Biomedical subjects

K Junge

Publications and source records attributed to K Junge.

At least 55 records · Page 3Linked to original sources

PubMed2002

PVDF as a new polymer for the construction of surgical meshes.

Abdominal hernia repair is the most frequently performed operation in surgery. Mostly due to lowered recurrence rates mesh repairs in hernia surgery have become an integral component despite increasing mesh-related complications. Current available mesh prosthesis are made of polypropylene (PP). polyethylene-terephtalat or polytetrafluorethylene. though all of them reveal some disadvantages. The introduction of new materials seems to be advisable. Caused by supposed advantageous textile properties and tissue response two mesh modifications made of polyvinylidene fluoride (PVDF) for abdominal hernia repair were developed. In the present study the PVDF meshes were compared to a common heavy weight PP-mesh (Prolene) in regard to functional consequences and morphological tissue response. After implantation in rats as inlay for 3, 14, 21, 42 and 90 days abdominal wall mobility was recorded by three-dimensional photogrammetry. Tensile strength of the suture zone and the mesh itself were determined. Explanted tissue samples have been investigated for their histological reaction in regard to the inflammatory infiltrate. vascularisation, connective and fat tissue ingrowth. Number of granulocytes, macrophages, fibroblasts, lymphocytes and foreign giant body cells have been evaluated to reflect quality of tissue response. The cellular response was grasped by measurement of DNA strand breaks and apoptosis (TUNEL), proliferation (Ki67) and cell stress (HSP70). Analyzing the results confirmed that construction of hernia meshes made of PVDF could be an advantageous alternative to the commonly used materials due to an improved biostability. lowered bending stiffness and a minimum tissue response.

Animals↗

PubMed2002

Influence of implantation interval on the long-term biocompatibility of surgical mesh.

BACKGROUND: The aim was to study the long-term tissue response to polypropylene mesh. METHODS: This was a retrieval study that investigated 76 polypropylene meshes with a median implantation interval of 18 (range 2-180) months. Mesh was explanted following hernia recurrence, infection or pain. The median implantation interval was 20 (range 4-180) months in the recurrence group, 30 (range 5-48) months in the pain group and 10 (range 2-56) months in the infection group (P < 0.05, infection versus pain or recurrence). The inflammatory response was determined by immunohistochemistry of macrophages (CD68), polymorphonuclear granulocytes (CD15) and T and B lymphocytes (CD3 and CD20). The cell turnover within the interface mesh fibre-recipient tissue was measured by TUNEL for apoptosis or DNA strand breaks, Ki67 for cell proliferation and heat-shock protein (HSP) 70 for cell stress. RESULTS: With the exception of HSP-70, levels of all variables decreased over time. Sex, age, type of previous operation or location of the mesh did not have a significant influence. CONCLUSION: Long-term incorporated polypropylene mesh in humans has a more favourable tissue response with increasing implantation interval.

Adult↗

PubMed2002

[Meshes in inguinal hernia repair].

Repair of a groin hernia is strongly influenced by prosthetic mesh implantation carried out in nearly 50 % of all operations. Recurrency rates, however, did not decrease by this policy. Many different materials are available. Due to bioinstability on the long-term and elevated infection rates PTFE is not suitable for inguinal hernia repair. Polyester also provides no long-term stability and induces a chronic foreign body reaction. Polypropylene initially leads to an acute inflammatory reaction and often ends in fibrosis. Both reactions are related to the weight of the used mesh. All materials may lead to specific complications. These include seroma formation, infection, migration of the prosthesis with arrosion of organs, damage of the vas deferens, development of recurrency by shrinkage of the fibers around the mesh, formation of adhesions in the preperitoneal position, and chronic inguinal pain. Therefore, meshes should be used only after individual estimation of risks and benefit. This includes the hernia classification, the number of previous operations and the possibility of a defect in collagen metabolism. The unknown long-term risks for the patient may be taken only in strong indications.

Hernia, Inguinal↗

PubMed2001

[Primary angiosarcoma of the lung].

INTRODUCTION: Angiosarcomas are uncommon neoplasias, normally located in the skin, liver or heart. Primary angiosarcoma of the lung is rare. CASE REPORT: We report on a 41-year-old patient who presented increasing dyspnea. A 10-cm-angiosarcoma of the inferior lobe of the left lung was detected. After preoperative chemo- and radiotherapy the patient was referred to our clinic for surgical intervention. Resection of the inferior lobe of the lung, resection of part of the diaphragm, lymphadenectomy and replacement with a Vypro-II mesh was performed. Histological examination showed a mesenchymal neoplasia with myxoid tumor tissue, variable cell density and small proliferations of vessels. The immunohistochemical analysis confirmed the diagnosis of an angiosarcoma. The patient was discharged in a good general state for further ambulatory radiochemotherapy. DISCUSSION: Angiosarcoma of the lung must always be included in the differential diagnosis of lung nodules and diffuse infiltrates despite its rare occurrence. Success with neoadjuvant therapy has been reported, but radical resection is recommended due to the cumulative bad prognosis.

Adult↗

PubMed2001

Elasticity of the anterior abdominal wall and impact for reparation of incisional hernias using mesh implants.

Mesh implantation to repair incisional hernia involves extensive disturbance of the integrity of the abdominal wall. To define the physiological requirements, we measured the elasticity of the abdominal wall of 14 anatomic samples. The complete abdominal wall was excised and stretched at a strain of 0-24 N in horizontal, vertical and oblique (upper and lower abdomen) directions. The resulting mean distension at 16 N was in the range between 11% and 32% for all directions. Furthermore, we found significant differences between tissue samples from male and female subjects, as well as considerable inter-individual differences in each group. Textile analysis of common mesh materials at 16 N showed elasticities in the range of 4%-16%. Comparing the textile characteristics with the physiological elasticity revealed inadequate properties in at least some of the mesh materials. Our findings indicate that the flexibility of the abdominal wall must be more or less restricted by extensive implantation of large meshes and recurrences may possibly be provoked at the margins of implanted materials.

Abdominal Muscles↗

PubMed2001

Inguinal tensile strength and pain level after Shouldice repair.

BACKGROUND: Tension of the abdominal wall in the inguinal region induced by Shouldice repair of an inguinal hernia is said to be responsible for elevated postoperative pain levels. PATIENTS AND METHODS: In 20 patients we recorded the inguinal tensile strength during closure of the hernial gap using a wound retractor equipped with strain gauges. Postoperative pain levels were scaled using a visual analogous score, and correlated with the tensile strength of the inguinal abdominal wall together with peak flow and forced expiratory volume in 1 s (FEV1) 8, 24, and 48 h after the time of operation. RESULTS: Shouldice repair caused an average increase in inguinal tensile strength of 2.9 +/- 0.58 N (mean +/- SEM). The pain level expressed by active patients was twice the value obtained from resting patients (41.55 +/- 6.3% vs 20.81 +/- 7.1% 8 h after operation), but decreased slightly later on. Peak flow during forced expiration was depressed to about 80% of the control values, whereas the 1-s volume during forced expiration decreased only to 95% of the control value. We excluded any correlation between the recorded individual inguinal tensile strength or the changes in distance between the lateral edge of the rectus sheath and the base of the inguinal ligament and the postoperative pain level. CONCLUSION: We failed to see any evidence for the hypothesis that higher inguinal tensile strength induced by Shouldice repair leads to an elevated level of postoperative pain. If there is any effect, it may be masked by other factors with a stronger influence.

Abdominal Muscles↗

PubMed2001

Load on the inguinal region under standard conditions in pigs.

OBJECTIVE: To find out the effect of standardised stress on the load of the inguinal region. DESIGN: Experimental study. SETTING: Surgical university clinic, Germany. SUBJECTS: 15 uncastrated adult male pigs. INTERVENTIONS: The tension force between the lateral edge of the rectus sheath and the base of the inguinal ligament was measured after simulation of the Shouldice repair. Standard stresses (coughing, straightening up into the upright position, small or large pneumoperitoneum, and electrical stimulation of abdominal muscles) were imposed. MAIN OUTCOME MEASURES: Intra-abdominal pressure and tension force in the inguinal region. RESULTS: We found the highest (mean, SEM) intra-abdominal pressure during coughing (33.1, 5.2 mm Hg) with an increase in inguinal tension force of 4.1, 0.5 N. The upright position (20, 0.7 mm Hg) and the large pneumoperitoneum (25 mm Hg) produced similar values (4.7, 0.8 N and 3.7, 0.4 N, respectively), whereas the small pneumoperitoneum (10 mm Hg) and the electrical stimulation of muscles of the abdominal wall (4.4, 0.1 mm Hg) resulted in distinctly smaller changes (1.1, 0.2 N and 0.7, 0.1 N, respectively). CONCLUSIONS: The amount of tension on the simulated Shouldice repair depended largely on the increase in intra-abdominal pressure. Compared with the force required to disrupt the normal inguinal canal (68.6 N) the inguinal load seems to be negligibly low. This finding strengthens the modern recommendation to allow only a short convalescence after Shouldice hernia repair.

Anastomosis, Surgical↗

PubMed1998

[Intraoperative measurement of suture forces in Shouldice repair of primary inguinal hernias].

A special instrument was developed in order to quantify intraoperatively the traction forces which are employed during Shouldice repair of a primary inguinal hernia while adapting the lateral edge of the rectus sheath and the iliopubic tract. Further investigations were performed under the Valsalva manoeuvre and simultaneous measurement of the intra-abdominal pressure. In 25 patients an average increase in traction forces of 3.62 +/- 0.60 N was registered when the hernial gap was decreased to 0.3 cm. By applying the Valsalva manoeuvre with an average increase of 32 mm Hg in intra-abdominal pressure, traction was increased by a further 1.67 +/- 0.20 N on average. Hernia repair, tensing of the abdominal muscles and increasing the intra-abdominal pressure, however, have a small effect on the traction forces affecting the edges of the hernial gap. It may therefore be concluded that these factors, frequently believed causal for early hernia recurrence, are actually less influential as the force vector stressing the repair zone points in a different direction.

Adult↗

PubMed1998

Arthrobacter, Brachybacterium and Planococcus isolates identified from antarctic sea ice brine. Description of Planococcus mcmeekinii, sp. nov.

Three facultative psychrophilic Gram-positive bacterial strains were isolated from brine samples from the sea ice community in Antarctica. All strains were coccoid to rod-shaped and exhibited broad salinity and temperature ranges for growth. The three strains were subjected to 16S rDNA sequencing and subsequent phylogenetic analysis. All possess unique 16S rDNA sequences indicating they are new, previously unreported organisms. Phylogenetic analyses coupled with phenotypic characterization indicated that one of the strains is most closely related to the low mol% G + C genus Planococcus for which a new species, P. mcmeekinii, is proposed. The two other strains are members of the high mol% G + C Gram-positive bacteria and most closely related to the genera Arthrobacter and Brachybacterium. This study reports the first phylogenetic evidence that Gram-positive bacteria reside in the marine sea ice brine.

Actinomycetales↗

PubMed1990

[Biochemical aspects of the evaluation of fixed drug combinations].

Various disciplines have to contribute to the general problem of the evaluation of fixed dose combination drugs, as for instance (clinical) pharmacology, biometry, scientific drug regulations and public health officials. The EC guideline 75/318/EWG and its eludications as well as the German "Arzneimittelprüfrichtlinien" of Dec. 14, 1989 (as referred to in the "Arzneimittelgesetz" of 1986) required that such issues concerning fixed dosage combination drugs must be considered and taken into account. In this framework it is the responsibility of biometry to both to guarantee the use of a valid study design to assure interpretation of the results and to quantify the reliability of pharmacological and clinical considerations. The following paper is concerned with biometrical aspects of the combination drug problem. Basic considerations from a clinical or a pharmacological point of view with respect to the question of whether fixed combination drugs are reasonable or not are not discussed. To support the use of combinations of drugs, a central argument is the improvement of the benefit risk relation compared with that of an adequate monotherapy. Beyond this the fixed combination drugs require additional arguments regarding the enhencement of the safety or the simplicity of the therapy fixing the ratio. It follows that fixed combination drugs have to be supported twice, first with respect to the combination itself, and second with respect to the fixed mixing ratio of its components. The biometrical aspects of the assessment of the gains from (fixed) drug combinations are related to the kind of benefit/risk improvement that is expected. In the first section we discuss some possible types of benefit and risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1972