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Biomedical subjects

U Markert

Publications and source records attributed to U Markert.

At least 19 recordsLinked to original sources
PubMed2002

[Polypropylene synthetic mesh modifies growth of human cells in vitro. An experimental study].

INTRODUCTION: The aim of our study was to investigate the influence of polypropylene meshes on the proliferation and apoptosis of human cell cultures in vitro. METHODS: Human fibroblasts and HeLa cells were incubated in different densities (10(4), 3.10(4), 10(5) cells/well) together with polypropylene meshes (Prolene, 2 x 2 cm) in six-well culture dishes over a 48-h period. Cells without meshes served as controls. Cells were spun on slides and stained with the monoclonal antibody MIB-1. To calculate the proliferation indices, stained nuclei were counted. Apoptotic indices were determined by flow cytometric analysis, using FITC-conjugated Annexin-V and propidiumjodide for staining. RESULTS: Fibroblasts showed only a slight reduction of the proliferation index (PI) from 64% (controls) to 60% (meshes). Increasing cell density leads to a decrease in the PI of both groups. The PI of HeLa cells was similar in mesh groups and controls and independent of cell density. The apoptotic index (AI) of fibroblasts was significantly higher in the mesh group (3.7%) in comparison with the controls (1.9%). The same was observed for HeLa cells (AI mesh group: 4.5%, AI controls: 1.2%). Furthermore, an increase of AI was found with increasing cell density in both cell lines. CONCLUSION: Whereas meshes did not influence the proliferation of the cell lines examined, they seem to have a marked influence on apoptosis, as a significant increase of AI was observed in the mesh group in contrast to controls.

Adult↗
PubMed2002

[Simulation of surgical techniques in graduate education of the surgeon. An analysis of value and effect].

The course in Gastrointestinal Surgery (GISC) aims at teaching and training resection, reconstruction and suture techniques of the upper gastrointestinal tract. Prior to, after and 5 years following the first course, participants were asked to answer a questionnaire requesting information regarding the adequacy of surgical training in their residency program and how much they had benefited from the GISC. While 1/3 of the participants described the surgical training during their residency as inadequate, more than 90% benefited from the GISC. Although the single-layer-continuous suture technique was implemented by only 8% of the participating surgeons, other techniques such as cross-section gastroenterostomy were accepted by 38%. Only 7% of the participants rejected these new techniques, while 41% of the senior surgeons at home could not be convinced. Besides the teaching of new techniques, participants benefited above all from the repetitive training in surgical procedures.

Animals↗
PubMed2002

[Influence of resterilized polypropylen meshes on growth of human fibroblasts--an experimental in vitro study].

INTRODUCTION: We investigated the influence of resterilized polypropylen meshes (Prolene(R)) on proliferation and apoptosis of human fibroblasts in an experimental in vitro study. METHOD: Human fibroblasts were seeded into six-well culture dishes in a density of 3 x 10 (4) cells/well. After resterilization of meshes (steam autoclave, 121 degrees C, 20 min.) according to the manufacturer's recommendations (Ethicon, Norderstedt) square sheets of 2 x 2 cm were incubated with fibroblasts over a period of 6, 12, 18, 24, 30, 36, 42 and 48 h. Preparations of fibroblasts with non-resterilized meshes and without meshes served as controls. Proliferation index and apoptotic index were estimated by flow cytometry after cell staining with an FITC-conjugated antibody against the Ki-67 antigen or with FITC-conjugated Annexin-V and propidium jodide, respectively. RESULTS: A significant reduction of the proliferation index from 86 % to 42 % was found after 48 h incubation of cells with resterilized meshes, whereas only a slight decrease was found in the group with non-resterilized meshes (75 %) and in controls without meshes (80 %). Apoptotic index increased significantly from 2 % to 48 % after 48 h incubation with resterilized meshes in comparison to both control groups, where only a slight increase could be observed: non-resterilized meshes to 19 % and without meshes to 10 %. CONCLUSION: Resterilized meshes inhibit growth of human fibroblats in vitro significantly, demonstrated by a reduced proliferative activity and an increased apoptotic index. This could be caused by a release of toxic substances from the meshes, which have a negative influence on cell growth. Therefore, resterilization cannot be recommended.

Adult↗
PubMed2001

Vascular endothelial growth factor (VEGF)--a valuable serum tumour marker in patients with colorectal cancer?

INTRODUCTION: Neo-angiogenesis, of great importance for tumour growth and nutrition, is preferentially mediated by the cytokine vascular endothelial growth factor (VEGF), which has a direct effect on vascular endothelial cell proliferation and migration. This study was designed to clarify whether VEGF is a suitable tumour marker in sera of patients with a colorectal cancer, and whether VEGF concentrations in sera and tumour tissues are correlated with tumour extension (pTNM) and especially with tumour volume or size. Furthermore, the influence of VEGF levels on patients >> prognosis was examined. METHODS: VEGF serum concentrations of 122 patients with colorectal cancer and 65 controls were determined with an ELISA kit. Additionally, VEGF concentrations of tumour and normal tissue were measured in 38 patients using the same ELISA. RESULTS: Our results demonstrate that VEGF is not a suitable diagnostic tumour marker in patients with colorectal cancer due to its low sensitivity (36%). However, a combination of the serum tumour markers CEA and VEGF can significantly increase the pre-operative diagnostic sensitivity to 62%. VEGF serum levels differed significantly between patients (mean 438 pg/ml) and controls (mean 203 pg/ml), and also between tumour and normal tissue (984 vs 89 pg/mg protein). Serum concentration showed a significant correlation to tumour volume and size. Patients with VEGF serum levels greater than cut-off had a poorer prognosis than those less than or equal to cut-off. For this reason VEGF could be used as a predictor of patients >> outcome.

Adult↗
PubMed2001

Nearly fatal complications of cervical lymphadenitis following BCG immunotherapy for superficial bladder cancer.

This report describes the case of a 68-year-old man with bilateral cervical lymphadenitis and chorioretinitis due to bacille Calmette-Guérin (BCG), originating from BCG immunotherapy for treatment of superficial bladder cancer 2 years ago. During antimycobacterial therapy a fistula between the right-sided lymph node and an aneurysm of the carotid artery developed. This led to life-threatening spontaneous bleeding which required vascular graft surgery. Like other known systemic side effects, cervical lymphadenitis may also occur following intravesical BCG immunotherapy, and life-threatening complications cannot be excluded despite adequate medical treatment.

Aged↗
PubMed2000

[Biliary endo-to-end anastomosis with extramucosal titanium clips. Initial results of a new technique].

BACKGROUND: Bile duct anastomoses are still associated with a high failure rate. Although following iatrogenic bile duct transection only a positive selected group of patients get a primary end-to-end reconstruction, long-term results demonstrate an incidence of postoperative strictures up to 78%. Also in orthotopic liver transplantation biliary tract complications remain a significant cause of morbidity with an incidence of up to 49%. Since these complications can also be seen under optimal circumstances, the methodically based disadvantages of the conventional hand suturing like perforating needle injury of the choledochal wall with intraluminal suture material, the suboptimal approximation of the mucosal edges and an inhibited blood flow in the choledochal stumps caused by a suture related tissue strangulation may also responsible. Thus there is a search for alternative anastomosis techniques. METHOD: To test extramucous placed titanium clips for biliary reconstruction after complete division of the bile duct we performed an end-to-end-anastomosis in 9 pigs. Therefore we used the VCS (Vascular Closure Staples)-instruments (Auto Suture). RESULTS: The application of the VCS-clips (medium size) permitted the technical realization of a tension free, everted anastomosis with an exact approximation of the mucosal edges. One of the animals died from aero embolism intraoperatively. All the others showed a complication-free postoperative period without any signs of anastomotic leakage or stenosis (follow-up: 6 months). At histological examination there were smooth and intact mucosal surfaces in all pigs and--especially important for the development of strictures--only a very mild fibrosis and inflammation. CONCLUSIONS: The potential advantage of the VCS-clip-technique is the non-penetrating tissue approximation with optimal contact of the mucosal layers that does not compromise the blood flow in the choledochal stumps. Before clinical use can be recommended further studies are required.

Anastomosis, Surgical↗
PubMed1999

[Immunotesting--a conditio sine qua non for therapeutic BCG instillation in bladder neck carcinoma?].

The intravesical instillation of BCG (Bacillus Calmette-Guérin) in cases of relapsed superficial bladder cancer is an acknowledged kind of prophylaxis. It is uncertainly up to now whether a verification of the immune systems competence is necessary. The recommendations in this problem are very different. In conclusion to the recent literature we think that a verification of the immune system before BCG installation in the urinary bladder has not a prognostic value. Additionally, the legal obligingness of this immunotest is doubtful.

Administration, Intravesical↗
PubMed1999

Measurement of peripheral tissue thickness by ultrasound during the perioperative period.

We have studied changes in peripheral tissue thickness with a novel hand-held ultrasound device during the perioperative course of 60 healthy surgical patients in three different intraoperative body positions. The nil-by-mouth period led to a significant decrease in forehead tissue thickness. Standardized infusion therapy with Ringer's solution at a rate of 8 ml kg-1 h-1 resulted in a gradual increase in tissue thickness, which was significantly different from preoperative baseline values after 90 min. Packed cell volume decreased significantly after the start of infusion and remained low over the rest of the observation time. Different body positions did not influence changes in tissue thickness. We conclude that changes in perioperative tissue thickness in healthy patients can be detected easily by ultrasound, independent of body position. This method may prove useful for the non-invasive assessment of fluid balance state.

Adult↗
PubMed1999

[Thrombosed temporary vena cava filter].

The application of temporary vena cava filters for the treatment of deep venous thrombosis of the lower extremity has become increasingly important in recent years. The filters are supposed to guarantee temporary protection from more extensive pulmonary embolism. Occlusion of the filter system by a larger embolus as well as vena cava thrombosis including the filter struts present major therapeutic problems. We report on one patient in whom the temporarily inserted filter was trapped in a large vena cava thrombus and had to be removed surgically by caval thrombectomy. Because of possible complications such as the above, the indication for insertion of temporary vena cava filters requires thorough consideration. Their duration of stay should be as short as possible and should be limited to the high risk phase, not exceeding ten days.

Equipment Failure↗
PubMed1999

[Peritoneal lavage in standardized peritonitis models].

The peritoneal lavage in peritonitis can be studied in a standardized manner only in animal models, because peritonitis is too variable and dependent on too many patient related factors. In this article answers are given to questions on the influence of different lavage substances on survival, local and systemic concentrations of bacteria, endotoxin, and TNF as well as on mesothelial adherence of bacteria. These data refer to results from acute models of infection published in the literature. Furthermore, we show from our own chronic peritonitis model the influence of the peritoneal lavage on abscess formation and translocation. After inoculation of a Bacteroides fragilis suspension, a chronic abscess forming peritonitis was induced. At day 3/7/14 intraabdominal abscesses were found in 2/4/6 of 8/5/6 animals in an untreated, in 1/3/5 of 5/5/5 animals in a saline lavaged, and in 5/0/2 of 5/5/5 animals in a Taurolidin lavaged group, respectively. Both, the intraabdominal and the systemic bacterial dissemination were more effectively inhibited by the Taurolidin lavage than by the saline lavage.

Animals↗
PubMed1998

[The infected arterial stent].

Vascular infections after percutaneous endovascular procedures are rare. We report a case of bacterial arteritis following PTA and stent implantation into an iliac artery. It was complicated by septic embolization, ipsilateral empyema of the knee joint and formation of an infected false aneurysm. Contamination of the stent with Staphylococcus aureus is likely to be the cause. The treatment included resection of the infected arterial segment, removal of the stent, and autologous reconstruction.

Aged↗
PubMed1996

Immunosuppressive properties of monoclonal antibodies and human polyclonal alloantibodies to the R80K protein of trophoblast.

PROBLEM: The R80K protein on human trophoblast is antigenically polymorphic, and in all placentae of successful pregnancies, the protein is covered by maternal alloantibody. Alloantibody eluted from human placenta has been shown to inhibit killing by human NK cells. Do those antibodies to R80K that inhibit NK killing also affect the murine abortion models? METHODS: We made three murine monoclonal antibodies to conserved epitopes, on human R80K, all of which also reacted with the homologous murine molecule. One antibody only, BA11, suppressed NK cytotoxicity to K562 and of mouse spleen NK cells to murine trophoblast. All three were tested in mouse models of abortion: the CBA x DBA/2 model with a high resorption rate of F1 embryos compared with the parental strains, an endotoxin induced abortion/resorption model and a third model in which the pregnant mouse is subject to sonic stress. CONCLUSION: Those IgG antibodies eluted from microvesicles which bound to K562, and one of the three monoclonals, BA11, inhibited NK killing. The antibodies react with the murine molecule, and BA11 inhibited abortion in all three mouse abortion models. This reinforces the thesis that interference with NK killing can influence abortion/resorption in mice, and the BA11 antibody may effect similar results in analogous human situations.

Animals↗
PubMed1996

[Laparoscopy in diagnosis and therapy of advanced abdominal malignancies].

Fifty-seven patients with abdominal and retroperitoneal malignancies were examined by laparoscopy mainly to establish operability (n = 29), to gain histology (n = 20), or to carry out laparoscopic (assisted) palliative procedures. Early explorative laparoscopy is recommended if large tumours, ascites or metastases are suspected because of the high sensitivity in confirming inoperability.

Abdominal Neoplasms↗
PubMed1994

[MR tomography of acute pancreatitis: initial results].

Magnetic resonance imaging (MRI) was evaluated for its potential in assessment of acute pancreatitis compared to computed tomography (CT). 15 patients with acute pancreatitis were examined using a routine protocol including T1- and T2-weighted sequences and a fat-suppressed T1-weighted spin-echo sequence. Gadopentant-Dimeglumin (Gd-DTPA) was given. For comparison, plain and contrast-enhanced CT was performed prior to MRI. MRI proved to be superior to CT in detection of bleeding, duodenitis and ascites. MRI failed to detect concrements. These first results show that, considering the latest development in technology, MRI is not inferior to CT in diagnostic imaging of acute pancreatitis.

Acute Disease↗
PubMed1990

[Problems and incidence of abdominoperineal impalement injuries].

In our population of trauma patients abdomino-perineal impalement injuries are very rare. With reference to our own patients we demonstrate the problems that arise with impalement injuries: infection, hemorrhage, intraabdominal organ lesions and difficulty in recognizing these. The necessity for elicitation of a precise history and meticulous diagnostic examination is undisputed. In our own patients we have always tried to achieve definitive therapy as a primary procedure. There have been no lethal complications.

Abdominal Injuries↗