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Biomedical subjects

Uwe Klinge

Publications and source records attributed to Uwe Klinge.

At least 19 recordsLinked to original sources
PubMed2007

Polymeric meshes induce zonal regulation of matrix metalloproteinase-2 gene expression by macrophages and fibroblasts.

Matrix metalloproteinase-2 (MMP-2) is a key regulator in wound healing that orchestrates tissue remodeling. In the present study the spatial and temporal distribution of MMP-2 gene transcription, protein synthesis, and enzymatic activity were analyzed following polymeric mesh (polyglactin, polypropylene) implantation in transgenic reporter mice harboring MMP-2 regulatory sequences -1686/+423 or -1241/+423. Polymers induced MMP-2 promoter activity in macrophages within the foreign body granuloma via sequences -1686/+423 with concomitantly up-regulated protein synthesis and enzymatic activity. Macrophages distant from mesh filaments exhibited low MMP-2 expression levels. Fibroblasts surrounding mesh material displayed strong MMP-2 gene transcription independent of the included promoter sequences, whereas fibroblasts without close contact to mesh material had low MMP-2 synthesis rates due to silencing activity of sequences -1686/-1241. In vitro studies support a cellular crosstalk concept, as macrophages trans-repressed MMP-2 gene transcription in fibroblasts. The zonal and cell-specific regulation of MMP-2 gene transcription illuminates an intimate cellular crosstalk in foreign body reaction that may provide a new approach for mesh modification.

Animals↗
PubMed2006

Hernia fibroblasts lack beta-estradiol-induced alterations of collagen gene expression.

BACKGROUND: Estrogens are reported to increase type I and type III collagen deposition and to regulate Metalloproteinase 2 (MMP-2) expression. These proteins are reported to be dysregulated in incisional hernia formation resulting in a significantly decreased type I to III ratio. We aimed to evaluate the beta-estradiol mediated regulation of type I and type III collagen genes as well as MMP-2 gene expression in fibroblasts derived from patients with or without history of recurrent incisional hernia disease. We compared primary fibroblast cultures from male/female subjects without/without incisional hernia disease. RESULTS: Incisional hernia fibroblasts (IHFs) revealed a decreased type I/III collagen mRNA ratio. Whereas fibroblasts from healthy female donors responded to beta-estradiol, type I and type III gene transcription is not affected in fibroblasts from males or affected females. Furthermore beta-estradiol had no influence on the impaired type I to III collagen ratio in fibroblasts from recurrent hernia patients. CONCLUSION: Our results suggest that beta-estradiol does not restore the imbaired balance of type I/III collagen in incisional hernia fibroblasts. Furthermore, the individual was identified as an independent factor for the beta-estradiol induced alterations of collagen gene expression. The observation of gender specific beta-estradiol-dependent changes of collagen gene expression in vitro is of significance for future studies of cellular response.

Abdomen↗
PubMed2006

Incisional hernia: challenge of re-operations after mesh repair.

BACKGROUND AND AIMS: The widespread use of meshes for the repair of incisional hernia is currently followed by an increasing number of re-operations. The incidence of incisional hernia recurrence after mesh repair varies between 3 and 32%. The problem of mesh failure and options for another surgical intervention seem rather unattended. METHODS: We present our experience of 77 re-operations after previous mesh repair that were performed between 1995 and 2004 out of a total of 1,070 operations for incisional hernia. The retrospective analysis focused on recurrence in relation to location, material of the previous mesh repair and the surgical procedure to resolve the problem. RESULTS: The locations of the preceding meshes were epifascial as onlays (n=23), retromuscular as sublays (n=46), within the defect as inlays (n=6) or intraperitoneally (n=2). The direction of the incision was vertical medial (n=41) or horizontal crossing the linea semilunaris (n=36). Recurrences after median incisional hernia mesh repair mainly occurred at the cranial border of the mesh subxiphoidal. Except for two patients, all recurrences manifested at the margin of the enclosed mesh. CONCLUSIONS: Re-operation after previous mesh repair is a surgical challenge. The type of revision procedure has to consider the position and material of the previous mesh. In our clinic recurrences, heavyweight polypropylene meshes were mostly treated with mesh exchange and lightweight polypropylene meshes could be treated by extension with a second mesh. In contrast to suture techniques, deficient mesh repairs are more evidently related to technical problems.

Aged↗
PubMed2006

Hernia disease and collagen gene regulation: are there clues for intervention?

Collagens belong to the most abundant proteins in the body. After tissue injury, a coordinated regulation of collagen gene expression guides the formation of a provisional matrix that subsequently evolves into a mature scar with tensile strength. In the following, knowledge regarding collagen gene regulation that may provide insight into how to specifically address the biological problem of soft tissue weakness and recurrent hernia disease is summarized.

Animals↗
PubMed2006

Collagen in colon disease.

The pathophysiology of wound healing in the bowel wall suggests that collagen and matrix metalloproteinases (MMPs) have an important role in the changes of the bowel wall seen in several colonic diseases. Several recent studies suggest that disturbances of the collagen texture and the extracellular matrix (ECM) metabolism are major factors leading to the onset of diverticular disease. Changes of the ECM also play a role in the development of inflammatory bowel diseases. Regarding the permanent remodeling of the bowel wall, any imbalance of the ECM could support the onset of chronic inflammation and the development of fistula formation, such as that seen in patients with Crohn's disease. Disturbances of the ECM play a role in the pathogenesis of anastomotic leakage after large bowel surgery and suggest the presence of a genetically defined risk population with disturbed wound healing mechanisms. This concept could explain the well known situation where an anastomotic breakdown is observed, despite the absence of other known risk factors and after a technically correct anastomosis.

Collagen↗
PubMed2005

Is there a risk of infertility after inguinal mesh repair? Experimental studies in the pig and the rabbit.

The implantation of a non-absorbable polypropylene mesh during hernia repair causes chronic foreign body reaction involving the surrounding tissue. In case of inguinal hernia repair using mesh techniques, the spermatic cord is potentially affected by this chronic inflammatory tissue remodeling. This effect has been investigated using standardized animal models (pig and rabbit). Fifteen adult male pigs underwent transinguinal preperitoneal implantation of a polypropylene mesh. The contralateral side with a Shouldice repair served as control. After 7, 14, 21, 28, and 35 days, three animals were sacrificed. The spermatic cords were resected and analyzed histologically. In a second experiment Lichtenstein repair using the same polypropylene mesh and Shouldice repair on the contralateral side was done in eight chinchilla rabbits. Three animals served as controls. Three months after operation, the analysis included testicular size, testicular temperature, and testicular and spermatic cord perfusion. We added histological evaluation of the foreign body reaction and the spermatogenesis using the Johnsen score. In the pig, we observed a certain foreign body reaction with diffuse infiltrating inflammatory cells after mesh implantation. Venous thrombosis of the spermatic veins occurred in five of 15 cases. One animal presented focal fibrinoid necrosis of the deferent duct wall. The side of Shouldice repair showed only minor postoperative changes. In the rabbit, we also observed a typical foreign body reaction at the interface between mesh and surrounding tissue, which was not detectable after Shouldice repair. The mesh repair led to a decrease of arterial perfusion, testicular temperature, and the rate of seminiferus tubules with regular spermatogenesis classified as Johnsen 10 (Lichtenstein: 48.1%, Shouldice: 63.8%, controls: 65.8%). Testicular volume increased about 10% after each operation. The implantation of a polypropylene mesh in the inguinal region induces major response of the structures of the spermatic cord. This may have an influence also on spermatogenesis. Due to this a strict indication for implantation of a prosthetic mesh during inguinal hernia repair is recommended.

Animals↗
PubMed2005

Missing effects of zinc in a porcine model of recurrent endotoxemia.

BACKGROUND: Chronic human sepsis often is characterised by the compensatory anti-inflammatory response syndrome (CARS). During CARS, anti-inflammatory cytokines depress the inflammatory response leading to secondary and opportunistic infections. Proved in vitro as well as in vivo, zinc's pro-inflammatory effect might overcome this depression. METHODS: We used the model of porcine LPS-induced endotoxemia established by Klosterhalfen et al. 10 pigs were divided into two groups (n = 5). Endotoxemia was induced by recurrent intravenous LPS-application (1.0 microg/kg E. coli WO 111:B4) at hours 0, 5, and 12. At hour 10, each group received an intravenous treatment (group I = saline, group II = 5.0 mg/kg elementary zinc). Monitoring included hemodynamics, blood gas analysis, and the thermal dilution technique for the measurement of extravascular lung water and intrapulmonary shunt. Plasma concentrations of IL-6 and TNF-alpha were measured by ELISA. Morphology included weight of the lungs, width of the alveolar septae, and rate of paracentral liver necrosis. RESULTS: Zinc's application only trended to partly improve the pulmonary function. Compared to saline, significant differences were very rare. IL-6 and TNF-alpha were predominately measured higher in the zinc group. Again, significance was only reached sporadically. Hemodynamics and morphology revealed no significant differences at all. CONCLUSION: The application of zinc in this model of recurrent endotoxemia is feasible and without harmful effects. However, a protection or restoration of clinical relevance is not evident in our setting. The pulmonary function just trends to improve, cytokine liberation is only partly activated, hemodynamics and morphology were not influenced. Further pre-clinical studies have to define zinc's role as a therapeutic tool during CARS.

Animals↗
PubMed2005

Incisional hernia: open techniques.

Even with the routine use of mesh, repairing an incisional hernia is a challenge. Increasing evidence of impaired wound healing in these patients supports routine use of an open prefascial, retromuscular mesh repair. Basic pathophysiologic principles dictate that for a successful long-term outcome and prevention of recurrence a wide overlap underneath healthy tissue is required. The extent of this overlap should be 5 cm in all directions: surrounding the wound closure, subxiphoidal underneath the ribs, below the arcuate line, and retropubic.

Hernia, Ventral↗
PubMed2005

Gentamicin supplementation of polyvinylidenfluoride mesh materials for infection prophylaxis.

Hernia repair evolved from pure tissue repair to mesh repair due to decreased recurrence rates. However, concern exists about mesh-related infections occurring even several years after initial operation. Therefore, a polyvinylidenfluoride (PVDF) mesh material was constructed and surface modified by plasma-induced graft polymerization of acrylic acid (PVDF+PAAc). Antimicrobial treatment was sought by binding of gentamicin (PVDF+PAAc+Gentamicin). In vitro efficacy and cytotoxicity was measured by agar diffusion test, L929 cytotoxicity testing and by analyzing the amount of gentamicin release from the mesh surface. In vivo biocompatibility was evaluated in 45 Sprague-Dawley rats. 7, 21 and 90 days after mesh implantation the amount of inflammatory and connective tissue as well as the percentage of proliferating (Ki67) and apoptotic cells (TUNEL) were analyzed at the perifilamentary region. Agar diffusion tests showed sufficient local antimicrobiotic effects against the bacteria tested after 24h of incubation. No signs of cytotoxicity could be identified by L929 testing. Furthermore, surface modification did not affect the in vivo biocompatibility. At the end of the observation period, no significant differences were found for the perifilamentary amount of inflammatory cells and connective tissue and the percentage of Ki67 and TUNEL positive stained cells. The presented data confirm that an antibiotic surface modification of PVDF mesh samples is feasible. By analyzing cytotoxicity in vitro as well as biocompatibility in vivo no side effects were observed.

Animals↗
PubMed2005

Effect of zinc pretreatment on pulmonary endothelial cells in vitro and pulmonary function in a porcine model of endotoxemia.

BACKGROUND: During endotoxemia, the systemic inflammatory response often leads to severe pulmonary damages. Destruction of endothelial cells, interstitial edema, and interstitial alveolitis depress pulmonary circulation and raise extravascular lung water and intrapulmonary shunt. As protective effects of zinc are described in vitro as well as in vivo, this study investigates its impact on septic porcine pulmonary endothelial monolayers as well as on the pulmonary function of endotoxemic pigs. MATERIALS AND METHODS: Cell culture: Endothelial cells were incubated with ascending doses of zinc and pooled with septic plasma. Cellular damage, metabolism, and proliferation were measured by vital stain, XTT-assay, and BrDU-ELISA. HSP70 was visualized by immunohistochemistry. Animal study: We used an established porcine model. Twenty-four hours before endotoxemia (intravenous infusion of 1.0 microg/kg Escherichia coli endotoxin WO111:B4), each animal received an intravenous pretreatment. Group I (n = 3): saline pretreatment, group II (n = 5): zinc pretreatment (5 mg/kg elementary zinc). Monitoring included blood gas analysis and the thermal dye dilution technique. RESULTS: In vitro, zinc leads to significantly altered rates of viable cells, metabolism, and proliferation with the strongest cell-protective effect at moderate concentrations of 1 microg/ml Zn2+. This correlates with a qualitatively increased expression of HSP70. In vivo, the zinc pretreatment before LPS-induced endotoxemia grossly improves all measured hemodynamic and pulmonary parameters. CONCLUSION: Zinc pretreatment of endotoxemia decreases cellular damages in vitro and improved pulmonary function in vivo. This could be mediated by the heat shock response. Further studies, particularly concerning the dose-effect relationship and the underlying mode of action, are mandatory.

Animals↗
PubMed2005

Changes of the extracellular matrix as a risk factor for anastomotic leakage after large bowel surgery.

BACKGROUND: Despite improved surgical techniques, anastomotic leakage remains as a serious complication in colorectal surgery, producing increased morbidity and mortality. This prospective study was initiated to test the hypothesis that preexisting disorders in the extracellular matrix (ECM) may be a factor influencing the onset of anastomotic wound healing complications. METHODS: In this prospective study of 119 patients with colorectal anastomoses, 30 clinical parameters with possible influence on anastomotic complications were evaluated. From all patients, samples of macroscopically intact colonic tissue were obtained at the index operation. Crosspolarization microscopy was performed to analyze the collagen type I/III ratio, and immunohistochemical studies were done to determine the expression of matrix metalloproteinase (MMP) 1, 2, 9, and 13. The patients with uncomplicated postoperative healing were compared with those developing anastomotic leakage. RESULTS: Patients with impaired anastomotic healing exhibited a significantly lower collagen type I/III ratio compared with the controls. Significantly higher expression of MMP-1 and MMP-2 in the mucosal layers and of MMP-2 and MMP-9 in the submucosal layers was found in the normal bowel wall of the leakage group. These findings were statistically independent from the clinical parameters. CONCLUSION: The present study confirms the hypothesis that disturbances of the ECM play a role in the pathogenesis of anastomotic leakage after large bowel surgery.

Anastomosis, Surgical↗
PubMed2005

The lightweight and large porous mesh concept for hernia repair.

In modern hernia surgery, there are two competing mesh concepts which often lead to controversial discussions, on the one hand the heavyweight small porous model and on the other, the lightweight large porous hypothesis. The present review illustrates the rationale of both mesh concepts and compares experimental data with the first clinical data available. In summary, the lightweight large porous mesh philosophy takes into consideration all of the recent data regarding physiology and mechanics of the abdominal wall and inguinal region. Furthermore, the new mesh concept reveals an optimized foreign body reaction based on reduced amounts of mesh material and, in particular, a significantly decreased surface area in contact with the recipient host tissues by the large porous model. Finally, recent data demonstrate that alterations in the extracellular matrix of hernia patients play a crucial role in the development of hernia recurrence. In particular, long-term recurrences months or years after surgery and implantation of mesh can be explained by the extracellular matrix hypothesis. However, if the altered extracellular matrix proves to be the weak area, the decisive question is whether the amount of material as well as mechanical and tensile strength of the surgical mesh are really of significant importance for the development of recurrent hernia. All experimental evidence and first clinical data indicate the superiority of the lightweight large porous mesh concept with regard to a reduced number of long-term complications and particularly, increased comfort and quality of life after hernia repair.

Biocompatible Materials↗
PubMed2004

Transcription factor YB-1 mediates DNA polymerase alpha gene expression.

Y-box protein-1 involvement in cyclin A and B1 gene regulation has recently been demonstrated. A more generalized role of this protein for cell replication is hypothesized as numerous regulatory sequences of cell cycle-related genes contain putative binding sites. In the present study the DNA polymerase alpha (DPA) gene is identified as another YB-1-responsive gene with a Y-box and 3' inverted repeat sequence, designated DPA RE-1, in the serum-responsive promoter region. Overexpressed YB-1 concentration-dependently trans-activated DPA gene expression in reporter assays and Southwestern blotting as well as DNA binding analyses revealed binding of distinct endogenous proteins to the RE-1 with molecular sizes of 26, 32 and 52 kDa. Among these, YB-1 binding was confirmed using recombinant as well as endogenous proteins, with preferential single-stranded DNA binding. Early serum growth response in mesangial cells was accompanied by a nuclear YB-1 shift and nucleocomplex formation at the RE-1. Fine mapping of the DPA RE-1 sequence unraveled a dependence on co-factors for trans-regulation with gene activation in the context of a heterologous SV40 promoter but suppression in the context of the abbreviated homologous promoter sequence. A YB-1 knock down resulted in decreased DPA transcription rates and abrogated the serum-dependent induction of DPA transcription. These results link YB-1 with serum responsiveness of DPA gene expression and provide insight into the required sequence and protein binding context.

Acetylcysteine↗
PubMed2004

Ki67, HSP70 and TUNEL for the specification of testing of silicone breast implants in vivo.

This investigation of capsular tissue adjacent to silicone breast implants concerns the long-term tissue response to the implant environment. Fifty-three silicone breast implants have been analyzed at the time of explantation. The implant duration ranged from 2 months to 153 months. The reason for explantation was capsular contracture (57%), dissatisfaction with the effect (11%), local inflammation (6%), implant rupture (4%) and exchange of tissue expanders (21%). The cell turnover within the interface of the silicone device and the fibrous capsule was detected by specific antibodies against Ki67 for cell proliferation, by TUNEL for apoptosis, and by DNA strand breaks and heat shock protein 70 (HSP70) for cell stress. We found a negative correlation between the expression of HSP 70 and the capsular thickness (p < 0.043) and decreased levels in specimens obtained from Baker IV implant capsules. Ki67, and TUNEL were significantly positive (p < 0.001 for both) and HSP 70 were significantly negative (p < 0.001) with signs of inflammation. Both Ki67 and TUNEL indicated decreasing values over time. Ki67 and TUNEL showed no correlation with clinical signs of implant failure, such as the Baker score. The expression of HSP70, on the other hand, was connected with structural changes of the implant capsule, in terms of capsular thickness and the Baker score.

Adult↗
PubMed2003

Decreased collagen type I/III ratio in patients with recurring hernia after implantation of alloplastic prostheses.

BACKGROUND: Abnormal collagen metabolism is suspected to play an important role in the pathogenesis of recurring inguinal and incisional hernias. Whereas alloplastic prostheses are nowadays routinely used, the quantity and quality of collagen formation after repair in humans has not been analysed in a large cohort. METHOD: Seventy-eight prostheses (Prolene, Atrium, Marlex, Vypro, Mersilene, Gore-Tex) implanted for inguinal and incisional hernia repair were explanted because of recurrence, chronic pain or infection. The mean implantation period was 17.9+/-11.2 (range 0.5-48) months. Collagen formation was investigated quantitatively (collagen-protein ratio) and qualitatively (collagen type I/III ratio). Results were related to clinical data that included gender, age, implantation period, indication for implantation/explantation, type and location of prosthesis. RESULTS: Mean collagen-protein ratio was 45.3+/-8.5 microg/mg, with significant differences between male (43.8+/-9.1 microg/mg) and female tissue samples (48.1+/-6.8 microg/mg, P=0.033). The mean collagen type I/III ratio of all samples investigated was 2.1+/-1.4. Samples explanted for recurring hernias exhibited a significantly decreased ratio (1.3+/-0.7, P<0.05) compared to samples explanted because of pain (3.4+/-1.2) or infection (2.9+/-1.6). Multivariate analysis excluded independent effects of age, gender, indication for implantation of prostheses, location and implantation period on collagen type I/III ratio. CONCLUSION: The present study confirms the importance of a biological approach, next to technical aspects, to the understanding of the pathogenesis of recurrent hernia formation and underscores the presence of a disturbed scarring process. The composition of scar tissue with a lowered collagen type I/III ratio and, therefore, reduced tensile strength may be a major contribution to hernia recurrence.

Cicatrix↗
PubMed2003

Histological analysis of silicone breast implant capsules and correlation with capsular contracture.

BACKGROUND: A study was undertaken to investigate long-term histological changes in the environment of breast implants and their correlation with complains at the time of capsular contracture defined by the Baker score. METHOD: The collagenous capsules of 53 silicone breast implants from 43 patients (23 smooth and 30 textured devices) were evaluated histologically for capsular thickness, the presence of histiocytes, the amount of silicone and calcification in the capsule, and the presence of synovial-like metaplasia of the inner surface of the capsule with light microscopy and polarised light. All parameters were correlated with the Baker score. RESULTS: A significantly higher degree of the Baker score was found with increasing patient age (p<0.001), implant duration (p<0.02), and capsular thickness (p<0.009). A trend towards greater capsular thickness was documented in patients who had a breast augmentation for cosmetic reasons. Synovial-like metaplasia was seen in 28 capsules (52.8%). The highest incidence was found in textured implants with a duration of less than 5 years. Histiocytic inflammation was more common in patients with clinical symptoms (p<0.001) and around subglandular implants (p<0.096). CONCLUSIONS: The histological findings of breast capsules were related to: the nature of the device surface (smooth versus textured), implant duration, and the degree of capsular contracture. Capsular contracture (Baker score of 3 or 4) was related to implant duration, capsule thickness, patient age, and inflammation.

Adult↗
PubMed2002

Tension banding closure of laparotomies: results of an experimental study in dogs.

BACKGROUND: Conventional laparotomy closure may cause ischemia, edema, and necrosis of the incisional edges, weakening of the tissue, and incisional hernia formation. Two experimental closure techniques were established to investigate laparotomy healing without suturing the incisional edges. METHODS AND MATERIALS: In 24 dogs median laparotomies were closed applying two techniques following the principle of tension banding. Investigations after 3, 9, and 15 months were laparoscopy, tensiometry, light and electron microscopy and measurement of collagen fibril diameters. RESULTS: Incisions healed without incisional hernias with only minimal adhesion formation. At all time points the tensile strength after the bridging technique (BT) did not differ significantly from that in the control group. Mean tensile strength after BT was higher than after the onlay technique (OT) at all time points but did not reach statistical significance. After 3 months the incisions after OT were significantly weaker than the control group. At all time points fibril diameters after OT were significantly smaller than in the control group. After 3 and 9 months the fibril diameters after OT were significantly smaller than after BT. Incisions healed with little scar formation in spite of a chronic inflammatory reaction. This reaction was more pronounced after OT and made access to the fascia difficult after 3 months. Both techniques led to early postoperative seroma formation. CONCLUSIONS: Applying the principle of tension banding, laparotomies healed without suturing the incisional edges. The effect of foreign material on the ultrastructure of regenerating tissue in direct contact to the incisional region was demonstrated by the OT, in which chronic inflammation disturbed the adequate formation of collagen. Further development of both techniques might allow laparotomy closure according to the physiological requirements of wound healing.

Abdominal Wall↗