The role of videourodynamic studies in diagnosis and treatment of vesicoureteral reflux

Abstract From January 1986 to January 1988, 63 children with 95 refluxing ureters have been studied in a prospective study with videourodynamic examination. All children with reflux grades I, II, and III received antibacterial treatment. Surgical treatment was adopted for reflux grades IV and V, provided detrusor instability had been excluded. However, if there was detrusor instability, anticholinergic drugs and antibacterial treatment were given in all grades of reflux and videourodynamic examination was repeated after 3 to 6 months and after 12 months of therapy. Bilateral reflux was found in 22 of 38 patients with a stable bladder, and reimplantation was performed in 11 patients with 18 refluxing ureters. In 25 children with 35 refluxing ureters of various grades of reflux, detrusor instability was found and unilateral reflux was noted more frequently than bilateral reflux. Surgery was necessary for only five children, because in the majority of the patients detrusor instability and reflux could be treated by anticholinergic drugs and antibacterial treatment. For the decision as to which treatment should be given in vesicoureteral reflux, a videourodynamic study is mandatory

Efficient storage of urodynamic signals by computer: application of FAN adaptive sampling

Digital storage of urodynamic signals such as detrusor pressure and flowrate at a sufficiently high sampling rate (10 samples per second) to allow subsequent analysis requires considerable computer memory. A procedure for compressing these data by deleting redundant samples (the fan method of adaptive sampling) was tested. The method allows a flexible adaptation to specific hardware and a compromise between storage requirements and accuracy. In this study the number of samples required for adequate reconstruction of the detrusor pressure signal could be varied from 80% to 4% of the original number of samples by varying the average difference between reconstructed and original signal from 0.01 to 2 cm H2O. Fast components of the measurements (for example cough peaks) which were lost if a lower sampling rate or averaging was used to obtain equally low storage requirements were unaffected by this compression technique

An Evaluation of Contractility Parameters Determined from Isometric Contractions and Micturition Studies

In a group of 110 patients of mixed pathology 218 micturitions were investigated. Using an on-line computer, two contractility parameters were calculated: the parameter U/l, which is derived from the isometric pressure rise in the detrusor before micturition actually started, and the parameter wmax, which is derived from flow and pressure during micturition. It was found that neither of the parameters conforms to the definition of an ideal contractility parameter. Both parameters are subject to the influence of the urethral resistance or the degree of neurogenic stimulation of the bladder, and both measure to some degree the actual performance of the detrusor during a given micturition instead of its myogenic properties. Nevertheless, by dividing patients into groups according to these two measured values, it was shown that clinically relevant types of detrusor behaviour can be distinguished

Clinical comparison of bladder contractility parameters calculated from isometric contractions and pressure-flow studies

Parameters describing the contractility of the urinary bladder can be calculated from both isometric contractions and pressure-flow studies. The first method has the advantage of making very little demand either on the patient or on the urodynamicist, and the disadvantage of yielding a parameter that is not clearly related to muscle physiology. The second method demands more from both patient and experimenter but yields straightforward parameters. For a group of 86 patients with mixed pathologic findings, a correlation between the two types of parameters was demonstrated, showing that both methods test, at least partly, the same mechanism

Standardization of terminology of lower urinary tract function: pressure-flow studies of voiding, urethral resistance, and urethral obstruction

The 1988 version of the collated reports on standardisation of terminology, which appeared in Neurourology and Urodynamics, vol. 7, pp. 403–427, contains material relevant to pressure flow studies in many different sections. This report is a revision and expansion of Sections 4.2 and 4.3 and parts of Sections 6.2 and 7 of the 1988 report. It contains a recommendation for a provisional standard method for defining obstruction on the basis of pressure-flow data. 2. Evaluation of Micturition 2.1. Pressure-Flow Studies At present, the best method of analysing voiding function quantitatively is the pressure-flow study of micturition, with simultaneous recording of abdominal, intravesical and detrusor pressures and flow rate (Fig. A.1.6.1). Direct inspection of the raw pressure and flow data before, during and at the end of micturition is essential, because it allows artefacts and untrustworthy data to be recognised and eliminated. More detailed analyses of pressure-flow relationships, described below, are advisable to aid diagnosis and to quantify data for research studies. The flow pattern in a pressure-flow study should be representative of free flow studies in the same patient. It is important to eliminate artefacts and unrepresentative studies before applying more detailed analyses. Pressure-flow studies contain information about the behaviour of the urethra and the behaviour of the detrusor.This report has been produced at the request of the International Continence Society. It was approved at the twenty-fifth annual meeting of the society in Sydney, Australia

Evolution of genes and genomes on the Drosophila phylogeny

Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species