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Biomedical subjects

C Mittermayer

Publications and source records attributed to C Mittermayer.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Expanded, radical perineal prostatectomy].

One hundred and twenty-five consecutive patients with prostate cancer underwent an extended, radical perineal prostatectomy according to the technique described by VE Weldon. This technique was modified by an initial complete mobilization of the posterior aspect of the prostate and seminal vesicles from the rectum and pelvic wall, incision of the endopelvic fascia, and partial resection of the dorsal vein complex after suture ligature. The perioperative morbidity was low. An operative revision was necessary in four (3.2%) patients because of arterial bleeding from a drainage channel (n = 1), wound infection (n = 2), and rectocutaneous fistula (n = 1). The in-dwelling catheter was removed on day 4-8 in 104 (83%) patients. Positive surgical margins were diagnosed in 22 (17.6%) patients only. These patients had pT3 (n = 17) and pT4 (n = 5) tumors with a Gleason score > or = 7 (n = 17) mostly; extensive, multifocal capsular penetration (n = 18); seminal vesicle invasion (n = 11); and lymph node metastases (n = 4). The unifocal positive margins were localized at the apex (n = 3), dorsolateral (n = 6) aspect, and bladder neck (n = 4). In nine patients, multifocal positive surgical margins were noted. The risk for a positive surgical margin depends on the serum PSA level, Gleason score, and tumor volume. In case potency preservation is not considered, the extended, radical perineal prostatectomy with the above mentioned modifications should be considered to guarantee a low rate of surgical margins.

Aged↗
PubMed2000

Increased apoptosis of hepatocytes in vascular occlusion after orthotopic liver transplantation.

Early vascular occlusion is liable to cause graft failure, and differential diagnosis between this condition and primary nonfunction (PNF) caused by preservation injury may be difficult. Apoptosis has been detected in immunomediated cytotoxicity and is known to be triggered by mild ischemia. In a retrospective analysis we investigated the role of apoptosis in vascular occlusion, PNF, and acute allograft rejection to improve the differential diagnosis of early graft failure. The liver graft histology of 75 patients (46 male, 29 female) a median 47 (1-64) years of age was screened semiquantitatively for the rate of apoptosis on the hematoxylin-eosin stain (HE) and by the in situ end nick labeling technique (TUNEL). This cohort included all patients who developed PNF (n = 9) or vascular occlusion (n = 11) after orthotopic liver transplantation (OLT) in the years 1992 to 1996. Within this period of time we performed 205 OLTs on 189 patients. We further included 22 patients with early acute rejection and 11 controls. The highest rates of apoptotic hepatocytes were seen in vascular occlusion (P < 0.001). Grafts with PNF were explanted 1-3 days after OLT and showed hepatocytes that were 100% necrotic. Cases of acute early rejection showed a significantly higher apoptotic cell count than did normal controls (P < 0.003), increasing in direct proportion to the severity of rejection. Screening biopsies for the rate of apoptosis can improve the efficacy and accuracy of differential diagnosis of early graft failure.

Adolescent↗
PubMed2000

Von Willebrand's factor mediates the adherence of human tumoral cells to human endothelial cells and ticlopidine interferes with this effect.

The aim of this study was to explore whether von Willebrand's factor (vWF) plays a role in the adhesion of human colon tumor cells to human endothelial cells in our coculture system. Cell colony density was evaluated basally (endothelial plus colon tumor cells) and following the addition of: purified vWF, vWF plus vWF-blocking antibodies, antibodies against various integrins and adhesion molecules (alpha2 b integrin, beta1 integrin, beta3 integrin, intercellular adhesion molecule-I, intercellular adhesion molecule-II, vitronectin receptor CD61 CD51, laminin alpha6/beta4 receptor), and various drugs inhibiting the hemostatic system (ticlopidine, heparin, acetyl salicylic acid [ASA], defibrotide, indobuphen, dipyridamole, sulfinpyrazone). Furthermore, vWF concentration was measured in the supernatant fluid of the coculture system basally and following the addition of the above-listed drugs. Cell colony density (as measured by light absorption) increased by 33% following the addition of vWF and returned to a value similar to the basal level with antibodies against vWF, while it did not change significantly following the addition of antibodies against the other integrins or adhesion molecules tested. The same parameter was reduced by 35% following the addition of ticlopidine, while it showed a smaller or no change with the other drugs tested. Similarly, vWF concentration in the cell coculture supernatant showed the greatest reduction (from 0.22 to 0.11 mg/mL) following the addition of ticlopidine. These data suggest that vWF mediates the adherence of human tumor cells to human endothelial cells and that ticlopidine interferes with this effect.

Cell Adhesion↗
PubMed2000

Expression of heat shock protein 70 (HSP70) at the interface of polymer-implants in vivo.

Synthetic polymer meshes are widely applied in the modern surgical approach for repairing abdominal wall defects. The implanted material is often observed leading to post-operative complications such as deficient abdominal wall mobility and adhesion formation with the abdominal cavity and/or abdominal organs. However, the functioning of the implant is primarily affected by the wound healing process guided by inflammatory events occurring at the tissue-material interface. This could presumably be influenced by the physicochemical properties of the polymer. With regard to it, the cellular and molecular processes involved in the successful restoration of the abdominal wall function are poorly understood. The present in vivo study, therefore, exemplary investigated in a rat model, the commercially available polymer-meshes Prolene (polypropylene, PP), Mersilene (polyester, PE) and Vicryl (polyglactin 910), as well as new mesh variants consisting either of PP (EB) or a combination of PP and polyglactin 910 (A plus or Vypro). The implanted material was evaluated by light and electron microscopy, immunohistochemistry as well as morphometry over an implantation period of 90 days. The data show that polymers induce heat shock protein (HSP)70, and its expression at the interface correlates inversely with the activity of the inflammatory reaction in vivo. Further, an ascent in HSP70 expression parallels the increasing implantation period and evolving foreign-body granulomas. Accordingly, a major role for HSP70 in modulating the local acceptance of polymers and as an additional marker for in vivo testing of polymers is suggestive.

Journal Article↗
PubMed2000

Interphase cytogenetics of multicentric renal cell tumours confirm associations of specific aberrations with defined cytomorphologies.

To demonstrate associations of certain chromosomal aberrations with defined renal cell tumour (RCT) subtypes, we analysed 239 tumour nephrectomy cases for specimens with multicentric tumours. Chromosomal in situ hybridization was then performed on 15 cases with 34 foci (16 conventional renal cell carcinomas (RCCs), and 18 papillary RCTs (11 carcinomas and seven adenomas) for specific chromosomal aberrations, using alpha-satellite probes for chromosomes 3, 7 or 17. Particular preference was given to cases which had separate foci with different cytomorphologies. Furthermore, we compared aberrations in relation to tumour size, stage, grade and between different foci in a specimen. Thirty-four cases had multiple tumours. Forty-seven per cent of the multicentric tumours were conventional RCCs and 53% papillary RCTs (against 83% solitary conventional RCCs and 5% solitary papillary RCTs). Three conventional RCCs sized 8 mm (G3), 13 cm (pT2, G2) and 15 cm (pT3b, G3), respectively, revealed monosomy 3, and 13 were disomic. Seventeen papillary RCTs (11 carcinomas and six adenomas) displayed trisomy 17, irrespective of size or grade. Four papillary carcinomas and six papillary adenomas had trisomy 7, and the rest (seven papillary carcinomas and one papillary adenoma) revealed disomy 7. In conclusion, papillary RCTs were tendentially multicentric. Although specific for conventional RCCs heedless of size, monosomy 3 was only observed in high-grade and/or advanced tumours. Trisomy 17 was only detectable in papillary RCTs irrespective of tumour state, showing increased copies with tumour growth. Papillary RCTs also appeared to lose some copies of chromosome 7 with tumour progress, possibly reflecting malignancy.

Carcinoma, Papillary↗
PubMed2000

Expression of heat shock proteins 72/73 in human peritoneal mesothelial cells in vivo and in vitro.

Leukocyte accumulation during peritonitis leads to an injurious microenvironment which is involved in the host defense reaction but is also thought to cause peritoneal damage. We tested the hypothesis that mesothelial cells (MC) respond to the injurious microenvironment during peritonitis by an increased expression of heat shock proteins (HSP 72/73), a basic way by which cells are protected against injury. Comparison of resting MC and activated MC during peritonitis in vivo by means of immunohistochemistry revealed an increased expression of HSP 72/73. As assessed by Western immunoblotting, incubation of MC in vitro with tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) caused a time-dependent induction of HSP 72/73 expression, which was maximal 6 h after stimulation. We suggest that the increased HSP 72/73 expression of MC during peritonitis is in part induced by TNF-alpha and IL-1beta and may exert a cell-protective function, lessening MC damage during peritonitis.

Base Sequence↗
PubMed2000

MIB-1 immunohistometry of follicular adenoma and follicular carcinoma of the thyroid gland.

OBJECTIVE: To analyze cellular proliferative activity, MIB-1 immunopositivity of normal tissue (n = 20), follicular adenoma (n = 30) and follicular carcinoma (n = 32) of the thyroid gland was analyzed by means of immunohistometry. STUDY DESIGN: Immunohistochemical reactions were performed on 3-micron sections from routinely formalin fixed and paraffin embedded surgical specimens using an indirect peroxidase method. The rate of immunostained cells was determined using the CM-2 TV image analysis system (Hund, Wetzlar, Federal Republic of Germany). Forty viewing fields (1.94 mm2) were measured with 20:1 objective magnification. An average of 5,965 cells were assessed in each case. RESULTS: Mean MIB-1 immunopositivity was higher in follicular carcinoma (average, 2.30%) and follicular adenoma (0.58%) than in normal thyroid tissue (0.14%). The distribution of single values differed significantly between groups (P < .001). To test the suitability of MIB-1 immunohistometry for the differential diagnosis of follicular adenoma and follicular carcinoma, different four-field tables with varying thresholds were calculated. Using a threshold of 0.9%, follicular carcinoma could be detected with a sensitivity of 75% (24/32) and a specificity of 83% (25/30). If a specificity of 90% is required (27/30), the sensitivity of the test decreases to 69% (22/32), based on a threshold of 1.1%. CONCLUSION: As some overlap of single values has to be considered, MIB-1 immunohistometry, although presenting new insights into the proliferative potential of thyroid lesions, is of only limited value for the differential diagnosis of follicular lesions in routine surgical pathology.

Adenocarcinoma, Follicular↗
PubMed1999

The role of soluble adhesion molecules in evaluating endothelial cell activation in preeclampsia.

OBJECTIVE: Adhesion molecules, such as vascular cell adhesion molecule 1, are known to be increased in the serum of patients with preeclampsia, indicating that these molecules are possible markers of endothelial cell activation. We investigated the influence of serum from women with preeclampsia on the expression of adhesion molecules by cultured endothelial cells. STUDY DESIGN: Human umbilical vein endothelial cells were cultured in Ham/Iscove modified Dulbecco's medium containing 20% pooled human serum, l -glutamine (200 mmol/L), penicillin, and streptomycin. We stimulated these cells for 24 hours with sera from patients with preeclampsia and then determined the levels of vascular cell adhesion molecule 1, intercellular cell adhesion molecule 1, E-selectin, and P-selectin in the supernatant and in the maternal serum by means of enzyme-linked immunosorbent assay. These results were compared with those of sera obtained from normotensive pregnant and nonpregnant women. In addition, the expressions of these adhesion molecules on the endothelial surface were determined by immunofluo-rescence microscopy. RESULTS: Only for vascular cell adhesion molecule 1 and E-selectin were elevated plasma levels found in hypertensive patients, whereas intercellular cell adhesion molecule 1 and P-selectin showed similar plasma levels in all the patients. No differences in the levels of the adhesion molecules were found between the supernatants of endothelial cell cultures after stimulation with sera from patients with preeclampsia and those after stimulation with normotensive control sera. In contrast, with immunofluorescence microscopy we could detect higher amounts of vascular cell adhesion molecule 1, intercellular cell adhesion molecule 1, and E-selectin on the endothelial surface after stimulation with sera from women with preeclampsia. CONCLUSION: Although vascular cell adhesion molecule 1 and E-selectin were elevated in maternal serum samples from women with preeclampsia and on the endothelial surface after stimulation with such sera, there were no detectable increases in the levels of both of these adhesion molecules in the supernatant of cultured endothelial cells. We therefore assume that sera from women with preeclampsia may cause endothelial cell activation. Because we could not detect elevated concentrations of any of the investigated adhesion molecules in the supernatant of endothelial cells, we believe that factors other than sera from women with preeclampsia seem to play a major role in the release of soluble forms of adhesion molecules from the endothelial membrane.

Adult↗
PubMed1999

Preservation solutions for transplantation.

Eurocollins has almost been abandoned because of the glucose disadvantage. UW is certainly the most used preservation solution for livers, kidneys, and pancreases with excellent clinical and experimental preservation data. UW can certainly be considered the current golden standard solution. However, the disadvantage of high viscosity, high price, uneasy handling of many 1-L bags, and the fact that the radical scavenger glutathion cannot be detected in the bags by chemical analysis (presumably due to diffusion) encourage competitors to produce new compounds with better cost to effect ratios. HTK has a firm place in cardiac preservation; by demonstration of equal safety and efficacy in preserving livers and kidneys, at least in the middle and lower range of cold ischemia time, HTK will be sued more frequently, particularly with the consideration of lower price and more easy handling aspects. The suggested high volume perfusion is not really necessary, calculation based on a total volume of 10 L for a multiorgan donor show significant cost reductions. Celsior is current only used for cardiac preservation. Beyond all aspects of conservation and preservation potencies of all these fluids, it must not be forgotten that cold ischemia itself is a risk factor for organ function. Therefore, cold ischemia time should be kept as short as possible. People are willing to accept 24 hours or more cold ischemia time in kidney transplantation because organ failure can be treated by dialysis. In other organs, where immediate organ function is essential, like in clinical heart transplantation, cold ischemia is hardly ever extended beyond 6 hours. Why are hearts and kidneys so different? Very likely, there is no difference, and the outstanding results in living unrelated kidney transplants is mostly due to short cold ischemia time.

Adenosine↗
PubMed1999

Elevated soluble adhesion molecules in women with pre-eclampsia. Do cytokines like tumour necrosis factor-alpha and interleukin-1beta cause endothelial activation.

OBJECTIVE: The purpose of the present study was to evaluate the clinical significance of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) for endothelial cell activation in pre-eclampsia. Therefore, we determined and compared the correlations between these cytokines and circulating adhesion molecules in the sera of pre-eclamptic pregnant women, normotensive pregnant women and nonpregnant women. METHODS: The soluble adhesion molecules VCAM-1, ICAM-1, E-selectin, and P-selectin were determined in the serum of 38 pre-eclamptic pregnant women and 40 normotensive pregnant and nonpregnant controls using ELISA-techniques. We correlated these serum concentrations with the serum levels of TNF-alpha and IL-1beta, respectively, also determined by ELISA. RESULTS: Elevated serum levels of VCAM-1 and E-selectin could be detected in pre-eclamptic patients, with and without HELLP-syndrome. In contrast, no increased serum concentration of ICAM-1, P-selectin, TNF-alpha and IL-1beta were found in these patients. While significant correlation between VCAM-1 and E-selectin could be determined (r=0.604; p<0.001) no unambiguous correlations, however, were found between TNF-alpha or between IL-1beta and the examined adhesion molecules or the selectins. CONCLUSIONS: In contrast to in vitro investigations on cultured umbilical vein endothelium, our experimental results indicate that the cytokines TNF-alpha and IL-1beta can not explain endothelial cell activation, and that their measurement in serum is not useful for the detection of pre-eclampsia.

Adult↗
PubMed1999

Diagnostic relevance of chromosomal in-situ hybridization in Merkel cell carcinoma: targeted interphase cytogenetic tumour analyses.

AIMS: To resolve the conflicting diagnoses of five pathologists (which included well-differentiated neuroendocrine carcinoma, malignant carcinoid, undifferentiated small-cell carcinoma, primitive neuroectodermal tumour, metastases of small-cell lung carcinoma (SCLC) and Merkel cell carcinoma (MCC)), and tumour-free lungs after necropsy, we investigated an alarmingly metastasizing MCC in a 32-year-old Caucasian man using chromosomal in-situ hybridization (CISH). Differences in incidence and course in males and females also prompted targeted analyses for chromosomes X and Y. The lesion was also analysed for p53 gene mutations. METHODS AND RESULTS: Paraffin sections of the thorax, buccal lymph nodes and scalp tumours were stained with haematoxylin and eosin. Immunohistochemistry was performed with antibodies against pancytokeratin, keratin 20, neuron-specific enolase (NSE), chromogranin, neurofilaments and vimentin, among others. Sections (5-6 microm) of the tumours were analysed with alpha-satellite probes for chromosomes 1, 6, 7, 11, 12, 17, 18, X and Y using CrSH; and exons 5-9 of the p53 gene were examined by polymerase chain reaction and single strand conformation polymorphism (PCR-SSCP) methods. Although positive for pancytokeratin, keratin 20, chromogranin, NSE, synaptophysin and vimentin, the similarity in antigen profiles expressed by SCLC and MCC prevented a definitive tumour diagnosis. Chromosomal in-situ hybridization, however, revealed trisomies 1 and 11, two frequent aberrations in MCC, and trisomy 18. Moreover, 71% of the tumour cells had two to three copies of X, whereas 98% of the cell nuclei in the hair follicles and normal epidermis (purported Merkel cell origins) displayed one X chromosome. No mutations were detected in the five exons of the p53 gene examined. CONCLUSIONS: Had CISH been performed earlier, treatment may have been tailored specifically to suit MCC, since MCC and SCLC have different therapeutic strategies. Finally, chromosome X may be of prognostic relevance in MCC, which apparently predominates in females and yet shows poorer prognosis in males, and hence be worthy of further investigation.

Adult↗
PubMed1999

Intraperitoneal transplantation of isologous mesothelial cells for prevention of adhesions.

OBJECTIVE: To study the effect of transplantation of mesothelial cells on the formation of adhesions after peritoneal abrasion. DESIGN: Animal study. SETTING: Teaching hospital, Germany. ANIMALS: 30 isologous eight-week old Lewis rats to allow for harvesting of the greater omentum from a separate group. INTERVENTIONS: The first group (n = 10) served as mesothelial cell donors. The other animals had laparotomy and induction of adhesions by standardised abrasion of the peritoneum. The trial group (n = 10) were given a suspension of 10(6) mesothelial cells/100 g body weight intraperitoneally and the control group (n = 10) an equal volume of culture medium. After 10 days the animals were killed. MAIN OUTCOME MEASURES: Measurements of the areas of adhesions by computer aided morphometry. RESULTS: The trial group developed a mean (SD) adhesion area of 122.7 (176.7) mm2, and the controls 310.5 (179.1) mm2. The corresponding medians (range) were 51.2 (0-547.1) and 274.3 (100.6-575.4). Transplantation of mesothelial cells resulted in a significant reduction in adhesion formation (Wilcoxon test, p<0.01). CONCLUSION: Intraperitoneal transplantation of mesothelial cells is an effective way of reducing the formation of adhesions.

Animals↗
PubMed1999

Inhalation of nitric oxide as a life-saving therapy in a patient after pulmonary embolectomy.

We describe a 54-yr-old man with cardiogenic shock caused by acute right heart failure after pulmonary embolectomy. Inhalation of nitric oxide led to immediate improvement in respiratory and haemodynamic variables. Inhaled nitric oxide can be used to reduce acute right heart failure until conventional therapy can provide successful haemodynamic stability.

Administration, Inhalation↗
PubMed1999

Successful long-term implantation of electrically inactive epiretinal microelectrode arrays in rabbits.

BACKGROUND: In the ongoing discussion concerning the realization of an epiretinal prosthesis for electric stimulation of retinal ganglion cells, long-term fixation of such a device is a crucial question. We evaluated surgical techniques for implantation and fixation of electrically inactive microelectrode arrays (MA) into the retinas of rabbits and secondary tissue reactions to the implant. METHODS: Vitrectomy and laser coagulation of the prospective fixation area were performed in rabbits. Implantation of MAs was performed 3 weeks later in 10 animals. The MA was fixated using retinal tacks. The follow-up included ophthalmoscopy and electrophysiology. At the end of the follow-up, the enucleated eyes were processed for light microscopy using standard procedures and grinding techniques. RESULTS: Nine of 10 rabbits were implanted without serious complications. Clinical and electrophysiologic data through 6 months of follow-up did not indicate any adverse effect of the surgery, the implant, or the tack itself. No change in retinal architecture underneath the implant was found by light microscopy. In these cases, the implant was stable at its original fixation area. In three cases, mild cataract formation was observed, and in one case, a total retinal detachment was found. CONCLUSION: Tack fixation of electrode arrays for electric stimulation of the inner retinal surface seems to be a useful approach in long-term implantation of an epiretinal prosthesis.

Animals↗
PubMed1999

Inhaled nitric oxide in a patient with severe pulmonary embolism.

We describe a 66-year-old woman with right-sided heart failure and cardiogenic shock resulting from severe pulmonary embolism. Her hemodynamic status improved dramatically with the use of inhaled nitric oxide. A proposed mechanism of action and a review of the literature are presented.

Administration, Inhalation↗
PubMed1998

Effects of Nd:YAG-laser irradiation on monolayer cell cultures.

BACKGROUND AND OBJECTIVE: The clinical applications of Nd:YAG lasers on oral soft tissues include a wide field of surgical and periodontal procedures. This in vitro study focuses on the histological effects of Nd:YAG-laser irradiation on a fibroblast monolayer cell culture especially with regard to thermal damage and cell necrosis. The results of this basic research study provide us with clear power settings for a safe soft tissue laser treatment. STUDY DESIGN/MATERIALS AND METHODS: Two hundred forty multiwell cell cultures and 24 micro-slide Leighton tubes were laser treated. Laser irradiation was performed with a commercial free-running pulse Nd:YAG laser and a quartz fiber with a diameter of 200 microns on L-929 fibroblast cell cultures. The variable parameters were pulse energy (30-120 mJ), pulse rate (20-100 Hz), power output (1.5-3.0 W), and time of irradiation (10-60 s). The cultures were analyzed with help of vital staining, autoradiography, and cytomorphology examination. RESULTS: Depending on the different settings the laser irradiation caused inhibitions of the DNA metabolism rate and the cell division rate, a degeneratively changed cytomorphology up to cell pyknosis. An increasing pulse energy, pulse rate, or an increased time of irradiation created an extended diameter of the pyknotic cell zone. CONCLUSIONS: The laser beam creates an exactly bordered damage between cells. The cells had a very good inherent mobility, but the border between eliminated and unloaded cell zone was sharp, even after an incubation of 24 h. These stable results prove that the laser can be applied up to a micrometer distance. With the help of cell clusters it was proved that the laser beam is also able to eliminate exactly one monolayer. Cells which had been covered by another cell layer (in a cluster) were not eliminated.

Autoradiography↗
PubMed1998

Cytogenetic analysis of 11 renal oncocytomas: further evidence of structural rearrangements of 11q13 as a characteristic chromosomal anomaly.

We carried out cytogenetic analysis on 11 renal oncotytomas by using G-banding and DAPI-banding techniques. Four of our tumors exhibited structural rearrangements affecting chromosome 11 at band q13. Together with another case previously described by us, our tumors constitute the largest series of renal oncocytomas displaying translocations involving 11q13. A review of the literature disclosed only 6 similar oncocytomas, 1 tumor with a t(9;11)(p23;q12), 2 tumors with a nearly identical t(9;11)(p23;q13), and 3 tumors with a t(5;11)(q35;q13). Therefore, our findings provide further cytogenetic evidence that genes located on 11q12-13 may be involved in the tumorigenesis of renal oncocytomas.

Adenoma, Oxyphilic↗