Biomedical subjects

M Koen

Publications and source records attributed to M Koen.

4 recordsLinked to original sources

PubMed2007

[Pelvic kidney in childhood. Specific features, concomitant pathologies and useful diagnostic investigations].

In a retrospective analysis we studied the case histories of 31 children who had been seen in our department for investigation of pelvic ectopic kidney between January 1994 and June 2005. The evaluation of each involved the medical history, ultrasound examination, VCUG, and DMSA scan or MAG3 diuresis renogram. Of the 31 children, 21 (67.7%) had initially been referred to our department for further investigation and clarification because renal agenesis was suspected. In the remaining 10 (32.3%) children the pelvic kidney was an incidental finding observed during investigation of various other conditions. Overall, 7 (22.6%) of the 31 were symptomatic (recurrent urinary tract infections, abdominal pain, hypertension, hydronephrosis), while 77.4% (24/31) were completely free of symptoms at the time of follow-up. Ultrasound revealed that the ectopic kidney was on the left in 64.5% (20/31) of these cases. Nuclear scans performed both at the time of the initial diagnosis and at follow-up were available for 11 of the 31 children and showed a mild improvement of the partial function of the pelvic kidney, from a mean of 25.6% to a mean of 34.6%. In conclusion, whenever renal agenesis is suspected on ultrasonographic examination, the investigator should first consider renal ectopia; ultrasound examination with the bladder full is the definitive diagnostic procedure. For asymptomatic cases we recommend regular ultrasound monitoring of the kidney -- at first every 6 months and later once a year. In cases with complex anatomy MRI is a suitable method for further diagnostic work-up.

Abnormalities, Multiple↗

PubMed2006

In vitro transposon mutagenesis of an equine herpesvirus 1 genome cloned as a bacterial artificial chromosome.

The 150-kbp genome of the alphaherpesvirus equine herpesvirus 1 (EHV-1) strain HVS25A was cloned as a bacterial artificial chromosome (EHV-1 BAC), with mini F plasmid sequences inserted between genes 62 and 63. Transfection of EHV-1 BAC DNA purified from E. coli gave rise to progeny virus that had a similar growth rate and yield in mammalian cell culture to those of parental wild-type EHV-1. Using in vitro mutagenesis with a Mu transposon, a large library of EHV-1 BAC mutants was generated, and sequence analysis indicated that insertions were dispersed randomly across the EHV-1 genome. Following transfections of a pilot sample of mutant EHV-1 BAC DNAs into mammalian cells, no CPE was observable by light microscopy for mutants carrying insertions in genes for the major capsid protein, large tegument protein, glycoprotein K, catalytic subunit of DNA polymerase, or single-stranded DNA-binding protein. Mutants that were able to produce CPE similar to wild-type EHV-1 included those with interruptions in ORFs of several tegument proteins. Analysis of several glycoprotein gene mutants indicated that those carrying insertions near the start of genes encoding glycoproteins E and I were viable, but showed markedly diminished plaque areas. These results were supported by confocal microscopy of transfected or infected cultures. Electron microscopy of cells infected with a gE mutant revealed accumulations of particles within cytoplasmic vesicles, consistent with a partial obstruction of maturation. The transposon library is a resource for comprehensive functional analysis of the HVS25A genome, with multiple mutants available in any of the predicted genes of EHV-1.

Animals↗

PubMed2004

[Minimally invasive, safe treatment of the neurogenic bladder with botulinum-A-toxin in children with myelomeningocele].

PURPOSE: The efficacy and durability of botulinum-A toxin in the treatment of detrusor hyperreflexia in myelomeningocele (MMC) children was evaluated prospectively. MATERIALS AND METHODS: A total of 15 children (10 male and 5 female, mean age 5.8 years), all on clean intermittent catheterisation (CIC) due to MMC, were "non responders" to orally and intravesically administered anticholinergic medication. Pretreatment assessment included a videourodynamic evaluation, incontinence scoring and a mercaptoacetyltriglycine-3 renal scan. We injected from 10 U/kg up to a maximum of 360 U botulinum-A toxin at 25-40 sites of the detrusor, sparing the trigone. Follow-up was 24 months. All children had a urodynamic reevaluation with assessment of bladder capacity and incontinence score at 3, 9 and 12 months. RESULTS: Mean bladder reflex volume increased from 72.00 +/- 28.12 ml to 298 +/- 32.45 ml (p < 0.001). The maximal detrusor pressure decreased from 78.76 +/- 23.14 cm H(2)O to 42.76 +/- 24.34 cm H(2)O (p < 0.001). Maximal bladder capacity increased from 136.34 +/- 45.71 ml to 297.02 +/- 87.17 ml (p < 0.001). Detrusor compliance increased from 18.29 +/- 27.19 ml/cm H(2)O to 51.17 +/- 38.17 ml/mmH(2)O (p < 0.001). While 10 patients became completely dry between CIC, the remaining 2 patients improved from score 3 to 1. Results at 9 months were similar to the ones at 3 months. The mean efficacy and durability of the toxin was 10.5 months after the first intravesical injection. CONCLUSIONS: Botulinum-A toxin is a safe alternative in the management of detrusor hyperreflexia in MMC children. Preliminary results are promising concerning urodynamic parameters and continence.

Botulinum Toxins, Type A↗

PubMed2003

[Bladder exstrophy-epispadias complex: management and preliminary results].

PURPOSE: Retrospective evaluation of operative techniques and perioperative management as related to the primary anatomical and functional situation as well as analysis of the preliminary postoperative results regarding kidney function, continence and complications. MATERIALS AND METHODS: From October 1992 to April 2003, 21 patients with bladder exstrophy-epispadias complex were treated, consisting of 12 children with untreated exstrophy and 9 who had undergone unsuccessful previous operations. Single-stage complete repair using the Erlangen concept was done during the first weeks of life in 8 infants and before school age in 3 children. One 13 year old girl had received a primary Mainz pouch II. The 9 unsuccessfully operated patients required a variety of different operations. The mean follow-up of 17 regularly controlled children was 62 months (range 3 to 129 months). RESULTS: In all children global kidney function remained stable, while reflux or obstruction was responsible for impaired unilateral split function ranging between 31 % and 45 % in 5. Four children were continent day and night after complete single-stage repair, 4 after ureterosigmoidostomy or Mainz pouch II and 5 after augmentation. CONCLUSIONS: In the newborn with previously untreated exstrophy-epispadias, we recommend single-stage complete functional reconstruction within the first weeks of life. Continence without loss of kidney function can be achieved in 50 % of these children. If adequate bladder capacity and continence cannot be achieved, an augmentation procedure or Mainz pouch II is our method of choice.

Adolescent↗