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Biomedical subjects

C Hutton

Publications and source records attributed to C Hutton.

At least 19 recordsLinked to original sources
PubMed2000

Visual attention to the periphery is enhanced in congenitally deaf individuals.

We compared normally hearing individuals and congenitally deaf individuals as they monitored moving stimuli either in the periphery or in the center of the visual field. When participants monitored the peripheral visual field, greater recruitment (as measured by functional magnetic resonance imaging) of the motion-selective area MT/MST was observed in deaf than in hearing individuals, whereas the two groups were comparable when attending to the central visual field. This finding indicates an enhancement of visual attention to peripheral visual space in deaf individuals. Structural equation modeling was used to further characterize the nature of this plastic change in the deaf. The effective connectivity between MT/MST and the posterior parietal cortex was stronger in deaf than in hearing individuals during peripheral but not central attention. Thus, enhanced peripheral attention to moving stimuli in the deaf may be mediated by alterations of the connectivity between MT/MST and the parietal cortex, one of the primary centers for spatial representation and attention.

Adolescent↗
PubMed2000

Characterization and correction of interpolation effects in the realignment of fMRI time series.

Subject motion in functional magnetic resonance imaging (fMRI) studies can be accurately estimated using realignment algorithms. However, residual changes in signal intensity arising from motion have been identified in the data even after realignment of the image time series. The nature of these artifacts is characterized using simulated displacements of an fMRI image and is attributed to interpolation errors introduced by the resampling inherent within realignment. A correction scheme that uses a periodic function of the estimated displacements to remove interpolation errors from the image time series on a voxel-by-voxel basis is proposed. The artifacts are investigated using a brain phantom to avoid physiological confounds. Small- and large-scale systematic displacements show that the artifacts have the same form as revealed by the simulated displacements. A randomly displaced phantom and a human subject are used to demonstrate that interpolation errors are minimized using the correction.

Algorithms↗
PubMed2000

Randomized controlled trial of nettle sting for treatment of base-of-thumb pain.

There are numerous published references to use of nettle sting for arthritis pain but no randomized controlled trials have been reported. We conducted a randomized controlled double-blind crossover study in 27 patients with osteoarthritic pain at the base of the thumb or index finger. Patients applied stinging nettle leaf (Urtica dioica) daily for one week to the painful area. The effect of this treatment was compared with that of placebo, white deadnettle leaf (Lamium album), for one week after a five-week washout period. Observations of pain and disability were recorded for the twelve weeks of the study. After one week's treatment with nettle sting, score reductions on both visual analogue scale (pain) and health assessment questionnaire (disability) were significantly greater than with placebo (P = 0.026 and P = 0.0027).

Aged↗
PubMed1998

Blood oxygenation level dependent signal time courses during prolonged visual stimulation.

Previous functional magnetic resonance imaging (MRI) studies using extended visual stimulation have reported disparate results. Two studies have shown that blood oxygen level dependent (BOLD) contrast decays over time which is cited as evidence of recoupling between oxygen utilisation and cerebral blood flow during stimulus presentation. These findings have serious implications for the design of functional MRI experiments because they raise the possibility that BOLD contrast may not accurately reflect neuronal activity. Another study reported no decay of BOLD contrast. These studies used different visual stimuli and imaging techniques. We have performed a series of experiments, using different MRI techniques (echo-planar imaging and fast low angle shot) and two different visual stimuli to assess which of these factors may explain the previous results. In all of our experiments the signal time course from areas of significant activation remained largely elevated throughout the duration of stimulation and this is not affected by the imaging method used. Our data, in accordance with that of Bandettini et al., suggest that recoupling between blood flow and oxygen extraction is not a general phenomenon in the human brain when visual stimuli are presented for an extended time.

Adult↗
PubMed1998

Familial dermatomyositis.

A case of familial dermatomyositis (DM) is reported in a 27-yr-old mother and her daughter aged 2 yr and 8 months. Familial DM is a rare occurrence and has never been reported in a child of < 4 yr old, although isolated cases of DM have been found in infants as young as 1 yr. The mother responded readily to corticosteroids; however, the child proved resistant to steroids and was eventually successfully managed on a combination of methotrexate and prednisolone. Another daughter presented with the dermatological stigmata of DM, but with no evidence of muscle involvement.

Adult↗
PubMed1998

Identifying global anatomical differences: deformation-based morphometry.

The aim of this paper is to illustrate a method for identifying macroscopic anatomical differences among the brains of different populations of subjects. The method involves spatially normalizing the structural MR images of a number of subjects so that they all conform to the same stereotactic space. Multivariate statistics are then applied to the parameters describing the estimated nonlinear deformations that ensue. To illustrate the method, we compared the gross morphometry of male and female subjects. We also assessed brain asymmetry, the effect of handedness, and interactions among these effects.

Adult↗
PubMed1986

An intraoral positive-pressure device for treatment of trismus.

Trismus is a challenging clinical problem that may result from several different causes. The dentist may choose from a wide spectrum of treatment modalities, depending on the severity of the individual case and the health and cooperation of the patient. An individual course of treatment must be planned for each patient. It is important to monitor the treatment closely for effectiveness of the therapy and to ensure the patient's compliance. Treatment should be modified as necessary, according to the patient's progress. We have described an intraoral dynamic device that may be used as part of a treatment program and that enhances patient compliance as compared to traditional extraoral devices.

Equipment Design↗
PubMed1986

Defective production of leucocytic endogenous mediator (interleukin 1) by peripheral blood leucocytes of patients with systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis and mixed connective tissue disease.

Leucocytic endogenous mediator is one of the activities ascribed to the cytokine or family of cytokines known as interleukin 1. In this study we have examined the ability of circulating blood leucocytes from patients with rheumatic diseases to produce this mediator in vitro. Leucocytic endogenous mediator production was found to be significantly decreased below normal values (mean 107 units, s.e.m. +/- 25) in systemic sclerosis (-6 units +/- 18), systemic lupus erythematosus (-25 units +/- 13), rheumatoid arthritis (-3 units +/- 13) and mixed connective tissue disease (-4 units +/- 40). A control group of ill patients with cancer produced 57 units +/- 8.

Adult↗
PubMed1985

A comparison of normal and pathological synovial fluid.

Synovial fluid from 16 normal subjects was compared with that from 149 patients with a variety of rheumatic disorders. Normal fluid had fewer cells and a lower content of beta-glucuronidase than osteoarthritic samples. Particles, including occasional birefringent crystals, were seen in normal fluids as well as pathological samples. Alizarin red staining particles (presumed to contain apatite) were seen in all diagnostic groups; their numbers showed some correlation with radiological calcification in and around the joints and with a hypertrophic subchondral bone response. Lactate levels were highest in septic arthritis. No assay showed disease specificity.

Adult↗
PubMed1984

Polycystic ovarian syndrome in identical twins.

Two 21-year-old female twins are described. They presented simultaneously with hirsutism and oligomenorrhoea. Investigation showed they had polycystic ovaries, they were identical and were not cases of post-pubertal adrenogenital syndrome.

Adult↗
PubMed1984

Defective regulation of the immune response to tetanus toxoid in Hashimoto's disease.

The humoral immune response to tetanus toxoid has been studied in patients with Hashimoto's disease. Although the magnitude of the response was similar to that observed in normal subjects, the Hashimoto patients demonstrated an inability to regulate their levels of tetanus toxoid antibody. This apparent defect in the control of antibody synthesis may be an important factor in both the initiation and perpetuation of autoimmune thyroid disease.

Adolescent↗
PubMed1983

Monomorphic adenoma of the nasal septum in a newborn (case report and ultrastructural findings).

Salivary gland type adenomas of the nasal septum are rare tumors in adults and even rarer in children. There has been no previous report of such a tumor in a neonate. We have described a tumor of the nasal septum whose light and electron microscopic appearances are consistent with an origin from minor salivary gland or nasal mucous glands. Ultrastructural findings presented do not suggest an origin from the embryonic organ of Jacobson (vomeronasal organ). The biological behaviour of this tumor in the neonate is unknown. A study of similar cases will be necessary to elucidate the incidence and natural history of intranasal adenomas in the neonate.

Adenoma↗
PubMed1983

Fenclofenac-secondary effects upon the pituitary thyroid axis.

To elucidate the mechanism of suppression of TSH responsiveness to TRH induced by the initiation of fenclofenac therapy, the early period of drug administration was examined in detail and the effect of the drug during a thyrotrophin releasing hormone infusion was assessed. In addition, the effect of fenclofenac upon the response of ACTH, cortisol, growth hormone and prolactin to insulin-induced hypoglycaemia was examined. The effect of fenclofenac upon an equilibrium dialysis method for estimating free thyroid hormones was evaluated and was found to be insignificant within the therapeutic concentration range of the drug. A sharp, short-lived rise in free thyroxine (21.7 +/- 2.0 to 26.8 +/- 1.9 pmol/l; P less than 0.03) was observed 60 min after the first dose of fenclofenac. Repeated peaks of free thyroxine during chronic fenclofenac treatment, superimposed upon the previously described steady decline of free and total serum thyroxine, are postulated to cause the observed suppression of TSH release which is present only until free and total serum thyroxine levels reach their nadir. The time course of the changes seen during thyrotrophin releasing hormone infusion suggested that the pituitary suppression was secondary to a rise in free thyroxine. The responses to hypoglycaemia of those pituitary hormones examined were not affected by fenclofenac.

Adult↗