with evidence-based guidelines, is recommended.

Adolescent↗
PubMed1998

Finding out about filling-in: a guide to perceptual completion for visual science and the philosophy of perception.

In visual science the term filling-in is used in different ways, which often leads to confusion. This target article presents a taxonomy of perceptual completion phenomena to organize and clarify theoretical and empirical discussion. Examples of boundary completion (illusory contours) and featural completion (color, brightness, motion, texture, and depth) are examined, and single-cell studies relevant to filling-in are reviewed and assessed. Filling-in issues must be understood in relation to theoretical issues about neural-perceptual isomorphism and linking propositions. Six main conclusions are drawn: (1) visual filling-in comprises a multitude of different perceptual completion phenomena; (2) certain forms of visual completion seem to involve spatially propagating neural activity (neural filling-in) and so, contrary to Dennett's (1991; 1992) recent discussion of filling-in, cannot be described as results of the brain's "ignoring an absence" or "jumping to a conclusion"; (3) in certain cases perceptual completion seems to have measurable effects that depend on neural signals representing a presence rather than ignoring an absence; (4) neural filling-in does not imply either "analytic isomorphism" or "Cartesian materialism," and thus the notion of the bridge locus--a particular neural stage that forms the immediate substrate of perceptual experience--is problematic and should be abandoned; (5) to reject the representational conception of vision in favor of an "enactive" or "animate" conception reduces the importance of filling-in as a theoretical category in the explanation of vision; and (6) the evaluation of perceptual content should not be determined by "subpersonal" considerations about internal processing, but rather by considerations about the task of vision at the level of the animal or person interacting with the world.

Humans↗
PubMed1998

A model for estimating the cost-utility of clinical audit. The example of thrombolysis for suspected acute myocardial infarction.

Economic evaluation of quality assurance programs is often called for but rarely reported. A study was designed to estimate the cost-utility of audit of thrombolysis in four U.K. district general hospitals, using the quality-adjusted life year. Although the results obtained were imprecise, the model used could be applied in future evaluations.

Cost-Benefit Analysis↗
PubMed1998

CAG repeat expansion in autosomal dominant familial spastic paraparesis: novel expansion in a subset of patients.

Autosomal dominant familial spastic paraplegia (FSP) is a genetically heterogeneous neurodegenerative disorder displaying anticipation for which three loci have been mapped to the chromosomal positions 14q11.2-q24.3 (SPG3), 2p21-p24 (SPG4) and 15q11.1 (SPG6). The repeat expansion detection (RED) method has been used to demonstrate expanded CAG repeats in some FSP families that map to SPG4. We analyzed 20 FSP families, including four for which there is evidence for linkage to SPG4, and found that in most cases the repeat expansion detected by RED is due to non-pathogenic expansions of the chromosome 18q21.1 SEF2-1 or 17q21.3 ERDA1 locus. Polymorphic expansions at SEF2-1 and ERDA1 appear frequent and may confound RED studies in the search for genes causing disorders demonstrating anticipation. In six FSP families, however, CAG repeat expansion was detected in a subset of affected and at-risk individuals that did not result from expansion of the SEF2-1 and ERDA1 loci. Overall, 11 of 37 (30%) of the FSP patients with a CAG/CTG repeat expansion are unaccounted for by the SEF2-1 and ERDA1 loci, compared with two of 23 (9%) of the unaffected at-risk individuals and none of 19 controls. In the majority of cases these novel expansions were shorter than those previously reported.

Basic Helix-Loop-Helix Leucine Zipper Transcriptio↗
PubMed1998

Baller-Gerold syndrome associated with congenital portal venous malformation.

We report a 4 year old boy in whom the clinical features of craniosynostosis and bilateral absent radii led to a diagnosis of Baller-Gerold syndrome. Additional congenital abnormalities included midface hypoplasia, atrial and ventricular septal defects, right hydronephrosis, partial sacral agenesis, and anterior ectopic anus. Evidence of portal venous hypertension was present from 8 months and a congenital portal venous malformation was discovered at 2 years. This is the first reported case of Baller-Gerold syndrome associated with a congenital portal venous malformation. We discuss the diagnostic confusion between this syndrome and other overlapping malformation syndromes and propose optimal evaluation strategies aimed at clarifying the nosology of these syndromes.

Abnormalities, Multiple↗
PubMed1998

Why is evaluation of the cost effectiveness of audit so difficult? The example of thrombolysis for suspected acute myocardial infarction.

BACKGROUND: Cost effectiveness analysis is an established technique for evaluation of delivery of health care, but its use to evaluate clinical audit is rarely reported. Thrombolysis for suspected acute myocardial infarction is a commonly used therapy of established effectiveness and an appropriate subject for audit in many healthcare settings. OBJECTIVE: To measure the cost effectiveness of audit of thrombolysis in some district general hospitals. MAIN OUTCOME MEASURE: Cost of audit per extra patient treated with thrombolysis (incremental cost effectiveness ratio). DESIGN: Prospective agreement with physicians to undertake repeated audits of a specific aspect of the management of patients with acute myocardial infarction. Baseline measurement of the proportion of these patients given thrombolysis in each hospital were made, as were three subsequent retrospective audits, giving time series of measurements. Costs were estimated from records of staff time and other resources used in each hospital; effectiveness was estimated by fitting the results to a model which assumed a uniform rate of increase over time in the proportion of eligible patients given thrombolysis which might be accelerated by regular audit. Upper and lower limits for main outcome measure were derived from sensitivity analysis of costs and logistic regression of time series data. SETTING: Five district general hospitals in North West Thames Regional Health Authority including one control hospital were used, starting in April 1991 when widespread medical audit was first introduced. RESULTS: Between the first and last audits, the proportion of patients with suspected acute myocardial infarctions receiving thrombolysis rose in three of the hospitals undertaking audit by 20% to 37% and fell by 6% in the fourth (although this hospital started with a rate in excess of 90%). The corresponding change in the control hospital was an increase of 15%. The differences between each of the auditing hospitals and control hospital were not significant, except in one case, where 51 extra treatments per year were attributable to audit (95% confidence intervals (95% CIs) 0.5 to 61 cases per year). Estimated overall costs in each hospital ranged from 3700 Pounds to 5200 Pounds for data collection, a series of four audit meetings, and subsequent actions. The central estimate of cost effectiveness in the three responsive hospitals ranged from 101 Pounds to 392 Pounds per extra case given thrombolysis, with very wide 95% CIs. In the fourth hospital audit had zero effectiveness as defined in this study. CONCLUSIONS: Methodological difficulties were encountered which need to be considered in future economic evaluations of clinical audit and related activities. These were: (a) adequate control for other factors influencing clinical behaviour; (b) uncertainties about the sustainability of changes in behaviour associated with audit; and (c) the relative infrequency in a single hospital of specific clinical events leading to small numbers for analysis. These difficulties constitute major challenges for the economic evaluation of clinical audit. They are most likely to be overcome in a large study which compares clinical audit with other interventions aiming for the same quality improvement, such as patient specific reminders or educational programmes.

Cost-Benefit Analysis↗
PubMed1998

Intrathecal baclofen and homeopathy for the treatment of painful muscle spasms associated with malignant spinal cord compression.

In this case study we describe a dual approach to the palliation of difficult muscle spasms using intrathecal baclofen via a fully implanted system, together with the homeopathic approach to symptom control. The homeopathy is seen to complement rather than to replace conventional prescribing and using both approaches together appears to have avoided the necessity for increasing drug doses and to have minimized side-effects. As well as encouraging us to take on experience from other disciplines, this case study also suggests that palliative care could be a forum for evaluating the effectiveness of the homeopathic approach in symptom control in carefully designed studies.

Aged↗
PubMed1998

Meta-analysis of chemotherapy versus combined modality treatment trials in Hodgkin's disease. International Database on Hodgkin's Disease Overview Study Group.

DESIGN: To perform a meta-analysis of all randomized trials that compared chemotherapy (CT) alone versus combined modality treatment (CT + radiotherapy [RT]) for which individual patient data could be made available. PATIENTS AND METHODS: Data on 1,740 patients treated on 14 different trials that included 16 relevant comparisons have been analysed. Eight comparisons were designed to evaluate the benefit of additional RT after the same CT (CT1 v CT1 + RT; additional RT design). Eight comparisons were designed to evaluate whether RT in a combined modality setting can be substituted by CT using either more cycles of the same CT or regimens that contain additional drugs (CT1 + CT2 v CT1 + RT or CT1 v CT2 + RT; parallel RT/CT design). RESULTS: Additional RT showed an 11% overall improvement in tumor control rate after 10 years (P = .0001; 95% confidence interval [CI], 4% to 18%). No difference could be detected with respect to overall survival (P = .57; 95% CI, -10% to 4%). In contrast, when combined modality treatment was compared with CT alone in the parallel-design trials, no difference could be detected in tumor control rates (P = .43; 95% CI, -6% to 9%), but overall survival was significantly better after 10 years in the group that did not receive RT (P = .045; 8% difference; 95% CI, 1% to 15%). There were significantly fewer fatal events among patients in continuous complete remission (relative risk [RR], 1.73; 95% CI, 1.17 to 2.53; P = .005) if no RT was given. CONCLUSION: Combined modality treatment in patients with advanced-stage Hodgkin's disease overall has a significantly inferior long-term survival outcome than CT alone if CT is given over an appropriate number of cycles. The role of RT in this setting is limited to specific indications.

Antineoplastic Agents↗
PubMed1998

Autosomal dominant Klippel-Feil anomaly with cleft palate.

Klippel-Feil anomaly is characterized by the fusion of two or more cervical vertebrae. Most cases are sporadic but dominant and recessive inheritance are well described. Associated anomalies such as a cleft palate are common. We describe a unique family with autosomal dominantly inherited Klippel-Feil anomaly in six individuals associated with a cleft palate in four. One patient, a child, has a cleft palate only but may develop radiological cervical fusion with time, as documented in two other family members.

Adult↗
PubMed1998

Utility and cost-savings of diagnostic laparoscopy in low-probability gunshot wounds of the abdomen.

Gunshot wounds of the abdomen are associated with a 90% or greater incidence of intra-abdominal injury, prompting many trauma centers to routinely explore these patients via laparotomy. Increasingly, diagnostic laparoscopy has been used to evaluated the abdomen to exclude peritoneal violation by the missile. Retrospective analysis of the experience at a Level I Trauma Center with 20 isolated abdominal gunshot wound patients who did not have obvious indications for laparotomy such as peritonitis or shock is detailed. Outcome and cost analysis were compared in patients who had diagnostic laparoscopy or laparotomy. Patients who underwent diagnostic laparoscopy instead of laparotomy had a 42% reduction in operative time, a 33% reduction in hospital charges, and a reduction in hospital length of stay from an average of 3.5 days to less than one day. The only operative complication noted was in a patient who underwent laparotomy. Diagnostic laparoscopy may be used in select patients to exclude significant intra-abdominal injuries following gunshot wounds of the abdomen with reduction in health care costs and morbidity.

Abdominal Injuries↗
PubMed1997

A gene for FG syndrome maps in the Xq12-q21.31 region.

FG syndrome is an X-linked recessive condition in which mental retardation is associated with congenital hypotonia, macrocephaly, characteristic face, and constipation. This syndrome was mapped by Zhu et al. [Cytogenet Cell Genet 1991;58:2091A] to Xq21.31-q22 by linkage analysis with a max lod score of 1.2 for the DXYS1X, DXS178, DXS101, and DXS94 loci and crossovers at DXS16 (Xp22.31) and DXS287 (Xq22.3). However, this mapping was only provisional and needed to be refined. In this paper, we report the results of a new linkage analysis performed on 10 families including that studied by Zhu et al. [1991]. Two-point analysis demonstrated linkage with DXS441 (Zmax = 3.39 at theta = 0.12) at Xq13. In addition, separate analysis of the lod scores obtained for the Xq13 markers suggested linkage exclusion for three families. Genetic heterogeneity was confirmed by analysis of the linkage results with the HOMOG program (max logL = 4.07, theta = 0, alpha = 0.65). Localization of one FG gene between DXS135 and DXS1066 was suggested by analysis of crossovers found in those three families which were assumed to be linked to Xq13 with a probability of 0.95 or more. This region could be reduced to the DXS135-DXS72 interval after combining our data with those from deletions previously described in males in the Xq13-q21 region.

Abnormalities, Multiple↗
PubMed1997

Genetic and phenotypic analysis of a large (122-member) protein S-deficient kindred provides an explanation for the familial coexistence of type I and type III plasma phenotypes.

Protein S deficiency is a known risk factor for thrombosis. The coexistence of phenotypic type I (reduction in total and free antigen) and type III (reduction in free antigen only) protein S deficiencies in 14 of 18 families was recently reported. We investigated the cause of this phenotypic variation in the largest of these families (122 family members, including 44 affected individuals) using both molecular genetic and phenotypic analysis. We have identified a sole causative mutation (Gly295Val) in three family members representative of the variable phenotype. Complete cosegregation of the mutation with reduced free protein S antigen levels was found, regardless of the total antigen level. Analysis of phenotypic data showed high correlations between total protein S antigen and age in both normal and protein S-deficient family members, irrespective of gender. Free protein S antigen levels were not influenced by age, a finding explained by an association between beta-chain containing C4b-binding protein (C4bBP-beta+) antigen levels and age. We propose that the identified Gly295Val mutation causes quantitative, or type I, protein S deficiency, and that as age increases the total protein S antigen level normalizes with respect to the reference plasma pool, giving rise to a type III protein S-deficient phenotype.

Adolescent↗
PubMed1997

Symbol grounding: a bridge from artificial life, to artificial intelligence.

This paper develops a bridge from AL issues about the symbol-matter relation to AI issues about symbol-grounding by focusing on the concepts of formality and syntactic interpretability. Using the DNA triplet-amino acid specification relation as a paradigm, it is argued that syntactic properties can be grounded as high-level features of the non-syntactic interactions in a physical dynamical system. This argument provides the basis for a rebuttal of John Searle's recent assertion that syntax is observer-relative (1990, 1992). But the argument as developed also challenges the classic symbol-processing theory of mind against which Searle is arguing, as well as the strong AL thesis that life is realizable in a purely computational medium. Finally, it provides a new line of support for the autonomous systems approach in AL and AI (Varela & Bourgine 1992a, 1992b).

Animals↗
PubMed1997

Mutation detection in FGFR2 craniosynostosis syndromes.

Five autosomal dominant craniosynostosis syndromes (Apert, Crouzon, Pfeiffer, Jackson-Weiss and Crouzon syndrome with acanthosis nigricans) result from mutations in FGFR genes. Fourteen unrelated patients with FGFR2-related craniosynostosis syndromes were screened for mutations in exons IIIa and IIIc of FGFR2. Eight of the nine mutations found have been reported, but one patient with Pfeiffer syndrome was found to have a novel G-to-C splice site mutation at-1 relative to the start of exon IIIc. Of those mutations previously reported, the mutation C1205G was unusual in that it was found in two related patients, one with clinical features of Pfeiffer syndrome and the other having mild Crouzon syndrome. This degree of phenotypic variability shows that the clinical features associated with a specific mutation do not necessarily breed true.

Adult↗
PubMed1997

Involvement of an octamer-like sequence within a crucial region of the androgen-dependent Slp enhancer.

Androgen dependence of the mouse sex-limited protein (Slp) gene is conferred by an enhancer encompassing a consensus hormone response element (HRE) and sites for several nonreceptor factors. The footprint IV (FPIV) region of the enhancer plays a key role in hormone- and tissue-specific response, both in vitro and in vivo. We characterized FPIV-binding factors by methylation interference analysis and UV cross-linking of several complexes evident in gel mobility-shift assays. The footprinting analysis revealed that distinct base contacts within the multiple nuclear protein-DNA complexes occurred primarily within a sequence similar to an octamer transcription factor (Oct-1) binding site. With additional data on approximate molecular weights from UV cross-linking, several plausible candidates were tested for their DNA binding and functional activity at FPIV. Oct-like protein binding in gel-shift assays with several cell and tissue extracts was evident using specific competitors and antibodies, but was lower in affinity for FPIV than for an Oct-1 consensus site. Site-directed mutation of the FPIV sequence to a consensus Oct-1 element within the Slp enhancer context increased Oct-1 binding in vitro, but greatly reduced hormonal induction in vivo. This suggested that Oct-1 is not directly involved in response, or alternatively, that Oct-1 bound to the lower-affinity site interacts with neighboring factors significantly differently than Oct-1 bound to a consensus sequence. A sequence overlapping the Oct-like element that was similar to a hepatic nuclear factor-4 (HNF-4) site showed no ability to bind HNF-4 in vitro, nor the related orphan receptor, chicken ovalbumin upstream promoter factor (COUP-TF). Intriguingly, however, expression of COUP-TF in transfection had a dramatic inhibitory effect on response of the androgen-specific enhancer (C' delta9), but did not affect other enhancer configurations that can also be induced by glucocorticoid (C 'delta2). This underscores that, despite extensive sequence identity of C' delta9 and C' delta2, components of the androgen-specific transcription complex differ significantly from that of one that is more generally steroid responsive.

Androgens↗