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Biomedical subjects

E Stewart

Publications and source records attributed to E Stewart.

At least 19 recordsLinked to original sources
PubMed2006

CT imaging of wet specimens from a pathology museum: How to build a "virtual museum" for radiopathological correlation teaching.

X-rays and CT have been used to examine specimens such as human remains, mummies and formalin-fixed specimens. However, CT has not been used to study formalin-fixed wet specimens within their containers. The purpose of our study is firstly to demonstrate the role of CT as a non-destructive imaging method for the study of wet pathological specimens and secondly to use the CT data as a method for teaching pathological and radiological correlation. CT scanning of 31 musculoskeletal specimens from a pathology museum was carried out. Images were reconstructed using both soft-tissue and bone algorithms. Further processing of the data produced coronal and sagittal reformats of each specimen. The container and storage solution were manually removed using Volume Viewer Voxtool software to produce a 3D reconstruction of each specimen. Photographs of each specimen (container and close-up) were displayed alongside selected coronal, sagittal, 3D reconstructions and cine sequences in a specially designed computer program. CT is a non-destructive imaging modality for building didactic materials from wet specimens in a Pathology Museum, for teaching radiological and pathological correlation.

Algorithms↗
PubMed2004

Lambing rates and litter sizes following intrauterine or cervical insemination of frozen/thawed semen with or without oxytocin administration.

Intrauterine insemination by laparoscopy is required to achieve acceptable lambing rates in ewes when using frozen semen but the procedure has evoked welfare concerns. Oxytocin has been used to dilate the cervix as a means of accessing the uterus during conventional cervical insemination, but its effect on fertility is not well documented. Three hundred crossbred ewes were synchronised in estrus and randomly allocated to one of three insemination procedures using frozen/thawed semen containing 400 x 10(6)/ml progressively motile sperm: single cervical (0.2 ml), multiple cervical (4 x 0.05 ml) or laparoscopic (0.05 ml per uterine horn). The effects of each insemination procedure on lambing rate (percentage of treated ewes lambing) and litter size (lambs per ewe lambing) were tested with and without oxytocin (10 IU given i.m.) prior to fixed-time insemination. Oxytocin did not permit complete cervical penetration in any ewes and neither lambing rate nor litter size was influenced by the number of inseminations. Lambing percentages were 69 and 42 (P < 0.01) for the laparoscopic and cervical insemination methods, respectively, and oxytocin reduced these to 58 (NS) and 10 (P < 0.001) percent, respectively. Corresponding litter sizes for ewes not receiving oxytocin were 1.91 and 1.51 and for those receiving oxytocin, 1.83 and 1.41 (laparoscopic versus cervical, P < 0.02). Thus, in the absence of complete cervical penetration at insemination, 10 IU oxytocin decreased the number of ewes lambing but had no effect on their litter size.

Animals↗
PubMed2003

CT imaging of angiogenesis.

Tumor angiogenesis has significant implications in the diagnosis and treatment of various solid tumors. With the advent of fast, multi-slice CT scanners, CT imaging techniques capable of qualitative and quantitative analysis of tumor angiogenesis have been the subject of extensive investigation in the past 2 decades. The fundamental bases for CT imaging of angiogenesis are both the transport by blood flow of intravenously administered iodinated contrast material to tissue and the exchange by diffusion of these contrast molecules between the intravascular space and the extravascular interstitial space. With current fast CT scanners both tissue and vascular enhancement can be measured and traced over time at small time intervals to allow detailed modeling of the distribution of contrast agent in tissue. Both compartmental and distributed parameter models for contrast transport and exchange have been developed to quantify from the CT data the following angiogenesis related parameters: tissue blood flow, blood volume, mean transit time, contrast arrival time, capillary permeability surface area product and hepatic arterial fraction in case of the liver. This review addresses the following aspects of CT imaging of angiogenesis: 1) basic concepts related to the understanding of both compartmental and distributed parameter models; 2) comparison between both types of models; 3) practical issues with respect to the measurement of the arterial input function, which is required for the solution of both types of models; and, 4) illustration of the application of a distributed parameter model, the Johnson and Wilson model, in a number of experimental studies.

Angiography↗
PubMed2002

Antinuclear autoantibodies (ANA) in Gulf War-related illness and chronic fatigue syndrome (CFS) patients.

It is established that veterans of the 1991 Gulf War have an increased frequency of experiencing multiple symptoms. The underlying mechanism of these ailments is unclear, although they do not correspond to any clearly defined syndrome. The most common symptoms overlap with those of chronic fatigue syndrome (CFS). CFS was recently associated with a novel subtype of antinuclear autoantibody (ANA) that reacts with nuclear envelope (NE) antigens. NE autoantibodies are not known to be linked with any distinct clinical condition, but have been observed in patients with unusual mixed chronic autoimmune disorders and connective tissue diseases. In this study we examined whether NE ANAs are a feature of patients with CFS and symptomatic Gulf War veterans (sGWV). We studied the prevalence of ANA in 130 sGWV, 90 well Gulf War veterans (wGWV), 128 symptomatic Bosnia and Era veterans (sBEV), 100 CFS patients, and 111 healthy control subjects matching for age and sex. We found no significant difference in the prevalence of ANAs between any of the groups. None of the patients/or veterans we studied had ANA of the NE type. Our results show that multisymptom illness due to CFS or related to Gulf War service is not associated with antinuclear autoimmunity.

Adult↗
PubMed2002

Reliability of postal questionnaires for the Glasgow Outcome Scale.

The purpose of the study was to investigate if a questionnaire sent by mail can give a reliable assessment of outcome on the Glasgow Outcome Scale. A questionnaire was developed for the Glasgow Outcome Scale (GOS) and a second questionnaire for the Extended Glasgow Outcome Scale (GOSE). The questionnaires were self-contained and designed to be completed by either a head-injured person or a proxy. The questionnaires were studied in two ways: each questionnaire was administered twice (at an interval of approximately 2 weeks), and ratings from the postal questionnaires were compared to ratings from a structured interview conducted by telephone. The four studies were carried out in separate groups of head-injured participants consisting of 32-38 individuals. For the test-retest comparison, k(w) (quadratic weights) was 0.94 for the GOS questionnaire and 0.98 for the GOSE questionnaire. For the comparison with the telephone interview, k(w) was 0.67 for the GOS and 0.92 for the GOSE. The values of k(w) indicate good agreement for all comparisons. We conclude that it is possible to obtain reliable outcome data after head injury using postal questionnaires.

Adolescent↗
PubMed2002

Decreased youth tobacco use in Massachusetts 1996 to 1999: evidence of tobacco control effectiveness.

OBJECTIVE: To evaluate tobacco control in Massachusetts through examining trends in youth tobacco use from 1996 to 1999. DESIGN: Data are from the 1996 and 1999 Massachusetts Prevalence Study survey of public school students in the state. PARTICIPANTS: Participants consisted of 6800 (1996) and 6980 (1999) students in Massachusetts public school grades 6-12 (approximate ages 11-18 years). MAIN OUTCOME MEASURES: Outcomes are changes in lifetime and current (past month) cigarette, cigar, and smokeless tobacco. RESULTS: In grades 7-12, there were significant decreases in lifetime (48.3% to 41.9%) and current (30.7% to 23.7%) cigarette use, smokeless tobacco use (lifetime 16.5% to 9.9%; current 4.55 to 2.6%), and current cigar use (12.2% to 8.6%). Decreases occurred for both male and female 7-8th graders. In grades 9-12 decreases were somewhat greater for females than males. Trends for grades 8, 10, and 12 were compared to those seen nationally and in the northeast region in the Monitoring the Future study. For the pooled grades the decreases for cigarettes were greater than those seen nationally or in the northeast region. CONCLUSIONS: Results support the effectiveness of the comprehensive Massachusetts Tobacco Control Program. The increasing tobacco rates in the first half of the 1990s have been dramatically reversed. These results suggest that programme efforts should be supported or even expanded in order to decrease further the state's rates of youth tobacco use. The findings suggest that other states may learn useful lessons from Massachusetts' successes.

Adolescent↗
PubMed2001

Patient satisfaction with teledermatology is related to perceived quality of life.

BACKGROUND: There is a lack of good data about patient satisfaction with teledermatology and about its potential interaction with quality-of-life factors. OBJECTIVES: To assess the association between perceived skin-related quality of life and patient satisfaction with a nurse-led teledermatology service. METHODS: In a mobile nurse-led teledermatology clinic located in four inner city general practices in Manchester, the teledermatology service used digital cameras to capture and store images of skin conditions for remote diagnosis by dermatologists. One hundred and twenty-three adult patients, non-urgent dermatology referrals from primary care, completed the Dermatology Life Quality Index (DLQI) and a 15-item patient satisfaction questionnaire. RESULTS: In common with other studies of patient satisfaction, subjects reported highly favourable views of 'hotel' aspects of the service (93%) and found it 'convenient' (86%). However, 40% of patients would have preferred to have had a conventional face-to-face consultation with a dermatologist, and 17% felt unable to speak freely about their condition. Patient satisfaction with the service was related to quality of life. Patients reporting lower quality of life as measured by the DLQI were more likely to prefer a face-to-face encounter with a dermatologist (r = 0.216, P < 0.05), and to evince anxiety about being photographed (r = 0.223, P < 0.05). CONCLUSIONS: Patient acceptance and satisfaction with telemedicine services is complicated by patients' subjective health status. Telehealthcare providers need to recognize that patients with poor quality of life may want and benefit from face-to-face interaction with expert clinicians.

Adolescent↗
PubMed2001

The influence of apolipoprotein E genotype on outcome after spontaneous subarachnoid hemorrhage: a preliminary study.

OBJECTIVE: Possession of an apolipoprotein E (APOE)epsilon4 allele has been shown to be associated with a poor outcome after closed head injury and spontaneous intracerebral hemorrhage but not after ischemic stroke. This study assessed the influence of the APOE genotype on outcome in patients admitted to a neurosurgical unit with spontaneous subarachnoid hemorrhage. METHODS: A total of 100 patients with spontaneous subarachnoid hemorrhage were studied. Four patients were excluded because the diagnosis of subarachnoid hemorrhage was not confirmed. The incidence of rehemorrhage and delayed ischemia and the outcome at 6 months were determined using the Glasgow Outcome Scale. APOE genotypes were determined by polymerase chain reaction and restriction enzyme digestion. RESULTS: Allele frequencies in this patient group were 0.04 for epsilon2, 0.86 for epsilon3, and 0.1 for epsilon4. Of 96 patients, 72 had an aneurysmal hemorrhage and 1 had a hemorrhage from an arteriovenous malformation. In 14 patients, the results of angiography were negative, and in 9, no angiogram was performed. Of the 96 patients, 20 had one or more epsilon4 allele. Outcome at 6 months was no worse in patients with one or more epsilon4 allele than in those with no epsilon4 allele (odds ratio, 0.98; 95% confidence interval, 0.35-2.74). None of the 12 patients who experienced delayed ischemic deterioration had an epsilon4 allele. Of the 20 patients with an epsilon4 allele, 3 had a rehemorrhage, as compared with 6 of 76 patients without an epsilon4 allele. CONCLUSION: There was underrepresentation of the epsilon4 allele in this group when compared with previously studied cases of subarachnoid hemorrhage with a fatal outcome and with the general population. This suggests that patients with the epsilon4 allele who have a subarachnoid hemorrhage are less likely to be admitted to a neurosurgical unit. This study does not support an association between possession of an epsilon4 allele and poor outcome in patients admitted to a neurosurgical unit with spontaneous subarachnoid hemorrhage, although the wide confidence interval does not preclude a clinically relevant association between APOE genotype and outcome. The findings indicate that an association between genotype and the development of delayed ischemic complications after subarachnoid hemorrhage may be possible.

Adult↗
PubMed2001

Patient satisfaction with store-and-forward teledermatology.

We assessed patient satisfaction with a nurse-led store-and-forward teledermatology service in Manchester. A teledermatology nurse obtained the patient's history, took digital photographs of the patient's skin lesion and then sent the information to a hospital dermatologist, who responded with management advice the following week. Of 141 patients who attended their teledermatology appointment, 123 (50 male, 73 female) completed the study questionnaire (87%). The average age of respondents was 42 years (SD 17, range 18-90 years). Ninety-three per cent reported that they were happy with the teleconsultation while 86% reported that it was more convenient than going to the outpatient clinic. Forty per cent agreed that they would feel more comfortable seeing the dermatologist in person while only 58% were comfortable with not speaking to the dermatologist about their skin condition. The absence of interaction with the dermatologist and the delay in receiving management advice may have contributed to the somewhat low satisfaction rates.

Adolescent↗
PubMed2000

Solving the coincidence problem: tracking oscillating energy.

Recent cosmological observations strongly suggest that the Universe is dominated by an unknown form of energy with negative pressure. Why is this dark energy density of order the critical density today? We propose that the dark energy has periodically dominated in the past so that its preponderance today is natural. We illustrate this paradigm with a model potential and show that its predictions are consistent with all observations.

Journal Article↗
PubMed1999

Perceived discomfort in running: scale development and theoretical considerations.

The aim of this study was to develop a discomfort questionnaire to elicit the feelings and thoughts of people engaged in running activities. Ten runners who completed a particularly demanding 9-km run were asked to express their feelings and thoughts during the run they had just completed. These responses were recorded and later used as the first pool of items (k = 36). The questionnaire was then given to 171 runners in different distance races throughout the 1995 competitive season. These responses were analysed using exploratory factor analytic techniques and Rasch probabilistic analysis, as well as traditional reliability and validity procedures. The final version of the questionnaire consisted of 32 items divided into eight correlated subscales: proprioceptive symptoms, leg symptoms, respiratory difficulties, disorientation, dryness and heat, task completion thoughts, mental toughness, and head or stomach symptoms. These eight categories can be collapsed into three global categories suggested by researchers of pain: sensory-discriminative, motivational-affective and cognitive-evaluative. Rasch analysis suggested that the motivational-affective and cognitive-evaluative dimensions (i.e. the psychological) are the most experienced (i.e. rated highest). The eight subscales have ecological validity and were found to alter with the demands of different running distances.

Adolescent↗
PubMed1998

Phase II study of carboplatin (CBDCA) in progressive low-grade gliomas.

In this study, the authors sought to investigate the response rate and toxicity of carboplatin in patients with progressive low-grade glioma (LGG). Thirty-two patients with progressive LGG were treated with carboplatin at a dosage of 560 mg/m(2). Treatment was given at 4-week intervals and continued until the disease progressed, unacceptable toxicity supervened, or for 12 additional courses after achieving maximal response. Patients with stable disease were treated with a total of 12 cycles. All patients were treated as outpatients. Patients were evaluated for response to treatment and toxicity. All patients received a minimum of two cycles of carboplatin, and were examined for response. A partial response was achieved in nine patients (28%) and a minimal response in two (6%), for an overall response rate of 34% (11 of 32 patients). Eighteen patients (56%) had stable disease. A partial response was achieved in the nine patients after a median of six cycles (range 4-11 cycles), a minimal response was achieved in the two patients after five cycles. Glioma progression was noted in three patients after three, five, and five cycles, respectively. The 11 patients in whom some response was achieved had either an optic pathway tumor or a juvenile pilocytic astrocytoma. Twenty-six of the 32 patients had those characteristics, making the response rate in that group 42% (11 of 26 patients). Thirty-two patients received a total of 387 cycles of chemotherapy. Hematological toxicity was moderate. Twenty-one patients developed thrombocytopenia (platelet count < 50,000/microl); three patients required one platelet transfusion each. Nine patients developed neutropenia (absolute neutrophil count < 500/microl); one developed fever and required administration of antibiotic agents. One dose adjustment in each of the patients prevented further thrombocytopenia and neutropenia. Two patients with stable disease died of respiratory complications. One patient developed Grade III ototoxicity after receiving five cycles, one patient developed hypersensitivity to carboplatin, and none developed nephrotoxicity. Carboplatin given at a dosage of 560 mg/m(2) every 4 weeks has activity in patients with progressive LGG. This drug regimen is relatively simple and well tolerated. Further investigation and longer follow-up study are warranted.

Journal Article↗
PubMed1998

Activity of high-dose cyclophosphamide in the treatment of childhood malignant gliomas.

Seventeen patients less than or equal to 20 years of age with newly diagnosed (n = 10) or recurrent (n = 7) malignant gliomas (anaplastic astrocytoma and glioblastoma multiforme) were treated with cyclophosphamide in association with hematopoietic cytokines (GM-CSF or G-CSF). Cyclophosphamide was given at a dose of 2 g/m2 daily for 2 days at 4-week intervals. Toxicity consisted of grade IV neutropenia and thrombocytopenia in 95% and 48% of cycles, respectively. There were no cyclophosphamide-related cardiac, pulmonary, or urothelial toxicities observed. Four of 10 patients with newly diagnosed disease demonstrated responses (three complete and one partial responses; one CR was only of 2 months duration). None of the seven patients with recurrent tumors demonstrated a response. We conclude that high-dose cyclophosphamide warrants further evaluation in children with newly diagnosed malignant glioma.

Adolescent↗
PubMed1998

Temporary exposure of ovine embryos to an advanced uterine environment does not affect fetal weight but alters fetal muscle development.

Embryo transfer techniques may result in fetuses that are heavier at birth and that have been described as highly muscled. The aim of this study was to investigate myogenesis in lambs derived from embryo transfer. Embryos were transferred at Day 3 (estrus = Day 0) to a 3 days-advanced uterine environment, maintained there for 3 days, recovered, and then returned to a synchronous (Day 6) uterus; these fetuses comprised the asynchronous group. Control animals were created by synchronous embryo recovery and single transfer at Day 3. Asynchronous transfer did not affect fetal weight or curved crown-rump length between 46 and 135 days of gestation. No differences were detected between groups at Days 110-135 with respect to muscle mass or protein, RNA, and DNA content. However, total muscle fiber number was significantly increased in plantaris muscles from the asynchronous groups at Day 110 and Day 125, suggestive of prolonged hyperplasia. In addition, the levels of Myf 5 protein and the secondary-to-primary fiber ratio were altered in plantaris muscle from the asynchronous group. The growth data are in contrast to previously reported findings. The results show that fetal myogenesis can be altered by very early events in embryogenesis and suggest that any inferences made solely on the basis of fetal or muscle weight may be fallacious.

Animals↗
PubMed1998

DNA mismatch repair and O6-alkylguanine-DNA alkyltransferase analysis and response to Temodal in newly diagnosed malignant glioma.

PURPOSE: We evaluated the response to Temodal (Schering-Plough Research Institute, Kenilworth, NJ) of patients with newly diagnosed malignant glioma, as well as the predictive value of quantifying tumor DNA mismatch repair activity and O6-alkylguanine-DNA alkyltransferase (AGT). PATIENTS AND METHODS: Thirty-three patients with newly diagnosed glioblastoma multiforme (GBM) and five patients with newly diagnosed anaplastic astrocytoma (AA) were treated with Temodal at a starting dose of 200 mg/m2 daily for 5 consecutive days with repeat dosing every 28 days after the first daily dose. Immunochemistry for the detection of the human DNA mismatch repair proteins MSH2 and MLH1 and the DNA repair protein AGT was performed with monoclonal antibodies and characterized with respect to percent positive staining. RESULTS: Of the 33 patients with GBM, complete responses (CRs) occurred in three patients, partial responses (PRs) occurred in 14 patients, stable disease (SD) was seen in four patients, and 12 patients developed progressive disease (PD). Toxicity included infrequent grades 3 and 4 myelosuppression, constipation, nausea, and headache. Thirty tumors showed greater than 60% cells that stained for MSH2 and MLH1, with three CRs, 12 PRs, three SDs, and 12 PDs. Eight tumors showed 60% or less cells that stained with antibodies to MSH2 and/or MLH1, with 3 PRs, 3 SDs, and 2 PDs. Eleven tumors showed 20% or greater cells that stained with an antibody to AGT, with 1 PR, 2 SDs, and 8 PDs. Twenty-five tumors showed less than 20% cells that stained for AGT, with 3 CRs, 12 PRs, 4 SDs, and 6 PDs. CONCLUSION: These results suggest that Temodal has activity against newly diagnosed GBM and AA and warrants continued evaluation of this agent. Furthermore, pretherapy analysis of tumor DNA mismatch repair and, particularly, AGT protein expression may identify patients in whom tumors are resistant to Temodal.

Adult↗