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L Wünsch

Publications and source records attributed to L Wünsch.

15 recordsLinked to original sources
PubMed2006

Tissue-specific transcription profiles of sex steroid biosynthesis enzymes and the androgen receptor.

17beta-hydroxysteroid dehydrogenase (17beta-HSD) and 5alpha-reductase isoenzymes play a crucial role in the formation and metabolism of sex steroids. Not only the key androgens testosterone and dihydrotestosterone but also their precursors are potent activators of the androgen receptor and are, therefore, likely to act as determinants of male sexual differentiation and maturation in a differentially regulated way. The aim of the present study was to relatively quantify the expression of the mRNA of 17beta-HSD isoenzymes, namely, type 1, 2, 3, 4, 5, 7, and 10, together with the 5alpha-reductase type 1 and 2, and the androgen receptor in normal human males and females. RNA was isolated from peripheral blood cells of both sexes and from genital skin fibroblasts (GSFs) of two different localizations (foreskin and scrotal skin) obtained from phenotypically normal males. mRNA expression was semi-quantified by quantitative reverse-transcriptase polymerase chain reaction with the LightCycler Instrument (Roche). The examined enzymes show statistically significant differences in their transcription pattern between the blood and the GSF RNA samples. Within the GSF samples, there are also significant variations between the two examined localizations in the transcription of 17beta-HSD type 1, 2, 4, and 5 as well as for the androgen receptor. We found large interindividual variation of enzyme transcription patterns in all investigated tissues. In peripheral blood cells, no sex-specific differences were seen. We conclude that sex steroid enzymes are expressed not only in genital primary target tissues but also in peripheral blood. The expression in different target tissues may contribute to both the individual sexual and tissue-specific phenotype in humans.

17-Hydroxysteroid Dehydrogenases↗
PubMed2005

Matrix testing for urothelial tissue engineering.

INTRODUCTION: Surgical reconstruction of the bladder is associated with many well-known complications. Tissue engineering is under discussion as a potential therapeutic strategy and many of the proposed benefits are of special interest for children. Biomaterials play a key role in tissue engineering. Many materials have been proposed for the experimental reconstruction of the bladder and urethra. They determine the biological and mechanical characteristics of the reconstructed tissues. Most publications focus on a single material. In order to identify the most suitable biomaterial it was the aim of this study to compare biological and mechanical features of different biomaterials seeded with urothelial cells in vitro. MATERIALS AND METHODS: Commercially available biomaterials (Biogide, Ethisorb, Lyoplant, SIS, Vicryl, Xenoderm) of biologic or synthetic origin were seeded with urothelial cells. Cell-matrix constructs were cultured and investigated by scanning electron microscopy for surface structure and cell morphology. They were also subjected to extension until failure and the force required was reported as f (max). Values obtained and curve shape were compared to specimens of bladder mucosa and submucosa. RESULTS: Cell adhesion and morphology showed marked differences between materials. Cell shape varied from single spherical cells to confluent layers of flat urothelium. f (max) ranged from 0.02 N to 48.86 N for tested materials and 1.19 N for native bladder mucosa/submucosa. DISCUSSION: The materials showed marked differences in biological and mechanical features in vitro. Cells cultured on biogenic matrices were more similar to native urothelium. Most of the tested materials showed different curve shapes and higher f (max) values than native bladder mucosa.

Animals↗
PubMed2004

Measurement of bowing of the radius.

Fractures and plastic deformities of the forearm are common in children. While axial deformities are easily recognised and treated, bowing of the radius may be overlooked. Physiological bowing is essential for full rotation of the forearm. We have used the method of Schemitsch and Richards to estimate the degree of bowing in 100 children who had not suffered a fracture of the forearm. The site of maximum bowing remained constant at 60.39% of the length of the radius (95% CI 59.65 to 61.14). The value of maximum bowing did not exceed 10% of the total length (mean value 7.21%; 95% CI 7.00 to 7.41). This study provides information that can be useful for the diagnosis of bowing and for the evaluation of post-traumatic deformities.

Adolescent↗
PubMed2003

Urothelial mesh--a new technique of cell culture on biomaterials.

INTRODUCTION: Urogenital malformations, trauma or tumours may demand surgical reconstruction in children. Cell culture is an important technology in biomaterial research and tissue engineering. Tissue-engineering of urothelial organs is of interest in children, because the number of complications and re-operations may be reduced. Actually, monolayer cultures of urothelium are used for tissue engineering and biocompatibility testing. A culture system that more closely mimics the physiologic environment of the urothelium would be of interest. The aim of this study was to determine the biological and mechanical characteristics of urothelial mesh cultured in vitro. METHODS: Meshes containing urothelium, lamina propria, and submucosal tissue were generated using a skin mesh graft cutter. Meshes were cultured in 6-well plates, on collagen I/III, polydioxanone/polylactic acid and silicone matrices. Cell morphology was examined by inversion microscopy, histology, and scanning electron microscopy. It was compared to urothelium cultured by methods reported in the literature. To define the basic mechanical properties, meshes were extended longitudinally by a servohydraulic testing machine and strain diagrams generated. RESULTS: Urothelium was reproducibly cultured from meshes. Cell growth could be induced onto fibrillary collagen, polydioxanone-polylactic acid matrices and shaped polyurethane surfaces. Cells formed confluent layers of flat cells, resembling native urothelium. The meshes have unique mechanical properties, allowing for stable fixation, surgical handling and mechanical stimulation. CONCLUSIONS: Meshes can be used for cell culture on biomaterials. They maintain epithelial-stromal integrity and mechanic stability. The small size of tissue bridges allows in vitro culture for long periods with many potential advantages for tissue engineering and biologic research. Applications are possible both in vitro and in vivo.

Biocompatible Materials↗
PubMed2002

A cell-seeded biocomposite for cartilage repair.

Chondrocytes in monolayer cultures lose their phenotype and capability to express type-II collagen, they dedifferentiate into a fibroblastic cell type. Using three-dimensional culture systems a redifferentiation of these cells may occur. In the present study we investigated the morphology and biosynthetic activity of human articular chondrocytes seeded on porous matrices of type I/III collagen (Chondrogide, Geistlich Biomaterials, Wolhusen, Switzerland). Microscopical examinations showed that chondrocytes adhere firmly to a collagen-I/III-membrane exhibiting their characteristic spherical cell shape. Cell numbers after enzymatic digestion of the membrane showed a 93% recovery of seeded cells. Immunohistological examination revealed positive staining for type-II collagen in some areas. The generated biocomposite withstands mechanical stress, keeps its size and design and does not shrink in culture. It is therefore easy to handle, can be sutured, glued or fixed with pins. This study shows, that in vitro production of autologous cartilage-like tissue could be established using a bilayer collagen type I/III fleece. This biocomposite carries active chondrocytes and is currently being evaluated in vivo in a sheep model as well as in a clinical trial for the repair of localized cartilage defects in the knee.

Arthroplasty, Replacement, Hip↗
PubMed2001

Effects of hyaluronic acid on the morphology and proliferation of human chondrocytes in primary cell culture.

Hyaline articular cartilage is a specialised connective tissue with weight bearing and adsorbing functions. Injury or loss of which often leads to impaired joint function and severe pain. Since the self-renewing abilities of hyaline articular cartilage are limited, there is major interest in the development of bioengineered cartilaginous implants. A cell-matrix-biocomposite composed of a collagen I/III scaffold seeded with autologous chondrocytes is currently being used in clinical trials; however, in order to optimise culture conditions, we cultured human condrocytes and seeded them on type I/III collagen membranes and on Thermanox plastic coverslips with media containing 0 to 500 microg/ml Hyaluronic Acid. After 4 days, the cells were either fixed or BrdU incorporation procedures begun. HE staining clearly demonstrated that cells grown in HA form three dimensional clusters and produce secretory vesicles as opposed to the monolayer control cells with noticeably fewer secretory vesicles. BrdU incorporation revealed a noticeable increase in cell proliferation in cells grown in 100 microg/ml; however, no comparable increase in 500 micorg/ml but rather a slight depression in proliferation. Immunohistochemistry for collagen II and aggrecan revealed an obvious increase in deposition of these two substances with increased HA administration as compared to the control; however, again, the higher concentration of HA, 500 microg/ml, did not result in a further increase in production. These results suggest that HA at 100 microg/ml not only influences chondrocytes to differentiate and produce more Collagen II and aggrecan, but also increases proliferation. We, therefore, propose that the addition of HA at low to middle dosages in condrocyte culturing might help improve condrocyte redifferentation and thus, the bioengineered cartilage.

Cartilage, Articular↗
PubMed2001

Expression of MIB and BCL-2 in patients with nephrogenic rests with and without associated Wilms' tumors.

Nephrogenic rests (NR) are foci of persistent embryonal renal tissue. Because it has been suggested that NRs are precursor lesions to Wilms' tumor (WT), they are of considerable clinical interest. NRs vary from microscopic foci to macroscopic renal tumors, but only a few progress to WT. In this study, patients with NRs detected during the treatment of bilateral WT were compared to a group of patients with NRs incidentally discovered in various clinical settings. Because mechanisms leading to NR growth and WT formation are poorly understood, bcl-2 and MIB expression were studied by immunohistochemistry in both groups. Bcl-2 is an oncoprotein with inhibitory effects on apoptosis and MIB is a well-established marker of cell proliferation. Both mechanisms may be of interest for the growth, regression and transformation of NRs. Intense positive staining for bcl-2 was found in microscopic NRs. Blastemal cells and cells with epithelial differentiation were bcl-2-positive. The same pattern of bcl-2 expression was found in NRs with and without associated WT. High proliferative activity with intense MIB expression was found in blastemal areas of WT. Bcl-2 expression in NR is reported for the first time. Inhibition of apoptosis as a mechanism of NR formation is suggested. This is of special interest, because bcl-2 is under transcriptional control of the WT-1 gene.

Child, Preschool↗
PubMed2000

Long-term results of treatment of single-system ectopic ureters.

Single-system ureteral ectopia (UE) encompasses a spectrum of malformations involving the bladder trigone, ureter, and kidney. The clinical presentation is variable, and both diagnostic and therapeutic problems are common. Reduced renal function in these patients may result from primary dysplasia, obstruction, vesicoureteral reflux, or recurrent infection. Based on our experience of seven patients, suggestions for diagnostic procedures and criteria for renal saving versus nephrectomy are offered. The relationship between ostium localization, renal function, and long-term results was investigated. From 1972 to 1990, five female and two male patients were studied. During the same period, 31 patients with UE and duplex kidneys were seen. Ages ranged from 1 day to 7 years. A ureteric opening into the bladder neck was associated with dilatation of the ureter and renal pelvis. Two patients had vaginal ectopia and severe renal dysplasia. In one, a cyst of the vaginal wall (Gardner's cyst) was detected at birth. A male newborn had multicystic renal dysplasia on the left and ureteric ectopia to the ductus deferens on the right side. To our knowledge, he is the first patient reported with renal function totally dependent on a kidney with severe UE. Follow-up ranged from 4 to 9 years. One patient died in the postoperative period because of renal failure and sepsis. All the others are well and have normal creatinine values. Improvement of renal function was noted after ureteral reimplantation (URI) in patients with bladder-neck ectopia. The numbers of infections were also drastically reduced. Our observations suggest that the combination of ultrasound, cyst urethrography, and cystoscopy will be diagnostic in most patients. A suspicion of UE should be raised in symptomatic patients with apparently solitary kidneys, enuresis ureterica, or atypical obstructive uropathy. Reduced renal function in some patients with ectopia to the bladder neck will improve after URI. This may be of importance in patients with bilateral anomalies and marginal renal function.

Cause of Death↗
PubMed1999

Color Doppler energy--a new technique to study tissue perfusion in renal transplants.

Information on renal tissue perfusion after transplantation remains important for renal allograft monitoring. Findings obtained by conventional Doppler sonography are limited to vascular resistance (RI). The new technique color Doppler energy (CDE) is Doppler angle independent, omits flow velocity and direction, and is proportional to the returning signal strength. The aim of our study was to standardize the application of this technique and to analyze the information obtained. Forty-six CDE studies were performed with an Acuson 128XP in 28 children (mean age 12.4+/-5.3 years) between 4 days and 10 years after renal transplantation. The most-reproducible information was obtained with a 5-MHz linear probe and a constant area of 2x3 cm (log compression 40 dB, filter 3). CDE provided a high-resolution cross-sectional display of perfused cortical tissue vessels. According to the density of signals, the perfusion could be grouped into six perfusion scores (PS). The interobserver concordance was more than 85%. No correlation was found between PS and RI or blood pressure. However, there was a significant correlation between PS and glomerular filtration rate (r=-0.78, P<0. 001). These first results demonstrate a significant relationship between PS and chronic rejection. Non-rejection-related functional impairment exhibited no decrease in PS. We conclude that our proposed standardized CDE renal study is observer independent. CDE is a promising new technique that provides information on renal allograft dysfunction that is different from classical color Doppler findings. Further studies will clarify its role in renal transplant monitoring and its ability to replace more-invasive techniques.

Adolescent↗
PubMed1999

Nephron-sparing surgery in synchronous bilateral Wilms' tumors.

BACKGROUND: Synchronous bilateral Wilms' tumor is rare and experience with renal salvage procedures and their limitations accumulates slowly at single institutions. The authors analyzed whether their growing experience with atypical renal resections and awareness of nephroblastomatosis had influenced the outcome of surgical procedures. METHODS: Retrospective analysis of patients treated from 1977 to 1995 was performed. Surgical reports, clinical sheets, and follow-up data were evaluated. All pathology slides were reviewed for histological classification and presence of nephroblastomatosis. Renal function was evaluated pre- and postoperatively and at final follow-up. RESULTS: Fourteen patients were treated. Two to 20 years after surgery, 13 patients are alive, and none has had renal failure. Five patients had unilateral nephrectomies, and a renal salvage procedure was performed on 22 kidneys. One patient with an anaplastic bilateral Wilms' tumor died of tumor progress 1 year after surgery. Several kidneys, which would have been sacrificed by application of traditional criteria, could be salvaged by atypical and unconventional tumor resections and by superficial dissection and enucleation of supposed nephroblastomatosis. Nephrectomy appeared unavoidable with hilar invasion by tumor. CONCLUSION: Atypical resections of localized lesions and superficial dissections of suspected nephroblastomatosis appeared as valid surgical treatment options for patients who would otherwise have been candidates for nephrectomy. In the case of hilar tumor invasion, however, nephrectomy seems unavoidable.

Child, Preschool↗
PubMed1997

Arthroscopic repair of the posterior cruciate ligament in a 3-year-old child.

We report a case of symptomatic acute posterior cruciate ligament (PCL) rupture in a 3-year-old boy. At arthroscopy, the PCL was avulsed from the femoral attachment with intact ligament substance. Arthroscopic repair of the PCL was performed by transosseous sutures, which were placed using a suture-punch and an anterior cruciate ligament drill guide. Two years later there was a perfect objective and functional result.

Arthroscopy↗