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D F Marshall

Publications and source records attributed to D F Marshall.

12 recordsLinked to original sources
PubMed2001

Does the absence of anal reflexes guarantee a "safe bladder" in children with spina bifida?

INTRODUCTION: Increased detrusor pressure is a risk factor for renal damage in patients with neuropathic bladder, and probably requires inappropriate contraction of the external urethral sphincter. It seems logical that the absence of sacrally-mediated anal reflexes in a child with spina bifida makes such sphincteric spasm unlikely. One report has suggested that, in such circumstances, neuropathic bladder behaviour is usually predictable and safe. This article examines the reliability of this assumption, and whether routine urodynamic studies can be, therefore, safely omitted in this group. MATERIALS AND METHODS: 76 children and adolescents (aged 3 - 18 years) with spina bifida were tested for the presence of the anocutaneous reflex immediately prior to video-urodynamic studies, on entry into a therapeutic trial. The relationship between the anal reflex status and two surrogate indicators of urethral sphincter function, namely maximal detrusor pressure (MDP) and leak point pressure (LPP), was analysed. RESULTS: Only 11 (14 %) children had a positive reflex. Their mean MDP and their mean LPP were not statistically significantly greater than those in children without an intact reflex. Indeed the reflex was absent in the only two patients with MDP, > or = 100 cm H2O, and in the only five children with LPP, > or = 60 cm H2O. CONCLUSION: The absence of anal reflexes is a poor predictor of safe bladder pressures in children with spina bifida. There is no justification for depriving such a population of routine urodynamic assessment on this basis. Our impression remains that there is probably no such entity as a predictably safe neuropathic bladder.

Adolescent↗
PubMed2001

Does bladder capacity assessment by frequency/volume chart correlate well with urodynamic estimation in children with spina bifida?

INTRODUCTION: Reduced capacity is a common feature of the neuropathic bladder seen in children with spina bifida. This impacts on urinary continence and, in severe cases, may require augmentation cystoplasty. The traditional means of assessing bladder size has been urodynamics. A frequency/volume chart may also provide this information, but the technique may not be so scientifically controlled. It is unclear how well the results of these two modalities correlate. MATERIALS AND METHODS: One hundred and twenty-two urodynamic studies and one-week frequency/volume charts were completed by 77 children and adolescents (aged 3 - 18 years) involved in a therapeutic trial. The maximum bladder capacity at urodynamics and the largest of the listed voided urinary volumes over the week for each child were compared using the paired, samples t-test. A scatter plot correlation analysis was performed, along with a Bland-Altman test for method comparison. RESULTS: A mean difference in bladder capacity estimation, between the two methods of between 12 and 18 ml was encountered, which was statistically non-significant. While a generally good correlation was seen, there was poor agreement between the two modalities. CONCLUSION: Frequency/volume charts provide a reliable non-invasive estimate of bladder size in children with neuropathic bladder. However, the potential for poor agreement with urodynamic measurements means the two techniques should be seen as supplementary, rather than interchangeable, in this group.

Adolescent↗
PubMed1999

Analysis of Arabidopsis genome sequence reveals a large new gene family in plants.

A detailed analysis of the currently available Arabidopsis thaliana genomic sequence has revealed the presence of a large number of open reading frames with homology to the stigmatic self-incompatibility (S) genes of Papaver rhoeas. The products of these potential genes are all predicted to be relatively small, basic, secreted proteins with similar predicted secondary structures. We have named these potential genes SPH (S-protein homologues). Their presence appears to have been largely missed by the prediction methods currently used on the genomic sequence. Equivalent homologues could not be detected in the human, microbial, Drosophila or C. elegans genomic databases, suggesting a function specific to plants. Preliminary RT-PCR analysis indicates that at least two members of the family (SPH1, SPH8) are expressed, with expression being greatest in floral tissues. The gene family may total more than 100 members, and its discovery not only illustrates the importance of the genome sequencing efforts, but also indicates the extent of information which remains hidden after the initial trawl for potential genes.

Arabidopsis↗
PubMed1998

The association of flowering time quantitative trait loci with duplicated regions and candidate loci in Brassica oleracea.

A population of 150 doubled haploid lines of rapid cycling Brassica oleracea, derived from an F1 from a var. alboglabra x var. italica cross, was scored for flowering time in two trials. Using information on 82 mapped molecular markers, spread evenly across the nine linkage groups, QTL were identified at six locations; one each on linkage groups O2 and O3 and two each on linkage groups O5 and O9. In total, these QTL explained 58 and 93% of the genetical variation in the two trials. Three of these QTL, on linkage groups O2, O3, and O9, were situated in regions showing considerable homology both with each other and with chromosome regions of B. nigra that have been shown to affect flowering time. These same regions are all homologous to a single tract of Arabidopsis chromosome 5, which contains a number of the flowering-related genes, one or more of which may be candidates for the QTL found in Brassica.

Brassica↗
PubMed1997

Altered bladder and bowel function following cutaneous electrical field stimulation in children with spina bifida--interim results of a randomized double-blind placebo-controlled trial.

Bladder and bowel dysfunction in spina bifida are the result of abnormal electrical input, secondary to the neurological lesion of the spinal cord. Experimental attempts to correct this deficit with invasive electrical stimulation have demonstrated promising effects, as has a recent preliminary study of transcutaneous electro-stimulation in children with myelomeningocoele. A randomized controlled trial of non-invasive electrical stimulation in children with neuropathic bladder and bowel has been established. Interim results of 50 patients are presented. Treatment was performed at home for one hour daily for a mean period of 45 days. The only statistically significant difference between the active and placebo-groups was a 32% relative decrease in night-time urinary incontinence, favoring the placebo group. However there were non-significant trends of preferential improvement in the active group for the relative increases in maximum and average bladder content and episodes of spontaneous normal defecation. It is anticipated that a continued increase in patient numbers will overcome the large placebo effect observed and yield more significant results.

Adolescent↗