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H Lottmann

Publications and source records attributed to H Lottmann.

At least 19 recordsLinked to original sources
PubMed2001

The Tet-On system in transgenic mice: inhibition of the mouse pdx-1 gene activity by antisense RNA expression in pancreatic beta-cells.

To elucidate the function of pancreas duodenal homeobox 1 (PDX-1; insulin promoter factor 1/somatostatin transcription factor 1/islet duodenum homeobox 1/insulin upstream factor 1) in differentiated beta-cells of adult animals we generated transgenic mice using the Tet-On system. Inducible expression of an antisense RNA should down-regulate the PDX-1 protein. The selective and continuous inhibition of PDX-1 gene expression should impair the expression of PDX-1 dependent beta-cell specific genes. A gene switch such as the Tet-On system provides a powerful tool to analyze eukaryotic gene expression and function in transgenic mice. The original Tet system contained two transcriptional units, transactivator and target of control, on two plasmids. We combined the two transcriptional units on a single DNA molecule. The transactivator was placed under control of the mouse insulin promoter. The tet responsive element, driving the gene of interest, was inserted further down-stream into the same vector. The tet regulatory system in this approach permitted a tissue-specific and a doxycycline-inducible control of PDX-1 expression in transgenic mice. The expression of glucose transporter 2 and glucokinase was markedly reduced in dox-treated transgenic mice. In contrast, the number of insulin- and amylin-expressing cells was only slightly decreased, whereas the expression of glucagon was increased distinctly in islets of these mice. Furthermore, the exposure to doxycycline resulted in a progressive impairment of glucose tolerance. The characterization of our transgenic mouse model demonstrates the suitability of the Tet-On system for analyzing physiological consequences emerging from a stepwise decrease in a given protein. Using this system we confirmed the essential role of PDX-1 in pancreatic islets and demonstrated that an antisense-mediated PDX-1 deficiency provokes a beta-cell dysfunction.

Amyloid↗
PubMed2001

Scintigraphic screening for renal damage in siblings of children with symptomatic primary vesico-ureteric reflux.

OBJECTIVE: To define prospectively the incidence of renal parenchymal lesions in the siblings of patients treated at one institution for primary vesico-ureteric reflux (VUR). PATIENTS AND METHODS: From January 1997 to October 1998, a prospective study including renal scintigraphy (using dimercaptosuccinic acid, DMSA) and a radionuclide cystogram was proposed systematically to the asymptomatic siblings of children treated for primary VUR. The radionuclide cystograms were interpreted as showing the presence or absence of VUR and the DMSA scan as symmetrical or asymmetrical differential function, with or with no renal defect. RESULTS: Fifty-five families gave informed consent, of whom 46 completed the study (eight refused secondarily and one was omitted by exclusion criteria), representing 46 symptomatic patients and 65 siblings. There were 17 siblings with VUR (26%) including two of 13 infants and 15 of 52 children aged > 18 months. One radionuclide cystogram failed. Of the 17 refluxing siblings, four had a history of symptomatic urinary tract infection; 62 of the 65 siblings had a DMSA scan, of which 56 were normal and six (10%) showed abnormalities (five asymmetrical differential function and one parenchymal defect). Only one of these six patients had VUR at the time of the evaluation and only one had a small kidney detected by ultrasonography on one side (and no VUR). There were no adverse effects associated with screening. CONCLUSION: This study confirms a significant overall incidence of VUR (26%) in the asymptomatic siblings of patients treated for primary VUR. From the results of the DMSA scan (only one sibling had a parenchymal defect), the systematic screening of asymptomatic siblings does not appear to be beneficial.

Adolescent↗
PubMed2000

Laparoscopic retroperitoneal nephrectomy in high risk children.

PURPOSE: Nephrectomy may be indicated in children with end stage renal disease before transplantation. We studied the feasibility and results of nephrectomy performed via a retroperitoneal laparoscopic approach in these high risk children. MATERIALS AND METHODS: We performed 12 nephrectomies in 9 children with end stage renal disease and a mean age of 7 years (range 7 months to 13 years) through a 3 trocar retroperitoneal laparoscopic approach. Cases were classified as American Society of Anesthesiologists grade III and presented with end stage renal disease, hypertension, thrombocytopenia and/or the nephrotic syndrome. The renal artery and vein were ligated separately with endocorporeal knots and clips. Mean size of the kidney was 8 cm. (range 5 to 12). Bilateral nephrectomy was performed simultaneously in 2 patients 7 and 12 months old, respectively. Cardiorespiratory changes related to retroperitoneal gas insufflation were assessed prospectively. To compare laparoscopic versus open nephrectomy we retrospectively analyzed the data of 12 open nephrectomies performed in 9 children with similar nephrological indications. RESULTS: The procedure was feasible in all cases without conversion to open surgery, and no intraoperative incident occurred. Mean operative time of laparoscopic nephrectomy was 2 hours (range 1 hour 20 minutes to 3 hours 10 minutes). After retroperitoneal carbon dioxide insufflation systolic arterial pressure and end-tidal carbon dioxide were significantly increased without the need for specific measure to correct these modifications. Hemodialysis began 1 day postoperatively and feeding began 2 days postoperatively. Mean hospital stay was 5.2 days (range 3 to 7). The comparative study of the open nephrectomy group showed no significant difference in mean operating time (p = 0.07), and hospital stay was significantly shorter for the laparoscopic group (p <0.001). CONCLUSIONS: Retroperitoneal laparoscopic nephrectomy is safe and feasible for high risk children. The relatively long operating time is necessary for hemostasis in these children at risk for hemorrhagic complications.

Adolescent↗
PubMed2000

[Extra-corporeal lithotripsy in children].

Extracorporeal shock-wave lithotripsy (ESWL) constitutes the reference treatment for renal and ureteric stones in adults, but its use and development in children have been accompanied by a certain degree of caution and reticence. A large number of paediatric series have been published since 1986, confirming the efficacy and minimally invasive nature of this technique. Modification of the nature of the shock waves and release onto the market of second and third generation apparatuses have simplified the management of urinary stones in children. However, several questions persist concerning the maximum number of impacts, the recommended interval between two sessions and the long-term effects of shock waves on the growing renal parenchyma. The objective of this study was to review the current state of ESWL in children based on a review of the literature, the GEUP report and our own experience.

Adolescent↗
PubMed1999

Cystography after the Cohen ureterovesical reimplantation: is it necessary at a training center?

PURPOSE: Reimplantation by the Cohen procedure has a low rate of recurrent reflux, although postoperative cystography is done routinely at most centers. According to the French training program for pediatric surgery and urology residents, reimplantation is the main pediatric urology procedure performed during residency. We determine whether it is necessary to perform postoperative cystography routinely and whether the fact that the procedure is done by a junior surgeon modifies management. MATERIALS AND METHODS: A total of 268 children with primary vesicoureteral reflux underwent ureteral reimplantation by the Cohen transtrigonal technique. Bilateral reimplantation was done in 97% of the cases. Reimplantation was performed by a surgery resident assisted by a clinical fellow or senior consultant surgeon in 37% of the cases. Routine cystography and renal ultrasound were done in all patients postoperatively. Followup ranged from 6 months to 5 years (mean 10 months). RESULTS: In 2 children (0.7%) with recurrent reflux surgery was not performed by a resident. One of the 2 children had asymptomatic persistent reflux and no further surgery was done. In the other child postoperative cystography was normal at 6 months. One year later she had acute pyelonephritis with recurrent unilateral reflux and underwent repeat reimplantation. CONCLUSIONS: Routine cystography is not necessary after bilateral Cohen reimplantation. Reflux recurrence is low even at a training center where surgery may be performed by junior surgeons.

Child↗
PubMed1999

[Extracorporeal lithotripsy in children. Study of its efficacy and evaluation of renal parenchymal damage by DMSA-Tc 99m scintigraphy: a series of 39 children].

AIM: The objectives of the study were to confirm the efficacy of extracorporeal shock wave lithotripsy (ESWL) in infants and children and to evaluate potential long-term renal parenchymal damage by 99m Tc DMSA renal scan. MATERIALS AND METHODS: Between November 1989 and November 1997, 39 children between 10 months and 17-1/2 years of age (average: 7 years) were treated by extracorporeal shock wave lithotripsy for kidney or ureteral stones with a Sonolith 3000 lithotriptor (Technomed Corp). Forty-six stones were treated. Eight metabolic and 11 urological abnormalities were identified. The evaluation of the treatment and its consequences were based on a clinical examination, conventional imaging and a DMSA renal scan performed 24 h before extracorporeal shock wave lithotripsy and at least 6 months after treatment. RESULTS: Treatment was successful (stone fragmented and eliminated) in 84.6% at 3 months after one to four sessions. Sixty-one sessions were necessary and two patients underwent open surgery for failed extracorporeal shock wave lithotripsy. Three recurrences were also retreated. At long term follow-up (6 months to 8 years) no incidents of high blood pressure were observed, nor parenchymal lesions imputable to extracorporeal shock wave lithotripsy. CONCLUSIONS: The efficacy of the extracorporeal shock wave lithotripsy for children is proven. This study also confirms the innocuousness of extracorporeal shock wave lithotripsy for renal parenchyma even in infants. However, long term follow-up and further evaluation with the other categories of lithotriptors are necessary to make definitive conclusions.

Adolescent↗
PubMed1999

Enuresis treatment in France.

The aim of this study was to describe the current management of nocturnal enuresis (NE) in France. A survey was carried out among 3803 schoolchildren (5-10 years of age) and treatments proposed by French experts were also noted. The prevalence of NE was 9.2%. Sixty-six percent of mothers of children with moderate to severe NE consulted a doctor; 20% of these doctors did not prescribe treatment, and the majority offered advice on lifestyle and diet in the first instance. The treatments proposed consisted of drugs rather than alarm therapy. The opinions of the experts varied widely, indicating a need for a consensus about the management of NE in France.

Child↗
PubMed1999

Nocturnal enuresis: a suggestion for a European treatment strategy.

The objective of this study was to review the published literature on aetiology and treatment of nocturnal enuresis, with the aim of providing a treatment strategy which is easy for the patient and their family to follow. Results from European studies conducted over the last 15 y were included in this review. It can be concluded from the results of these studies that enuresis is the cause and not the result of a psychiatric disorder. However, there is still considerable variation in success rates, from 28 to 90%. It is of vital importance that a caring approach from the doctor and a positive family and patient attitude are present for successful treatment. The first choice of treatment should be the one most acceptable to the family, e.g. alarm, desmopressin and combination treatment.

Age Factors↗
PubMed1999

Outcome of posterior urethral valves: to what extent is it improved by prenatal diagnosis?

PURPOSE: To assess the impact of prenatal diagnosis and evaluation on the outcome of posterior urethral valves we studied all cases of valves detected prenatally, including cases of pregnancy termination due to posterior urethral valves. MATERIALS AND METHODS: Between 1989 and 1996, 30 neonates with prenatally detected posterior urethral valves were treated at our hospital. The prenatal parameters analyzed were age of gestation at diagnosis, ultrasonographic appearance of renal parenchyma and amniotic fluid volume. Fetal urine was analyzed in 9 cases. We reviewed the outcome of 10 neonates treated for posterior urethral valves which were not diagnosed prenatally during the same period. RESULTS: Of the 30 neonatal survivors 6 (20%) had renal failure, including end stage renal disease in 2, after a mean followup of 4 years. Renal failure developed in 2 of 5 cases detected before 24 weeks of gestation, in 1 of 6 with oligohydramnios and in 2 of 5 with abnormal parenchymal renal ultrasound. Normal parenchymal ultrasound and amniotic volume could not predict for good outcome. Renal failure developed in 2 of 7 cases predicted by fetal urinalysis as good prognosis and in 1 of 2 cases predicted as poor prognosis. Pregnancy was terminated for posterior urethral valves in 5 cases based on prenatal criteria of severe renal impairment. Considering these cases as poor outcome, the rate of poor prognosis increased from 20 to 31%. Among the 10 neonates without a prenatal diagnosis of posterior urethral valves renal failure developed in 2 (20%), including end stage renal disease in 1. CONCLUSIONS: When negative parameters were absent and/or fetal urine predicted good outcome there were no cases of end stage renal disease in early infancy, which was a significant help in parent counseling. The predictive value of the currently available prenatal parameters needs to be updated with larger series specifically dealing with posterior urethral valves. According to the current data, the outcome of posterior urethral valves is not yet significantly improved by prenatal diagnosis.

Female↗
PubMed1999

[Urinary lithotripsy in children. Multicenter study of the Pediatric Urology Study Group].

The authors present the results of a survey conducted among French paediatric urologists belonging to the Groupe d'Etudes en Urologie Pédiatrique (GEUP) (Paediatric Urology Study Group). This study, based on 122 cases observed in 13 centres, is not exhaustive, but is nevertheless statistically significant. The preoperative assessment confirms the usual findings of urinary stones in children: pyelonephritis, haematuria and abdominal pain, the usual presenting complaint, concomitant malformative uropathy (10% of cases) and a predominance of calcium stones. More than 200 stones were treated, larger than 10 millimeters in diameter in one-third of cases. Renal stones, mainly caliceal (more than 50%), included 11 staghorn calculi. This study also included 22 ureteric stones, mainly in the pelvic ureter, and 2 bladder stones. Lithotripsy was ultrasound-guided in 2/3 of cases and required general anaesthesia in about 3/4 of cases. Ureteric catheterization was required in 19 infants preoperatively, but in only 2 infants (stein strasse) postoperatively. One or two lithotripsy sessions were sufficient in most cases, but 4 sessions were necessary in 5 patients, to the same kidney in 1 case. The mean hospital stay was 2 to 3 days, but the procedure was performed on an outpatient basis in 15 cases. The immediate postoperative course was uneventful and asymptomatic. This survey revealed about 10% of complete failures, corresponding to solitary caliceal stones in 2/3 of cases; 29 partial failures were essentially due to lower caliceal stones and staghorn calculi; 84 successes (stone-free), mainly pelvic or simple caliceal stones. Scintigraphy did not reveal any immediate postoperative impairment of renal function. This study reported a success rate of about 70%, regardless of the type of apparatus used. Assessment of the results of ESWL requires sufficient follow-up both concerning the outcome of fragmented stones and evaluation of possible functional repercussions. This survey defines the main indications: although ESWL can be applied to most stones, some stones constitute poor indications (cystine stones, stenotic malformative uropathy) or dubious indications: small lower caliceal stones, densely calcified staghorn calculi in older children. This study confirmed the efficacy and low morbidity of ESWL in children. A prospective study needs to be conducted according to a rigorous protocol in order to refine the technique and indications while reducing the possible long-term risks.

Abdominal Pain↗
PubMed1999

[Posterior approach to the bladder for implantation of the 800 AMS artificial sphincter in children and adolescents: techniques and results in eight patients].

Blind dissection of the bladder neck during implantation of an artificial urinary sphincter (AMS 800) may lead to injury of either the bladder, genital tract or even the rectum. Significant bleeding may occur. A posterior approach to the bladder neck allowing visual control of the anatomical structures is described. From November 1995 to February 1998, 8 adolescents (12-19 years old) underwent AMS 800 artificial urinary sphincter implantation for the treatment of severe incontinence associated with neurogen bladder; one patient had had a previous augmentation. Three had a simultaneous ileocystoplasty and another patient had a simultaneous bilateral extravesical ureteric reimplant. The procedure consisted of separation of the bladder from the peritoneum, allowing the development of a dissection plane between the rectum and genital tracts posteriorly and the ureters and bladder neck anteriorly; the dissection is extended to the base of the prostate. The endopelvic fascia is then incised laterally and on both sides the neurovascular bundles are perforated under visual control and the cuff is positioned safely around the bladder neck, above the prostate and in front of the genital tract. The bladder was opened only in the case of associated ileocystoplasty, thus avoiding prolonged bladder drainage. The mean operating time was 2.5 hours and the blood loss never exceeded 300 cc. This route was not found to be convenient in the case of the patient with a previous augmentation; 7 sphincters function normally with a follow-up of 18 to 44 months; one was never activated and the patient is dry under CIC. This route for exposure of the bladder neck allows visual control of the anatomical structures, accurate positioning of the cuff, avoids bladder opening and reduces bleeding. It can be used for other procedures such as bladder neck suspension or Müllerian cavity removal.

Adolescent↗
PubMed1998

[Urology and nuclear medicine in children. Experience from a series of 1200 renal scintigraphies].

During the last 4 years, we have performed 1200 renal scintigraphies in children under the age of 6 years: 57% of dynamic renal scintigraphies using MAG3 for antenatally diagnosed uropathies (mainly pelvic dilatations and megaureters), 36% of static renal scintigraphies using DMSA for renal sequelae of pyelonephritis with or without vesicoureteric reflux, and 6% of direct isotope cystography for follow-up of vesicoureteric reflux. Renal scintigraphy, which provides low radiation hazards (1 mSv), is now a major imaging modality for paediatric urinary tract disease.

Child, Preschool↗
PubMed1998

[Extracorporeal shock-wave lithotripsy in infants. Study of its repercussions on the renal parenchyma].

PURPOSE: To evaluate the efficacy of extracorporeal shock-wave lithotripsy (ESWL) in infants (less than 2-years-old) and study the potential long-term renal parenchymal damage by 99 m Tc DMSA renal scan. MATERIALS AND METHODS: Between November 1993 and February 1998, 12 children underwent ESWL treatment for kidney and ureter urolithiasis with a Sonolith 3,000 lithotriptor (Technomed-Corp). All children were less than 2-years-old. Evaluation of treatment and its consequences was based on clinical examination, conventional imaging (plain abdominal radiography excretory urogram) and a DMSA renal scan performed 24 hours before ESWL and at least 6 months after treatment. RESULTS: Treatment was successful in 84.6% of cases, by achieving stone-free status after one session and 100% after 2 sessions. Long-term follow-up (one month to four years) did not reveal any blood pressure or renal function changes. No acquired parenchymal scar was identified. On DMSA renal scan. CONCLUSIONS: The efficacy of ESWL in treating infant urolithiasis is clearly established. Renal parenchymal damage associated with ESWL did not appear in this study, but long-term follow-up mandatory (blood pressure) and each infant should have a DMSA renal scan before and after ESWL to confirm these preliminary results on a larger series.

Humans↗
PubMed1998

[First-line vesico-psoas hitch ureteroneocystostomy for primary obstructive megaureter].

Between 1989 and 1997, 23 children with primary obstructive megaureter underwent surgical repair, routinely using a vesico-psoas hitch ureteroneocystostomy. Ten of them had a antenatal diagnosis. Mean postoperative follow-up was 3 years. No postoperative obstruction and no vesicoureteric reflux occurred. Assessment of renal function on the operated side showed improvement in 7 cases and stabilization in all other cases. No bladder dysfunction was observed. Vesicopsoas hitch is an advantageous procedure in this indication. It is almost always unnecessary to perform ureteral tailoring and its specific complications can be avoided. Psoas hitch is easily performed in infants and young children and this technique is particularly appropriate in the subgroup of patients with antenatal diagnosis.

Child, Preschool↗
PubMed1998

[Pathology of the ureterovesical junction in neurogenic bladders in children and adolescents. A retrospective study of 119 patients].

Ureterovesical junction dysfunction in congenital or acquired neurogenic bladders represents a threat for the renal parenchyma. In order to evaluate the incidence, mechanisms of development and preventive and curative treatments proposed in diseases of the ureterovesical junction associated with neurogenic bladders, the files of 119 children were retrospectively evaluated. 68 patients suffered from congenital neurogenic bladder and 51 had an acquired neurogenic bladder. In the congenital neurogenic bladder group, vesico-ureteric reflux was observed in 22 cases (32%) and dilatation was observed in 18 cases (26.5%), while 21 patients had both dilatation and reflux. In the acquired neurogenic bladder group, reflux was observed in 8 cases (16%) and dilatation was observed in 3 cases (10%), one of whom had both reflux and dilatation. The predominant mechanism of decompensation of the ureterovesical junction in the two groups was a combination of low compliance and high peripheral resistance. In patients with abnormalities of the ureterovesical junction, the incidence of associated parenchymal lesions was similar (30%) whether neurogenic bladder was congenital or acquired. The disparities between these two comparable patient groups, the preventive and curative treatments proposed and their results are analysed in comparison with the data reported in the literature.

Adolescent↗