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Biomedical subjects

P Goddard

Publications and source records attributed to P Goddard.

At least 37 records · Page 2Linked to original sources

The STIR sequence MRI in the assessment of extraocular muscles in thyroid eye disease.

Nineteen patients with thyroid eye disease were examined with magnetic resonance imaging using the Short Tau Inversion Recovery (STIR) sequence and compared with normal controls. The Signal Intensity Ratio (SIR) of each of the four recti was obtained by comparison with the signal intensity of the adjacent temporalis muscle. The SIR was compared with disease activity assessed using Werner's grading system, a clinical inflammatory score, and the range of extraocular movements. Results show that a high SIR is associated with a high index of disease activity. This technique is likely to prove useful in assessing disease activity and planning the management of thyroid eye disease, particularly with respect to immunosuppression.

Adult↗

The value of the short tau inversion recovery sequence in magnetic resonance imaging of thyroid eye disease.

22 patients with thyroid eye disease were examined with magnetic resonance imaging (MRI) and the results compared with 10 controls. Imaging was performed on a 1.0 T scanner using a head coil. All patients were examined using both T1W and short tau inversion recovery (STIR) sequences. The relative signal intensity (SI) of individual extraocular muscles were quantified by comparison with SI from the adjacent temporalis muscle to give a signal intensity ratio (SIR). The results were compared with clinical disease activity assessed by the Werner grading system. Visual evaluation of muscle size and calculated SIRs showed an increase when compared to normals in 15 of the 22 patients. This difference was significant in patients with high grade (4-6) clinical disease. The known histological changes in this disease suggest that this increase in signal is caused by oedema secondary to acute inflammation. STIR sequences suppress the retro-orbital fat and thus enhance these changes both in the muscles and in the fat itself. The MR findings suggest that the STIR sequence can be used to predict those patients that will respond to anti-inflammatory treatment.

Adult↗

Subclavian artery aneurysm: the role of magnetic resonance imaging.

Subclavian artery aneurysms are rare. Diagnosis is important as complications can be life threatening. A case is reported which is diagnosed by magnetic resonance imaging; moreover it is suggested that magnetic resonance imaging is now the initial imaging modality of choice in the investigation of these lesions.

Aged↗

Identification, synthesis and properties of 5-(aziridin-1-yl)-2-nitro-4-nitrosobenzamide, a novel DNA crosslinking agent derived from CB1954.

5-(Aziridin-1-yl)-4-hydroxylamino-2-nitrobenzamide, the active form of 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB1954), can react spontaneously with oxygen, and in aqueous solution yields 5-(aziridin-1-yl)-2-nitro-4-nitrosobenzamide and hydrogen peroxide. Mild biological reducing agents such as NAD(P)H, reduced thiols and ascorbic acid rapidly re-reduced the nitroso compound to the hydroxylamine. Both compounds were equally efficient at inducing cytotoxicity and DNA interstrand crosslinking in cells when exposed in phosphate-buffered saline (PBS). Neither agent was capable of inducing cross-links in isolated DNA. When acetyl coenzyme A was included in the incubation, crosslink formation was seen with the hydroxylamine, but not with the nitroso compound. Thus, the nitroso compound is acting as a prodrug for the hydroxylamine, and needs to be reduced to this compound to exert its cytotoxic effects. In vivo anti-tumour tests showed that neither compound was effective in its own right. This may be due to the rapid reduction of the nitroso to the hydroxylamine, and the reaction of the hydroxylamine with serum proteins. The chemical synthesis of the 5-(aziridin-1-yl)-2-nitro-4-nitrosobenzamide, and an improved synthesis of 5-(aziridin-1-yl)-4-hydroxylamino-2-nitrobenzamide is described. These results emphasize the potential efficacy of the in situ activation of prodrugs such as CB1954 either by endogenous enzymes such as DT diaphorase, or by antibody directed enzyme prodrug therapy (ADEPT).

Animals↗

Cue exposure with coping skills treatment for male alcoholics: a preliminary investigation.

Although early investigations were promising, no controlled follow-up studies have investigated the effectiveness of cue exposure treatment for alcoholics. In this study, inpatient alcoholics received either cue exposure integrated with urge coping skills training (CET, n = 22) or a contrast condition (CC) involving daily contact with assessment only (n = 18) in addition to standard treatment. Comprehensive assessment measures were used to investigate change in process and outcome variables. In the second 3 months after treatment, the CET group included more patients who were completely abstinent, had a higher percentage of abstinent days, and tended to report fewer drinks per day than did patients in the contrast condition. The significantly greater use of coping skills during follow-up by the CET group and the significant relationship of these coping skills to decreased drinking suggest that treatment effects were due, at least in part, to the coping skills training, consistent with recent formulations. Theoretical and treatment implications are discussed.

Adaptation, Psychological↗

Cine magnetic resonance imaging of eye movements.

Cine magnetic resonance imaging (MRI) is a technique in which multiple sequential static orbital MRI films are taken while the patient fixates a series of targets across the visual field. These are then sequenced to give a graphic animation to the eyes. The excellent soft tissue differentiation of MRI, combined with the dynamic imaging, allows rapid visualisation, and functional assessment of the extraocular muscles. Good assessment of contractility can be obtained, but the technique does not allow study of saccadic or pursuit eye movements. We have used this technique in 36 patients with a range of ocular motility disorders, including thyroid-related ophthalmopathy, blow-out fracture, post-operative lost or slipped muscle, and Duane's syndrome.

Eye Movements↗

Magnetic resonance imaging of extracranial head and neck tumours.

The role of magnetic resonance imaging (MRI) in the investigation of head and neck tumours (excluding those primarily arising from the central nervous system or orbits) has been investigated. Follow-up data were obtained on 45 scans on 42 patients. MRI provided significant additional information compared with computed tomography (CT) in nine out of 17 (53%) scans performed for staging purposes. In the assessment of 19 patients with suspected tumour recurrence, MRI demonstrated a sensitivity of 100%, a specificity of 80% and an accuracy of 89%.

Follow-Up Studies↗

Formation of cage-like particles by poly(amino acid)-based block copolymers in aqueous solution.

When dissolved in N,N-dimethylformamide and then dialyzed against phosphate-buffered saline, A-B-A block copolymers composed of poly [N5-(2-hydroxyethyl)-L-glutamine]-block-poly(gamma-benzyl-L-glutamate)- block-poly [N5-(2-hydroxyethyl)-L-glutamine] form particles. The particles are cage-like structures with average diameters of 300 nm (average polydispersity, 0.3-0.5). They are stable in aqueous solution at 4 degrees C for up to 3 weeks, at which time flocculation becomes apparent. Negative staining and freeze-fracture electron microscopy suggest that cage-like particles are formed by selective association of segregated micelle populations. A model of particle formation is presented in which B blocks form micelles in dimethylformamide. On dialysis against an aqueous solution, the extended A blocks then associate intermolecularly to form rod-shaped micelles, which connect the B block micelles. The result is a meshed cage-like particle. The implications of these observations on the aggregation behavior of polymeric surfactants in dilute solution are discussed.

Journal Article↗

R-[N-acetyl]eglin c:poly(oxyethylene) conjugates: preparation, plasma persistence, and urinary excretion.

In this paper, we describe the preparation, purification, and characterization of conjugates of R-[N-acetyl]eglin c (Eglin c) with poly(oxyethylene) (POE; Eglin c:POE). The plasma profile and urinary excretion of the conjugates has been determined after iv administration in mice. The modification of Eglin c with POE does not significantly impair the ability of Eglin c to bind elastase as measured by an in vitro assay. In the best example, 79% of theoretical activity was retained by the conjugate. The in vivo results clearly show that the amount of Eglin c:POE in plasma after iv administration is much higher than comparative doses of unconjugated Eglin c. The time course of the plasma concentration of the conjugate matches closely that of the corresponding free polymer. Consequently, we can expect that higher plasma concentration could be achieved, if and when required, by selecting polymers of appropriate size.

Amino Acid Sequence↗

The role of magnetic resonance imaging in cystic fibrosis.

Magnetic resonance imaging (MRI) of the chest was performed on eight patients with known cystic fibrosis. Comparison was made with the findings on plain chest radiographs. MRI shows a greater extent of disease than that predicted by the chest films alone and clearly demonstrates peribronchial thickening and mucoid impacted bronchi. It also distinguishes between hilar lymphadenopathy and enlarged proximal pulmonary vessels as the cause of prominent hilar shadows without the need for contrast injection.

Adolescent↗

Comparison of transrectal ultrasound and magnetic resonance imaging in the staging of prostate cancer.

A group of 32 patients with a histological diagnosis of prostate cancer underwent transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI) to stage the disease. TRUS was more sensitive in the detection of tumour and in the detection of direct extracapsular spread. MRI was more sensitive in the detection of tumour involvement of the seminal vesicles and bladder base. MRI allowed the detection of lymphadenopathy and bone metastases in the lumbosacral spine and pelvis. During MRI the short tau inversion recovery (STIR) sequence was found to be particularly useful for the detection of tumour spread. TRUS and MRI are complementary investigations and for the accurate staging of prostatic malignancy both investigations should be used.

Bone Neoplasms↗

Magnetic resonance imaging in osteoarthritis of the knee: correlation with radiographic and scintigraphic findings.

Twelve knees with a range of severity of knee osteoarthritis were assessed by magnetic resonance imaging (MRI) and technetium-99m labelled hydroxymethylene diphosphonate scintigraphy. Five magnetic resonance pulse sequences were evaluated. Proton density (TR = 1000, TE = 26 ms) and STIR (TR = 1500, TI = 100, TE = 30 ms) were chosen for further use. Abnormalities shown by MRI included joint effusions, meniscal disruption, hyaline cartilage thinning, subchondral signal changes, pseudocysts, and heterogeneity of signal from osteophytes. Certain MRI and scintigraphic appearances correlated: (a) 'hyperintense osteophytosis' and ipsilateral 'tramline' scintigraphic uptake, suggesting increased fat content in 'active' osteophytes; (b) subchondral signal change and 'extended' pattern, possibly reflecting inflammation, synovial leak, or fibrovascular repair; (c) patellofemoral joint signal changes and patellar isotope uptake.

Aged↗