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T Schuster

Publications and source records attributed to T Schuster.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Lymphangioma colli--what are the prognostic factors? Experiences with 36 cases].

AIM: A new classification of the Lymphangioma colli (LC) should allow to inform about prognosis at the time of diagnosis or prenatal sonography. METHODS: Pre- and postoperative parameters in 36 operated children (1988-2000, Ø follow up 4.3 years) were evaluated dependent on the volume of the LC as defined. Type I: the tumor does not alter the normal shape of the neck; type II: the LC reaches a line placed at the lateral border of the head; type III: the LC does not respect this line; type IV: the LC exceeds the midline of the body. RESULTS: According to delivery, diagnostics, resection, reintervention, postoperative complications, nerve injury, hospital stay, aesthetics, tracheo- and gastrostoma predominantly significant differences were found. CONCLUSIONS: The proposed classification permits to advise the parents about the expected prognosis: Type I: it is excellent; type II: some asymmetry remains in 15%; type III: postoperative complications occur in up to 38%; type IV: morbidity increases and prognosis decreases significantly.

Child↗
PubMed2000

Catalysis of a Diels-Alder Reaction by Amidinium Ions.

Amidines and guanidines are important functional groups in molecular recognition and host-guest chemistry. Here it is shown that lipophilic amidinium ions catalyze a cycloaddition reaction representing the key step of the Quinkert-Dane estrone synthesis. Hydrogen-bond-mediated association with the organic cation leads to an electrophilic activation of the dienophile and to enhanced rates of the Diels-Alder reaction. The observed effects are similar to those expected from mild Lewis acids. In competition experiments, amidinium catalysis favors the reaction of the less electron deficient dienophile.

Journal Article↗
PubMed2000

Axially chiral amidinium ions as inducers of enantioselectivity in Diels-Alder reactions

[reaction: see text] Enantioselective catalysis of Diels-Alder reactions is mostly achieved by coordinating the dienophile to relatively strong chiral Lewis acids. Here we report on a novel approach employing the hydrogen-bond-mediated association of dienophiles to chiral host molecules. In a reaction forming the steroid skeleton of norgestrel, chiral amidinium ions induce 5:ent-5 ratios of up to 2.5:1. Improved and simplified amidinium catalysts may become interesting candidates to perform stereoselective transformations.

Journal Article↗
PubMed2000

[Leiomyoma of the glans penis].

Glans penis leiomyomas are uncommon as primary nonepithelial tumors of the urogenital tract. Only 4 cases are described until today. We saw an other case of an 12 years old boy with a leiomyoma of the glans penis. Clinically the lesion presented as a yellow induration with no symptoms as pain, pruritus or bleeding. The biopsy revealed histological a leiomyoma in the subcutis of the glans penis with no symptoms of malignancy. Because of suspected functional and cosmetic deficiency a total resection was not performed. None of the cases described in the literature showed in the follow up malignancy or recurrency. 18 months postoperatively our patient is furthermore well and without symptoms. Nevertheless the leiomyoma of that localization is rare, this tumor should be included in the differential diagnosis of the neoplasms of the glans penis.

Child↗
PubMed2000

Penoscrotal inversion, hypospadias, imperforate anus, facial anomalies, and developmental delay: definition of a new clinical syndrome.

We describe a 2-month-old boy with penoscrotal inversion, hypospadias, imperforate anus, facial anomalies, developmental retardation, and a subtelomeric deletion of chromosome 13q. His phenotype with anogenital malformations and characteristic facies closely resembled two unrelated patients with minute deletions of chromosome 13q who we reported earlier. In addition, he had unilateral renal agenesis. We propose that these patients represent a clinically recognizable, novel chromosomal microdeletion syndrome. The findings indicate the presence of a major gene(s) on chromosome 13q33.2qter that regulate(s) the migration and development of ano-reno-genital cells and organs. We speculate that mutations of this developmental gene(s) may also result in more frequent congenital malformations (isolated hypospadias, uterus bicornis, unilateral renal agenesis). Additional studies are needed to further delineate the genetic defect.

Abnormalities, Multiple↗
PubMed2000

A computerised vector manometry study of the so-called ectopic anus.

There are several totally different definitions of the so-called ectopic anus. To determine whether computerized eight-channel manometry helps to define the entity of the ectopic anus, ten patients (nine females) were operated upon for an ectopic anus by the anal transposition technique (perineal pull-through procedure). Besides the software-supported manometric data, the qualitative imaging analysis was of interest. We calculated the factor by which the pressure of the three ventrally-located segments was lower than the mean segmental pressure at this part of the anal canal. The results were compared to standard age-related values established in a former study in 100 children. Besides pre- and postoperative manometry, barium roentgenograms were obtained. The anal-canal length at rest in the ectopic anus was significantly (P < 0.0001) longer. The segmental asymmetry index in the lower anal canal (LAC) was increased, but not significantly. The pressure in the ventral segments of the LAC was significantly (P < 0.0001) decreased and was less than one-half of the mean segmental pressure in this zone. We found a significant correlation between the degree of anterior displacement and the factor by which the ventrally-located pressure values were decreased. Postoperatively, this factor increased significantly. From a functional point of view, the definition of the ectopic anus includes a deficient high-pressure zone ventrally in the LAC. The LAC seems to run out or nearly out of the ventral sphincteric issue to end ectopically on the perineal surface.

Age Factors↗
PubMed2000

Recovery of emotional behaviour in neural cell adhesion molecule (NCAM) null mutant mice through transgenic expression of NCAM180.

In the present study we further investigate functions of the neural cell adhesion molecule (NCAM) in the mature central nervous system and its implications for animal behaviour. To this end we generated transgenic mice expressing the major NCAM isoform with the largest cytoplasmic domain, NCAM180, under control of a promoter for the small form neurofilament gene. Transgenic mice were also bred with mice deficient in endogenous NCAM (Ncam-/- mice) so that effects of NCAM180 could be analysed in the presence and absence of endogenous NCAM. While overexpression of transgenic NCAM180 was without apparent behavioural or morphological effect, its expression in Ncam-/- mice counteracted NCAM ablation-induced aggressive, anxiety-like and antidepressant-like behaviour. It furthermore prevented a hypersensitivity of Ncam-/- mice to the anxiolytic serotonin1A (5-HT1A) receptor agonist buspirone. Such recovery of emotional behaviour and behavioural 5-HT1A response occurred in spite of misdevelopment of the olfactory bulb and hippocampus that is characteristic of Ncam-/- mice, and without an apparent change in the expression of 5-HT1A binding sites in the brain. Hippocampus- and amygdala-dependent learning, though disturbed in Ncam-/- mice, remained unaffected by the transgenic NCAM180. We suggest an involvement of NCAM180-mediated cell recognition processes in the serotonergic modulation of emotional behaviour in adult mice.

Aggression↗
PubMed2000

[Prognostic value of hepatobiliary functional scintigraphy in diagnosis and after-care of biliary atresia].

AIM: To investigate the prognostic relevance of hepatobiliary scintigraphy (HBS) in newborns suffering from biliary atresia (BA) for establishing the primary diagnosis and in the postoperative follow-up after portoenterostomy (Kasai). METHODS: Twenty newborns with direct hyperbilirubinemia and 6 children after operative treatment of BA (Kasai) underwent HBS with Tc-99m-DEIDA. In patients without intestinal drainage, hepatocellular extraction was estimated visually and calculated semiquantitatively by means of liver/heart-ratio 5 min p.i. RESULTS: 10/20 patients with hyperbilirubinemia did not display biliary drainage; 6 had BA, 3 intrahepatic hypoplasia, and one showed a bile plug syndrome. 4/6 with BA but none of the 4 children with diagnoses other than BA presented with a good extraction. All of the 4 children with BA, who had either pre- or postoperatively a bad extraction, needed liver transplantation due to liver failure. Both of the two newborns with BA and favourable outcome after Kasai had a good extraction in the preoperative HBS and demonstrated good intestinal drainage in the postoperative scan. CONCLUSION: HBS rules out BA with high accuracy by demonstrating drainage of bile into the intestine. In newborns without drainage a good extraction favours the diagnosis of BA. In newborns with BA a bad extraction seems to indicate a poor postoperative prognosis after Kasai operation. HBS might therefore help to select those children who will not benefit from portoenterostomy. Postoperatively, HBS can easily and quickly confirm the successful hepatobiliary anastomosis by demonstrating biliary drainage into the intestine.

Biliary Atresia↗
PubMed2000

[Selected secondary reconstructive procedures for improvement of urinary incontinence in bladder exstrophy and neurogenic bladder dysfunction in childhood].

Partial or complete urinary and stool incontinence due to malformation of the genito-urinary tract and the pelvic floor despite of several operative reconstructions is the most important handicap in the patients life. Often this problems seems to be unsoluble. In recent time we secondarily reconstructed 7 patients suffering from urinary incontinence: 1 girl and 4 boys with bladder ekstrophy; 1 boy with a complex anomaly with menigomyelocele, sinus urogenitalis, single kidney with vesicorenal reflux and neurogene bladder; 1 boy with complex anomaly of the pelvis and the lower limbs with duplication of the bladder with an ekstrophic left part. All patients underwent multiple operative trials of reconstruction. Until that time all patients suffered from complete urinary incontinence. At the age of 5 to 14 years we performed the secondary reconstruction: bladder-neck-plasty and ileumaugmentation (3 patients), closure of the bladder-neck, ileumaugmentation and a continent appendicostoma (Mitrofanoff's method)), Mainz-I-pouch and a continent appendicostoma respectively ileostoma (Monti's technique) (2 patients), Mainz-II-pouch. With a normal bladder-capacity all patients are completely continent postoperatively; one patient has regained partial continence. The emptying of the bladder is carried out by clean intermittent catheterism (CIC) with the exception of the one patient with the Mainz-II-pouch. Even in patients with complex anomalies of the pelvic floor and the genitourinary tract complete urinary continence is possible in consequence of recently developed operative techniques. Because of a high rate of complications we reject the primary use of artificial sphincter systems for children.

Abnormalities, Multiple↗
PubMed1999

Preliminary experiences with triple therapy including nelfinavir and two reverse transcriptase inhibitors in previously untreated HIV-infected children.

OBJECTIVE: In an intent-to-treat study increase in CD4 cell count, reduction of viral load, clinical benefit and adverse reactions were examined in HIV-infected previously treatment-naive children taking triple therapy. METHODS: sixteen HIV-infected children in category A or B on antiretroviral triple therapy were followed-up for a period of 12 months. In group I eight patients received zidovudine, lamivudine and nelfinavir; in group II eight patients received stavudine, didanosine and nelfinavir. Viral load and CD4 cell count were measured every 4-8 weeks. Plasma nelfinavir levels were assessed once in all patients at baseline and monitored in patients with increasing viral load. RESULTS: No significant differences were observed between treatment groups in terms of CD4 cell counts and viral load. A median viral load reduction of 2.8 log10 (range, 1.4-4.2 log10) was achieved over a period of 12 months in both groups. Viral load < 500 copies/ml was found in 69% of patients and viral load < 50 copies/ml in 44% of patients after 12 months. Median CD4 cell count increased from 656 x 10(6) to 850 x 10(6) cells/l after 3 months and was maintained at 813 x 10(6) cells/l after 12 months of treatment. Main side-effects were diarrhoea, rash and hyperlipidaemia. Except for application problems, both regimens were well tolerated. Appropriate formula and individual counselling must be performed during the first weeks of treatment in order to achieve good compliance in paediatric patients. CONCLUSION: Triple antiretroviral therapy shows a stronger and more sustained reduction of viral load in HIV-infected children compared with studies combining two nucleoside analogues.

Anti-HIV Agents↗
PubMed1999

Functional analysis of 150 deletion mutants in Saccharomyces cerevisiae by a systematic approach.

In a systematic approach to the study of Saccharomyces cerevisiae genes of unknown function, 150 deletion mutants were constructed (1 double, 149 single mutants) and phenotypically analysed. Twenty percent of all genes examined were essential. The viable deletion mutants were subjected to 20 different test systems, ranging from high throughput to highly specific test systems. Phenotypes were obtained for two-thirds of the mutants tested. During the course of this investigation, mutants for 26 of the genes were described by others. For 18 of these the reported data were in accordance with our results. Surprisingly, for seven genes, additional, unexpected phenotypes were found in our tests. This suggests that the type of analysis presented here provides a more complete description of gene function.

Cell Differentiation↗
PubMed1999

Anderson-Hynes pyeloplasty in horseshoe kidney in children: is it effective without symphysiotomy?

Contemporary reports on surgery for horseshoe kidney (HK) still recommend isthmotomy and lateropexy to complete an open pyeloplasty. To evaluate whether simple Anderson-Hynes pyeloplasty without symphysiotomy is effective for relief of ureteropelvic junction obstruction (UPJO) in HK, we studied the records of ten children, two of whom had bilateral UPJO. Only one child presented with calculi; 11 units were operated upon for UPJO, 1 needed a partial nephrectomy. The surgical outcome was evaluated with emphasis on the changes in renal drainage and function assessed by ultrasonography and diuretic renal scans. Associated vesicoureteral reflux was observed more often (25%) than with UPJO in normal kidneys. Obstruction was caused by a crossing lower-pole vessel in three cases, a high ureteral insertion in two and narrowing of the UPJ 7. Postoperative follow-up (mean 5.5 years) revealed improved renal function and good drainage in all cases. Hydronephrosis vanished in 7, whereas grade 2 hydronephrosis remained in two children with former refluxive megaureter and grade 3 in one. All children are doing well and have no symptoms due to the persistent isthmus (Rovsing syndrome). It is concluded that simple Anderson-Hynes pyeloplasty via a flank incision is a highly effective and safe procedure for treating UPJO in HK.

Child↗
PubMed1998

Increase in proportion of hippocampal spine synapses expressing neural cell adhesion molecule NCAM180 following long-term potentiation.

Neural recognition molecules such as the neural cell adhesion molecule (NCAM) have been implicated in synaptic plasticity, including long-term potentiation (LTP), sensitization, and learning and memory. The major isoform of NCAM carrying the longest cytoplasmic domain of all NCAM isoforms (NCAM180) is predominantly localized in postsynaptic membranes and postsynaptic densities of hippocampal neurons, with only a proportion of synapses carrying detectable levels of NCAM180. To investigate whether this differential expression of NCAM180 may correlate with distinct states of synaptic activity, LTP was induced by high-frequency stimulation of the perforant path and the percentage of NCAM180 immunopositive spine synapses determined in the outer third of the dentate molecular layer of the dentate gyrus by immunoelectron microscopy. Twenty-four hours following induction of LTP by high-frequency stimulation, the percentage of spine synapses expressing NCAM180 increases from 37% (passive control) to 70%. This increase was inhibited by the noncompetitive N-methyl-D-aspartate receptor antagonist MK801. Following repeated LTP induction at 10 consecutive days with one tetanization each day, 60% of all spine synapses were NCAM180 immunoreactive. Compared to passive control animals, the percentage of NCAM180 expressing synapses in low-frequency stimulated animals decreased from 37% to 28%. Spine synapses in the inner part of the dentate molecular layer not contacted by the afferents of the perforant path did not change the percentage of NCAM180-expressing synapses. The results obtained by the postembedding immunogold staining technique confirmed the difference in NCAM180 expression of spine synapses between passive control and potentiated animals. These observations suggest a role for NCAM180 in synaptic remodeling accompanying LTP.

Animals↗
PubMed1998

Interaction between the protein kinase B-Raf and the alpha-subunit of the 11S proteasome regulator.

Protein kinases of the Raf family act as signal-transducing elements downstream of activated cell surface receptors and are involved in the regulation of proliferation, differentiation, and cell survival. Whereas the role of c-Raf-1 as a mitogen-activated protein/extracellular signal-regulated kinase activator within the mitogenic cascade is well established, less is known about the mammalian Raf isoforms A-Raf and B-Raf. Here we report that B-Raf binds to PA28alpha, one of two subunits of the 11S regulator of proteasomes. PA28alpha was isolated as a B-Raf-binding protein in a yeast two-hybrid screen of a PC12 cDNA library. Both proteins can be coimmunoprecipitated after transient expression in 293 cells. No association could be found between PA28alpha and A-Raf or c-Raf-1. B-Raf binds to a region in PA28alpha that is important for its proteasome-activating function.

Animals↗
PubMed1998

[Urethral valves and urinary incontinence: bladder function in temporary high diversion].

UNLABELLED: We report on urodynamic follow-up studies in patients (mean age 8.4 years) with posterior urethral valves (PUV), in which the operative management was finished between 1992 and 1997. The initial therapy included valve resection and transurethral or suprapubic vesical diversion. QUESTION: Does a temporary high diversion have a negative effect on bladder function? Study A was performed at a mean age of 14 months after a high diversion (Sober-non end ureterocutaneostomy) was required for the protection of the dilated upper urinary tract in 7 patients and 13 ureterorenal units. In mean 5.2 years later Study B was performed after undiversion and, in most cases, ureteral reimplantation. In study A the boys with ureterostomy demonstrated higher pathological compliance, capacity and detrusor function. In study B all patients showed improvement of compliance, capacity and detrusor hyperactivity. Surprisingly we found higher values for compliance and capacity in the children with temporary high diversion. CONCLUSION: Improvement of urodynamic results after valve ablation is possible even after bilateral temporary high diversion (Sober stoma). No 'low compliance-low capacity-bladder' developed.

Adolescent↗
PubMed1998

[Enuresis and pediatric urinary incontinence--epidemiology, diagnosis and therapy today].

To describe epidemiology, diagnosis and therapy of enuresis and urinary incontinence in children we have to work with exact definitions. Enuresis is defined as a normal nearly complete emptying of the bladder at a wrong locality at a wrong time at least twice a month after the 5th year of life. Enuresis is regarded as delayed development of bladder function. From enuresis we have to differentiate urinary incontinence in children, which is any kind of loss of urine without normal emptying the bladder. Wetting in those cases is a symptom of a disease (structural, neurogenic, psychogenic or functional). A detailed anamnesis is the most important diagnostic tool in enuresis whereas in the case of urinary incontinence a lot of diagnostics from non-invasive to invasive have to be performed. Enuresis can be treated with alarm or you can apply Desmopressin (DDAVP). Therapy of urinary incontinence in children depends on the disease causing the symptom of wetting.

Adolescent↗